Harvard Medical School, Boston, MA

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Stop Animal Exploitation NOW!
S. A. E. N.
"Exposing the truth to wipe out animal experimentation"

Government Grants Promoting Cruelty to Animals

Harvard Medical School, Boston, MA

JOHN H.R. MAUNSELL - Primate Testing - 2006

Grant Number: 5R01EY005911-22
Project Title: Visual Processing in Cerebral Cortex
PI Information: INVESTIGATOR & PROFESSOR OF NEUROSCIENCE JOHN HR. MAUNSELL, maunsell@hms.harvard.edu 

Abstract: DESCRIPTION (provided by applicant):
Attention to particular stimuli greatly improves performance that depends on those stimuli, while degrading performance on other stimuli. Neurophysiological studies have shown that attention changes the responses of neurons in visual cerebral cortex, but many questions remain about the neuronal mechanisms through which attention alters behavior. The proposed experiments will address two specific questions about how spatial attention affects visual processing in the visual cortex of monkeys. The first specific aim will examine how attention affects the responses of individual neurons in visual cortex. Many studies have shown that attending to a stimulus enhances the responses of neurons that represent that stimulus, but few have examined the form of this enhancement. Measurement of the effects of attention on responses to stimuli of different orientations and different contrasts have led to different views about whether attention acts by uniformly increasing the strength of neuronal responses to all stimuli. Experiments of the first specific aim will resolve this discrepancy by examining interactions among attention, orientation and contrast in determining the responses of individual neurons. Additionally, they will examine about how attention affects the timing of visual responses. The second specific aim will examine how attention affects the relationship between neuronal responses and behavior. It has been observed that the ability of individual neurons to discriminate stimuli can approach or match the performance of the subject, suggesting a close link between neuronal and behavioral performance. Recent results show that attention alters this link for some neurons, but leave open the possibility that a close relationship between neuronal and behavioral performance persists across attentional states for those neurons that are best suited for current task. The second specific aim will test this possibility by examining how attention affects the relationship between neuronal and behavioral performance for neurons during the performance of different visual tasks. The results from these experiments will greatly extend our understanding of how attention changes visual representations in cerebral cortex and improves behavioral performance, and will provide new insight about how individual neurons contribute to visual behaviors.

Thesaurus Terms:
attention, neural information processing, neuropsychology, performance, visual cortex
action potential, cue, eye movement, neurophysiology, operant conditioning, visual stimulus
Macaca mulatta, behavior test, behavioral /social science research tag

Institution: HARVARD UNIVERSITY (MEDICAL SCHOOL)
MEDICAL SCHOOL CAMPUS
BOSTON, MA 02115
Fiscal Year: 2006
Department: NEUROBIOLOGY
Project Start: 01-SEP-1986
Project End: 31-AUG-2008
ICD: NATIONAL EYE INSTITUTE
IRG: VISB

J Neurophysiol 96: 40-54, 2006

Effects of Spatial Attention on Contrast Response Functions in Macaque Area V4
 
Tori Williford and John H. R. Maunsell

Department of Neuroscience, Howard Hughes Medical Institute and Baylor College of Medicine, Houston, Texas

Submitted 14 November 2005; accepted in final form 19 April 2006

Behavioral task
The animal protocols used in this study were approved by the Baylor College of Medicine Institutional Animal Care and Use Committee. Two male monkeys (Macaca mulatta, 8 and 9 kg) served as subjects. Each was implanted with a scleral search coil and a head post under general anesthesia. After recovery, the animal was trained to do an orientation-change detection task (Fig. 2). On each trial, the animal maintained fixation (within 1) on a small central spot (0.10.2 diameter) while series of Gabor stimuli were flashed on either side. On each trial, most of the Gabors had the same orientation. The animal's task was to detect when a Gabor with a different orientation (the target) appeared on the cued side and respond by making a saccade to the target's location within 500 ms of its appearance. The animal received a juice reward for correctly completed trials. 

Please email: JOHN HR. MAUNSELL, maunsell@hms.harvard.edu to protest the inhumane use of animals in this experiment. We would also love to know about your efforts with this cause: saen@saenonline.org

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Rats, mice, birds, amphibians and other animals have been excluded from coverage by the Animal Welfare Act. Therefore research facility reports do not include these animals. As a result of this situation, a blank report, or one with few animals listed, does not mean that a facility has not performed experiments on non-reportable animals. A blank form does mean that the facility in question has not used covered animals (primates, dogs, cats, rabbits, guinea pigs, hamsters, pigs, sheep, goats, etc.). Rats and mice alone are believed to comprise over 90% of the animals used in experimentation. Therefore the majority of animals used at research facilities are not even counted.

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