Examining the biomarkers of visual crowding in visual impairments

The project is supervised by Frans Cornelissen and Nomdo Jansonius and located in the Laboratory of Experimental Ophthalmology of the University Medical Center Groningen. The current project aims to examine the biomarkers of visual crowding and object recognition and come up with natural tasks to assess these visual phenomena using eye movements.

Personal Background and Interest:

I am from Istanbul, Turkey. I received my BA in Psychology and MA in Psychological Sciences. For my master thesis I investigated the changes in chromatic contrast sensitivity during smooth pursuit eye movements using eye tracking and psychophysical methods. I am interested in spatial and functional vision, visual crowding, eye movements, and interaction between vision and action.

Aim of the project: 

Visual crowding is the inability to distinguish an object in the presence of clutter and is increased in several neurological and ophthalmic disorders. However, conventional methods for measuring crowding rely on classical psychophysical methods that are time-consuming and attentionally demanding, making it difficult to routinely examine. The objective of my project is to create functional vision measurement tools assessing several aspects of object recognition, such as visual crowding and figure-ground segregation, with the ultimate goal of implementing this tool in the diagnosis and prognosis of visually impaired individuals.

Current activities:

To date, I have devised a novel approach to evaluate peripheral crowding, called serial search paradigm, using continuous eye movements. This paradigm required participants to spot a target in a crowded screen and move their eyes to the location of the target. I’ve tested the potential of this paradigm in enabling more accessible crowding assessments. To do so, I have compared its performance to conventional crowding assessments that utilizes alternative forced choice (AFC) paradigms.

Recently (May 2023), I’ve started my secondment at the Otto-von-Guericke University in Magdeburg. Here, I’m collecting data from individuals with visual impairments using this serial search task. With this study, I aim to test the paradigm’s usefulness in vulnerable populations and in clinical settings.

Future directions:

As a future direction I am planning to examine the effects of external (e.g. luminance) signals on visual crowding in visually impaired population.