Research

Topics: Neuropsychology of visual perception, attention, and eye movements.

At any typical instance, our senses are overwhelmed with incoming information. For example, while reading this sentence, one is visually confronted with hundreds of words as well as other sources of visual stimulation, such as perhaps a desk, a phone, and a lamp in the immediate surrounds of this page. Despite this sensory overload, we are usually able to select the relevant sources of information while ignoring the irrelevant ones, and to provide the appropriate actions based upon this selection. How does the human brain accomplish these seemingly simple, yet enormous feats?

Research in our laboratory is primarily concerned with understanding the cognitive and neural mechanisms underlying attention, perception, and action. We seek answers to questions such as how it is that the human brain encodes the vast arrays of sensory information and what proportion of this information enters our awareness for conscious perception. We are also concerned with how attention influences our perceptual representations of the external world and the effects of attention on subsequently related actions. Addressing these issues has lead us to also become interested in how different areas of the brain are orchestrated with one another to provide coherent perceptions and actions in our everyday life.

Patients with focal brain damage and those with damage affecting attention and eye movements are of particular interest in our research. For example, patients with the syndrome of hemispatial neglect, most commonly from brain insult to the right inferior parietal lobe, have deficits of spatial attention and loss of awareness of the left half of the world. Such patients provide us with important insights and clues as to how normal attention and conscious perception operate. Psychophysical investigations are also conducted on neurologically intact participants as are recent techniques in cognitive neuroscience for studying brain function. Such techniques allow us to determine the anatomical underpinnings of these behaviors and include transcranial magnetic stimulation (TMS), a non-invasive method of disrupting normal brain function, and functional neuroimaging, methods for viewing and measuring brain activity under different states of mind.