Research at my lab deals with the neural basis of attention, awareness, and action. Event-related potentials (ERPs), startle-blink, and neuroimaging techniques are used to identify the locus and time course of relevant brain processes in normal and neurologically impaired adults.

Current studies of visual awareness employ two paradigms. In patients with unilateral cortical blindness due to stroke, responses to physically identical stimuli presented within the blind or intact hemifield are compared. In healthy participants, we study conscious versus unconscious visual processes using binocular rivalry. Different images are simultaneously presented to the left and right eyes to induce perceptual oscillations between the eyes. Monocular probes delivered to the suppressed or dominant eye allow the mechanisms that underlie rivalry to be examined with ERPs and neuroimaging.

Our research on motor processes includes studies of the lateralized readiness potential and the startle-blink reflex in patients with Parkinson's disease and in healthy young and older adults. Using these two measures, selective deficits at the cortical and brainstem levels are investigated using paradigms adapted from cognitive psychology. In particular, our most recent research on Parkinson's disease focuses on deficits in response selection (assessed with the Eriksen flanker task) and impaired response preparation in a forewarned reaction time task.
 

Optical image of visual cortex activity superimposed on an MRI scan

Clinical and Cognitive Neuroscience Laboratory

Lab personnel 2003 Back row, left to right: Dr. Steve Hackley, Sam Mattox, Tim Hutchins; front row: Elizabeth Stepp, Dr. Jun Zhao

Research opportunities are often available at the CCN lab for undergraduates, graduate students, postdocs, and visiting faculty. The current focus of research is on understanding the neural mechanisms that underlie selective attention, unconscious visual processes, voluntary versus reflexive reactions, response selection, and reward processing in patients with Parkinson’s disease or focalized brain lesions. For further information, contact Dr. Hackley at HackleyS@Missouri.edu.