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I am very pleased to welcome Ângela Gomes Tomaz who joined the Baldwin Vision Lab as a postdoctoral fellow in Fall 2026.

Ângela Gomes Tomaz is a postdoctoral fellow at the Baldwin Vision Laboratory investigating visual snow syndrome - an ophthalmic disorder only recently recognized as distinct from migraine. Previously, Ângela was a postdoctoral researcher at the Levi Laboratory at UC Berkeley where her research focused on appearance in amblyopia (a neurodevelopmental disorder of spatial vision), suppression and stereopsis, as well redundancy masking. Prior to Berkeley, Ângela was a PhD student at the University of Lille (SCALab, CNRS UMR 9193) in France. During her PhD, Ângela was a member of the Psychophysics of Appearance Laboratory (PALab) working with Bilge Sayim and Wolf Harmening (AOVision Lab) on appearance and performance at the limits of spatial vision.

I am very pleased to welcome Anna Hillstrom who joined the Baldwin Vision Lab as a graduate student in Fall 2026.

My research focuses on Visual Snow Syndrome, a condition where people see TV static-like flickering specks across their field of vision, along with other visual symptoms. Before joining the Baldwin Vision Lab, I obtained a Bachelor of Science in Psychology with minors in Neuroscience, Pharmacology and Public Health from the University of Minnesota in the United States. I also worked in Visual Snow Syndrome research during my undergraduate years. In my free time, I enjoy rock climbing, music, art, and being outside.

In this July 2026 editorial, we highlight recent advances in visual system development and neuroplasticity, and explore how research on amblyopia informs our understanding of visual function, recovery, and treatment.

For over 60 years, the mammalian visual system has been a stalwart model for investigating experience-dependent brain development and plasticity. This includes seminal studies of visual deprivation (Wiesel and Hubel, 1963), critical periods (Olson and Freeman, 1980; Birch and Stager, 1996), and plasticity mechanisms (Heynen et al., 2003; Hensch, 2005), as well as contemporary investigations of neural reorganization and recovery (Echavarri-Leet et al., 2025; Birch et al., 2025; Bohnsack et al., 2026). Studies of the visual system have provided fundamental insights into how neural circuits are cultivated and impoverished by sensory experience. Research on amblyopia, a visual disorder that arises from abnormal development of neural connections, is particularly suited to expose meaningful characteristics of developmental neuroplasticity because its emergence and recovery are enabled by the pliability of neurons early in postnatal life.

In June 2026, we published a study investigating spatial summation across the visual field, finding that a common fourth-root summation rule applies across central and peripheral vision.

Increasing the area of grating-like stimuli reduces their contrast detection thresholds. Characterizing the visual system’s summation rule this way provides insights into early visual architecture. Previous work in the fovea has found linear summation over short distances, consistent with integration within the receptive fields of early cortical neurons. Beyond this range, the benefit of stimulus area is reduced. Here, we investigated whether the same integration rule holds for stimulus elongations centred at different positions across the visual field. We did this for “tiger tail” strips of grating (growing orthogonally to the major axis of the early receptive fields) in the fovea, parafovea (3 deg), and periphery (10.5 deg). The interpretation of results from previous studies has been complicated by variation in local contrast sensitivity across the visual field. We addressed this here by using detailed maps of the inhomogeneity for each participant (their “witch hat”) to generate “compensated” stimuli where the stimulus contrast was amplified by the reciprocal of their local sensitivity. Our results followed a common fourth-root summation rule for tiger-tails in the fovea, parafovea, and periphery. We explained this by a “noisy energy” model that combined: i) a “witch hat” sensitivity surface, ii) linear filtering by receptive fields, iii) square-law contrast transduction, and iv) an internal template to direct the observer’s attention to the spatial extent of the stimulus. Fitting this model with a single global sensitivity parameter accounted for foveal and parafoveal results (56 thresholds), with one further parameter needed to model the periphery (84 thresholds).

In May 2026, we published a study in which we developed and evaluated D.E.B.R.A., a dichoptic e-book reading application, as a reading-based treatment for amblyopia.

Recent advancements in the treatment of amblyopia have adapted visual media (video games and movies) into dichoptic tasks to promote binocular function. This study demonstrates the feasibility of a treatment based on another important daily task: reading. We propose that dichoptic e-book applications may serve as an alternative treatment for binocular vision in amblyopia. We developed a prototype of a dichoptic e-book reading application (D.E.B.R.A), that was installed on Android tablets used for participant assessments. Participants read e-books in anaglyph red/green/black presentation, which allowed for monocular and binocular contrast to be adjusted independently. Amblyopic and control participants were then tested on their reading speed and questioned about their comfort using the application. We found that participants were able to read in the dichoptic presentation, albeit slower than when the books were presented in the typical “binocular” form. This suggests that the visual system can integrate information from both eyes to support reading. For some amblyopic participants, reducing the contrast of text seen by the fellow eye increased their reading speed in accordance with current research on balancing the contrast of the two eyes to unlock binocularity. At the end of each session, participants provided feedback on their comfort using the application. Overall, this study demonstrated that amblyopes can read with both eyes when text is presented in a dichoptic format. Thus, our findings suggests that the dichoptic e-book reading application could provide an effective framework for an amblyopia treatment protocol.

Please note: this position is no longer available

Supervisor: Alex Baldwin, Assistant Professor, McGill University

Institution: Research Institute of the McGill University Health Centre

Location: Montreal, Canada

We are recruiting a postdoctoral fellow to play a key role in our project to investigate Visual Snow Syndrome (VSS). The main approach will be through psychophysics, with the aim of developing quantitative measures of visual function that bridge the gap between the subjective phenomena described by patients and potential underlying mechanisms.

The project involves a team of researchers, clinicians, and partner organisations, and is supported by CIHR Project Grant funding.

Our goal is for these findings to: i) advance our scientific understanding of VSS, ii) form a basis for the development of objective tools to diagnose and quantify its severity, and iii) point the way toward future management or treatment approaches. We will also apply our methods in related clinical populations (e.g. Migraine) that overlap with VSS.

The fellow will contribute to developing, refining, and implementing the planned work, and also propose and lead additional studies within the scope of the project.

Postdoctoral Fellows at the RI-MUHC are trainees (enrolled at McGill University) and receive pay as a stipend. The stipend amount will be above typical Canadian rates.

Required qualifications for the position include:

• Holding (before the start date) a PhD in a relevant field
• Having a background in visual psychophysics, including the programming of experiments (e.g. PsychoPy / Psychtoolbox) and the analysis of data from psychophysical experiments
• Experience conducting behavioural experiments with human participants

The following would be an asset:

• Experience conducting research with clinical populations
• Experience working with questionnaire data, especially QOL measures
• French language skills

To apply for this position, please submit (e-mail: alexander.baldwin@mcgill.ca):

1. Curriculum Vitae
2. Cover Letter (listing two references)
3. An example of your published research

We would also welcome any informal enquiries to be sent to that address. Applications will be reviewed on a rolling basis until the position is filled.

We have launched a new website dedicated to our ongoing research on Visual Snow Syndrome:

visualsnowresearch.ca

The site provides information about our current studies, the goals of our research program, and opportunities for individuals to participate in research.

I am very pleased to welcome Tara Nichols who joined the Baldwin Vision Lab as a graduate student in Fall 2025.

My research interests include binocular vision and stereopsis, especially in the context of understanding amblyopia in adults and children. Prior to joining the Baldwin Vision Lab at McGill I completed my undergraduate studies at McMaster University, receiving a Bachelor of Science in Biology and Psychology, Neuroscience & Behaviour. At McMaster I was able to gain valuable research experience working on multiple projects aimed at developing and testing more sensitive measures of binocular vision for patients with amblyopia. I am excited to further my training and experience in my graduate studies where I will be investigating different aspects and anomalies of stereoscopic vision in both normally sighted and amblyopic individuals. Outside of the lab I enjoy running, reading, and baking.

In July 2025, we published a study investigating spatial scrambling in amblyopia, finding that disruptions in early visual processing may contribute to reduced visual acuity.

Behavioural research in amblyopia has shown evidence of a “spatial scrambling”. These effects would be consistent with a topographical disorganization affecting neural projections in the visual system. We investigated where in the processing hierarchy this scrambling might occur, and how it might contribute to the letter acuity deficit that is used clinically to characterize the severity of amblyopia. We constructed our stimuli using a physiologically-inspired algorithm. We consider two possible sites for scrambling to occur, either affecting: i) the outputs of log-Gabor filters (which mimic the oriented simple cell receptive field in V1), or ii) the inputs from isotropic subunits (i.e. LGN afferents) that form those oriented receptive fields. We refer to these image space manipulations as cortical and subcortical scrambling (CS and SCS), respectively. These distortions differ from typical additive noise such as bandpass noise, which we also tested for the purpose of comparison. The experiment involved a monocular task where the participant identified one of four possible noisy letters (bandpass and centered at 3 cycles/letter). Their sizes were rendered at half of the eye’s acuity limit, obtained through a separate monocular letter acuity experiment. We hypothesized that amblyopic participants should exhibit different patterns of mistakes (obtained from confusion matrices) based on viewing condition as a result of spatial scrambling for amblyopic eye viewing. In total 18 amblyopic (13 strabismic, 5 anisometropic) participated in this study. We found moderate correlations between the ratio of interocular acuity difference and our metric of the mistake pattern divergence in the two eyes when stimuli were affected by scrambling noise (SCS: r=0.65, P=0.0038; CS: r=0.47, P=0.047) but not for letters shown in bandpass noise (P=0.35). These results suggest neural scrambling, as early as the monocular inputs to the cortex, may play an important role in limiting letter acuity in amblyopia.

In January 2025, we published a study in which we developed a clinical method for measuring interocular suppression in amblyopia, and found that suppression measures correlated with visual acuity and stereopsis.

In amblyopia, abnormal binocular interactions lead to an overwhelming dominance of one eye. One mechanism implied in this imbalance is the suppression between the inputs from the two eyes. This interocular suppression involves two components: an overlay suppression and a surround suppression. Here, we propose a new method for measuring surround suppression which has been demonstrated in both strabismic and anisometropic amblyopes, based on a novel interocular contrast scaling task, suitable for use as a clinical tool. We compare the results obtained with this method against those from another method designed to measure overlay suppression: the Dichoptic Letter Test. We find a strong correlation between the results obtained with the two methods. Additionally, we observe strong correlations between the imbalance measured with the two tests and visual acuity and stereopsis. Altogether this suggests that amblyopic suppression is spatially broad and has direct relevance in global vision. So our new method is a relevant, clinically suitable tool to track the disease state in amblyopia.