Open Access Publications

@article{laurin_reduced_2024,

title = {Reduced spatial attentional distribution in older adults},

author = {Anne-Sophie Laurin and Julie Ouerfelli-Ethier and Laure Pisella and Aarlenne Zein Khan},

url = {https://doi.org/10.1167/jov.24.4.8},

doi = {10.1167/jov.24.4.8},

issn = {1534-7362},

year  = {2024},

date = {2024-04-01},

urldate = {2024-04-11},

journal = {Journal of Vision},

volume = {24},

number = {4},

pages = {8},

abstract = {Older adults show decline in visual search performance, but the underlying cause remains unclear. It has been suggested that older adults’ altered performance may be related to reduced spatial attention to peripheral visual information compared with younger adults. In this study, 18 younger (M = 21.6 years) and 16 older (M = 69.1 years) participants performed pop-out and serial visual search tasks with variously sized gaze-contingent artificial central scotomas (3°, 5°, or 7° diameter). By occluding central vision, we measured how attention to the periphery was contributing to the search performance. We also tested the effect of target eccentricity on search times and eye movements. We hypothesized that, if attention is reduced primarily in the periphery in older adults, we would observe longer search times for more eccentric targets and with central occlusion. During the pop-out search, older adults showed a steeper decline in search performance with increasing eccentricity and central scotoma size compared with younger adults. In contrast, during the serial search, older adults had longer search times than younger adults overall, independent of target eccentricity and scotoma size. Longer search times were attributed to higher cost-per-item slopes, indicating increased difficulty in simultaneously processing complex symbols made up of separable features in aging, possibly stemming from challenges in spatially binding individual features. Altogether, our findings point to fewer attentional resources of simultaneous visual processing to distribute over space or separable features of objects, consistent with decreased dorsal visual stream functioning in aging.},

keywords = {RESPONSEPixx, VIEWPixx3D},

pubstate = {published},

tppubtype = {article}

}

@article{aljassmi_visual_2024,

title = {Visual similarity effects in the identification of Arabic letters: evidence with masked priming},

author = {Maryam A. AlJassmi and Manuel Perea},

url = {https://www.cambridge.org/core/product/identifier/S1866980824000206/type/journal_article},

doi = {10.1017/langcog.2024.20},

issn = {1866-9808, 1866-9859},

year  = {2024},

date = {2024-04-01},

urldate = {2024-05-09},

journal = {Language and Cognition},

pages = {1–21},

abstract = {Research using masked priming and parafoveal preview techniques has shown that visual letter similarity has an impact on word processing during the initial stages in Latin-derived scripts. However, these effects appear to be absent in Arabic. One reason for this discrepancy could be attributed to the distinctive features of the Arabic script, which includes numerous letters sharing a basic form while varying in the location or number of diacritics. To shed light on this issue, the present study employed Arabic letters rather than words in two masked priming experiments: an alphabetic decision task and a letter-matching task. Both experiments showed that visually similar letters were more effective as primes than visually dissimilar letters. These findings suggest that the processes of letter identification in Arabic and Latin scripts may be roughly alike, implying that differences in visual letter similarity across scripts may arise at later stages of processing.},

keywords = {RESPONSEPixx},

pubstate = {published},

tppubtype = {article}

}

@article{schmitz_attentional_2024,

title = {Attentional cueing: Gaze is harder to override than arrows},

author = {Inka Schmitz and Hanna Strauss and Ludwig Reinel and Wolfgang Einhäuser},

url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0301136},

doi = {10.1371/journal.pone.0301136},

issn = {1932-6203},

year  = {2024},

date = {2024-03-01},

urldate = {2024-04-02},

journal = {PLOS ONE},

volume = {19},

number = {3},

pages = {e0301136},

abstract = {Gaze is an important and potent social cue to direct others’ attention towards specific locations. However, in many situations, directional symbols, like arrows, fulfill a similar purpose. Motivated by the overarching question how artificial systems can effectively communicate directional information, we conducted two cueing experiments. In both experiments, participants were asked to identify peripheral targets appearing on the screen and respond to them as quickly as possible by a button press. Prior to the appearance of the target, a cue was presented in the center of the screen. In Experiment 1, cues were either faces or arrows that gazed or pointed in one direction, but were non-predictive of the target location. Consistent with earlier studies, we found a reaction time benefit for the side the arrow or the gaze was directed to. Extending beyond earlier research, we found that this effect was indistinguishable between the vertical and the horizontal axis and between faces and arrows. In Experiment 2, we used 100% “counter-predictive” cues; that is, the target always occurred on the side opposite to the direction of gaze or arrow. With cues without inherent directional meaning (color), we controlled for general learning effects. Despite the close quantitative match between non-predictive gaze and non-predictive arrow cues observed in Experiment 1, the reaction-time benefit for counter-predictive arrows over neutral cues is more robust than the corresponding benefit for counter-predictive gaze. This suggests that–if matched for efficacy towards their inherent direction–gaze cues are harder to override or reinterpret than arrows. This difference can be of practical relevance, for example, when designing cues in the context of human-machine interaction.},

note = {Publisher: Public Library of Science},

keywords = {RESPONSEPixx, VIEWPixx},

pubstate = {published},

tppubtype = {article}

}

@article{varkuti_conversion_2024,

title = {Conversion of a medical implant into a versatile computer-brain interface},

author = {Bálint Várkuti and László Halász and Saman Hagh Gooie and Gabriella Miklós and Ricardo Smits Serena and Gijs Elswijk and Cameron C. McIntyre and Scott F. Lempka and Andres M. Lozano and Loránd Erōss},

url = {https://www.sciencedirect.com/science/article/pii/S1935861X23019769},

doi = {10.1016/j.brs.2023.12.011},

issn = {1935-861X},

year  = {2024},

date = {2024-01-01},

urldate = {2024-02-06},

journal = {Brain Stimulation},

volume = {17},

number = {1},

pages = {39–48},

abstract = {Background 

Information transmission into the human nervous system is the basis for a variety of prosthetic applications. Spinal cord stimulation (SCS) systems are widely available, have a well documented safety record, can be implanted minimally invasively, and are known to stimulate afferent pathways. Nonetheless, SCS devices are not yet used for computer-brain-interfacing applications. 

Objective 

Here we aimed to establish computer-to-brain communication via medical SCS implants in a group of 20 individuals who had been operated for the treatment of chronic neuropathic pain. 

Methods 

In the initial phase, we conducted interface calibration with the aim of determining personalized stimulation settings that yielded distinct and reproducible sensations. These settings were subsequently utilized to generate inputs for a range of behavioral tasks. We evaluated the required calibration time, task training duration, and the subsequent performance in each task. 

Results We could establish a stable spinal computer-brain interface in 18 of the 20 participants. Each of the 18 then performed one or more of the following tasks: A rhythm-discrimination task (n = 13), a Morse-decoding task (n = 3), and/or two different balance/body-posture tasks (n = 18; n = 5). The median calibration time was 79 min. The median training time for learning to use the interface in a subsequent task was 1:40 min. In each task, every participant demonstrated successful performance, surpassing chance levels. 

Conclusion 

The results constitute the first proof-of-concept of a general purpose computer-brain interface paradigm that could be deployed on present-day medical SCS platforms.},

keywords = {RESPONSEPixx},

pubstate = {published},

tppubtype = {article}

}

@article{aldrich_vision_2019,

title = {Vision and Hyper-Responsiveness in Migraine},

author = {Amelia Aldrich and Paul Hibbard and Arnold Wilkins},

url = {https://www.mdpi.com/2411-5150/3/4/62},

doi = {10.3390/vision3040062},

issn = {2411-5150},

year  = {2019},

date = {2019-12-01},

urldate = {2023-12-21},

journal = {Vision},

volume = {3},

number = {4},

pages = {62},

abstract = {We investigated contrast processing in relation to visual comfort from coloured light in individuals with migraine. In Experiment 1, 24 individuals who experienced migraine with aura (MA), 15 migraine without aura (MO), and 23 healthy controls, identified which of four patterns, one in each quadrant, had the greatest contrast. Although there were no significant differences between groups, contrast discrimination was superior in the visual field affected by aura in all eight participants in whom the aura was consistently lateralised. In Experiment 2, 20 participants without aura and 20 controls selected comfortable light with a chromaticity close to the daylight (Planckian) locus, whilst 20 individuals with aura chose more strongly saturated colours, mostly distant from the locus. In Experiment 3, nine participants with consistently unilateral aura undertook the contrast discrimination task wearing (a) lenses that provided a comfortable colour of light and (b) grey lenses of similar transmission. With grey lenses, seven of the nine individuals with unilateral aura showed a superior performance in the affected field, as before. With lenses providing a comfortable colour, however, the performance was relatively poor for the nine individuals with unilateral aura, but not for the 10 controls. This was the case in both visual fields. The cortical hyper-responsiveness with which migraine is associated may improve the perception of contrast. The perception is poorer (and more normal) with ophthalmic lenses having a comfortable colour.},

note = {Number: 4 

Publisher: Multidisciplinary Digital Publishing Institute},

keywords = {DATAPixx, RESPONSEPixx},

pubstate = {published},

tppubtype = {article}

}

@article{webb_effect_2019,

title = {The effect of facial expression on contrast sensitivity: A behavioural investigation and extension of Hedger, Adams & Garner (2015)},

author = {Abigail L. M. Webb and Paul B. Hibbard},

url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0205621},

doi = {10.1371/journal.pone.0205621},

issn = {1932-6203},

year  = {2019},

date = {2019-11-01},

urldate = {2024-01-18},

journal = {PLOS ONE},

volume = {14},

number = {11},

pages = {e0205621},

abstract = {It has been argued that rapid visual processing for fearful face expressions is driven by the fact that effective contrast is higher in these faces compared to other expressions, when the contrast sensitivity function is taken into account. This proposal has been upheld by data from image analyses, but is yet to be tested at the behavioural level. The present study conducts a traditional contrast sensitivity task for face images of various facial expressions. Findings show that visual contrast thresholds do not differ for different facial expressions We re-conduct analysis of faces’ effective contrast, using the procedure developed by Hedger, Adams and Garner, and show that higher effective contrast in fearful face expressions relies on face images first being normalised for RMS contrast. When not normalised for RMS contrast, effective contrast in fear expressions is no different, or sometimes even lower, compared to other expressions. However, the effect of facial expression on detection in a backward masking study did not depend on the type of contrast normalisation used. These findings are discussed in relation to the implications of contrast normalisation on the salience of face expressions in behavioural and neurophysiological experiments, and also the extent that natural physical differences between facial stimuli are masked during stimulus standardisation and normalisation.},

note = {Publisher: Public Library of Science},

keywords = {RESPONSEPixx, VIEWPixx3D},

pubstate = {published},

tppubtype = {article}

}

@article{asher_spatial_2019,

title = {Spatial Frequency Tuning and Transfer of Perceptual Learning for Motion Coherence Reflects the Tuning Properties of Global Motion Processing},

author = {Jordi M. Asher and Vincenzo Romei and Paul B. Hibbard},

url = {https://www.mdpi.com/2411-5150/3/3/44},

doi = {10.3390/vision3030044},

issn = {2411-5150},

year  = {2019},

date = {2019-09-01},

urldate = {2024-01-17},

journal = {Vision},

volume = {3},

number = {3},

pages = {44},

abstract = {Perceptual learning is typically highly specific to the stimuli and task used during training. However, recently, it has been shown that training on global motion can transfer to untrained tasks, reflecting the generalising properties of mechanisms at this level of processing. We investigated (i) if feedback was required for learning in a motion coherence task, (ii) the transfer across the spatial frequency of training on a global motion coherence task and (iii) the transfer of this training to a measure of contrast sensitivity. For our first experiment, two groups, with and without feedback, trained for ten days on a broadband motion coherence task. Results indicated that feedback was a requirement for robust learning. For the second experiment, training consisted of five days of direction discrimination using one of three motion coherence stimuli (where individual elements were comprised of either broadband Gaussian blobs or low- or high-frequency random-dot Gabor patches), with trial-by-trial auditory feedback. A pre- and post-training assessment was conducted for each of the three types of global motion coherence conditions and high and low spatial frequency contrast sensitivity (both without feedback). Our training paradigm was successful at eliciting improvement in the trained tasks over the five days. Post-training assessments found evidence of transfer for the motion coherence task exclusively for the group trained on low spatial frequency elements. For the contrast sensitivity tasks, improved performance was observed for low- and high-frequency stimuli, following motion coherence training with broadband stimuli, and for low-frequency stimuli, following low-frequency training. Our findings are consistent with perceptual learning, which depends on the global stage of motion processing in higher cortical areas, which is broadly tuned for spatial frequency, with a preference for low frequencies.},

note = {Number: 3 

Publisher: Multidisciplinary Digital Publishing Institute},

keywords = {RESPONSEPixx, VIEWPixx3D},

pubstate = {published},

tppubtype = {article}

}

@article{johns_mixing_2019,

title = {Mixing things up: How blocking and mixing affect the processing of codemixed sentences},

author = {Michael A Johns and Jorge R Valdés Kroff and Paola E Dussias},

url = {https://doi.org/10.1177/1367006917752570},

doi = {10.1177/1367006917752570},

issn = {1367-0069},

year  = {2019},

date = {2019-04-01},

urldate = {2024-01-12},

journal = {International Journal of Bilingualism},

volume = {23},

number = {2},

pages = {584–611},

abstract = {Aims and objectives/purpose/research questions: The goal of this study is to determine if the way in which codemixed sentences are presented during experimental lab sessions affects the way they are processed, and how experimental design approximates (or not) patterns of language use in bilingual populations. 

Design/methodology/approach: An eye-tracking study was conducted comparing reading times on codemixed and unilingual Spanish sentences across two modes of presentation: (a) a blocked mode, where one block contained unilingual Spanish sentences and another one contained codemixed sentences; and (b) a mixed mode, where both unilingual and codemixed sentences were mixed together in a randomized fashion. 

Data and analysis: 20 heritage speakers of Spanish were tested. Four reading measures extracted from the eye-tracking data were subjected to linear mixed-effects regression, with significance determined via backwards likelihood ratio tests, to examine differences across modes of presentation. 

Findings/conclusions: Codemixes took significantly longer to process in the blocked mode than in the mixed mode. This is in line with corpus data suggesting that intra-sentential codemixing does not occur for long stretches of time and is broken up by unilingual discourse. 

Originality: While a few studies have hinted at the potential confounds related to the presentation of codemixed or language-switching stimuli, the direct effects of experimental manipulation coupled with insights from sociolinguistic or corpus-based studies have not been tested. 

Significance/implications: To better understand bilingual codemixing, as well as the cost (or lack thereof) associated with it, lab-based studies of codemixing should take insights from sociolinguistic and corpus-based research. The results of this study suggest that the experience that participants bring into the lab can interact with experimental design and result in unexpected results.},

note = {Publisher: SAGE Publications Ltd},

keywords = {RESPONSEPixx},

pubstate = {published},

tppubtype = {article}

}

@article{zhang_behavioural_2019,

title = {Behavioural oscillations in visual orientation discrimination reveal distinct modulation rates for both sensitivity and response bias},

author = {Huihui Zhang and Maria Concetta Morrone and David Alais},

url = {https://www.nature.com/articles/s41598-018-37918-4},

doi = {10.1038/s41598-018-37918-4},

issn = {2045-2322},

year  = {2019},

date = {2019-02-01},

urldate = {2023-12-21},

journal = {Scientific Reports},

volume = {9},

number = {1},

pages = {1115},

abstract = {Perception is modulated by ongoing brain oscillations. Psychophysical studies show a voluntary action can synchronize oscillations, producing rhythmical fluctuations of visual contrast sensitivity. We used signal detection to examine whether voluntary action could also synchronize oscillations in decision criterion, and whether that was due to the oscillations of perceptual bias or of motor bias. Trials started with a voluntary button-press. After variable time lags, a grating at threshold contrast was presented briefly and participants discriminated its orientation (45° or −45°) with a mouse-click. Two groups of participants completed the experiment with opposite mappings between grating orientations and response buttons. We calculated sensitivity and criterion in the 800 ms period following the button press. To test for oscillations, we fitted first-order Fourier series to these time series. Alpha oscillations occurred in both sensitivity and criterion at different frequencies: textasciitilde8 Hz (sensitivity) and textasciitilde10 Hz (criterion). Sensitivity oscillations had the same phase for both stimulus-response mappings. Criterion oscillations, however, showed a strong anti-phase relationship when the two groups were compared, suggesting a motor bias rather than perceptual bias. Our findings suggest two roles for alpha oscillations: in sensitivity, reflecting rhythmic attentional inhibition, and in criterion, indicating dynamic motor-related anticipation or preparation.},

note = {Number: 1 

Publisher: Nature Publishing Group},

keywords = {PROPixx, RESPONSEPixx},

pubstate = {published},

tppubtype = {article}

}

@article{peacock_meaning_2019,

title = {Meaning guides attention during scene viewing, even when it is irrelevant},

author = {Candace E. Peacock and Taylor R. Hayes and John M. Henderson},

url = {https://doi.org/10.3758/s13414-018-1607-7},

doi = {10.3758/s13414-018-1607-7},

issn = {1943-393X},

year  = {2019},

date = {2019-01-01},

urldate = {2024-01-12},

journal = {Attention, Perception, & Psychophysics},

volume = {81},

number = {1},

pages = {20–34},

abstract = {During real-world scene viewing, humans must prioritize scene regions for attention. What are the roles of low-level image salience and high-level semantic meaning in attentional prioritization? A previous study suggested that when salience and meaning are directly contrasted in scene memorization and preference tasks, attentional priority is assigned by meaning (Henderson & Hayes in Nature Human Behavior, 1, 743–747, 2017). Here we examined the role of meaning in attentional guidance using two tasks in which meaning was irrelevant and salience was relevant: a brightness rating task and a brightness search task. Meaning was represented by meaning maps that captured the spatial distribution of semantic features. Meaning was contrasted with image salience, represented by saliency maps. Critically, both maps were represented similarly, allowing us to directly compare how meaning and salience influenced the spatial distribution of attention, as measured by fixation density maps. Our findings suggest that even in tasks for which meaning is irrelevant and salience is relevant, meaningful scene regions are prioritized for attention over salient scene regions. These results support theories in which scene semantics play a dominant role in attentional guidance in scenes.},

keywords = {RESPONSEPixx},

pubstate = {published},

tppubtype = {article}

}

@article{ouerfelli-ethier_anti-saccades_2018,

title = {Anti-saccades predict cognitive functions in older adults and patients with Parkinson’s disease},

author = {Julie Ouerfelli-Ethier and Basma Elsaeid and Julie Desgroseilliers and Douglas P. Munoz and Gunnar Blohm and Aarlenne Zein Khan},

url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6261587/},

doi = {10.1371/journal.pone.0207589},

issn = {1932-6203},

year  = {2018},

date = {2018-11-01},

urldate = {2023-12-21},

journal = {PLoS ONE},

volume = {13},

number = {11},

pages = {e0207589},

abstract = {A major component of cognitive control is the ability to act flexibly in the environment by either behaving automatically or inhibiting an automatic behaviour. The interleaved pro/anti-saccade task measures cognitive control because the task relies on one’s abilities to switch flexibly between pro and anti-saccades, and inhibit automatic saccades during anti-saccade trials. Decline in cognitive control occurs during aging or neurological illnesses such as Parkinson’s disease (PD), and indicates decline in other cognitive abilities, such as memory. However, little is known about the relationship between cognitive control and other cognitive processes. Here we investigated whether anti-saccade performance can predict decision-making, visual memory, and pop-out and serial visual search performance. We tested 34 younger adults, 22 older adults, and 20 PD patients on four tasks: an interleaved pro/anti-saccade, a spatial visual memory, a decision-making and two types of visual search (pop-out and serial) tasks. Anti-saccade performance was a good predictor of decision-making and visual memory abilities for both older adults and PD patients, while it predicted visual search performance to a larger extent in PD patients. Our results thus demonstrate the suitability of the interleaved pro/anti-saccade task as a cognitive marker of cognitive control in aging and PD populations.},

keywords = {RESPONSEPixx, VIEWPixx3D},

pubstate = {published},

tppubtype = {article}

}

@article{arranz-paraiso_testing_2018,

title = {Testing the link between visual suppression and intelligence},

author = {Sandra Arranz-Paraíso and Ignacio Serrano-Pedraza},

url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0200151},

doi = {10.1371/journal.pone.0200151},

issn = {1932-6203},

year  = {2018},

date = {2018-07-01},

urldate = {2023-12-21},

journal = {PLOS ONE},

volume = {13},

number = {7},

pages = {e0200151},

abstract = {The impairment to discriminate the motion direction of a large high contrast stimulus or to detect a stimulus surrounded by another one is called visual suppression and is the result of the normal function of our visual inhibitory mechanisms. Recently, Melnick et al. (2013), using a motion discrimination task, showed that intelligence strongly correlates with visual suppression (r = 0.71). Cook et al. (2016) also showed a strong link between contrast surround suppression and IQ (r = 0.87), this time using a contrast matching task. Our aim is to test this link using two different visual suppression tasks: a motion discrimination task and a contrast detection task. Fifty volunteers took part in the experiments. Using Bayesian staircases, we measured duration thresholds in the motion experiment and contrast thresholds in the spatial experiment. Although we found a much weaker effect, our results from the motion experiment still replicate previous results supporting the link between motion surround suppression and IQ (r = 0.43). However, our results from the spatial experiment do not support the link between contrast surround suppression and IQ (r = -0.09). Methodological differences between this study and previous studies which could explain these discrepancies are discussed.},

note = {Publisher: Public Library of Science},

keywords = {DATAPixx, RESPONSEPixx},

pubstate = {published},

tppubtype = {article}

}

@article{vancleef_two_2018,

title = {Two choices good, four choices better: For measuring stereoacuity in children, a four-alternative forced-choice paradigm is more efficient than two},

author = {Kathleen Vancleef and Jenny C. A. Read and William Herbert and Nicola Goodship and Maeve Woodhouse and Ignacio Serrano-Pedraza},

url = {https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0201366},

doi = {10.1371/journal.pone.0201366},

issn = {1932-6203},

year  = {2018},

date = {2018-07-01},

urldate = {2024-01-18},

journal = {PLOS ONE},

volume = {13},

number = {7},

pages = {e0201366},

abstract = {Purpose Measuring accurate thresholds in children can be challenging. A typical psychophysical experiment is usually too long to keep children engaged. However, a reduction in the number of trials decreases the precision of the threshold estimate. We evaluated the efficiency of forced-choice paradigms with 2 or 4 alternatives (2-AFC, 4-AFC) in a disparity detection experiment. 4-AFC paradigms are statistically more efficient, but also more cognitively demanding, which might offset their theoretical advantage in young children. Methods We ran simulations evaluating bias and precision of threshold estimates of 2-AFC and 4-AFC paradigms. In addition, we measured disparity thresholds in 43 children (aged 6 to 17 years) with a 4-AFC paradigm and in 49 children (aged 4 to 17 years) with a 2-AFC paradigm, both using an adaptive weighted one-up one-down staircase. Results Simulations indicated a similar bias and precision for a 2-AFC paradigm with double the number of trials as a 4-AFC paradigm. On average, estimated threshold of the simulated data was equal to the model threshold, indicating no bias. The precision was improved with an increasing number of trials. Likewise, our data showed a similar bias and precision for a 2-AFC paradigm with 60 trials as for a 4-AFC paradigm with 30 trials. Trials in the 4-AFC paradigm took slightly longer as participants scanned more alternatives. However, the 4-AFC task still ended up faster for a given precision. Conclusion Bias and precision were similar in a 4-AFC task compared to a 2-AFC task with double the number of trials. However, a 4-AFC paradigm was more time efficient and is therefore recommended.},

note = {Publisher: Public Library of Science},

keywords = {RESPONSEPixx},

pubstate = {published},

tppubtype = {article}

}

@article{tarawneh_contrast_2018,

title = {Contrast thresholds reveal different visual masking functions in humans and praying mantises},

author = {Ghaith Tarawneh and Vivek Nityananda and Ronny Rosner and Steven Errington and William Herbert and Sandra Arranz-Paraíso and Natalie Busby and Jimmy Tampin and Jenny Read and Ignacio Serrano-Pedraza},

url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5936055/},

doi = {10.1242/bio.029439},

issn = {2046-6390},

year  = {2018},

date = {2018-04-01},

urldate = {2024-01-02},

journal = {Biology Open},

volume = {7},

number = {4},

pages = {bio029439},

abstract = {Recently, we showed a novel property of the Hassenstein–Reichardt detector, namely that insect motion detection can be masked by ‘undetectable’ noise, i.e. visual noise presented at spatial frequencies at which coherently moving gratings do not elicit a response (). That study compared the responses of human and insect motion detectors using different ways of quantifying masking (contrast threshold in humans and masking tuning function in insects). In addition, some adjustments in experimental procedure, such as presenting the stimulus at a short viewing distance, were necessary to elicit a response in insects. These differences offer alternative explanations for the observed difference between human and insect responses to visual motion noise. Here, we report the results of new masking experiments in which we test whether differences in experimental paradigm and stimulus presentation between humans and insects can account for the undetectable noise effect reported earlier. We obtained contrast thresholds at two signal and two noise frequencies in both humans and praying mantises (Sphodromantis lineola), and compared contrast threshold differences when noise has the same versus different spatial frequency as the signal. Furthermore, we investigated whether differences in viewing geometry had any qualitative impact on the results. Consistent with our earlier finding, differences in contrast threshold show that visual noise masks much more effectively when presented at signal spatial frequency in humans (compared to a lower or higher spatial frequency), while in insects, noise is roughly equivalently effective when presented at either the signal spatial frequency or lower (compared to a higher spatial frequency). The characteristic difference between human and insect responses was unaffected by correcting for the stimulus distortion caused by short viewing distances in insects. These findings constitute stronger evidence that the undetectable noise effect reported earlier is a genuine difference between human and insect motion processing, and not an artefact caused by differences in experimental paradigms., Summary: We investigate alternative explanations for a reported difference between human and insect responses to masked moving gratings, and demonstrate that it is a genuine feature of their visual systems.},

keywords = {DATAPixx, RESPONSEPixx},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@article{webb_natural_2018,

title = {Natural variation in female reproductive hormones does not affect contrast sensitivity},

author = {Abigail L. M. Webb and Paul B. Hibbard and Rick O'Gorman},

url = {https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5830758/},

doi = {10.1098/rsos.171566},

issn = {2054-5703},

year  = {2018},

date = {2018-02-01},

urldate = {2024-01-12},

journal = {Royal Society Open Science},

volume = {5},

number = {2},

pages = {171566},

abstract = {Evidence suggests that females experience adaptive shifts in facial preferences across the menstrual cycle. However, recent discussions and meta-analyses suggest that these findings are equivocal. A previously unexplored question is the extent to which shifts in female preferences are modulated by hormone-dependent changes occurring in low-level vision, such as visual sensitivity. This mechanistic approach has been a novel method for investigating the extent to which complex perceptual phenomena are driven by low-level versus higher-level perceptual processes. We investigated whether the contrast sensitivity function—an early dimension of vision—is also influenced by variation in female reproductive hormones. Visual contrast thresholds were measured for 1, 4 and 16 cycles/degree gratings during the ovulatory, luteal and menstrual phases of the menstrual cycle in naturally cycling women, and women using oral contraceptives. Male participants were tested at similar time intervals. Results showed that visual contrast sensitivity does not differ according to sex, or use of oral contraception, nor does it vary relative to hormonal shifts across the menstrual cycle. These findings suggest that shifts in female preferences are not driven by changes in visual sensitivity, and are therefore likely attributable to changes in higher-level perception or cognition.},

keywords = {RESPONSEPixx, VIEWPixx3D},

pubstate = {published},

tppubtype = {article}

}

@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}

}

@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}

}

@article{ho_auditory_2017,

title = {Auditory Sensitivity and Decision Criteria Oscillate at Different Frequencies Separately for the Two Ears},

author = {Hao Tam Ho and Johahn Leung and David C. Burr and David Alais and Maria Concetta Morrone},

url = {https://www.sciencedirect.com/science/article/pii/S0960982217313209},

doi = {10.1016/j.cub.2017.10.017},

issn = {0960-9822},

year  = {2017},

date = {2017-12-01},

urldate = {2023-12-21},

journal = {Current Biology},

volume = {27},

number = {23},

pages = {3643–3649.e3},

abstract = {Many behavioral measures of visual perception fluctuate continually in a rhythmic manner, reflecting the influence of endogenous brain oscillations, particularly theta (∼4–7 Hz) and alpha (∼8–12 Hz) rhythms [1, 2, 3]. However, it is unclear whether these oscillations are unique to vision or whether auditory performance also oscillates [4, 5]. Several studies report no oscillatory modulation in audition [6, 7], while those with positive findings suffer from confounds relating to neural entrainment [8, 9, 10]. Here, we used a bilateral pitch-identification task to investigate rhythmic fluctuations in auditory performance separately for the two ears and applied signal detection theory (SDT) to test for oscillations of both sensitivity and criterion (changes in decision boundary) [11, 12]. Using uncorrelated dichotic white noise to induce a phase reset of oscillations, we demonstrate that, as with vision, both auditory sensitivity and criterion showed strong oscillations over time, at different frequencies: ∼6 Hz (theta range) for sensitivity and ∼8 Hz (low alpha range) for criterion, implying distinct underlying sampling mechanisms [13]. The modulation in sensitivity in left and right ears was in antiphase, suggestive of attention-like mechanisms sampling alternatively from the two ears.},

keywords = {RESPONSEPixx},

pubstate = {published},

tppubtype = {article}

}

@article{ohl_selective_2017,

title = {Selective enhancement of orientation tuning before saccades},

author = {Sven Ohl and Clara Kuper and Martin Rolfs},

url = {https://doi.org/10.1167/17.13.2},

doi = {10.1167/17.13.2},

issn = {1534-7362},

year  = {2017},

date = {2017-11-01},

urldate = {2023-12-21},

journal = {Journal of Vision},

volume = {17},

number = {13},

pages = {2},

abstract = {Saccadic eye movements cause a rapid sweep of the visual image across the retina and bring the saccade's target into high-acuity foveal vision. Even before saccade onset, visual processing is selectively prioritized at the saccade target. To determine how this presaccadic attention shift exerts its influence on visual selection, we compare the dynamics of perceptual tuning curves before movement onset at the saccade target and in the opposite hemifield. Participants monitored a 30-Hz sequence of randomly oriented gratings for a target orientation. Combining a reverse correlation technique previously used to study orientation tuning in neurons and general additive mixed modeling, we found that perceptual reports were tuned to the target orientation. The gain of orientation tuning increased markedly within the last 100 ms before saccade onset. In addition, we observed finer orientation tuning right before saccade onset. This increase in gain and tuning occurred at the saccade target location and was not observed at the incongruent location in the opposite hemifield. The present findings suggest, therefore, that presaccadic attention exerts its influence on vision in a spatially and feature-selective manner, enhancing performance and sharpening feature tuning at the future gaze location before the eyes start moving.},

keywords = {RESPONSEPixx, VIEWPixx3D},

pubstate = {published},

tppubtype = {article}

}