Open Access Publications
From research on the visual systems of turtles, to the perception of faces with or without makeup, to transaccadic perception and perceptual cycles in the brain– VPixx hardware and software solutions have supported research in vision science and beyond for over 20 years. We are immensely proud of the discoveries and accomplishments of our customers across the world.
On this page you will find a non-exhaustive list of peer-reviewed, open access publications citing VPixx tools dating back to 2003. Browse the list or use the tag filter to search for specific products. Note that we report the device used in the paper according to the authors; this may not accurately reflect the specific model of device used (e.g., VIEWPixx vs. VIEWPixx /3D). Nor do we guarantee the accuracy of published content. Please contact our team at [email protected] if you have any questions about a specific paper.
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Use the search tool below to search for specific terms among the titles, authors and abstracts in our library.
261.
Schütz, Alexander C.; Souto, David
Perceptual task induces saccadic adaptation by target selection Journal Article
In: Frontiers in Human Neuroscience, vol. 9, 2015, ISSN: 1662-5161.
Abstract | Links | BibTeX | Tags: VIEWPixx
@article{schutz_perceptual_2015,
title = {Perceptual task induces saccadic adaptation by target selection},
author = {Alexander C. Schütz and David Souto},
url = {https://www.frontiersin.org/articles/10.3389/fnhum.2015.00566},
issn = {1662-5161},
year = {2015},
date = {2015-01-01},
urldate = {2024-01-17},
journal = {Frontiers in Human Neuroscience},
volume = {9},
abstract = {Adaptation of saccades can be induced by different error signals, such as retinal position errors, prediction errors, or reinforcement learning. Recently, we showed that a shift in the spatial goal of a perceptual task can induce saccadic adaptation, in the absence of a bottom-up position error. Here, we investigated whether this top-down effect is mediated by the visibility of the task-relevant object, by reinforcement due to the feedback about the perceptual judgment or by a target selection mechanism. Participants were asked to discriminate visual stimuli arranged in a vertical compound. To induce adaptation, the discrimination target was presented at eccentric locations in the compound. In the first experiment, we compared adaptation with an easy and difficult discrimination. In the second experiment, we compared adaptation when feedback about the perceptual task was valid and when feedback was provided but was unrelated to performance. In the third experiment, we compared adaptation with instructions to fixate one of the elements in the compound—target selection—to the perceptual task condition—target selection and discrimination. To control for a bottom-up stimulus effect, we ran a fourth experiment in which the only instruction was to look at the compound. The saccade amplitude data were fitted by a two-state model distinguishing between an immediate and a gradual error correction process. We replicated our finding that a perceptual task can drive adaptation of saccades. Adaptation showed no effect of feedback reliability, nor an effect of the perceptual task beyond target selection. Adaptation was induced by a top-down signal since it was absent when there was no target selection instruction and no perceptual task. The immediate error correction was larger for the difficult than for the easy condition, suggesting that task difficulty affects mainly voluntary saccade targeting. In addition, the repetition of experiments one week later increased the magnitude of the gradual error correction. The results dissociate two distinct components of adaptation: an immediate and a gradual error correction. We conclude that perceptual-task induced adaptation is most likely due to top-down target selection within a larger object.},
keywords = {VIEWPixx},
pubstate = {published},
tppubtype = {article}
}
Adaptation of saccades can be induced by different error signals, such as retinal position errors, prediction errors, or reinforcement learning. Recently, we showed that a shift in the spatial goal of a perceptual task can induce saccadic adaptation, in the absence of a bottom-up position error. Here, we investigated whether this top-down effect is mediated by the visibility of the task-relevant object, by reinforcement due to the feedback about the perceptual judgment or by a target selection mechanism. Participants were asked to discriminate visual stimuli arranged in a vertical compound. To induce adaptation, the discrimination target was presented at eccentric locations in the compound. In the first experiment, we compared adaptation with an easy and difficult discrimination. In the second experiment, we compared adaptation when feedback about the perceptual task was valid and when feedback was provided but was unrelated to performance. In the third experiment, we compared adaptation with instructions to fixate one of the elements in the compound—target selection—to the perceptual task condition—target selection and discrimination. To control for a bottom-up stimulus effect, we ran a fourth experiment in which the only instruction was to look at the compound. The saccade amplitude data were fitted by a two-state model distinguishing between an immediate and a gradual error correction process. We replicated our finding that a perceptual task can drive adaptation of saccades. Adaptation showed no effect of feedback reliability, nor an effect of the perceptual task beyond target selection. Adaptation was induced by a top-down signal since it was absent when there was no target selection instruction and no perceptual task. The immediate error correction was larger for the difficult than for the easy condition, suggesting that task difficulty affects mainly voluntary saccade targeting. In addition, the repetition of experiments one week later increased the magnitude of the gradual error correction. The results dissociate two distinct components of adaptation: an immediate and a gradual error correction. We conclude that perceptual-task induced adaptation is most likely due to top-down target selection within a larger object.
262.
Olkkonen, Maria; McCarthy, Patrice F.; Allred, Sarah R.
The central tendency bias in color perception: Effects of internal and external noise Journal Article
In: Journal of Vision, vol. 14, no. 11, pp. 5, 2014, ISSN: 1534-7362.
Abstract | Links | BibTeX | Tags: DATAPixx
@article{olkkonen_central_2014,
title = {The central tendency bias in color perception: Effects of internal and external noise},
author = {Maria Olkkonen and Patrice F. McCarthy and Sarah R. Allred},
url = {https://doi.org/10.1167/14.11.5},
doi = {10.1167/14.11.5},
issn = {1534-7362},
year = {2014},
date = {2014-09-01},
urldate = {2024-01-18},
journal = {Journal of Vision},
volume = {14},
number = {11},
pages = {5},
abstract = {Perceptual estimates can be biased by previously seen stimuli in delayed estimation tasks. These biases are often toward the mean of the whole stimulus set. Recently, we demonstrated such a central tendency bias in delayed color estimation. In the Bayesian framework of perceptual inference, perceptual biases arise when noisy sensory measurements are combined with prior information about the world. Here, we investigate this idea in color perception by manipulating stimulus range and stimulus noise while characterizing delayed color estimates. First, we manipulated the experimental prior for stimulus color by embedding stimuli in collections with different hue ranges. Stimulus range affected hue bias: Hue estimates were always biased toward the mean of the current set. Next, we studied the effect of internal and external noise on the amount of hue bias. Internal noise was manipulated by increasing the delay between the reference and test from 0.4 to 4 s. External noise was manipulated by increasing the amount of chromatic noise in the reference stimulus, while keeping the delay between the reference and test constant at 2 s. Both noise manipulations had a reliable effect on the strength of the central tendency bias. Furthermore, there was a tendency for a positive relationship between variability of the estimates and bias in both noise conditions. In conclusion, observers are able to learn an experimental hue prior, and the weight on the prior can be manipulated by introducing noise in the estimation process.},
keywords = {DATAPixx},
pubstate = {published},
tppubtype = {article}
}
Perceptual estimates can be biased by previously seen stimuli in delayed estimation tasks. These biases are often toward the mean of the whole stimulus set. Recently, we demonstrated such a central tendency bias in delayed color estimation. In the Bayesian framework of perceptual inference, perceptual biases arise when noisy sensory measurements are combined with prior information about the world. Here, we investigate this idea in color perception by manipulating stimulus range and stimulus noise while characterizing delayed color estimates. First, we manipulated the experimental prior for stimulus color by embedding stimuli in collections with different hue ranges. Stimulus range affected hue bias: Hue estimates were always biased toward the mean of the current set. Next, we studied the effect of internal and external noise on the amount of hue bias. Internal noise was manipulated by increasing the delay between the reference and test from 0.4 to 4 s. External noise was manipulated by increasing the amount of chromatic noise in the reference stimulus, while keeping the delay between the reference and test constant at 2 s. Both noise manipulations had a reliable effect on the strength of the central tendency bias. Furthermore, there was a tendency for a positive relationship between variability of the estimates and bias in both noise conditions. In conclusion, observers are able to learn an experimental hue prior, and the weight on the prior can be manipulated by introducing noise in the estimation process.
263.
González, Esther G.; Lillakas, Linda; Greenwald, Naomi; Gallie, Brenda L.; Steinbach, Martin J.
Unaffected smooth pursuit but impaired motion perception in monocularly enucleated observers Journal Article
In: Vision Research, vol. 101, pp. 151–157, 2014, ISSN: 0042-6989.
Abstract | Links | BibTeX | Tags: DATAPixx, VPixxProgram
@article{gonzalez_unaffected_2014,
title = {Unaffected smooth pursuit but impaired motion perception in monocularly enucleated observers},
author = {Esther G. González and Linda Lillakas and Naomi Greenwald and Brenda L. Gallie and Martin J. Steinbach},
url = {https://www.sciencedirect.com/science/article/pii/S0042698914001503},
doi = {10.1016/j.visres.2014.06.014},
issn = {0042-6989},
year = {2014},
date = {2014-08-01},
urldate = {2024-01-18},
journal = {Vision Research},
volume = {101},
pages = {151–157},
abstract = {The objective of this paper was to study the characteristics of closed-loop smooth pursuit eye movements of 15 unilaterally eye enucleated individuals and 18 age-matched controls and to compare them to their performance in two tests of motion perception: relative motion and motion coherence. The relative motion test used a brief (150ms) small stimulus with a continuously present fixation target to preclude pursuit eye movements. The duration of the motion coherence trials was 1s, which allowed a brief pursuit of the stimuli. Smooth pursuit data were obtained with a step-ramp procedure. Controls were tested both monocularly and binocularly. The data showed worse performance by the enucleated observers in the relative motion task but no statistically significant differences in motion coherence between the two groups. On the other hand, the smooth pursuit gain of the enucleated participants was as good as that of controls for whom we found no binocular advantage. The data show that enucleated observers do not exhibit deficits in the afferent or sensory pathways or in the efferent or motor pathways of the steady-state smooth pursuit system even though their visual processing of motion is impaired.},
keywords = {DATAPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
The objective of this paper was to study the characteristics of closed-loop smooth pursuit eye movements of 15 unilaterally eye enucleated individuals and 18 age-matched controls and to compare them to their performance in two tests of motion perception: relative motion and motion coherence. The relative motion test used a brief (150ms) small stimulus with a continuously present fixation target to preclude pursuit eye movements. The duration of the motion coherence trials was 1s, which allowed a brief pursuit of the stimuli. Smooth pursuit data were obtained with a step-ramp procedure. Controls were tested both monocularly and binocularly. The data showed worse performance by the enucleated observers in the relative motion task but no statistically significant differences in motion coherence between the two groups. On the other hand, the smooth pursuit gain of the enucleated participants was as good as that of controls for whom we found no binocular advantage. The data show that enucleated observers do not exhibit deficits in the afferent or sensory pathways or in the efferent or motor pathways of the steady-state smooth pursuit system even though their visual processing of motion is impaired.
264.
Crewther, David
Temporal structure of Human Magnetic Evoked Fields to Colour, Form and Motion Journal Article
In: Journal of Vision, vol. 14, no. 10, pp. 984, 2014, ISSN: 1534-7362.
Abstract | Links | BibTeX | Tags: DATAPixx, VPixxProgram
@article{crewther_temporal_2014,
title = {Temporal structure of Human Magnetic Evoked Fields to Colour, Form and Motion},
author = {David Crewther},
url = {https://doi.org/10.1167/14.10.984},
doi = {10.1167/14.10.984},
issn = {1534-7362},
year = {2014},
date = {2014-08-01},
urldate = {2023-12-21},
journal = {Journal of Vision},
volume = {14},
number = {10},
pages = {984},
abstract = {The temporal structure of responses to colour, form and motion stimuli are little studied. Here, we have extended VEP studies of colour and form response to magnetoencephalography (MEG). Seven participants (young adult) observed a projected dartboard comprising 9 patches with red/grey or blue/grey stimuli, presented either as diffuse surface colours or as a radial pattern. Each stimulus was presented at 5 levels of desaturation levels (100%, 75%, 50%, 25%, 0%) with constant luminance contrast (30%), using pseudo-random binary m-sequences (VPixx/DataPixx). Five minute recordings on the 306 sensor Elekta Triux MEG system were made using a 60 Hz frame rate. A motion/stationary pattern of white dots on black was used to extract motion onset fields. Wiener kernel analysis of the first-order K1 and the first two slices of the second-order kernel (K2.1, K2.2) revealed that the surface colour responses were largely found in the second order, while the pattern based colour responses were mainly found in first order. The surface colour K2.1 response showed strong saturation dependence for both red and blue desaturation series, while for exactly the same stimulus colours, pattern evoked K1 responses were hardly dependent on saturation (Blue Surface: Rsq=.23},
keywords = {DATAPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
The temporal structure of responses to colour, form and motion stimuli are little studied. Here, we have extended VEP studies of colour and form response to magnetoencephalography (MEG). Seven participants (young adult) observed a projected dartboard comprising 9 patches with red/grey or blue/grey stimuli, presented either as diffuse surface colours or as a radial pattern. Each stimulus was presented at 5 levels of desaturation levels (100%, 75%, 50%, 25%, 0%) with constant luminance contrast (30%), using pseudo-random binary m-sequences (VPixx/DataPixx). Five minute recordings on the 306 sensor Elekta Triux MEG system were made using a 60 Hz frame rate. A motion/stationary pattern of white dots on black was used to extract motion onset fields. Wiener kernel analysis of the first-order K1 and the first two slices of the second-order kernel (K2.1, K2.2) revealed that the surface colour responses were largely found in the second order, while the pattern based colour responses were mainly found in first order. The surface colour K2.1 response showed strong saturation dependence for both red and blue desaturation series, while for exactly the same stimulus colours, pattern evoked K1 responses were hardly dependent on saturation (Blue Surface: Rsq=.23
265.
Meilleur, Andrée-Anne S.; Berthiaume, Claude; Bertone, Armando; Mottron, Laurent
Autism-Specific Covariation in Perceptual Performances: “g” or “p” Factor? Journal Article
In: PLOS ONE, vol. 9, no. 8, pp. e103781, 2014, ISSN: 1932-6203, (Publisher: Public Library of Science).
Abstract | Links | BibTeX | Tags: DATAPixx, RESPONSEPixx
@article{meilleur_autism-specific_2014,
title = {Autism-Specific Covariation in Perceptual Performances: “g” or “p” Factor?},
author = {Andrée-Anne S. Meilleur and Claude Berthiaume and Armando Bertone and Laurent Mottron},
url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0103781},
doi = {10.1371/journal.pone.0103781},
issn = {1932-6203},
year = {2014},
date = {2014-08-01},
urldate = {2023-12-21},
journal = {PLOS ONE},
volume = {9},
number = {8},
pages = {e103781},
abstract = {Background Autistic perception is characterized by atypical and sometimes exceptional performance in several low- (e.g., discrimination) and mid-level (e.g., pattern matching) tasks in both visual and auditory domains. A factor that specifically affects perceptive abilities in autistic individuals should manifest as an autism-specific association between perceptual tasks. The first purpose of this study was to explore how perceptual performances are associated within or across processing levels and/or modalities. The second purpose was to determine if general intelligence, the major factor that accounts for covariation in task performances in non-autistic individuals, equally controls perceptual abilities in autistic individuals. Methods We asked 46 autistic individuals and 46 typically developing controls to perform four tasks measuring low- or mid-level visual or auditory processing. Intelligence was measured with the Wechsler's Intelligence Scale (FSIQ) and Raven Progressive Matrices (RPM). We conducted linear regression models to compare task performances between groups and patterns of covariation between tasks. The addition of either Wechsler's FSIQ or RPM in the regression models controlled for the effects of intelligence. Results In typically developing individuals, most perceptual tasks were associated with intelligence measured either by RPM or Wechsler FSIQ. The residual covariation between unimodal tasks, i.e. covariation not explained by intelligence, could be explained by a modality-specific factor. In the autistic group, residual covariation revealed the presence of a plurimodal factor specific to autism. Conclusions Autistic individuals show exceptional performance in some perceptual tasks. Here, we demonstrate the existence of specific, plurimodal covariation that does not dependent on general intelligence (or “g” factor). Instead, this residual covariation is accounted for by a common perceptual process (or “p” factor), which may drive perceptual abilities differently in autistic and non-autistic individuals.},
note = {Publisher: Public Library of Science},
keywords = {DATAPixx, RESPONSEPixx},
pubstate = {published},
tppubtype = {article}
}
Background Autistic perception is characterized by atypical and sometimes exceptional performance in several low- (e.g., discrimination) and mid-level (e.g., pattern matching) tasks in both visual and auditory domains. A factor that specifically affects perceptive abilities in autistic individuals should manifest as an autism-specific association between perceptual tasks. The first purpose of this study was to explore how perceptual performances are associated within or across processing levels and/or modalities. The second purpose was to determine if general intelligence, the major factor that accounts for covariation in task performances in non-autistic individuals, equally controls perceptual abilities in autistic individuals. Methods We asked 46 autistic individuals and 46 typically developing controls to perform four tasks measuring low- or mid-level visual or auditory processing. Intelligence was measured with the Wechsler's Intelligence Scale (FSIQ) and Raven Progressive Matrices (RPM). We conducted linear regression models to compare task performances between groups and patterns of covariation between tasks. The addition of either Wechsler's FSIQ or RPM in the regression models controlled for the effects of intelligence. Results In typically developing individuals, most perceptual tasks were associated with intelligence measured either by RPM or Wechsler FSIQ. The residual covariation between unimodal tasks, i.e. covariation not explained by intelligence, could be explained by a modality-specific factor. In the autistic group, residual covariation revealed the presence of a plurimodal factor specific to autism. Conclusions Autistic individuals show exceptional performance in some perceptual tasks. Here, we demonstrate the existence of specific, plurimodal covariation that does not dependent on general intelligence (or “g” factor). Instead, this residual covariation is accounted for by a common perceptual process (or “p” factor), which may drive perceptual abilities differently in autistic and non-autistic individuals.
266.
Kéïta, Luc; Guy, Jacalyn; Berthiaume, Claude; Mottron, Laurent; Bertone, Armando
An early origin for detailed perception in Autism Spectrum Disorder: biased sensitivity for high-spatial frequency information. Journal Article
In: Scientific Reports, vol. 4, no. 1, pp. 5475, 2014, ISSN: 2045-2322, (Number: 1 Publisher: Nature Publishing Group).
Abstract | Links | BibTeX | Tags: VPixxProgram
@article{keita_early_2014,
title = {An early origin for detailed perception in Autism Spectrum Disorder: biased sensitivity for high-spatial frequency information.},
author = {Luc Kéïta and Jacalyn Guy and Claude Berthiaume and Laurent Mottron and Armando Bertone},
url = {https://www.nature.com/articles/srep05475},
doi = {10.1038/srep05475},
issn = {2045-2322},
year = {2014},
date = {2014-07-01},
urldate = {2023-12-21},
journal = {Scientific Reports},
volume = {4},
number = {1},
pages = {5475},
abstract = {Autistics demonstrate superior performances on several visuo-spatial tasks where local or detailed information processing is advantageous. Altered spatial filtering properties at an early level of visuo-spatial analysis may be a plausible perceptual origin for such detailed perception in Autism Spectrum Disorder. In this study, contrast sensitivity for both luminance and texture-defined vertically-oriented sine-wave gratings were measured across a range of spatial frequencies (0.5, 1, 2, 4 & 8 cpd) for autistics and non-autistic participants. Contrast sensitivity functions and peak frequency ratios were plotted and compared across groups. Results demonstrated that autistic participants were more sensitivity to luminance-defined, high spatial frequency gratings (8 cpd). A group difference in peak distribution was also observed as 35% of autistic participants manifested peak sensitivity for luminance-defined gratings of 4 cpd, compared to only 7% for the comparison group. These findings support that locally-biased perception in Autism Spectrum Disorder originates, at least in part, from differences in response properties of early spatial mechanisms favouring detailed spatial information processing.},
note = {Number: 1
Publisher: Nature Publishing Group},
keywords = {VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Autistics demonstrate superior performances on several visuo-spatial tasks where local or detailed information processing is advantageous. Altered spatial filtering properties at an early level of visuo-spatial analysis may be a plausible perceptual origin for such detailed perception in Autism Spectrum Disorder. In this study, contrast sensitivity for both luminance and texture-defined vertically-oriented sine-wave gratings were measured across a range of spatial frequencies (0.5, 1, 2, 4 & 8 cpd) for autistics and non-autistic participants. Contrast sensitivity functions and peak frequency ratios were plotted and compared across groups. Results demonstrated that autistic participants were more sensitivity to luminance-defined, high spatial frequency gratings (8 cpd). A group difference in peak distribution was also observed as 35% of autistic participants manifested peak sensitivity for luminance-defined gratings of 4 cpd, compared to only 7% for the comparison group. These findings support that locally-biased perception in Autism Spectrum Disorder originates, at least in part, from differences in response properties of early spatial mechanisms favouring detailed spatial information processing.
267.
Zeiner, Katharina; Maertens, Marianne
Linking luminance and lightness by global contrast normalization Journal Article
In: Journal of Vision, vol. 14, no. 7, pp. 3, 2014, ISSN: 1534-7362.
Abstract | Links | BibTeX | Tags: DATAPixx, RESPONSEPixx
@article{zeiner_linking_2014,
title = {Linking luminance and lightness by global contrast normalization},
author = {Katharina Zeiner and Marianne Maertens},
url = {https://doi.org/10.1167/14.7.3},
doi = {10.1167/14.7.3},
issn = {1534-7362},
year = {2014},
date = {2014-06-01},
urldate = {2024-01-12},
journal = {Journal of Vision},
volume = {14},
number = {7},
pages = {3},
abstract = {In the present experiment we addressed the question of how the visual system determines surface lightness from luminances in the retinal image. We measured the perceived lightness of target surfaces that were embedded in custom-made checkerboards. The checkerboards consisted of 10 by 10 checks of 10 different reflectance values that were arranged randomly across the board. They were rendered under six viewing conditions including plain view, with a shadow-casting cylinder, or with one of four different transparent media covering part of the board. For each reflectance we measured its corresponding luminance in the different viewing conditions. We then assessed the lightness matches of four observers for each of the reflectances in the different viewing conditions. We derived predictions of perceived lightness based on local luminance, Michelson contrast, edge integration, anchoring theory, and a normalized Michelson contrast measure. The normalized contrast measure was the best predictor of surface lightness and was almost as good as the actual reflectance values. The normalized contrast measure combines a local computation of Michelson contrast with a region-based normalization of contrast ranges with respect to the contrast range in plain view. How the segregation of image regions is accomplished remains to be elucidated.},
keywords = {DATAPixx, RESPONSEPixx},
pubstate = {published},
tppubtype = {article}
}
In the present experiment we addressed the question of how the visual system determines surface lightness from luminances in the retinal image. We measured the perceived lightness of target surfaces that were embedded in custom-made checkerboards. The checkerboards consisted of 10 by 10 checks of 10 different reflectance values that were arranged randomly across the board. They were rendered under six viewing conditions including plain view, with a shadow-casting cylinder, or with one of four different transparent media covering part of the board. For each reflectance we measured its corresponding luminance in the different viewing conditions. We then assessed the lightness matches of four observers for each of the reflectances in the different viewing conditions. We derived predictions of perceived lightness based on local luminance, Michelson contrast, edge integration, anchoring theory, and a normalized Michelson contrast measure. The normalized contrast measure was the best predictor of surface lightness and was almost as good as the actual reflectance values. The normalized contrast measure combines a local computation of Michelson contrast with a region-based normalization of contrast ranges with respect to the contrast range in plain view. How the segregation of image regions is accomplished remains to be elucidated.
268.
Komban, Stanley Jose; Kremkow, Jens; Jin, Jianzhong; Wang, Yushi; Lashgari, Reza; Li, Xiaobing; Zaidi, Qasim; Alonso, Jose-Manuel
Neuronal and Perceptual Differences in the Temporal Processing of Darks and Lights Journal Article
In: Neuron, vol. 82, no. 1, pp. 224–234, 2014, ISSN: 0896-6273, (Publisher: Elsevier).
Links | BibTeX | Tags: VIEWPixx3D
@article{komban_neuronal_2014,
title = {Neuronal and Perceptual Differences in the Temporal Processing of Darks and Lights},
author = {Stanley Jose Komban and Jens Kremkow and Jianzhong Jin and Yushi Wang and Reza Lashgari and Xiaobing Li and Qasim Zaidi and Jose-Manuel Alonso},
url = {https://www.cell.com/neuron/abstract/S0896-6273(14)00118-4},
doi = {10.1016/j.neuron.2014.02.020},
issn = {0896-6273},
year = {2014},
date = {2014-04-01},
urldate = {2024-01-12},
journal = {Neuron},
volume = {82},
number = {1},
pages = {224–234},
note = {Publisher: Elsevier},
keywords = {VIEWPixx3D},
pubstate = {published},
tppubtype = {article}
}
269.
Lange, Nicholas D.; Buttaccio, Daniel R.; Davelaar, Eddy J.; Thomas, Rick P.
Using the memory activation capture (MAC) procedure to investigate the temporal dynamics of hypothesis generation Journal Article
In: Memory & Cognition, vol. 42, no. 2, pp. 264–274, 2014, ISSN: 1532-5946.
Abstract | Links | BibTeX | Tags: RESPONSEPixx
@article{lange_using_2014,
title = {Using the memory activation capture (MAC) procedure to investigate the temporal dynamics of hypothesis generation},
author = {Nicholas D. Lange and Daniel R. Buttaccio and Eddy J. Davelaar and Rick P. Thomas},
url = {https://doi.org/10.3758/s13421-013-0354-1},
doi = {10.3758/s13421-013-0354-1},
issn = {1532-5946},
year = {2014},
date = {2014-02-01},
urldate = {2024-01-18},
journal = {Memory & Cognition},
volume = {42},
number = {2},
pages = {264–274},
abstract = {Research investigating top-down capture has demonstrated a coupling of working memory content with attention and eye movements. By capitalizing on this relationship, we have developed a novel methodology, called the memory activation capture (MAC) procedure, for measuring the dynamics of working memory content supporting complex cognitive tasks (e.g., decision making, problem solving). The MAC procedure employs briefly presented visual arrays containing task-relevant information at critical points in a task. By observing which items are preferentially fixated, we gain a measure of working memory content as the task evolves through time. The efficacy of the MAC procedure was demonstrated in a dynamic hypothesis generation task in which some of its advantages over existing methods for measuring changes in the contents of working memory over time are highlighted. In two experiments, the MAC procedure was able to detect the hypothesis that was retrieved and placed into working memory. Moreover, the results from Experiment 2 suggest a two-stage process following hypothesis retrieval, whereby the hypothesis undergoes a brief period of heightened activation before entering a lower activation state in which it is maintained for output. The results of both experiments are of additional general interest, as they represent the first demonstrations of top-down capture driven by participant-established WM content retrieved from long-term memory.},
keywords = {RESPONSEPixx},
pubstate = {published},
tppubtype = {article}
}
Research investigating top-down capture has demonstrated a coupling of working memory content with attention and eye movements. By capitalizing on this relationship, we have developed a novel methodology, called the memory activation capture (MAC) procedure, for measuring the dynamics of working memory content supporting complex cognitive tasks (e.g., decision making, problem solving). The MAC procedure employs briefly presented visual arrays containing task-relevant information at critical points in a task. By observing which items are preferentially fixated, we gain a measure of working memory content as the task evolves through time. The efficacy of the MAC procedure was demonstrated in a dynamic hypothesis generation task in which some of its advantages over existing methods for measuring changes in the contents of working memory over time are highlighted. In two experiments, the MAC procedure was able to detect the hypothesis that was retrieved and placed into working memory. Moreover, the results from Experiment 2 suggest a two-stage process following hypothesis retrieval, whereby the hypothesis undergoes a brief period of heightened activation before entering a lower activation state in which it is maintained for output. The results of both experiments are of additional general interest, as they represent the first demonstrations of top-down capture driven by participant-established WM content retrieved from long-term memory.
270.
Gnanaseelan, Roshani; Gonzalez, Dave A.; Niechwiej-Szwedo, Ewa
Binocular advantage for prehension movements performed in visually enriched environments requiring visual search Journal Article
In: Frontiers in Human Neuroscience, vol. 8, 2014, ISSN: 1662-5161.
Abstract | Links | BibTeX | Tags: DATAPixx, VPixxProgram
@article{gnanaseelan_binocular_2014,
title = {Binocular advantage for prehension movements performed in visually enriched environments requiring visual search},
author = {Roshani Gnanaseelan and Dave A. Gonzalez and Ewa Niechwiej-Szwedo},
url = {https://www.frontiersin.org/articles/10.3389/fnhum.2014.00959},
issn = {1662-5161},
year = {2014},
date = {2014-01-01},
urldate = {2023-12-21},
journal = {Frontiers in Human Neuroscience},
volume = {8},
abstract = {The purpose of this study was to examine the role of binocular vision during a prehension task performed in a visually enriched environment where the target object was surrounded by distractors/obstacles. Fifteen adults reached and grasped for a cylindrical peg while eye movements and upper limb kinematics were recorded. The complexity of the visual environment was manipulated by varying the number of distractors and by varying the saliency of the target. Gaze behavior (i.e., the latency of the primary gaze shift and frequency of gaze shifts prior to reach initiation) was comparable between viewing conditions. In contrast, a binocular advantage was evident in performance accuracy. Specifically, participants picked up the wrong object twice as often during monocular viewing when the complexity of the environment increased. Reach performance was more efficient during binocular viewing, which was demonstrated by shorter reach reaction time and overall movement time. Reaching movements during the approach phase had higher peak velocity during binocular viewing. During monocular viewing reach trajectories exhibited a direction bias during the acceleration phase, which was leftward during left eye viewing and rightward during right eye viewing. This bias can be explained by the presence of esophoria in the covered eye. The grasping interval was also extended by textasciitilde20% during monocular viewing; however, the duration of the return phase after the target was picked up was comparable across viewing conditions. In conclusion, binocular vision provides important input for planning and execution of prehension movements in visually enriched environments. Binocular advantage was evident, regardless of set size or target saliency, indicating that adults plan their movements more cautiously during monocular viewing, even in relatively simple environments with a highly salient target. Nevertheless, in visually-normal adults monocular input provides sufficient information to engage in online control to correct the initial errors in movement planning.},
keywords = {DATAPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
The purpose of this study was to examine the role of binocular vision during a prehension task performed in a visually enriched environment where the target object was surrounded by distractors/obstacles. Fifteen adults reached and grasped for a cylindrical peg while eye movements and upper limb kinematics were recorded. The complexity of the visual environment was manipulated by varying the number of distractors and by varying the saliency of the target. Gaze behavior (i.e., the latency of the primary gaze shift and frequency of gaze shifts prior to reach initiation) was comparable between viewing conditions. In contrast, a binocular advantage was evident in performance accuracy. Specifically, participants picked up the wrong object twice as often during monocular viewing when the complexity of the environment increased. Reach performance was more efficient during binocular viewing, which was demonstrated by shorter reach reaction time and overall movement time. Reaching movements during the approach phase had higher peak velocity during binocular viewing. During monocular viewing reach trajectories exhibited a direction bias during the acceleration phase, which was leftward during left eye viewing and rightward during right eye viewing. This bias can be explained by the presence of esophoria in the covered eye. The grasping interval was also extended by textasciitilde20% during monocular viewing; however, the duration of the return phase after the target was picked up was comparable across viewing conditions. In conclusion, binocular vision provides important input for planning and execution of prehension movements in visually enriched environments. Binocular advantage was evident, regardless of set size or target saliency, indicating that adults plan their movements more cautiously during monocular viewing, even in relatively simple environments with a highly salient target. Nevertheless, in visually-normal adults monocular input provides sufficient information to engage in online control to correct the initial errors in movement planning.
271.
Goutcher, Ross; Hibbard, Paul
Mechanisms for similarity matching in disparity measurement Journal Article
In: Frontiers in Psychology, vol. 4, 2014, ISSN: 1664-1078.
Abstract | Links | BibTeX | Tags:
@article{goutcher_mechanisms_2014,
title = {Mechanisms for similarity matching in disparity measurement},
author = {Ross Goutcher and Paul Hibbard},
url = {https://www.frontiersin.org/articles/10.3389/fpsyg.2013.01014},
issn = {1664-1078},
year = {2014},
date = {2014-01-01},
urldate = {2024-01-12},
journal = {Frontiers in Psychology},
volume = {4},
abstract = {Early neural mechanisms for the measurement of binocular disparity appear to operate in a manner consistent with cross-correlation-like processes. Consequently, cross-correlation, or cross-correlation-like procedures have been used in a range of models of disparity measurement. Using such procedures as the basis for disparity measurement creates a preference for correspondence solutions that maximize the similarity between local left and right eye image regions. Here, we examine how observers’ perception of depth in an ambiguous stereogram is affected by manipulations of luminance and orientation-based image similarity. Results show a strong effect of coarse-scale luminance similarity manipulations, but a relatively weak effect of finer-scale manipulations of orientation similarity. This is in contrast to the measurements of depth obtained from a standard cross-correlation model. This model shows strong effects of orientation similarity manipulations and weaker effects of luminance similarity. In order to account for these discrepancies, the standard cross-correlation approach may be modified to include an initial spatial frequency filtering stage. The performance of this adjusted model most closely matches human psychophysical data when spatial frequency filtering favors coarser scales. This is consistent with the operation of disparity measurement processes where spatial frequency and disparity tuning are correlated, or where disparity measurement operates in a coarse-to-fine manner.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Early neural mechanisms for the measurement of binocular disparity appear to operate in a manner consistent with cross-correlation-like processes. Consequently, cross-correlation, or cross-correlation-like procedures have been used in a range of models of disparity measurement. Using such procedures as the basis for disparity measurement creates a preference for correspondence solutions that maximize the similarity between local left and right eye image regions. Here, we examine how observers’ perception of depth in an ambiguous stereogram is affected by manipulations of luminance and orientation-based image similarity. Results show a strong effect of coarse-scale luminance similarity manipulations, but a relatively weak effect of finer-scale manipulations of orientation similarity. This is in contrast to the measurements of depth obtained from a standard cross-correlation model. This model shows strong effects of orientation similarity manipulations and weaker effects of luminance similarity. In order to account for these discrepancies, the standard cross-correlation approach may be modified to include an initial spatial frequency filtering stage. The performance of this adjusted model most closely matches human psychophysical data when spatial frequency filtering favors coarser scales. This is consistent with the operation of disparity measurement processes where spatial frequency and disparity tuning are correlated, or where disparity measurement operates in a coarse-to-fine manner.
272.
Serrano-Pedraza, Ignacio; Romero-Ferreiro, Verónica; Read, Jenny C. A.; Diéguez-Risco, Teresa; Bagney, Alexandra; Caballero-González, Montserrat; Rodríguez-Torresano, Javier; Rodriguez-Jimenez, Roberto
Reduced visual surround suppression in schizophrenia shown by measuring contrast detection thresholds Journal Article
In: Frontiers in Psychology, vol. 5, 2014, ISSN: 1664-1078.
Abstract | Links | BibTeX | Tags: DATAPixx, RESPONSEPixx
@article{serrano-pedraza_reduced_2014,
title = {Reduced visual surround suppression in schizophrenia shown by measuring contrast detection thresholds},
author = {Ignacio Serrano-Pedraza and Verónica Romero-Ferreiro and Jenny C. A. Read and Teresa Diéguez-Risco and Alexandra Bagney and Montserrat Caballero-González and Javier Rodríguez-Torresano and Roberto Rodriguez-Jimenez},
url = {https://www.frontiersin.org/articles/10.3389/fpsyg.2014.01431},
issn = {1664-1078},
year = {2014},
date = {2014-01-01},
urldate = {2024-01-17},
journal = {Frontiers in Psychology},
volume = {5},
abstract = {Visual perception in schizophrenia is attracting a broad interest given the deep knowledge that we have about the visual system in healthy populations. One example is the class of effects known collectively as visual surround suppression. For example, the visibility of a grating located in the visual periphery is impaired by the presence of a surrounding grating of the same spatial frequency and orientation. Previous studies have suggested abnormal visual surround suppression in patients with schizophrenia. Given that schizophrenia patients have cortical alterations including hypofunction of NMDA receptors and reduced concentration of GABA neurotransmitter, which affect lateral inhibitory connections, then they should be relatively better than controls at detecting visual stimuli that are usually suppressed. We tested this hypothesis by measuring contrast detection thresholds using a new stimulus configuration. We tested two groups: 21 schizophrenia patients and 24 healthy subjects. Thresholds were obtained using Bayesian staircases in a four-alternative forced-choice detection task where the target was a grating within a 3∘ Butterworth window that appeared in one of four possible positions at 5∘ eccentricity. We compared three conditions, (a) target with no-surround, (b) target embedded within a surrounding grating of 20∘ diameter and 25% contrast with same spatial frequency and orthogonal orientation, and (c) target embedded within a surrounding grating with parallel (same) orientation. Previous results with healthy populations have shown that contrast thresholds are lower for orthogonal and no-surround (NS) conditions than for parallel surround (PS). The log-ratios between parallel and NS thresholds are used as an index quantifying visual surround suppression. Patients performed poorly compared to controls in the NS and orthogonal-surround conditions. However, they performed as well as controls when the surround was parallel, resulting in significantly lower suppression indices in patients. To examine whether the difference in suppression was driven by the lower NS thresholds for controls, we examined a matched subgroup of controls and patients, selected to have similar thresholds in the NS condition. Patients performed significantly better in the PS condition than controls. This analysis therefore indicates that a PS raised contrast thresholds less in patients than in controls. Our results support the hypothesis that inhibitory connections in early visual cortex are impaired in schizophrenia patients.},
keywords = {DATAPixx, RESPONSEPixx},
pubstate = {published},
tppubtype = {article}
}
Visual perception in schizophrenia is attracting a broad interest given the deep knowledge that we have about the visual system in healthy populations. One example is the class of effects known collectively as visual surround suppression. For example, the visibility of a grating located in the visual periphery is impaired by the presence of a surrounding grating of the same spatial frequency and orientation. Previous studies have suggested abnormal visual surround suppression in patients with schizophrenia. Given that schizophrenia patients have cortical alterations including hypofunction of NMDA receptors and reduced concentration of GABA neurotransmitter, which affect lateral inhibitory connections, then they should be relatively better than controls at detecting visual stimuli that are usually suppressed. We tested this hypothesis by measuring contrast detection thresholds using a new stimulus configuration. We tested two groups: 21 schizophrenia patients and 24 healthy subjects. Thresholds were obtained using Bayesian staircases in a four-alternative forced-choice detection task where the target was a grating within a 3∘ Butterworth window that appeared in one of four possible positions at 5∘ eccentricity. We compared three conditions, (a) target with no-surround, (b) target embedded within a surrounding grating of 20∘ diameter and 25% contrast with same spatial frequency and orthogonal orientation, and (c) target embedded within a surrounding grating with parallel (same) orientation. Previous results with healthy populations have shown that contrast thresholds are lower for orthogonal and no-surround (NS) conditions than for parallel surround (PS). The log-ratios between parallel and NS thresholds are used as an index quantifying visual surround suppression. Patients performed poorly compared to controls in the NS and orthogonal-surround conditions. However, they performed as well as controls when the surround was parallel, resulting in significantly lower suppression indices in patients. To examine whether the difference in suppression was driven by the lower NS thresholds for controls, we examined a matched subgroup of controls and patients, selected to have similar thresholds in the NS condition. Patients performed significantly better in the PS condition than controls. This analysis therefore indicates that a PS raised contrast thresholds less in patients than in controls. Our results support the hypothesis that inhibitory connections in early visual cortex are impaired in schizophrenia patients.
273.
González, Esther G.; Lillakas, Linda; Lam, Alexander; Gallie, Brenda L.; Steinbach, Martin J.
Horizontal Saccade Dynamics After Childhood Monocular Enucleation Journal Article
In: Investigative Ophthalmology & Visual Science, vol. 54, no. 10, pp. 6463–6471, 2013, ISSN: 1552-5783.
Abstract | Links | BibTeX | Tags: DATAPixx, VPixxProgram
@article{gonzalez_horizontal_2013,
title = {Horizontal Saccade Dynamics After Childhood Monocular Enucleation},
author = {Esther G. González and Linda Lillakas and Alexander Lam and Brenda L. Gallie and Martin J. Steinbach},
url = {https://doi.org/10.1167/iovs.13-12481},
doi = {10.1167/iovs.13-12481},
issn = {1552-5783},
year = {2013},
date = {2013-10-01},
urldate = {2024-01-03},
journal = {Investigative Ophthalmology & Visual Science},
volume = {54},
number = {10},
pages = {6463–6471},
abstract = {We investigated the effects of monocularity on oculomotor control by examining the characteristics of the horizontal saccades of people with one eye, and comparing them to those of a group of age-matched controls who viewed the stimuli monocularly and binocularly. Participants were tested in a no-gap, no-overlap saccadic task using a video-based remote eye tracker. One group consisted of unilaterally eye enucleated participants (N = 15; mean age, 31.27 years), the other of age-matched people with normal binocular vision (N = 18; mean age, 30.17 years). The horizontal saccade dynamics of enucleated people are similar to those of people with normal binocularity when they view monocularly and, with the exception of latency, when they view binocularly. The data show that the monocular saccades of control and enucleated observers have longer latencies than the binocular saccades of the control group, the saccades of the enucleated observers are as accurate as those of the controls viewing monocularly or binocularly, smaller saccades are more accurate than the larger ones, and abducting saccades are faster than adducting saccades. Our data suggest that the true monocularity produced by early enucleation does not result in slower visual processing in the afferent (sensory) pathway, or in deficits in the efferent (motor) pathways of the saccadic system. Possible mechanisms to account for the effects of monocular vision on saccades are discussed.},
keywords = {DATAPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
We investigated the effects of monocularity on oculomotor control by examining the characteristics of the horizontal saccades of people with one eye, and comparing them to those of a group of age-matched controls who viewed the stimuli monocularly and binocularly. Participants were tested in a no-gap, no-overlap saccadic task using a video-based remote eye tracker. One group consisted of unilaterally eye enucleated participants (N = 15; mean age, 31.27 years), the other of age-matched people with normal binocular vision (N = 18; mean age, 30.17 years). The horizontal saccade dynamics of enucleated people are similar to those of people with normal binocularity when they view monocularly and, with the exception of latency, when they view binocularly. The data show that the monocular saccades of control and enucleated observers have longer latencies than the binocular saccades of the control group, the saccades of the enucleated observers are as accurate as those of the controls viewing monocularly or binocularly, smaller saccades are more accurate than the larger ones, and abducting saccades are faster than adducting saccades. Our data suggest that the true monocularity produced by early enucleation does not result in slower visual processing in the afferent (sensory) pathway, or in deficits in the efferent (motor) pathways of the saccadic system. Possible mechanisms to account for the effects of monocular vision on saccades are discussed.
274.
Serrano-Pedraza, Ignacio; Gamonoso-Cruz, María J.; Sierra-Vázquez, Vicente; Derrington, Andrew M.
Comparing the effect of the interaction between fine and coarse scales and surround suppression on motion discrimination Journal Article
In: Journal of Vision, vol. 13, no. 11, pp. 5, 2013, ISSN: 1534-7362.
Abstract | Links | BibTeX | Tags: RESPONSEPixx
@article{serrano-pedraza_comparing_2013,
title = {Comparing the effect of the interaction between fine and coarse scales and surround suppression on motion discrimination},
author = {Ignacio Serrano-Pedraza and María J. Gamonoso-Cruz and Vicente Sierra-Vázquez and Andrew M. Derrington},
url = {https://doi.org/10.1167/13.11.5},
doi = {10.1167/13.11.5},
issn = {1534-7362},
year = {2013},
date = {2013-09-01},
urldate = {2024-01-02},
journal = {Journal of Vision},
volume = {13},
number = {11},
pages = {5},
abstract = {Our ability to discriminate motion direction in a Gabor patch diminishes with increasing size and contrast, indicating surround suppression. Discrimination is also impaired by a static low-spatial-frequency patch added to the moving stimulus, suggesting an antagonism between sensors tuned to fine and coarse features. Using Bayesian staircases, we measured duration thresholds in motion-direction discrimination tasks using vertically oriented Gabor patches moving at 2°/s. In two experiments, we tested two contrasts (2.8% and 46%), five window sizes (from 0.7° to 5°), and two spatial frequencies (1 c/deg and 3 c/deg), either presented alone or added to a static pattern. When the moving pattern was presented alone, duration thresholds increased with size at high contrast and decreased with size at low contrast. At low contrast, when a static pattern of 3 c/deg was added to a moving pattern of 1 c/deg, duration thresholds were similar to the case when the moving pattern was presented alone; however, at high contrast, duration thresholds were facilitated, eliminating the effect of surround suppression. When a static pattern of 1 c/deg was added to a moving pattern of 3 c/deg, duration thresholds increased about 4 times for high contrast and 2 times for low contrast. These results show that the antagonism between sensors tuned to fine and coarse scales is more complex than surround suppression, suggesting that it reflects the operation of a different mechanism.},
keywords = {RESPONSEPixx},
pubstate = {published},
tppubtype = {article}
}
Our ability to discriminate motion direction in a Gabor patch diminishes with increasing size and contrast, indicating surround suppression. Discrimination is also impaired by a static low-spatial-frequency patch added to the moving stimulus, suggesting an antagonism between sensors tuned to fine and coarse features. Using Bayesian staircases, we measured duration thresholds in motion-direction discrimination tasks using vertically oriented Gabor patches moving at 2°/s. In two experiments, we tested two contrasts (2.8% and 46%), five window sizes (from 0.7° to 5°), and two spatial frequencies (1 c/deg and 3 c/deg), either presented alone or added to a static pattern. When the moving pattern was presented alone, duration thresholds increased with size at high contrast and decreased with size at low contrast. At low contrast, when a static pattern of 3 c/deg was added to a moving pattern of 1 c/deg, duration thresholds were similar to the case when the moving pattern was presented alone; however, at high contrast, duration thresholds were facilitated, eliminating the effect of surround suppression. When a static pattern of 1 c/deg was added to a moving pattern of 3 c/deg, duration thresholds increased about 4 times for high contrast and 2 times for low contrast. These results show that the antagonism between sensors tuned to fine and coarse scales is more complex than surround suppression, suggesting that it reflects the operation of a different mechanism.
275.
Geringswald, Franziska; Herbik, Anne; Hoffmann, Michael B.; Pollmann, Stefan
Contextual cueing impairment in patients with age-related macular degeneration Journal Article
In: Journal of Vision, vol. 13, no. 3, pp. 28, 2013, ISSN: 1534-7362.
Abstract | Links | BibTeX | Tags: RESPONSEPixx
@article{geringswald_contextual_2013,
title = {Contextual cueing impairment in patients with age-related macular degeneration},
author = {Franziska Geringswald and Anne Herbik and Michael B. Hoffmann and Stefan Pollmann},
url = {https://doi.org/10.1167/13.3.28},
doi = {10.1167/13.3.28},
issn = {1534-7362},
year = {2013},
date = {2013-09-01},
urldate = {2024-01-02},
journal = {Journal of Vision},
volume = {13},
number = {3},
pages = {28},
abstract = {Visual attention can be guided by past experience of regularities in our visual environment. In the contextual cueing paradigm, incidental learning of repeated distractor configurations speeds up search times compared to random search arrays. Concomitantly, fewer fixations and more direct scan paths indicate more efficient visual exploration in repeated search arrays. In previous work, we found that simulating a central scotoma in healthy observers eliminated this search facilitation. Here, we investigated contextual cueing in patients with age-related macular degeneration (AMD) who suffer from impaired foveal vision. AMD patients performed visual search using only their more severely impaired eye (n = 13) as well as under binocular viewing (n = 16). Normal-sighted controls developed a significant contextual cueing effect. In comparison, patients showed only a small nonsignificant advantage for repeated displays when searching with their worse eye. When searching binocularly, they profited from contextual cues, but still less than controls. Number of fixations and scan pattern ratios showed a comparable pattern as search times. Moreover, contextual cueing was significantly correlated with acuity in monocular search. Thus, foveal vision loss may lead to impaired guidance of attention by contextual memory cues.},
keywords = {RESPONSEPixx},
pubstate = {published},
tppubtype = {article}
}
Visual attention can be guided by past experience of regularities in our visual environment. In the contextual cueing paradigm, incidental learning of repeated distractor configurations speeds up search times compared to random search arrays. Concomitantly, fewer fixations and more direct scan paths indicate more efficient visual exploration in repeated search arrays. In previous work, we found that simulating a central scotoma in healthy observers eliminated this search facilitation. Here, we investigated contextual cueing in patients with age-related macular degeneration (AMD) who suffer from impaired foveal vision. AMD patients performed visual search using only their more severely impaired eye (n = 13) as well as under binocular viewing (n = 16). Normal-sighted controls developed a significant contextual cueing effect. In comparison, patients showed only a small nonsignificant advantage for repeated displays when searching with their worse eye. When searching binocularly, they profited from contextual cues, but still less than controls. Number of fixations and scan pattern ratios showed a comparable pattern as search times. Moreover, contextual cueing was significantly correlated with acuity in monocular search. Thus, foveal vision loss may lead to impaired guidance of attention by contextual memory cues.
276.
Risko, Evan F.; Maloney, Erin A.; Fugelsang, Jonathan A.
Paying attention to attention: evidence for an attentional contribution to the size congruity effect Journal Article
In: Attention, Perception, & Psychophysics, vol. 75, no. 6, pp. 1137–1147, 2013, ISSN: 1943-393X.
Abstract | Links | BibTeX | Tags: RESPONSEPixx
@article{risko_paying_2013,
title = {Paying attention to attention: evidence for an attentional contribution to the size congruity effect},
author = {Evan F. Risko and Erin A. Maloney and Jonathan A. Fugelsang},
url = {https://doi.org/10.3758/s13414-013-0477-2},
doi = {10.3758/s13414-013-0477-2},
issn = {1943-393X},
year = {2013},
date = {2013-08-01},
urldate = {2024-01-17},
journal = {Attention, Perception, & Psychophysics},
volume = {75},
number = {6},
pages = {1137–1147},
abstract = {Understanding the mechanisms supporting our comprehension of magnitude information represents a key goal in cognitive psychology. A major phenomenon employed in the pursuit of this goal has been the physical size congruity effect—namely, the observation that comparing the relative numerical sizes of two numbers is influenced by their relative physical sizes. The standard account of the physical size congruity effect attributes it to the automatic influence of the comparison of irrelevant physical magnitudes on numerical judgments. Here we develop an alternative account of this effect on the basis of the operation of attention in the typical size congruity display and the temporal dynamics of number comparison. We also provide a test of a number of predictions derived from this alternative account by combining a physical size congruity manipulation with a manipulation designed to alter the operation of attention within the typical size congruity display (i.e., a manipulation of the relative onsets of the digits). This test provides evidence consistent with an attentional contribution to the size congruity effect. Implications for our understanding of magnitude and the interactions between attention and magnitude are discussed.},
keywords = {RESPONSEPixx},
pubstate = {published},
tppubtype = {article}
}
Understanding the mechanisms supporting our comprehension of magnitude information represents a key goal in cognitive psychology. A major phenomenon employed in the pursuit of this goal has been the physical size congruity effect—namely, the observation that comparing the relative numerical sizes of two numbers is influenced by their relative physical sizes. The standard account of the physical size congruity effect attributes it to the automatic influence of the comparison of irrelevant physical magnitudes on numerical judgments. Here we develop an alternative account of this effect on the basis of the operation of attention in the typical size congruity display and the temporal dynamics of number comparison. We also provide a test of a number of predictions derived from this alternative account by combining a physical size congruity manipulation with a manipulation designed to alter the operation of attention within the typical size congruity display (i.e., a manipulation of the relative onsets of the digits). This test provides evidence consistent with an attentional contribution to the size congruity effect. Implications for our understanding of magnitude and the interactions between attention and magnitude are discussed.
277.
Crewther, David; Brown, Alyse; Hugrass, Laila
Spatio-temporal structure of multi-focal MEG potentials shows evidence of striate global/local signalling. Journal Article
In: Journal of Vision, vol. 13, no. 9, pp. 308, 2013, ISSN: 1534-7362.
Abstract | Links | BibTeX | Tags: VPixxProgram
@article{crewther_spatio-temporal_2013,
title = {Spatio-temporal structure of multi-focal MEG potentials shows evidence of striate global/local signalling.},
author = {David Crewther and Alyse Brown and Laila Hugrass},
url = {https://doi.org/10.1167/13.9.308},
doi = {10.1167/13.9.308},
issn = {1534-7362},
year = {2013},
date = {2013-07-01},
urldate = {2023-12-21},
journal = {Journal of Vision},
volume = {13},
number = {9},
pages = {308},
abstract = {Nonlinearities of the VEP, with signatures for magnocellular and parvocellular processing have provided useful insights into early cortical neural processing in normals (1) and autism spectrum (2). Signatures have been based on contrast response function, saturation and latency of response peaks. We extended these studies to magnetoencephalography (MEG). Five participants (young adult, 4 female, 1 male) observed a projected dartboard comprising 9 unstructured patches each executing pseudo-random binary m-sequences (VPixx). Four minute recordings on the 306 sensor Elekta Triux system were made at Michelson contrasts of 24% and 95% (60 Hz frame rate). Wiener kernel analysis (foveal patch) of the first-order K1 and the first two slices of the second-order kernel (K2 .1 & K2 .2) were characterized by an initial response latency of <50ms with major peaks with latencies of 95 ms (K1) 85 ms (K2.1) while the second slice (K2.2) demonstrated peaks rather more delayed in latency, similar to the electrical VEP. The early peak of the first slice K2.1 was already easily measurable with 24% contrast and did not grow at higher contrasts, indicative of the likely magnocellular origin. In a second experiment, a diamond illusion stimulus (3) was supposed over the randomly flashing central stimulus patch and participants reported global percepts (diamond shape oscillating horizontally) and local percepts (4 ungrouped moving lines) via pressing different buttons. Mean difference (Global – Local) magnetic evoked fields (MEF) showed little difference for times of <100ms, and a distinct peak with latency around 180ms centred over occipital cortex sensors. Thus perceptual rivalry exerts effects on the occipital MEF. References: (1) Klistorner A, et al (1997), Vis Res 37(15): 2161-9; (2) Sutherland A & Crewther DP, Brain 133: 2089-2097; (3) Fang F et al (2008), JVis 8(7):2, 2–9 Meeting abstract presented at VSS 2013},
keywords = {VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Nonlinearities of the VEP, with signatures for magnocellular and parvocellular processing have provided useful insights into early cortical neural processing in normals (1) and autism spectrum (2). Signatures have been based on contrast response function, saturation and latency of response peaks. We extended these studies to magnetoencephalography (MEG). Five participants (young adult, 4 female, 1 male) observed a projected dartboard comprising 9 unstructured patches each executing pseudo-random binary m-sequences (VPixx). Four minute recordings on the 306 sensor Elekta Triux system were made at Michelson contrasts of 24% and 95% (60 Hz frame rate). Wiener kernel analysis (foveal patch) of the first-order K1 and the first two slices of the second-order kernel (K2 .1 & K2 .2) were characterized by an initial response latency of <50ms with major peaks with latencies of 95 ms (K1) 85 ms (K2.1) while the second slice (K2.2) demonstrated peaks rather more delayed in latency, similar to the electrical VEP. The early peak of the first slice K2.1 was already easily measurable with 24% contrast and did not grow at higher contrasts, indicative of the likely magnocellular origin. In a second experiment, a diamond illusion stimulus (3) was supposed over the randomly flashing central stimulus patch and participants reported global percepts (diamond shape oscillating horizontally) and local percepts (4 ungrouped moving lines) via pressing different buttons. Mean difference (Global – Local) magnetic evoked fields (MEF) showed little difference for times of <100ms, and a distinct peak with latency around 180ms centred over occipital cortex sensors. Thus perceptual rivalry exerts effects on the occipital MEF. References: (1) Klistorner A, et al (1997), Vis Res 37(15): 2161-9; (2) Sutherland A & Crewther DP, Brain 133: 2089-2097; (3) Fang F et al (2008), JVis 8(7):2, 2–9 Meeting abstract presented at VSS 2013
278.
Thabet, Michel; Wilkinson, Frances; Wilson, Hugh R; Karanovic, Olivera
The locus of flicker adaptation in the migraine visual system: A dichoptic study Journal Article
In: Cephalalgia, vol. 33, no. 1, pp. 5–19, 2013, ISSN: 0333-1024, (Publisher: SAGE Publications Ltd STM).
Abstract | Links | BibTeX | Tags: DATAPixx, VPixxProgram
@article{thabet_locus_2013,
title = {The locus of flicker adaptation in the migraine visual system: A dichoptic study},
author = {Michel Thabet and Frances Wilkinson and Hugh R Wilson and Olivera Karanovic},
url = {https://doi.org/10.1177/0333102412462640},
doi = {10.1177/0333102412462640},
issn = {0333-1024},
year = {2013},
date = {2013-01-01},
urldate = {2024-01-18},
journal = {Cephalalgia},
volume = {33},
number = {1},
pages = {5–19},
abstract = {Background
Flickering light has been shown to sensitize the migraine visual system at high stimulus contrast while elevating thresholds at low contrast. The present study employs a dichoptic psychophysical paradigm to ask whether the abnormal adaptation to flicker in migraine occurs before or after the binocular combination of inputs from the two eyes in the visual cortex.
Methods
Following adaptation to high contrast flicker presented to one eye only, flicker contrast increment thresholds were measured in each eye separately using dichoptic viewing.
Results
Modest interocular transfer of adaptation was seen in both migraine and control groups at low contrast. Sensitization at high contrast in migraine relative to control participants was seen in the adapted eye only, and an unanticipated threshold elevation occurred in the non-adapted eye. Migraineurs also showed significantly lower aversion thresholds to full field flicker than control participants, but aversion scores and increment thresholds were not correlated.
Conclusions
The results are simulated with a three-stage neural model of adaptation that points to strong adaptation at monocular sites prior to binocular combination, and weaker adaptation at the level of cortical binocular neurons. The sensitization at high contrast in migraine is proposed to result from stronger adaptation of inhibitory neurons, which act as a monocular normalization pool.},
note = {Publisher: SAGE Publications Ltd STM},
keywords = {DATAPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Background
Flickering light has been shown to sensitize the migraine visual system at high stimulus contrast while elevating thresholds at low contrast. The present study employs a dichoptic psychophysical paradigm to ask whether the abnormal adaptation to flicker in migraine occurs before or after the binocular combination of inputs from the two eyes in the visual cortex.
Methods
Following adaptation to high contrast flicker presented to one eye only, flicker contrast increment thresholds were measured in each eye separately using dichoptic viewing.
Results
Modest interocular transfer of adaptation was seen in both migraine and control groups at low contrast. Sensitization at high contrast in migraine relative to control participants was seen in the adapted eye only, and an unanticipated threshold elevation occurred in the non-adapted eye. Migraineurs also showed significantly lower aversion thresholds to full field flicker than control participants, but aversion scores and increment thresholds were not correlated.
Conclusions
The results are simulated with a three-stage neural model of adaptation that points to strong adaptation at monocular sites prior to binocular combination, and weaker adaptation at the level of cortical binocular neurons. The sensitization at high contrast in migraine is proposed to result from stronger adaptation of inhibitory neurons, which act as a monocular normalization pool.
Flickering light has been shown to sensitize the migraine visual system at high stimulus contrast while elevating thresholds at low contrast. The present study employs a dichoptic psychophysical paradigm to ask whether the abnormal adaptation to flicker in migraine occurs before or after the binocular combination of inputs from the two eyes in the visual cortex.
Methods
Following adaptation to high contrast flicker presented to one eye only, flicker contrast increment thresholds were measured in each eye separately using dichoptic viewing.
Results
Modest interocular transfer of adaptation was seen in both migraine and control groups at low contrast. Sensitization at high contrast in migraine relative to control participants was seen in the adapted eye only, and an unanticipated threshold elevation occurred in the non-adapted eye. Migraineurs also showed significantly lower aversion thresholds to full field flicker than control participants, but aversion scores and increment thresholds were not correlated.
Conclusions
The results are simulated with a three-stage neural model of adaptation that points to strong adaptation at monocular sites prior to binocular combination, and weaker adaptation at the level of cortical binocular neurons. The sensitization at high contrast in migraine is proposed to result from stronger adaptation of inhibitory neurons, which act as a monocular normalization pool.
279.
Gerhard, Holly E.; Wichmann, Felix A.; Bethge, Matthias
How Sensitive Is the Human Visual System to the Local Statistics of Natural Images? Journal Article
In: PLOS Computational Biology, vol. 9, no. 1, pp. e1002873, 2013, ISSN: 1553-7358, (Publisher: Public Library of Science).
Abstract | Links | BibTeX | Tags: DATAPixx, RESPONSEPixx
@article{gerhard_how_2013,
title = {How Sensitive Is the Human Visual System to the Local Statistics of Natural Images?},
author = {Holly E. Gerhard and Felix A. Wichmann and Matthias Bethge},
url = {https://journals.plos.org/ploscompbiol/article?id=10.1371/journal.pcbi.1002873},
doi = {10.1371/journal.pcbi.1002873},
issn = {1553-7358},
year = {2013},
date = {2013-01-01},
urldate = {2024-01-03},
journal = {PLOS Computational Biology},
volume = {9},
number = {1},
pages = {e1002873},
abstract = {A key hypothesis in sensory system neuroscience is that sensory representations are adapted to the statistical regularities in sensory signals and thereby incorporate knowledge about the outside world. Supporting this hypothesis, several probabilistic models of local natural image regularities have been proposed that reproduce neural response properties. Although many such physiological links have been made, these models have not been linked directly to visual sensitivity. Previous psychophysical studies of sensitivity to natural image regularities focus on global perception of large images, but much less is known about sensitivity to local natural image regularities. We present a new paradigm for controlled psychophysical studies of local natural image regularities and compare how well such models capture perceptually relevant image content. To produce stimuli with precise statistics, we start with a set of patches cut from natural images and alter their content to generate a matched set whose joint statistics are equally likely under a probabilistic natural image model. The task is forced choice to discriminate natural patches from model patches. The results show that human observers can learn to discriminate the higher-order regularities in natural images from those of model samples after very few exposures and that no current model is perfect for patches as small as 5 by 5 pixels or larger. Discrimination performance was accurately predicted by model likelihood, an information theoretic measure of model efficacy, indicating that the visual system possesses a surprisingly detailed knowledge of natural image higher-order correlations, much more so than current image models. We also perform three cue identification experiments to interpret how model features correspond to perceptually relevant image features.},
note = {Publisher: Public Library of Science},
keywords = {DATAPixx, RESPONSEPixx},
pubstate = {published},
tppubtype = {article}
}
A key hypothesis in sensory system neuroscience is that sensory representations are adapted to the statistical regularities in sensory signals and thereby incorporate knowledge about the outside world. Supporting this hypothesis, several probabilistic models of local natural image regularities have been proposed that reproduce neural response properties. Although many such physiological links have been made, these models have not been linked directly to visual sensitivity. Previous psychophysical studies of sensitivity to natural image regularities focus on global perception of large images, but much less is known about sensitivity to local natural image regularities. We present a new paradigm for controlled psychophysical studies of local natural image regularities and compare how well such models capture perceptually relevant image content. To produce stimuli with precise statistics, we start with a set of patches cut from natural images and alter their content to generate a matched set whose joint statistics are equally likely under a probabilistic natural image model. The task is forced choice to discriminate natural patches from model patches. The results show that human observers can learn to discriminate the higher-order regularities in natural images from those of model samples after very few exposures and that no current model is perfect for patches as small as 5 by 5 pixels or larger. Discrimination performance was accurately predicted by model likelihood, an information theoretic measure of model efficacy, indicating that the visual system possesses a surprisingly detailed knowledge of natural image higher-order correlations, much more so than current image models. We also perform three cue identification experiments to interpret how model features correspond to perceptually relevant image features.
280.
Petrov, Yury; Nador, Jeffrey; Qian, Jiehui
VEP Correlates of Feedback in Human Cortex Journal Article
In: PLOS ONE, vol. 7, no. 12, pp. e51791, 2012, ISSN: 1932-6203, (Publisher: Public Library of Science).
Abstract | Links | BibTeX | Tags: DATAPixx
@article{petrov_vep_2012,
title = {VEP Correlates of Feedback in Human Cortex},
author = {Yury Petrov and Jeffrey Nador and Jiehui Qian},
url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0051791},
doi = {10.1371/journal.pone.0051791},
issn = {1932-6203},
year = {2012},
date = {2012-12-01},
urldate = {2024-01-18},
journal = {PLOS ONE},
volume = {7},
number = {12},
pages = {e51791},
abstract = {It is known that neural responses become less dependent on the stimulus size and location along the visual pathway. This study aimed to use this property to find evidence of neural feedback in visually evoked potentials (VEP). High-density VEPs evoked by a contrast reversing checkerboard were collected from 15 normal observers using a 128-channel EEG system. Surface Laplacian method was used to calculate skull-scalp currents corresponding to the measured scalp potentials. This allowed us to identify several distinct foci of skull-scalp currents and to analyse their individual time-courses. Response nonlinearity as a function of the stimulus size increased markedly from the occipital to temporal loci. Similarly, the nonlinearity of reactivations (late evoked response peaks) over the occipital, lateral-occipital, and frontal scalp regions increased with the peak latency. Response laterality (contralateral vs. ipsilateral) was analysed in lateral-occipital and temporal loci. Early lateral-occipital responses were strongly contralateral but the response laterality decreased and then disappeared for later peaks. Responses in temporal loci did not differ significantly between contralateral and ipsilateral stimulation. Overall, the results suggest that feedback from higher-tier visual areas, e.g., those in temporal cortices, may significantly contribute to reactivations in early visual areas.},
note = {Publisher: Public Library of Science},
keywords = {DATAPixx},
pubstate = {published},
tppubtype = {article}
}
It is known that neural responses become less dependent on the stimulus size and location along the visual pathway. This study aimed to use this property to find evidence of neural feedback in visually evoked potentials (VEP). High-density VEPs evoked by a contrast reversing checkerboard were collected from 15 normal observers using a 128-channel EEG system. Surface Laplacian method was used to calculate skull-scalp currents corresponding to the measured scalp potentials. This allowed us to identify several distinct foci of skull-scalp currents and to analyse their individual time-courses. Response nonlinearity as a function of the stimulus size increased markedly from the occipital to temporal loci. Similarly, the nonlinearity of reactivations (late evoked response peaks) over the occipital, lateral-occipital, and frontal scalp regions increased with the peak latency. Response laterality (contralateral vs. ipsilateral) was analysed in lateral-occipital and temporal loci. Early lateral-occipital responses were strongly contralateral but the response laterality decreased and then disappeared for later peaks. Responses in temporal loci did not differ significantly between contralateral and ipsilateral stimulation. Overall, the results suggest that feedback from higher-tier visual areas, e.g., those in temporal cortices, may significantly contribute to reactivations in early visual areas.