the eye cog lab

Greg Zelinsky
Associate Professor and Lab Director
Ph.D., Brown University, 1994
gregory.zelinsky@stonybrook.edu

My goal is to better understand visual cognition by following two interrelated research paths.  First, I monitor and analyze how people move their eyes as they perform various visual search and visual working memory tasks.  I do this in order to obtain an on-line and directly observable measure of how a behavior intimately associated with the selection and accumulation of information (i.e., eye movements) changes in space and time during a task.  Second, I attempt to describe this oculomotor behavior in the context of image-based neurocomputational models.  These models perform the same task and "see" the same stimuli as human observers, and output a sequence of simulated eye movements that can be compared to human behavior.  These comparisons are then used to generate new hypotheses to further test the representations and processes underlying task performance.

Joe Schmidt
Fifth-year graduate student

To date, I have been investigating the representations used during visual search, and how these representations are affected by visual memory.  I do this by giving subjects varying amounts of visual information regarding the search target.  By varying target cues from abstract categorical labels to pictures of specific targets, we can determine how search guidance is affected by the availability of target identifying information.  I also study the contribution of visual memory to search guidance by varying the time after target designation until the search process begins.  I do this for multiple levels of target cue specificity to observe the relative contributions of abstract categorical details and precise visual details to the guidance process.  By better understanding the representations used to guide search, I hope to gain insight into the processes involved in visual memory and how these processes are integrated into our broader cognitive function.

Robert Alexander
Fourth-year graduate student

My research is focused on the effects of item similarity and object part structure on eye movements during visual search tasks.  Both target-distractor similarity and distractor-distractor similarity are assumed to determine the difficulty of search tasks, but the evidence for these effects has only been shown on accuracy and reaction time using simple, synthetic stimuli.  I am working to extend the research on these effects into more realistic search tasks using complex, photorealistic images and to examine how these forms of item similarity affects eye movements.  I am examining both semantic similarity and visual feature similarity through the use of a variety of similarity measures.  I am also exploring how object part structure affects encoding of information from search previews and affects search for objects which can be encoded in terms of parts.

Justin Maxfield
First-year graduate student
Psychology, Stony Brook University

I research the relationship between visual search and object categorization.  I'm currently studying how varying the hierarchical level in which a target is cued influences search guidance and target verification, as measured by the time needed to first fixate the target after search display onset and the time needed to decide that it is the target once it has been fixated, respectively.   I am also interested in how other factors known to affect category verification times, such as object typicality or the feature overlap between categories of objects, might also affect search guidance and target verification. By investigating these relationships between categorization and search, we can better understand the representation of targets in categorical search tasks.  

Hyejin Yang
Lab Alum
Ph.D., Psychology, Stony Brook University, 2010

I am interested in the relationship between visual search and working memory.  My research focused on how the representation of target properties in working memory affects visual search guidance, as indicated by the preferential direction of gaze.  Using fMRI I also investigated the representation of target templates in the brain and the neural bases for search guidance, as well as the relationship between search guidance and working memory load.  I investigated this relationship by manipulating the number of targets one is searching for simultaneously and observing changes in behavioral guidance and brain activation.  Another research interest was guidance from categorically defined targets.  What categorical properties are retrieved from long term memory and used to guide search to categorical targets? 

Xin Chen
Lab Alum
Ph.D., Psychology, Stony Brook University, 2007

Currently a Research Scientist at the Medical College of Georgia.