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.
1.
Wang, Jianbao; Du, Xiao; Yao, Songping; Li, Lihui; Tanigawa, Hisashi; Zhang, Xiaotong; Roe, Anna Wang
Mesoscale organization of ventral and dorsal visual pathways in macaque monkey revealed by 7T fMRI Journal Article
In: Progress in Neurobiology, pp. 102584, 2024, ISSN: 0301-0082.
Abstract | Links | BibTeX | Tags: PROPixx, VPixxProgram
@article{wang_mesoscale_2024,
title = {Mesoscale organization of ventral and dorsal visual pathways in macaque monkey revealed by 7T fMRI},
author = {Jianbao Wang and Xiao Du and Songping Yao and Lihui Li and Hisashi Tanigawa and Xiaotong Zhang and Anna Wang Roe},
url = {https://www.sciencedirect.com/science/article/pii/S0301008224000200},
doi = {10.1016/j.pneurobio.2024.102584},
issn = {0301-0082},
year = {2024},
date = {2024-02-01},
urldate = {2024-02-06},
journal = {Progress in Neurobiology},
pages = {102584},
abstract = {In human and nonhuman primate brains, columnar (mesoscale) organization has been demonstrated to underlie both lower and higher order aspects of visual information processing. Previous studies have focused on identifying functional preferences of mesoscale domains in specific areas; but there has been little understanding of how mesoscale domains may cooperatively respond to single visual stimuli across dorsal and ventral pathways. Here, we have developed ultrahigh-field 7T fMRI methods to enable simultaneous mapping, in individual macaque monkeys, of response in both dorsal and ventral pathways to single simple color and motion stimuli. We provide the first evidence that anatomical V2 cytochrome oxidase-stained stripes are well aligned with fMRI maps of V2 stripes, settling a long-standing controversy. In the ventral pathway, a systematic array of paired color and luminance processing domains across V4 was revealed, suggesting a novel organization for surface information processing. In the dorsal pathway, in addition to high quality motion direction maps of MT, MST and V3A, alternating color and motion direction domains in V3 are revealed. As well, submillimeter motion domains were observed in peripheral LIPd and LIPv. In sum, our study provides a novel global snapshot of how mesoscale networks in the ventral and dorsal visual pathways form the organizational basis of visual objection recognition and vision for action.},
keywords = {PROPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
In human and nonhuman primate brains, columnar (mesoscale) organization has been demonstrated to underlie both lower and higher order aspects of visual information processing. Previous studies have focused on identifying functional preferences of mesoscale domains in specific areas; but there has been little understanding of how mesoscale domains may cooperatively respond to single visual stimuli across dorsal and ventral pathways. Here, we have developed ultrahigh-field 7T fMRI methods to enable simultaneous mapping, in individual macaque monkeys, of response in both dorsal and ventral pathways to single simple color and motion stimuli. We provide the first evidence that anatomical V2 cytochrome oxidase-stained stripes are well aligned with fMRI maps of V2 stripes, settling a long-standing controversy. In the ventral pathway, a systematic array of paired color and luminance processing domains across V4 was revealed, suggesting a novel organization for surface information processing. In the dorsal pathway, in addition to high quality motion direction maps of MT, MST and V3A, alternating color and motion direction domains in V3 are revealed. As well, submillimeter motion domains were observed in peripheral LIPd and LIPv. In sum, our study provides a novel global snapshot of how mesoscale networks in the ventral and dorsal visual pathways form the organizational basis of visual objection recognition and vision for action.
2.
Kryklywy, James H.; Forys, Brandon J.; Vieira, Joana B.; Quinlan, Derek J.; Mitchell, Derek G. V.
Dissociating representations of affect and motion in visual cortices Journal Article
In: Cognitive, Affective, & Behavioral Neuroscience, vol. 23, no. 5, pp. 1322–1345, 2023, ISSN: 1531-135X.
Abstract | Links | BibTeX | Tags: VPixxProgram
@article{kryklywy_dissociating_2023,
title = {Dissociating representations of affect and motion in visual cortices},
author = {James H. Kryklywy and Brandon J. Forys and Joana B. Vieira and Derek J. Quinlan and Derek G. V. Mitchell},
url = {https://doi.org/10.3758/s13415-023-01115-2},
doi = {10.3758/s13415-023-01115-2},
issn = {1531-135X},
year = {2023},
date = {2023-10-01},
urldate = {2024-01-02},
journal = {Cognitive, Affective, & Behavioral Neuroscience},
volume = {23},
number = {5},
pages = {1322–1345},
abstract = {While a delicious dessert being presented to us may elicit strong feelings of happiness and excitement, the same treat falling slowly away can lead to sadness and disappointment. Our emotional response to the item depends on its visual motion direction. Despite this importance, it remains unclear whether (and how) cortical areas devoted to decoding motion direction represents or integrates emotion with perceived motion direction. Motion-selective visual area V5/MT+ sits, both functionally and anatomically, at the nexus of dorsal and ventral visual streams. These pathways, however, differ in how they are modulated by emotional cues. The current study was designed to disentangle how emotion and motion perception interact, as well as use emotion-dependent modulation of visual cortices to understand the relation of V5/MT+ to canonical processing streams. During functional magnetic resonance imaging (fMRI), approaching, receding, or static motion after-effects (MAEs) were induced on stationary positive, negative, and neutral stimuli. An independent localizer scan was conducted to identify the visual-motion area V5/MT+. Through univariate and multivariate analyses, we demonstrated that emotion representations in V5/MT+ share a more similar response profile to that observed in ventral visual than dorsal, visual structures. Specifically, V5/MT+ and ventral structures were sensitive to the emotional content of visual stimuli, whereas dorsal visual structures were not. Overall, this work highlights the critical role of V5/MT+ in the representation and processing of visually acquired emotional content. It further suggests a role for this region in utilizing affectively salient visual information to augment motion perception of biologically relevant stimuli.},
keywords = {VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
While a delicious dessert being presented to us may elicit strong feelings of happiness and excitement, the same treat falling slowly away can lead to sadness and disappointment. Our emotional response to the item depends on its visual motion direction. Despite this importance, it remains unclear whether (and how) cortical areas devoted to decoding motion direction represents or integrates emotion with perceived motion direction. Motion-selective visual area V5/MT+ sits, both functionally and anatomically, at the nexus of dorsal and ventral visual streams. These pathways, however, differ in how they are modulated by emotional cues. The current study was designed to disentangle how emotion and motion perception interact, as well as use emotion-dependent modulation of visual cortices to understand the relation of V5/MT+ to canonical processing streams. During functional magnetic resonance imaging (fMRI), approaching, receding, or static motion after-effects (MAEs) were induced on stationary positive, negative, and neutral stimuli. An independent localizer scan was conducted to identify the visual-motion area V5/MT+. Through univariate and multivariate analyses, we demonstrated that emotion representations in V5/MT+ share a more similar response profile to that observed in ventral visual than dorsal, visual structures. Specifically, V5/MT+ and ventral structures were sensitive to the emotional content of visual stimuli, whereas dorsal visual structures were not. Overall, this work highlights the critical role of V5/MT+ in the representation and processing of visually acquired emotional content. It further suggests a role for this region in utilizing affectively salient visual information to augment motion perception of biologically relevant stimuli.
3.
Hauswald, Anne; Keitel, Anne; Chen, Ya-Ping; Rösch, Sebastian; Weisz, Nathan
Degradation levels of continuous speech affect neural speech tracking and alpha power differently Journal Article
In: European Journal of Neuroscience, vol. 55, no. 11-12, pp. 3288–3302, 2022, ISSN: 1460-9568, (_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/ejn.14912).
Abstract | Links | BibTeX | Tags: RESPONSEPixxMRI, SOUNDPixx, VPixxProgram
@article{hauswald_degradation_2022,
title = {Degradation levels of continuous speech affect neural speech tracking and alpha power differently},
author = {Anne Hauswald and Anne Keitel and Ya-Ping Chen and Sebastian Rösch and Nathan Weisz},
url = {https://onlinelibrary.wiley.com/doi/abs/10.1111/ejn.14912},
doi = {10.1111/ejn.14912},
issn = {1460-9568},
year = {2022},
date = {2022-01-01},
urldate = {2023-12-21},
journal = {European Journal of Neuroscience},
volume = {55},
number = {11-12},
pages = {3288–3302},
abstract = {Making sense of a poor auditory signal can pose a challenge. Previous attempts to quantify speech intelligibility in neural terms have usually focused on one of two measures, namely low-frequency speech-brain synchronization or alpha power modulations. However, reports have been mixed concerning the modulation of these measures, an issue aggravated by the fact that they have normally been studied separately. We present two MEG studies analyzing both measures. In study 1, participants listened to unimodal auditory speech with three different levels of degradation (original, 7-channel and 3-channel vocoding). Intelligibility declined with declining clarity, but speech was still intelligible to some extent even for the lowest clarity level (3-channel vocoding). Low-frequency (1–7 Hz) speech tracking suggested a U-shaped relationship with strongest effects for the medium-degraded speech (7-channel) in bilateral auditory and left frontal regions. To follow up on this finding, we implemented three additional vocoding levels (5-channel, 2-channel and 1-channel) in a second MEG study. Using this wider range of degradation, the speech-brain synchronization showed a similar pattern as in study 1, but further showed that when speech becomes unintelligible, synchronization declines again. The relationship differed for alpha power, which continued to decrease across vocoding levels reaching a floor effect for 5-channel vocoding. Predicting subjective intelligibility based on models either combining both measures or each measure alone showed superiority of the combined model. Our findings underline that speech tracking and alpha power are modified differently by the degree of degradation of continuous speech but together contribute to the subjective speech understanding.},
note = {_eprint: https://onlinelibrary.wiley.com/doi/pdf/10.1111/ejn.14912},
keywords = {RESPONSEPixxMRI, SOUNDPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Making sense of a poor auditory signal can pose a challenge. Previous attempts to quantify speech intelligibility in neural terms have usually focused on one of two measures, namely low-frequency speech-brain synchronization or alpha power modulations. However, reports have been mixed concerning the modulation of these measures, an issue aggravated by the fact that they have normally been studied separately. We present two MEG studies analyzing both measures. In study 1, participants listened to unimodal auditory speech with three different levels of degradation (original, 7-channel and 3-channel vocoding). Intelligibility declined with declining clarity, but speech was still intelligible to some extent even for the lowest clarity level (3-channel vocoding). Low-frequency (1–7 Hz) speech tracking suggested a U-shaped relationship with strongest effects for the medium-degraded speech (7-channel) in bilateral auditory and left frontal regions. To follow up on this finding, we implemented three additional vocoding levels (5-channel, 2-channel and 1-channel) in a second MEG study. Using this wider range of degradation, the speech-brain synchronization showed a similar pattern as in study 1, but further showed that when speech becomes unintelligible, synchronization declines again. The relationship differed for alpha power, which continued to decrease across vocoding levels reaching a floor effect for 5-channel vocoding. Predicting subjective intelligibility based on models either combining both measures or each measure alone showed superiority of the combined model. Our findings underline that speech tracking and alpha power are modified differently by the degree of degradation of continuous speech but together contribute to the subjective speech understanding.
4.
González, Esther G.; Mandelcorn, Mark S.; Mandelcorn, Efrem D.; Tarita-Nistor, Luminita
Effect of Visual Feedback on the Eye Position Stability of Patients with AMD Journal Article
In: Vision, vol. 3, no. 4, pp. 59, 2019, ISSN: 2411-5150.
Abstract | Links | BibTeX | Tags: Chromatrig, VPixxProgram
@article{gonzalez_effect_2019,
title = {Effect of Visual Feedback on the Eye Position Stability of Patients with AMD},
author = {Esther G. González and Mark S. Mandelcorn and Efrem D. Mandelcorn and Luminita Tarita-Nistor},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6969921/},
doi = {10.3390/vision3040059},
issn = {2411-5150},
year = {2019},
date = {2019-11-01},
urldate = {2024-01-02},
journal = {Vision},
volume = {3},
number = {4},
pages = {59},
abstract = {The sources of the reduced fixation stability exhibited by patients with central vision loss in the light are relatively well understood, but we have no information on how they control eye position in complete darkness, in the absence of visual error signals. We therefore explored the effect of visual feedback on eye position stability by testing patients with age-related macular degeneration (AMD) and controls with normal vision in the light and in complete darkness. Nine patients (ages 67 to 92 years) and 16 controls (ages 16 to 74 years) were tested binocularly in the light and in complete darkness while remembering the location of a now invisible target. Binocular eye position was recorded with a video-based eye tracker. Results show that eye position stability both in the light and in the dark is worse for patients than for controls and that, for the two groups, eye position stability in the dark is, on average, 5.9 times worse than in the light. Large instability of fixation in patients with AMD was found even in absolute darkness when the scotoma cannot impair vision. These data reflect permanent changes in the oculomotor reference of patients with AMD.},
keywords = {Chromatrig, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
The sources of the reduced fixation stability exhibited by patients with central vision loss in the light are relatively well understood, but we have no information on how they control eye position in complete darkness, in the absence of visual error signals. We therefore explored the effect of visual feedback on eye position stability by testing patients with age-related macular degeneration (AMD) and controls with normal vision in the light and in complete darkness. Nine patients (ages 67 to 92 years) and 16 controls (ages 16 to 74 years) were tested binocularly in the light and in complete darkness while remembering the location of a now invisible target. Binocular eye position was recorded with a video-based eye tracker. Results show that eye position stability both in the light and in the dark is worse for patients than for controls and that, for the two groups, eye position stability in the dark is, on average, 5.9 times worse than in the light. Large instability of fixation in patients with AMD was found even in absolute darkness when the scotoma cannot impair vision. These data reflect permanent changes in the oculomotor reference of patients with AMD.
5.
Brown, Alyse; Corner, Molly; Crewther, David; Crewther, Sheila
Age Related Decline in Cortical Multifocal Flash VEP: Latency Increases Shown to Be Predominately Magnocellular Journal Article
In: Frontiers in Aging Neuroscience, vol. 10, 2019, ISSN: 1663-4365.
Abstract | Links | BibTeX | Tags: DATAPixx, VPixxProgram
@article{brown_age_2019,
title = {Age Related Decline in Cortical Multifocal Flash VEP: Latency Increases Shown to Be Predominately Magnocellular},
author = {Alyse Brown and Molly Corner and David Crewther and Sheila Crewther},
url = {https://www.frontiersin.org/articles/10.3389/fnagi.2018.00430},
issn = {1663-4365},
year = {2019},
date = {2019-01-01},
urldate = {2023-12-21},
journal = {Frontiers in Aging Neuroscience},
volume = {10},
abstract = {As the visual system ages, flicker sensitivity decreases and the latencies of cortical visual evoked potentials (VEP) increase. However, the extent to which these effects reflect age-related changes in the magnocellular (M) and or parvocellular (P) pathways remain unclear. Here, we investigated the relation between flicker fusion frequencies and VEP non-linearities induced by rapid stimulation, as a function of age over 6 decades. The approach, using Wiener kernel analysis of multifocal flash (mf)VEP, allows the extraction of signatures of both M and P processing and hence establishing a neural basis of the known decline in flicker fusion threshold. We predicted that, in a sample of 86 participants, age would be associated with a latency increase in early mfVEP response components and that flicker fusion thresholds, for both low and high contrast stimuli, would relate to the temporal efficiency of the M-generated VEP component amplitudes. As expected, flicker fusion frequency reduced with age, while latencies of early second order peaks of the mfVEP increased with age, but M temporal efficiency (amplitude ratio of first to second order peaks) was not strongly age-related. The steepest increases in latency were associated with the M dominated K2.1 (second order first slice) N70 components recorded at low and high contrast (6.7 and 5.9 ms/decade, respectively). Interestingly, significant age-related latency shifts were not observed in the first order responses. Significant decreases in amplitude were found in multiple first and second order components up to 30 years of age, after which they remained relatively constant. Thus, aging and decline in visual function appears to be most closely related to the response latencies of non-linearities generated by the M pathway.},
keywords = {DATAPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
As the visual system ages, flicker sensitivity decreases and the latencies of cortical visual evoked potentials (VEP) increase. However, the extent to which these effects reflect age-related changes in the magnocellular (M) and or parvocellular (P) pathways remain unclear. Here, we investigated the relation between flicker fusion frequencies and VEP non-linearities induced by rapid stimulation, as a function of age over 6 decades. The approach, using Wiener kernel analysis of multifocal flash (mf)VEP, allows the extraction of signatures of both M and P processing and hence establishing a neural basis of the known decline in flicker fusion threshold. We predicted that, in a sample of 86 participants, age would be associated with a latency increase in early mfVEP response components and that flicker fusion thresholds, for both low and high contrast stimuli, would relate to the temporal efficiency of the M-generated VEP component amplitudes. As expected, flicker fusion frequency reduced with age, while latencies of early second order peaks of the mfVEP increased with age, but M temporal efficiency (amplitude ratio of first to second order peaks) was not strongly age-related. The steepest increases in latency were associated with the M dominated K2.1 (second order first slice) N70 components recorded at low and high contrast (6.7 and 5.9 ms/decade, respectively). Interestingly, significant age-related latency shifts were not observed in the first order responses. Significant decreases in amplitude were found in multiple first and second order components up to 30 years of age, after which they remained relatively constant. Thus, aging and decline in visual function appears to be most closely related to the response latencies of non-linearities generated by the M pathway.
6.
Wykes, Katie M.; Hugrass, Laila; Crewther, David P.
Autistic Traits Are Not a Strong Predictor of Binocular Rivalry Dynamics Journal Article
In: Frontiers in Neuroscience, vol. 12, pp. 338, 2018, ISSN: 1662-4548.
Abstract | Links | BibTeX | Tags: 3DPolarizer, PROPixx, VPixxProgram
@article{wykes_autistic_2018,
title = {Autistic Traits Are Not a Strong Predictor of Binocular Rivalry Dynamics},
author = {Katie M. Wykes and Laila Hugrass and David P. Crewther},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5967175/},
doi = {10.3389/fnins.2018.00338},
issn = {1662-4548},
year = {2018},
date = {2018-05-01},
urldate = {2023-12-21},
journal = {Frontiers in Neuroscience},
volume = {12},
pages = {338},
abstract = {It has been suggested that differences in binocular rivalry switching rates and mixed percept durations in ASD could serve as a biomarker of excitation/inhibition imbalances in the autistic brain. If so, one would expect these differences to extend to neurotypical groups with high vs. low levels of autistic tendency. Previous studies did not detect any correlations between binocular rivalry dynamics and Autism Spectrum Quotient (AQ) scores in neurotypical control groups; however it is unclear whether this was due to the characteristics of the rivalry stimuli that were used. We further investigated this possibility in a sample of neurotypical young adults. The binocular rivalry stimuli were simple gratings, complex objects, or scrambled objects, which were presented dichoptically, either at fixation or in the periphery. A Bayesian correlation analysis showed that individuals with higher AQ scores tended to have lower perceptual switching rates for the centrally presented, simple grating rival stimuli. However, there was no evidence of a relationship between AQ and switching rates, reversal rates or mixed percept durations for any of the other binocular rivalry conditions. Overall, our findings suggest that in the non-clinical population, autistic personality traits are not a strong predictor of binocular rivalry dynamics.},
keywords = {3DPolarizer, PROPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
It has been suggested that differences in binocular rivalry switching rates and mixed percept durations in ASD could serve as a biomarker of excitation/inhibition imbalances in the autistic brain. If so, one would expect these differences to extend to neurotypical groups with high vs. low levels of autistic tendency. Previous studies did not detect any correlations between binocular rivalry dynamics and Autism Spectrum Quotient (AQ) scores in neurotypical control groups; however it is unclear whether this was due to the characteristics of the rivalry stimuli that were used. We further investigated this possibility in a sample of neurotypical young adults. The binocular rivalry stimuli were simple gratings, complex objects, or scrambled objects, which were presented dichoptically, either at fixation or in the periphery. A Bayesian correlation analysis showed that individuals with higher AQ scores tended to have lower perceptual switching rates for the centrally presented, simple grating rival stimuli. However, there was no evidence of a relationship between AQ and switching rates, reversal rates or mixed percept durations for any of the other binocular rivalry conditions. Overall, our findings suggest that in the non-clinical population, autistic personality traits are not a strong predictor of binocular rivalry dynamics.
7.
Hugrass, Laila; Verhellen, Thomas; Morrall-Earney, Eleanore; Mallon, Caitlin; Crewther, David Philip
The effects of red surrounds on visual magnocellular and parvocellular cortical processing and perception Journal Article
In: Journal of Vision, vol. 18, no. 4, pp. 8, 2018, ISSN: 1534-7362.
Abstract | Links | BibTeX | Tags: PROPixx, RESPONSEPixx, VPixxProgram
@article{hugrass_effects_2018,
title = {The effects of red surrounds on visual magnocellular and parvocellular cortical processing and perception},
author = {Laila Hugrass and Thomas Verhellen and Eleanore Morrall-Earney and Caitlin Mallon and David Philip Crewther},
url = {https://doi.org/10.1167/18.4.8},
doi = {10.1167/18.4.8},
issn = {1534-7362},
year = {2018},
date = {2018-04-01},
urldate = {2024-01-18},
journal = {Journal of Vision},
volume = {18},
number = {4},
pages = {8},
abstract = {More than 50 years ago, Hubel and Wiesel identified a subpopulation of geniculate magnocellular (M) neurons that are suppressed by diffuse red light. Since then, many human psychophysical studies have used red and green backgrounds to study the effects of M suppression on visual task performance, as a means to better understand neurodevelopmental disorders such as dyslexia and schizophrenia. Few of these studies have explicitly assessed the relative effects of red backgrounds on the M and P (parvocellular) pathways. Here we compared the effects of red and green diffuse background illumination on well-accepted cortical M and P signatures, both physiologically through nonlinear analysis of visual evoked potentials (VEPs; N = 15), and psychophysically through pulsed and steady pedestal perceptual thresholds (N = 9 with gray pedestals and N = 8 with colored pedestals). Red surrounds reduced P-generated temporal nonlinearity in the VEPs, but they did not influence M-generated VEP signatures. The steady and pulsed pedestal results suggest that red surrounds can have different effects on M and P contrast sensitivities, depending on whether the target is colored gray or red, presented centrally or peripherally, or whether it is brighter or dimmer than the surround. Our results highlight difficulties in interpreting the effects of red backgrounds on human VEPs or perception in terms of M specific suppression.},
keywords = {PROPixx, RESPONSEPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
More than 50 years ago, Hubel and Wiesel identified a subpopulation of geniculate magnocellular (M) neurons that are suppressed by diffuse red light. Since then, many human psychophysical studies have used red and green backgrounds to study the effects of M suppression on visual task performance, as a means to better understand neurodevelopmental disorders such as dyslexia and schizophrenia. Few of these studies have explicitly assessed the relative effects of red backgrounds on the M and P (parvocellular) pathways. Here we compared the effects of red and green diffuse background illumination on well-accepted cortical M and P signatures, both physiologically through nonlinear analysis of visual evoked potentials (VEPs; N = 15), and psychophysically through pulsed and steady pedestal perceptual thresholds (N = 9 with gray pedestals and N = 8 with colored pedestals). Red surrounds reduced P-generated temporal nonlinearity in the VEPs, but they did not influence M-generated VEP signatures. The steady and pulsed pedestal results suggest that red surrounds can have different effects on M and P contrast sensitivities, depending on whether the target is colored gray or red, presented centrally or peripherally, or whether it is brighter or dimmer than the surround. Our results highlight difficulties in interpreting the effects of red backgrounds on human VEPs or perception in terms of M specific suppression.
8.
Alexander, Bonnie; Laycock, Robin; Crewther, David P.; Crewther, Sheila G.
An fMRI-Neuronavigated Chronometric TMS Investigation of V5 and Intraparietal Cortex in Motion Driven Attention Journal Article
In: Frontiers in Human Neuroscience, vol. 11, pp. 638, 2018, ISSN: 1662-5161.
Abstract | Links | BibTeX | Tags: DATAPixx, RESPONSEPixx, VPixxProgram
@article{alexander_fmri-neuronavigated_2018,
title = {An fMRI-Neuronavigated Chronometric TMS Investigation of V5 and Intraparietal Cortex in Motion Driven Attention},
author = {Bonnie Alexander and Robin Laycock and David P. Crewther and Sheila G. Crewther},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5758491/},
doi = {10.3389/fnhum.2017.00638},
issn = {1662-5161},
year = {2018},
date = {2018-01-01},
urldate = {2023-12-21},
journal = {Frontiers in Human Neuroscience},
volume = {11},
pages = {638},
abstract = {The timing of networked brain activity subserving motion driven attention in humans is currently unclear. Functional MRI (fMRI)-neuronavigated chronometric transcranial magnetic stimulation (TMS) was used to investigate critical times of parietal cortex involvement in motion driven attention. In particular, we were interested in the relative critical times for two intraparietal sulcus (IPS) sites in comparison to that previously identified for motion processing in area V5, and to explore potential earlier times of involvement. fMRI was used to individually localize V5 and middle and posterior intraparietal sulcus (mIPS; pIPS) areas active for a motion driven attention task, prior to TMS neuronavigation. Paired-pulse TMS was applied during performance of the same task at stimulus onset asynchronies (SOAs) ranging from 0 to 180 ms. There were no statistically significant decreases in performance accuracy for trials where TMS was applied to V5 at any SOA, though stimulation intensity was lower for this site than for the parietal sites. For TMS applied to mIPS, there was a trend toward a relative decrease in performance accuracy at the 150 ms SOA, as well as a relative increase at 180 ms. There was no statistically significant effect overall of TMS applied to pIPS, however, there appeared a potential trend toward a decrease in performance at the 0 ms SOA. Overall, these results provide some patterns of potential theoretical interest to follow up in future studies.},
keywords = {DATAPixx, RESPONSEPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
The timing of networked brain activity subserving motion driven attention in humans is currently unclear. Functional MRI (fMRI)-neuronavigated chronometric transcranial magnetic stimulation (TMS) was used to investigate critical times of parietal cortex involvement in motion driven attention. In particular, we were interested in the relative critical times for two intraparietal sulcus (IPS) sites in comparison to that previously identified for motion processing in area V5, and to explore potential earlier times of involvement. fMRI was used to individually localize V5 and middle and posterior intraparietal sulcus (mIPS; pIPS) areas active for a motion driven attention task, prior to TMS neuronavigation. Paired-pulse TMS was applied during performance of the same task at stimulus onset asynchronies (SOAs) ranging from 0 to 180 ms. There were no statistically significant decreases in performance accuracy for trials where TMS was applied to V5 at any SOA, though stimulation intensity was lower for this site than for the parietal sites. For TMS applied to mIPS, there was a trend toward a relative decrease in performance accuracy at the 150 ms SOA, as well as a relative increase at 180 ms. There was no statistically significant effect overall of TMS applied to pIPS, however, there appeared a potential trend toward a decrease in performance at the 0 ms SOA. Overall, these results provide some patterns of potential theoretical interest to follow up in future studies.
9.
Brown, Alyse; Corner, Molly; Crewther, David P.; Crewther, Sheila G.
Human Flicker Fusion Correlates With Physiological Measures of Magnocellular Neural Efficiency Journal Article
In: Frontiers in Human Neuroscience, vol. 12, 2018, ISSN: 1662-5161.
Abstract | Links | BibTeX | Tags: DATAPixx, VPixxProgram
@article{brown_human_2018,
title = {Human Flicker Fusion Correlates With Physiological Measures of Magnocellular Neural Efficiency},
author = {Alyse Brown and Molly Corner and David P. Crewther and Sheila G. Crewther},
url = {https://www.frontiersin.org/articles/10.3389/fnhum.2018.00176},
issn = {1662-5161},
year = {2018},
date = {2018-01-01},
urldate = {2023-12-21},
journal = {Frontiers in Human Neuroscience},
volume = {12},
abstract = {The rapidity with which the visual system can recover from stimulation in order to respond again has important implications for efficiently processing environmental stimuli in real time. To date, there has been little integration of the human psychophysical and physiological research underlying the neural mechanisms contributing to temporal limits on human visual perception. Hence, we investigated the relationship between achromatic flicker fusion frequency and temporal analysis of the magnocellular (M) and parvocellular (P) contributions to the achromatic non-linear multifocal Visual Evoked Potential (mfVEP) responses recorded from occipital scalp (Oz). It was hypothesized, on the basis of higher temporal cut-off frequencies reported for primate M vs. P neurons, that sinusoidal flicker fusion frequencies would negatively correlate with the amplitude of M- but not P-generated non-linearities of the mfVEP. This hypothesis was borne out in 72 typically developing young adults using a four-way forced choice sinusoidal flicker fusion task: amplitudes of all non-linearities that demonstrated a clear M-generated component correlated negatively with flicker thresholds. The strongest of these correlations were demonstrated by the main M non-linearity component (K2.1N70−P100) for both high contrast (r = −0.415},
keywords = {DATAPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
The rapidity with which the visual system can recover from stimulation in order to respond again has important implications for efficiently processing environmental stimuli in real time. To date, there has been little integration of the human psychophysical and physiological research underlying the neural mechanisms contributing to temporal limits on human visual perception. Hence, we investigated the relationship between achromatic flicker fusion frequency and temporal analysis of the magnocellular (M) and parvocellular (P) contributions to the achromatic non-linear multifocal Visual Evoked Potential (mfVEP) responses recorded from occipital scalp (Oz). It was hypothesized, on the basis of higher temporal cut-off frequencies reported for primate M vs. P neurons, that sinusoidal flicker fusion frequencies would negatively correlate with the amplitude of M- but not P-generated non-linearities of the mfVEP. This hypothesis was borne out in 72 typically developing young adults using a four-way forced choice sinusoidal flicker fusion task: amplitudes of all non-linearities that demonstrated a clear M-generated component correlated negatively with flicker thresholds. The strongest of these correlations were demonstrated by the main M non-linearity component (K2.1N70−P100) for both high contrast (r = −0.415
10.
Wise, Adrienne; Barnett-Cowan, Michael
Perceived Simultaneity and Temporal Order of Audiovisual Events Following Concussion Journal Article
In: Frontiers in Human Neuroscience, vol. 12, 2018, ISSN: 1662-5161.
Abstract | Links | BibTeX | Tags: VPixxProgram
@article{wise_perceived_2018,
title = {Perceived Simultaneity and Temporal Order of Audiovisual Events Following Concussion},
author = {Adrienne Wise and Michael Barnett-Cowan},
url = {https://www.frontiersin.org/articles/10.3389/fnhum.2018.00139},
issn = {1662-5161},
year = {2018},
date = {2018-01-01},
urldate = {2024-01-17},
journal = {Frontiers in Human Neuroscience},
volume = {12},
abstract = {The central nervous system allows for a limited time span referred to as the temporal binding window (TBW) in order to rapidly determine whether multisensory events correspond with the same event. Failure to correctly identify whether multisensory events occur simultaneously and their sequential order can lead to inaccurate representations of the physical world, poor decision-making and dangerous behavior. Damage to the neural systems that coordinate the relative timing of sensory events may explain some of the long-term consequences associated with concussion. The aim of this study was to investigate whether the perception of simultaneity and the discrimination of temporal order of audiovisual stimuli are impaired in those with a history of concussion. Fifty participants (17 with concussion history) were recruited to complete audiovisual simultaneity judgment (SJ) and temporal order judgment (TOJ) tasks. From these tasks, the TBW and point of subjective simultaneity (PSS) were extracted to assess whether the precision and or the accuracy of temporal perception changes with concussion, respectively. Results demonstrated that those with concussion history have a significantly wider TBW (less precise), with no significant change in the PSS (no change in accuracy), particularly for the TOJ task but no significant differences were found between the SJ and TOJ tasks. Importantly, a negative correlation between the time elapsed since last concussion and TBW width in the TOJ task suggests that precision in temporal perception does improve over time. These findings suggest that those with concussion history display an impairment in the perceived timing of sensory events and that monitoring performance in the SJ and TOJ tasks may be a useful additional assessment tool when making decisions about returning to regular work and play following concussion.},
keywords = {VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
The central nervous system allows for a limited time span referred to as the temporal binding window (TBW) in order to rapidly determine whether multisensory events correspond with the same event. Failure to correctly identify whether multisensory events occur simultaneously and their sequential order can lead to inaccurate representations of the physical world, poor decision-making and dangerous behavior. Damage to the neural systems that coordinate the relative timing of sensory events may explain some of the long-term consequences associated with concussion. The aim of this study was to investigate whether the perception of simultaneity and the discrimination of temporal order of audiovisual stimuli are impaired in those with a history of concussion. Fifty participants (17 with concussion history) were recruited to complete audiovisual simultaneity judgment (SJ) and temporal order judgment (TOJ) tasks. From these tasks, the TBW and point of subjective simultaneity (PSS) were extracted to assess whether the precision and or the accuracy of temporal perception changes with concussion, respectively. Results demonstrated that those with concussion history have a significantly wider TBW (less precise), with no significant change in the PSS (no change in accuracy), particularly for the TOJ task but no significant differences were found between the SJ and TOJ tasks. Importantly, a negative correlation between the time elapsed since last concussion and TBW width in the TOJ task suggests that precision in temporal perception does improve over time. These findings suggest that those with concussion history display an impairment in the perceived timing of sensory events and that monitoring performance in the SJ and TOJ tasks may be a useful additional assessment tool when making decisions about returning to regular work and play following concussion.
11.
Basharat, Aysha; Adams, Meaghan S.; Staines, William R.; Barnett-Cowan, Michael
Simultaneity and Temporal Order Judgments Are Coded Differently and Change With Age: An Event-Related Potential Study Journal Article
In: Frontiers in Integrative Neuroscience, vol. 12, 2018, ISSN: 1662-5145.
Abstract | Links | BibTeX | Tags: PROPixx, RESPONSEPixx, VPixxProgram
@article{basharat_simultaneity_2018,
title = {Simultaneity and Temporal Order Judgments Are Coded Differently and Change With Age: An Event-Related Potential Study},
author = {Aysha Basharat and Meaghan S. Adams and William R. Staines and Michael Barnett-Cowan},
url = {https://www.frontiersin.org/articles/10.3389/fnint.2018.00015},
issn = {1662-5145},
year = {2018},
date = {2018-01-01},
urldate = {2024-01-17},
journal = {Frontiers in Integrative Neuroscience},
volume = {12},
abstract = {Multisensory integration is required for a number of daily living tasks where the inability to accurately identify simultaneity and temporality of multisensory events results in errors in judgment leading to poor decision-making and dangerous behavior. Previously, our lab discovered that older adults exhibited impaired timing of audiovisual events, particularly when making temporal order judgments (TOJs). Simultaneity judgments (SJs), however, were preserved across the lifespan. Here, we investigate the difference between the TOJ and SJ tasks in younger and older adults to assess neural processing differences between these two tasks and across the lifespan. Event-related potentials (ERPs) were studied to determine between-task and between-age differences. Results revealed task specific differences in perceiving simultaneity and temporal order, suggesting that each task may be subserved via different neural mechanisms. Here, auditory N1 and visual P1 ERP amplitudes confirmed that unisensory processing of audiovisual stimuli did not differ between the two tasks within both younger and older groups, indicating that performance differences between tasks arise either from multisensory integration or higher-level decision-making. Compared to younger adults, older adults showed a sustained higher auditory N1 ERP amplitude response across SOAs, suggestive of broader response properties from an extended temporal binding window. Our work provides compelling evidence that different neural mechanisms subserve the SJ and TOJ tasks and that simultaneity and temporal order perception are coded differently and change with age.},
keywords = {PROPixx, RESPONSEPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Multisensory integration is required for a number of daily living tasks where the inability to accurately identify simultaneity and temporality of multisensory events results in errors in judgment leading to poor decision-making and dangerous behavior. Previously, our lab discovered that older adults exhibited impaired timing of audiovisual events, particularly when making temporal order judgments (TOJs). Simultaneity judgments (SJs), however, were preserved across the lifespan. Here, we investigate the difference between the TOJ and SJ tasks in younger and older adults to assess neural processing differences between these two tasks and across the lifespan. Event-related potentials (ERPs) were studied to determine between-task and between-age differences. Results revealed task specific differences in perceiving simultaneity and temporal order, suggesting that each task may be subserved via different neural mechanisms. Here, auditory N1 and visual P1 ERP amplitudes confirmed that unisensory processing of audiovisual stimuli did not differ between the two tasks within both younger and older groups, indicating that performance differences between tasks arise either from multisensory integration or higher-level decision-making. Compared to younger adults, older adults showed a sustained higher auditory N1 ERP amplitude response across SOAs, suggestive of broader response properties from an extended temporal binding window. Our work provides compelling evidence that different neural mechanisms subserve the SJ and TOJ tasks and that simultaneity and temporal order perception are coded differently and change with age.
12.
Hugrass, Laila; Slavikova, Jana; Horvat, Melissa; Musawi, Alaa Al; Crewther, David
Temporal brightness illusion changes color perception of “the dress” Journal Article
In: Journal of Vision, vol. 17, no. 5, pp. 6, 2017, ISSN: 1534-7362.
Abstract | Links | BibTeX | Tags: DATAPixx, RESPONSEPixx, VPixxProgram
@article{hugrass_temporal_2017,
title = {Temporal brightness illusion changes color perception of “the dress”},
author = {Laila Hugrass and Jana Slavikova and Melissa Horvat and Alaa Al Musawi and David Crewther},
url = {https://doi.org/10.1167/17.5.6},
doi = {10.1167/17.5.6},
issn = {1534-7362},
year = {2017},
date = {2017-06-01},
urldate = {2023-12-21},
journal = {Journal of Vision},
volume = {17},
number = {5},
pages = {6},
abstract = {“The dress” has provoked intensive commentary among psychophysicists, especially in relation to color vision. Researchers have shown that manipulating illuminance cues can influence the perceived colors of the dress. Here we investigate whether illusory shifts in brightness can shift color perception of the dress. Drifting achromatic gratings with fast off and fast on shading profiles are known to give an illusion of brightening or darkening, respectively. We superimposed rotating sawtooth gratings on a series of dress images that morphed from extreme white/gold through to blue/black. In a sample of 18 adults (11 with white/gold dress percept and seven with blue/black percept), a two-alternative, forced-choice constant stimulus task measured the morphed image point at which each observer was equally likely to categorize the dress as white/gold or blue/black (the point of subjective equality or PSE). Despite manifest individual differences in the PSE, the two sawtooth temporal profiles consistently changed the perceived colors of the dress. Perceptual dimming shifted color categorization toward blue/black whereas perceptual brightening shifted color categorization toward white/gold. We conclude that color categorization is influenced substantially by illusory shifts in brightness.},
keywords = {DATAPixx, RESPONSEPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
“The dress” has provoked intensive commentary among psychophysicists, especially in relation to color vision. Researchers have shown that manipulating illuminance cues can influence the perceived colors of the dress. Here we investigate whether illusory shifts in brightness can shift color perception of the dress. Drifting achromatic gratings with fast off and fast on shading profiles are known to give an illusion of brightening or darkening, respectively. We superimposed rotating sawtooth gratings on a series of dress images that morphed from extreme white/gold through to blue/black. In a sample of 18 adults (11 with white/gold dress percept and seven with blue/black percept), a two-alternative, forced-choice constant stimulus task measured the morphed image point at which each observer was equally likely to categorize the dress as white/gold or blue/black (the point of subjective equality or PSE). Despite manifest individual differences in the PSE, the two sawtooth temporal profiles consistently changed the perceived colors of the dress. Perceptual dimming shifted color categorization toward blue/black whereas perceptual brightening shifted color categorization toward white/gold. We conclude that color categorization is influenced substantially by illusory shifts in brightness.
13.
Brown, Alyse C.; Crewther, David P.
In: Frontiers in Human Neuroscience, vol. 11, pp. 239, 2017, ISSN: 1662-5161.
Abstract | Links | BibTeX | Tags: DATAPixx, VPixxProgram
@article{brown_autistic_2017,
title = {Autistic Children Show a Surprising Relationship between Global Visual Perception, Non-Verbal Intelligence and Visual Parvocellular Function, Not Seen in Typically Developing Children},
author = {Alyse C. Brown and David P. Crewther},
url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5425824/},
doi = {10.3389/fnhum.2017.00239},
issn = {1662-5161},
year = {2017},
date = {2017-05-01},
urldate = {2023-12-21},
journal = {Frontiers in Human Neuroscience},
volume = {11},
pages = {239},
abstract = {Despite much current research into the visual processing style of individuals with Autism Spectrum Disorder (ASD), understanding of the neural mechanisms is lagging, especially with respect to the contributions of the overlapping dichotomies of magnocellular/parvocellular (afferent neural pathways), global/local (perception) and dorsal/ventral (cortical streams). Here, we addressed this deficiency by measuring inspection times (ITs) for novel global/local stimuli as well as recording nonlinear visually evoked potentials (VEPs), in particular, magnocellular and parvocellular temporal efficiencies. The study was conducted on a group of male ASD children and a typically developing (TD) group matched for mean age and mean non-verbal intelligence, as measured by the Raven’s Progressive Matrices. The IT results did not differ between groups, however a negative correlation between global IT and Raven’s score was found in the ASD group, that was not evident in the TD group. Nonlinear VEP showed the ASD group had smaller amplitude parvocellular-generated second order responses compared to the TD group. This is a sign of improved temporal responsiveness in ASD vs. TD groups. Principal Component Analysis linked global IT, non-verbal intelligence scores and VEP parvocellular efficiency in a single factor for the ASD but not the TD group. The results are suggestive of a constraint on pathways available for cognitive response in the ASD group, with temporal processing for those with ASD becoming more reliant on the parvocellular pathway.},
keywords = {DATAPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Despite much current research into the visual processing style of individuals with Autism Spectrum Disorder (ASD), understanding of the neural mechanisms is lagging, especially with respect to the contributions of the overlapping dichotomies of magnocellular/parvocellular (afferent neural pathways), global/local (perception) and dorsal/ventral (cortical streams). Here, we addressed this deficiency by measuring inspection times (ITs) for novel global/local stimuli as well as recording nonlinear visually evoked potentials (VEPs), in particular, magnocellular and parvocellular temporal efficiencies. The study was conducted on a group of male ASD children and a typically developing (TD) group matched for mean age and mean non-verbal intelligence, as measured by the Raven’s Progressive Matrices. The IT results did not differ between groups, however a negative correlation between global IT and Raven’s score was found in the ASD group, that was not evident in the TD group. Nonlinear VEP showed the ASD group had smaller amplitude parvocellular-generated second order responses compared to the TD group. This is a sign of improved temporal responsiveness in ASD vs. TD groups. Principal Component Analysis linked global IT, non-verbal intelligence scores and VEP parvocellular efficiency in a single factor for the ASD but not the TD group. The results are suggestive of a constraint on pathways available for cognitive response in the ASD group, with temporal processing for those with ASD becoming more reliant on the parvocellular pathway.
14.
Bussières, L.; Casanova, C.
Neural Processing of Second-Order Motion in the Suprasylvian Cortex of the Cat Journal Article
In: Cerebral Cortex, vol. 27, no. 2, pp. 1347–1357, 2017, ISSN: 1047-3211.
Abstract | Links | BibTeX | Tags: DATAPixx, VPixxProgram
@article{bussieres_neural_2017,
title = {Neural Processing of Second-Order Motion in the Suprasylvian Cortex of the Cat},
author = {L. Bussières and C. Casanova},
url = {https://doi.org/10.1093/cercor/bhv320},
doi = {10.1093/cercor/bhv320},
issn = {1047-3211},
year = {2017},
date = {2017-02-01},
urldate = {2023-12-21},
journal = {Cerebral Cortex},
volume = {27},
number = {2},
pages = {1347–1357},
abstract = {Neuronal responses to second-order motion, that is, to spatiotemporal variations of texture or contrast, have been reported in several cortical areas of mammals, including the middle-temporal (MT) area in primates. In this study, we investigated whether second-order responses are present in the cat posteromedial lateral suprasylvian (PMLS) cortex, a possible homolog of the primate area MT. The stimuli used were luminance-based sine-wave gratings (first-order) and contrast-modulated carrier stimuli (second-order), which consisted of a high-spatial-frequency static grating (carrier) whose contrast was modulated by a low-spatial-frequency drifting grating (envelope). Results indicate that most PMLS neurons responded to second-order motion and for the vast majority of cells, first- and second-order preferred directions were conserved. However, responses to second-order stimuli were significantly reduced when compared to those evoked by first-order gratings. Circular variance was increased for second-order stimuli, indicating that PMLS direction selectivity was weaker for this type of stimulus. Finally, carrier orientation selectivity was either absent or very broad and had no influence on the envelope's orientation selectivity. In conclusion, our data show that PMLS neurons exhibit similar first- and second-order response profiles and that, akin primate area MT cells, they perform a form-cue invariant analysis of motion signals.},
keywords = {DATAPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Neuronal responses to second-order motion, that is, to spatiotemporal variations of texture or contrast, have been reported in several cortical areas of mammals, including the middle-temporal (MT) area in primates. In this study, we investigated whether second-order responses are present in the cat posteromedial lateral suprasylvian (PMLS) cortex, a possible homolog of the primate area MT. The stimuli used were luminance-based sine-wave gratings (first-order) and contrast-modulated carrier stimuli (second-order), which consisted of a high-spatial-frequency static grating (carrier) whose contrast was modulated by a low-spatial-frequency drifting grating (envelope). Results indicate that most PMLS neurons responded to second-order motion and for the vast majority of cells, first- and second-order preferred directions were conserved. However, responses to second-order stimuli were significantly reduced when compared to those evoked by first-order gratings. Circular variance was increased for second-order stimuli, indicating that PMLS direction selectivity was weaker for this type of stimulus. Finally, carrier orientation selectivity was either absent or very broad and had no influence on the envelope's orientation selectivity. In conclusion, our data show that PMLS neurons exhibit similar first- and second-order response profiles and that, akin primate area MT cells, they perform a form-cue invariant analysis of motion signals.
15.
Laycock, Robin; Chan, Daniel; Crewther, Sheila G.
Attention Orienting in Response to Non-conscious Hierarchical Arrows: Individuals with Higher Autistic Traits Differ in Their Global/Local Bias Journal Article
In: Frontiers in Psychology, vol. 8, 2017, ISSN: 1664-1078.
Abstract | Links | BibTeX | Tags: RESPONSEPixx, VPixxProgram
@article{laycock_attention_2017,
title = {Attention Orienting in Response to Non-conscious Hierarchical Arrows: Individuals with Higher Autistic Traits Differ in Their Global/Local Bias},
author = {Robin Laycock and Daniel Chan and Sheila G. Crewther},
url = {https://www.frontiersin.org/articles/10.3389/fpsyg.2017.00023},
issn = {1664-1078},
year = {2017},
date = {2017-01-01},
urldate = {2023-12-21},
journal = {Frontiers in Psychology},
volume = {8},
abstract = {One aspect of the social communication impairments that characterize autism spectrum disorder (ASD) include reduced use of often subtle non-verbal social cues. People with ASD, and those with self-reported sub-threshold autistic traits, also show impairments in rapid visual processing of stimuli unrelated to social or emotional properties. Hence, this study sought to investigate whether perceptually non-conscious visual processing is related to autistic traits. A neurotypical sample of thirty young adults completed the Subthreshold Autism Trait Questionnaire and a Posner-like attention cueing task. Continuous Flash Suppression (CFS) was employed to render incongruous hierarchical arrow cues perceptually invisible prior to consciously presented targets. This was achieved via a 10 Hz masking stimulus presented to the dominant eye that suppressed information presented to the non-dominant eye. Non-conscious arrows consisted of local arrow elements pointing in one direction, and forming a global arrow shape pointing in the opposite direction. On each trial, the cue provided either a valid or invalid cue for the spatial location of the subsequent target, depending on which level (global or local) received privileged attention. A significant autism-trait group by global cue validity interaction indicated a difference in the extent of non-conscious local/global cueing between groups. Simple effect analyses revealed that whilst participants with lower autistic traits showed a global arrow cueing effect, those with higher autistic traits demonstrated a small local arrow cueing effect. These results suggest that non-conscious processing biases in local/global attention may be related to individual differences in autistic traits.},
keywords = {RESPONSEPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
One aspect of the social communication impairments that characterize autism spectrum disorder (ASD) include reduced use of often subtle non-verbal social cues. People with ASD, and those with self-reported sub-threshold autistic traits, also show impairments in rapid visual processing of stimuli unrelated to social or emotional properties. Hence, this study sought to investigate whether perceptually non-conscious visual processing is related to autistic traits. A neurotypical sample of thirty young adults completed the Subthreshold Autism Trait Questionnaire and a Posner-like attention cueing task. Continuous Flash Suppression (CFS) was employed to render incongruous hierarchical arrow cues perceptually invisible prior to consciously presented targets. This was achieved via a 10 Hz masking stimulus presented to the dominant eye that suppressed information presented to the non-dominant eye. Non-conscious arrows consisted of local arrow elements pointing in one direction, and forming a global arrow shape pointing in the opposite direction. On each trial, the cue provided either a valid or invalid cue for the spatial location of the subsequent target, depending on which level (global or local) received privileged attention. A significant autism-trait group by global cue validity interaction indicated a difference in the extent of non-conscious local/global cueing between groups. Simple effect analyses revealed that whilst participants with lower autistic traits showed a global arrow cueing effect, those with higher autistic traits demonstrated a small local arrow cueing effect. These results suggest that non-conscious processing biases in local/global attention may be related to individual differences in autistic traits.
16.
Ebaid, Deena; Crewther, Sheila G.; MacCalman, Kirsty; Brown, Alyse; Crewther, Daniel P.
Cognitive Processing Speed across the Lifespan: Beyond the Influence of Motor Speed Journal Article
In: Frontiers in Aging Neuroscience, vol. 9, 2017, ISSN: 1663-4365.
Abstract | Links | BibTeX | Tags: VPixxProgram
@article{ebaid_cognitive_2017,
title = {Cognitive Processing Speed across the Lifespan: Beyond the Influence of Motor Speed},
author = {Deena Ebaid and Sheila G. Crewther and Kirsty MacCalman and Alyse Brown and Daniel P. Crewther},
url = {https://www.frontiersin.org/articles/10.3389/fnagi.2017.00062},
issn = {1663-4365},
year = {2017},
date = {2017-01-01},
urldate = {2023-12-21},
journal = {Frontiers in Aging Neuroscience},
volume = {9},
abstract = {Traditional neuropsychological measurement of cognitive processing speed with tasks such as the Symbol Search and Coding subsets of the WAIS-IV, consistently show decline with advancing age. This is potentially problematic with populations where deficits in motor performance are expected, i.e., in aging or stroke populations. Thus, the aim of the current study was to explore the contribution of hand motor speed to traditional paper-and-pencil measures of processing speed and to a simple computer-customized non-motor perception decision task, the Inspection Time (IT) task. Participants were 67 young university students aged between 18 and 29 (59 females), and 40 older adults aged between 40 and 81 (31 females) primarily with a similar education profile. As expected, results indicated that age group differences were highly significant on the motor dexterity, Symbol Search and Coding tasks. However, no significant differences or correlations were seen between age groups and the simple visual perception IT task. Furthermore, controlling for motor dexterity did not remove significant age-group differences on the paper-and-pencil measures. This demonstrates that although much of past research into cognitive decline with age is confounded by use of motor reaction times as the operational measure, significant age differences in cognitive processing also exist on more complex tasks. The implications of the results are crucial in the realm of aging research, and caution against the use of traditional WAIS tasks with a clinical population where motor speed may be compromised, as in stroke.},
keywords = {VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Traditional neuropsychological measurement of cognitive processing speed with tasks such as the Symbol Search and Coding subsets of the WAIS-IV, consistently show decline with advancing age. This is potentially problematic with populations where deficits in motor performance are expected, i.e., in aging or stroke populations. Thus, the aim of the current study was to explore the contribution of hand motor speed to traditional paper-and-pencil measures of processing speed and to a simple computer-customized non-motor perception decision task, the Inspection Time (IT) task. Participants were 67 young university students aged between 18 and 29 (59 females), and 40 older adults aged between 40 and 81 (31 females) primarily with a similar education profile. As expected, results indicated that age group differences were highly significant on the motor dexterity, Symbol Search and Coding tasks. However, no significant differences or correlations were seen between age groups and the simple visual perception IT task. Furthermore, controlling for motor dexterity did not remove significant age-group differences on the paper-and-pencil measures. This demonstrates that although much of past research into cognitive decline with age is confounded by use of motor reaction times as the operational measure, significant age differences in cognitive processing also exist on more complex tasks. The implications of the results are crucial in the realm of aging research, and caution against the use of traditional WAIS tasks with a clinical population where motor speed may be compromised, as in stroke.
17.
Low, Essie; Crewther, Sheila Gillard; Ong, Ben; Perre, Diana; Wijeratne, Tissa
Compromised Motor Dexterity Confounds Processing Speed Task Outcomes in Stroke Patients Journal Article
In: Frontiers in Neurology, vol. 8, 2017, ISSN: 1664-2295.
Abstract | Links | BibTeX | Tags: VPixxProgram
@article{low_compromised_2017,
title = {Compromised Motor Dexterity Confounds Processing Speed Task Outcomes in Stroke Patients},
author = {Essie Low and Sheila Gillard Crewther and Ben Ong and Diana Perre and Tissa Wijeratne},
url = {https://www.frontiersin.org/articles/10.3389/fneur.2017.00484},
issn = {1664-2295},
year = {2017},
date = {2017-01-01},
urldate = {2023-12-21},
journal = {Frontiers in Neurology},
volume = {8},
abstract = {Most conventional measures of information processing speed require motor responses to facilitate performance. However, although not often addressed clinically, motor impairment, whether due to age or acquired brain injury, would be expected to confound the outcome measure of such tasks. The current study recruited 29 patients (20 stroke and 9 transient ischemic attack) with documented reduction in dexterity of the dominant hand, and 29 controls, to investigate the extent to which 3 commonly used processing speed measures with varying motor demands (a Visuo-Motor Reaction Time task, and the Wechsler Adult Intelligence Scale-IV Symbol Search and Coding subtests) may be measuring motor-related speed more so than cognitive speed. Analyses include correlations between indices of cognitive and motor speed obtained from two other tasks (Inspection Time and Pegboard task, respectively) with the three speed measures, followed by hierarchical regressions to determine the relative contribution of cognitive and motor speed indices toward task performance. Results revealed that speed outcomes on tasks with relatively high motor demands, such as Coding, were largely reflecting motor speed in individuals with reduced dominant hand dexterity. Thus, findings indicate the importance of employing measures with minimal motor requirements, especially when the assessment of speed is aimed at understanding cognitive rather than physical function.},
keywords = {VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Most conventional measures of information processing speed require motor responses to facilitate performance. However, although not often addressed clinically, motor impairment, whether due to age or acquired brain injury, would be expected to confound the outcome measure of such tasks. The current study recruited 29 patients (20 stroke and 9 transient ischemic attack) with documented reduction in dexterity of the dominant hand, and 29 controls, to investigate the extent to which 3 commonly used processing speed measures with varying motor demands (a Visuo-Motor Reaction Time task, and the Wechsler Adult Intelligence Scale-IV Symbol Search and Coding subtests) may be measuring motor-related speed more so than cognitive speed. Analyses include correlations between indices of cognitive and motor speed obtained from two other tasks (Inspection Time and Pegboard task, respectively) with the three speed measures, followed by hierarchical regressions to determine the relative contribution of cognitive and motor speed indices toward task performance. Results revealed that speed outcomes on tasks with relatively high motor demands, such as Coding, were largely reflecting motor speed in individuals with reduced dominant hand dexterity. Thus, findings indicate the importance of employing measures with minimal motor requirements, especially when the assessment of speed is aimed at understanding cognitive rather than physical function.
18.
Burt, Adelaide; Hugrass, Laila; Frith-Belvedere, Tash; Crewther, David
Insensitivity to Fearful Emotion for Early ERP Components in High Autistic Tendency Is Associated with Lower Magnocellular Efficiency Journal Article
In: Frontiers in Human Neuroscience, vol. 11, 2017, ISSN: 1662-5161.
Abstract | Links | BibTeX | Tags: RESPONSEPixx, VPixxProgram
@article{burt_insensitivity_2017,
title = {Insensitivity to Fearful Emotion for Early ERP Components in High Autistic Tendency Is Associated with Lower Magnocellular Efficiency},
author = {Adelaide Burt and Laila Hugrass and Tash Frith-Belvedere and David Crewther},
url = {https://www.frontiersin.org/articles/10.3389/fnhum.2017.00495},
issn = {1662-5161},
year = {2017},
date = {2017-01-01},
urldate = {2024-01-08},
journal = {Frontiers in Human Neuroscience},
volume = {11},
abstract = {Low spatial frequency (LSF) visual information is extracted rapidly from fearful faces, suggesting magnocellular involvement. Autistic phenotypes demonstrate altered magnocellular processing, which we propose contributes to a decreased P100 evoked response to LSF fearful faces. Here, we investigated whether rapid processing of fearful facial expressions differs for groups of neurotypical adults with low and high scores on the Autistic Spectrum Quotient (AQ). We created hybrid face stimuli with low and high spatial frequency filtered, fearful, and neutral expressions. Fearful faces produced higher amplitude P100 responses than neutral faces in the low AQ group, particularly when the hybrid face contained a LSF fearful expression. By contrast, there was no effect of fearful expression on P100 amplitude in the high AQ group. Consistent with evidence linking magnocellular differences with autistic personality traits, our non-linear VEP results showed that the high AQ group had higher amplitude K2.1 responses than the low AQ group, which is indicative of less efficient magnocellular recovery. Our results suggest that magnocellular LSF processing of a human face may be the initial visual cue used to rapidly and automatically detect fear, but that this cue functions atypically in those with high autistic tendency.},
keywords = {RESPONSEPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Low spatial frequency (LSF) visual information is extracted rapidly from fearful faces, suggesting magnocellular involvement. Autistic phenotypes demonstrate altered magnocellular processing, which we propose contributes to a decreased P100 evoked response to LSF fearful faces. Here, we investigated whether rapid processing of fearful facial expressions differs for groups of neurotypical adults with low and high scores on the Autistic Spectrum Quotient (AQ). We created hybrid face stimuli with low and high spatial frequency filtered, fearful, and neutral expressions. Fearful faces produced higher amplitude P100 responses than neutral faces in the low AQ group, particularly when the hybrid face contained a LSF fearful expression. By contrast, there was no effect of fearful expression on P100 amplitude in the high AQ group. Consistent with evidence linking magnocellular differences with autistic personality traits, our non-linear VEP results showed that the high AQ group had higher amplitude K2.1 responses than the low AQ group, which is indicative of less efficient magnocellular recovery. Our results suggest that magnocellular LSF processing of a human face may be the initial visual cue used to rapidly and automatically detect fear, but that this cue functions atypically in those with high autistic tendency.
19.
Ford, Talitha C.; Woods, Will; Crewther, David P.
In: NeuroImage: Clinical, vol. 16, pp. 383–389, 2017, ISSN: 2213-1582.
Abstract | Links | BibTeX | Tags: VPixxProgram
@article{ford_spatio-temporal_2017,
title = {Spatio-temporal source cluster analysis reveals fronto-temporal auditory change processing differences within a shared autistic and schizotypal trait phenotype},
author = {Talitha C. Ford and Will Woods and David P. Crewther},
url = {https://www.sciencedirect.com/science/article/pii/S2213158217300992},
doi = {10.1016/j.nicl.2017.04.022},
issn = {2213-1582},
year = {2017},
date = {2017-01-01},
urldate = {2024-01-17},
journal = {NeuroImage: Clinical},
volume = {16},
pages = {383–389},
abstract = {Social Disorganisation (SD) is a shared autistic and schizotypal phenotype that is present in the subclinical population. Auditory processing deficits, particularly in mismatch negativity/field (MMN/F) have been reported across both spectrum disorders. This study investigates differences in MMN/F cortical spatio-temporal source activity between higher and lower quintiles of the SD spectrum. Sixteen low (9 female) and 19 high (9 female) SD subclinical adults (18–40years) underwent magnetoencephalography (MEG) during an MMF paradigm where standard tones (50ms) were interrupted by infrequent duration deviants (100ms). Spatio-temporal source cluster analysis with permutation testing revealed no difference between the groups in source activation to the standard tone. To the deviant tone however, there was significantly reduced right hemisphere fronto-temporal and insular cortex activation for the high SD group (p= 0.038). The MMF, as a product of the cortical response to the deviant minus that to the standard, did not differ significantly between the high and low Social Disorganisation groups. These data demonstrate a deficit in right fronto-temporal processing of an auditory change for those with more of the shared SD phenotype, indicating that right fronto-temporal auditory processing may be associated with psychosocial functioning.},
keywords = {VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
Social Disorganisation (SD) is a shared autistic and schizotypal phenotype that is present in the subclinical population. Auditory processing deficits, particularly in mismatch negativity/field (MMN/F) have been reported across both spectrum disorders. This study investigates differences in MMN/F cortical spatio-temporal source activity between higher and lower quintiles of the SD spectrum. Sixteen low (9 female) and 19 high (9 female) SD subclinical adults (18–40years) underwent magnetoencephalography (MEG) during an MMF paradigm where standard tones (50ms) were interrupted by infrequent duration deviants (100ms). Spatio-temporal source cluster analysis with permutation testing revealed no difference between the groups in source activation to the standard tone. To the deviant tone however, there was significantly reduced right hemisphere fronto-temporal and insular cortex activation for the high SD group (p= 0.038). The MMF, as a product of the cortical response to the deviant minus that to the standard, did not differ significantly between the high and low Social Disorganisation groups. These data demonstrate a deficit in right fronto-temporal processing of an auditory change for those with more of the shared SD phenotype, indicating that right fronto-temporal auditory processing may be associated with psychosocial functioning.
20.
Mueller, Alexandra S.; González, Esther G.; McNorgan, Chris; Steinbach, Martin J.; Timney, Brian
Effects of Vertical Direction and Aperture Size on the Perception of Visual Acceleration Journal Article
In: Perception, vol. 45, no. 6, pp. 670–683, 2016, ISSN: 0301-0066, (Publisher: SAGE Publications Ltd STM).
Abstract | Links | BibTeX | Tags: DATAPixx, VPixxProgram
@article{mueller_effects_2016,
title = {Effects of Vertical Direction and Aperture Size on the Perception of Visual Acceleration},
author = {Alexandra S. Mueller and Esther G. González and Chris McNorgan and Martin J. Steinbach and Brian Timney},
url = {https://doi.org/10.1177/0301006616629034},
doi = {10.1177/0301006616629034},
issn = {0301-0066},
year = {2016},
date = {2016-06-01},
urldate = {2024-01-03},
journal = {Perception},
volume = {45},
number = {6},
pages = {670–683},
abstract = {It is not well understood whether the distance over which moving stimuli are visible affects our sensitivity to the presence of acceleration or our ability to track such stimuli. It is also uncertain whether our experience with gravity creates anisotropies in how we detect vertical acceleration and deceleration. To address these questions, we varied the vertical extent of the aperture through which we presented vertically accelerating and decelerating random dot arrays. We hypothesized that observers would better detect and pursue accelerating and decelerating stimuli that extend over larger than smaller distances. In Experiment 1, we tested the effects of vertical direction and aperture size on acceleration and deceleration detection accuracy. Results indicated that detection is better for downward motion and for large apertures, but there is no difference between vertical acceleration and deceleration detection. A control experiment revealed that our manipulation of vertical aperture size affects the ability to track vertical motion. Smooth pursuit is better (i.e., with higher peak velocities) for large apertures than for small apertures. Our findings suggest that the ability to detect vertical acceleration and deceleration varies as a function of the direction and vertical extent over which an observer can track the moving stimulus.},
note = {Publisher: SAGE Publications Ltd STM},
keywords = {DATAPixx, VPixxProgram},
pubstate = {published},
tppubtype = {article}
}
It is not well understood whether the distance over which moving stimuli are visible affects our sensitivity to the presence of acceleration or our ability to track such stimuli. It is also uncertain whether our experience with gravity creates anisotropies in how we detect vertical acceleration and deceleration. To address these questions, we varied the vertical extent of the aperture through which we presented vertically accelerating and decelerating random dot arrays. We hypothesized that observers would better detect and pursue accelerating and decelerating stimuli that extend over larger than smaller distances. In Experiment 1, we tested the effects of vertical direction and aperture size on acceleration and deceleration detection accuracy. Results indicated that detection is better for downward motion and for large apertures, but there is no difference between vertical acceleration and deceleration detection. A control experiment revealed that our manipulation of vertical aperture size affects the ability to track vertical motion. Smooth pursuit is better (i.e., with higher peak velocities) for large apertures than for small apertures. Our findings suggest that the ability to detect vertical acceleration and deceleration varies as a function of the direction and vertical extent over which an observer can track the moving stimulus.