Faculty

Mark A. Segraves, PhD

Associate Professor
Neurobiology and Physiology
PhD, University of Pennsylvania

Email: m-segraves@northwestern.edu
Phone: (847) 491-5072
Fax: (847) 491-5211
Room: Cook Rm 2137

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Research Interests

Systems and cognitive neuroscience; sensorimotor integration; selection and control of eye movements in primates

The generation of eye movements is an important function of the brain's control systems. My laboratory uses the eye movement system as a model for how the brain of primates, including man, controls a variety of movements. Our work focuses upon areas of the rhesus monkey's prefrontal cortex and midbrain that help to control eye movements. We use behavioral and neurophysiological techniques in awake, behaving monkeys allow us to examine the processing of information taking place within these areas, and to enable us to understand the role these neural structures perform in the complex network of connections that make up the oculomotor system.

Recent experiments from this laboratory have:

1. Described neuronal activity in the cortical frontal eye field related to the selection of eye movement targets while monkeys look at natural inmages such as a face or visual landscape.
2. Used microinjections of excitatory and inhibitory drugs to demonstrate the importance of frontal eye field activity for the generation of both visually-guided and memory-guided movements.
3. Identified and characterized the population of frontal eye field neurons that project to the superior colliculus as well as characterizing the functional activity of collicular neurons that receive frontal eye field input.

These studies provide basic knowledge about the processes our brain uses to select and control movements. They afford a unique opportunity to examine the interactions taking place within cortical and subcortical regions that integrate sensory and cognitivie information to produce a quantifiable motor event.

Selected Publications

Hasegawa RP, Hasegawa YT, Segraves MA (2009) Neural mind reading of multi-dimensional decisions by monkey mid-brain activity. Neural Netw 22:1247-1256.  

Ratcliff R, Hasegawa YT, Hasegawa RP, Smith P, Segraves MA (2007) A dual diffusion model for single cell recording data from the superior colliculus in a brightness discrimination task. Journal of  Neurophysiology 97:1756-1774.

Hasegawa RP, Hasegawa YT, Segraves MA (2006) Single trial-based prediction of a go/no-go decision in monkey superior colliculus. Neural Networks 19:1223-1232.

Farrell S, Ratcliff R, Cherian A, Segraves M (2006) Modeling unidimensional categorization in monkeys. Learning and Behavior 34:86-101.

Campos, M., A. Cherian, and M. A. Segraves. (2006) Effects of eye position upon activity of neurons in macaque superior colliculus. Journal of Neurophysiology 95: 505-526.

Helminski, J. O., and M. A. Segraves (2003). Macaque frontal eye field input to saccade-related neurons in the superior colliculus. Journal of Neurophysiology, 90: 1046-62.

Dias, E. C., and M. A. Segraves (1999) Muscimol-induced inactivation of monkey frontal eye field: effects on visually and memory-guided saccades. Journal of Neurophysiology, 81: 2191-2214.

Burman, D. D., and M. A. Segraves (1994) Primate frontal eye field activity during natural scanning eye movements. Journal of Neurophysiology 71: 1266-1271.

View all publications by Mark Segraveslisted in the National Library of Medicine (PubMed).