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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, [email protected]
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 (0.1�0.2�
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,
[email protected] to protest the inhumane use of animals in this
experiment. We would also love to know about your efforts with this
cause:
[email protected]
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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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