The overarching goal of this research is to better understand the human visual system, and how objects and their locations are perceived and represented in the brain. The proposal investigates a fundamental challenge for our visual systems: Visual information is coded relative to the eyes, but the eyes are constantly moving. How, then, do we achieve spatial stability? The world does not appear to jump with each eye movement, but this seamless percept belies a complicated computational process. Prior work by the PI has made significant first steps in understanding how spatial attention and memory are represented (or remapped) across eye movements. The current proposal makes a critical advance over prior studies in two key ways: by taking into account (1) 3D depth information, and (2) feature/object recognition. The questions of spatial remapping, object recognition and depth perception are central to our understanding of human perception and brain functioning. These topics are typically investigated separately; the proposal takes the novel approach of trying to integrate them together into a single theory of visual stability.
In Aim 1 we investigate how remapping accounts for 3D spatial information: first by establishing a clearer picture of how 3D spatial information is represented in the brain (Aim 1.1), and then building off this knowledge to ask how depth information is remapped across eye movements (Aim 1.2).
Aim 2 investigates how remapping interacts with feature and object recognition: first asking what type of location information is bound to object features/identity (Aim 2.1) and then testing if (and when) feature content is remapped across eye movements (Aim 2.2). The interdisciplinary research plan combines several techniques - behavioral, eye-tracking, and neuroimaging (fMRI and EEG) - to achieve a more thorough and extensive understanding of spatial stability across eye movements. The research proposed here will have an immediate impact on our understanding of typical visual functioning in healthy human populations. These advances could also have a longer-term impact on a variety of clinical applications, informing our knowledge and assessment of visual disorders resulting from eye disease, injury, brain damage, and development/aging.
The research proposed here will improve our understanding of typical visual functioning in healthy human populations, which can open up broad reaching clinical applications for the future. In particular, the detailed mapping of 3D space in the brain could become a significant tool for understanding various visual disorders, including strabismus, macular degeneration, and stereo-blindness, and for assessing rehabilitation following treatment. Additionally, with a better understanding of spatial stability across eye movements, we can investigate whether this fundamental process is affected by aging, autism, schizophrenia, and depression (all of which are accompanied by changes in visual processing).
