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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
Dartmouth College, Hanover, NH
YALE E. COHEN - Primate Testing - 2005
Grant Number: 1R01DC007172-01A1
Project Title: Auditory response properties of the prefrontal
cortex
PI Information: PROFESSOR YALE E. COHEN,
yec@dartmouth.edu
Abstract: DESCRIPTION (provided by applicant): Communication is
one of the fundamental components of human and non-human animal
behavior. The ventrolateral prefrontal cortex (vPFC) in rhesus monkeys
has recently been identified as a cortical area that plays an important
role in auditory-object and vocalization processing. This grant proposal
tests the response properties of vPFC neurons in order to determine its
role in auditory-object processing. In Aim #1, we construct the
spectrotemporal receptive field (STRF) of vPFC neurons to determine how
the vPFC codes the features of ensembles of vocalizations and ripple
noise (an artificial stimulus with properties similar to vocalizations).
We test two alternative hypotheses. First, if the vPFC is involved in
low-level feature extraction, as measured by our STRF model, we
hypothesize that (1) a significant proportion of vPFC neurons have
significant STRFs and that (2) the STRFs are accurate predictors of a
neuron's response to an auditory stimulus. The second, alternative
hypothesis is that if the vPFC is involved in computations related to
higher-order mechanisms beyond feature extraction, such as
auditory-object processing, we hypothesize that a significant proportion
of vPFC neurons do not have significant or predictive STRFs. In Aim #2,
we test the selectivity of vPFC neurons for the spatial and non-spatial
attributes of an auditory stimulus. Since the vPFC is thought to be part
of a pathway involved in auditory-object processing, we hypothesize that
vPFC neurons should be modulated preferentially by the non-spatial
attributes of an auditory stimulus. We hypothesize that the
ventrolateral prefrontal cortex are more selective for the non-spatial
attributes of an auditory stimulus but only when monkeys attend
selectively to these attributes. To test this hypothesis, we compare the
selectivity of vPFC neurons to auditory stimuli when monkeys attend to
changes in the spatial or non-spatial attributes of an auditory stimulus
and (2) do not attend overtly to either of these attributes. In Aim #3,
we test whether vPFC neurons respond to auditory and visual
communication signals that convey similar information. We hypothesize
that vPFC neurons will respond preferentially to stimuli that transmit
complementary information. To test this hypothesis, vPFC activity is
obtained while species-specific vocalizations and the visual images of
the facial expressions that typically accompany or do not accompany the
production of these vocalizations are presented.
Thesaurus Terms:
auditory feedback, auditory stimulus, neural information processing,
neuron, prefrontal lobe /cortex, visual stimulus
neurophysiology, visual feedback, vocalization
Macaca mulatta, behavior test, computational biology, electrode
Institution: DARTMOUTH COLLEGE
Office of Sponsored Projects
HANOVER, NH 03755
Fiscal Year: 2005
Department: PSYCHOLOGICAL & BRAIN SCIS
Project Start: 01-JUL-2005
Project End: 30-JUN-2010
ICD: NATIONAL INSTITUTE ON DEAFNESS AND OTHER COMMUNICATION
DISORDERS
IRG: COG
Selectivity for the Spatial and Nonspatial Attributes
of Auditory Stimuli in the Ventrolateral Prefrontal Cortex
Yale E. Cohen,1,2
Brian E. Russ,1
Gordon W. Gifford, III,1
Ruwan Kiringoda,1
and Katherine A. MacLean1
1Department
of Psychological and Brain Sciences and 2Center
for Cognitive Neuroscience, Dartmouth College, Hanover, New Hampshire
03755
Subjects
Two female rhesus monkeys (Macaca mulatta) were used in these
experiments. Both monkeys (weighing between 8.0 and 9.0 kg) were trained
on both of the tasks described in this study. All surgical, recording,
and training sessions were in accordance with the National Institutes of
Health Guide for the Care and Use of Laboratory Animals and were
approved by the Dartmouth Institutional Animal Care and Use Committee.
Surgical procedures
Surgical procedures were conducted under aseptic, sterile conditions
using general anesthesia (isoflurane). These procedures were performed
in a dedicated surgical suite operated by the Animal Resource Center at
Dartmouth College.
In the first procedure, titanium bone screws were implanted in the
skull, and a methyl methacrylate implant was constructed. A
Teflon-insulated, 50 gauge, stainless-steel wire coil was also implanted
between the conjunctiva and the sclera; the wire coil allowed us to
monitor the monkey's eye position (Judge et al., 1980 ). Finally, a
head-positioning cylinder (FHC-S2; Crist Instruments, Hagerstown, MD)
was embedded in the implant. This cylinder connected to a primate chair
and stabilized the monkey's head during behavioral training and
recording sessions.
After the monkeys learned the behavioral tasks (see below), a craniotomy
was performed, and a recording cylinder (ICO-J20; Crist Instruments) was
implanted. This surgical procedure provided chronic access to the vPFC
for neurophysiological recordings.
Experimental setup
Behavioral training and recording sessions were conducted in a darkened
room with sound-attenuating walls. The walls and floor of the room were
covered with anechoic foam insulation (Sonomatt; Auralex, Indianapolis,
IN). When inside the room, the monkeys were seated in the primate chair
and placed in front of a stimulus array; because the room was darkened,
the speakers producing the auditory stimuli were not visible to the
monkeys. The primate chair was placed in the center of a 1.2 m diameter,
two-dimensional, magnetic coil (CNC Engineering, Seattle, WA) that was
part of the eye position-monitoring system (Judge et al., 1980 ). Eye
position was sampled with an analog-to-digital converter (PXI-6052E;
National Instruments, Austin, TX) at a rate of 1.0 kHz. The monkeys were
monitored during all sessions with an infrared camera |
Please email: YALE E. COHEN,
yec@dartmouth.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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