Perceptual and Motor Skills, 1977,45, 943-948. @ Perceptual and Motor Skills 1977
ELECTRODERMAL RESPONSE I N THE SQUIRREL MONKEY1 JOEL K. LEVY MAKOTO IGARASH13 JOHN C. LEDET Department o f Otorhinol~ryngologyand Communirariz~eScicnces Baylor College of Mediiint? MILLARD F. RESCHKE4 NASA-Johnson Space Center
Summary.-An effort to find evidence of electrodermal response in the squirrel monkey (Saimiri sriureus), as found in man, some infra-human genera of Simiae, and some lower mammals and amphibians, failed to locate an example. Given anatomical considerations, the availability of this response in Sairniri was suspected. In this study, using the skin conductance (constant voltage) method, monophasic electrodermal response as a result of novel or startle stimuli presentation was detected and a range of skin conductance level for test cases was determined.
Some subhuman species have been found to exhibit electrodermal activity, thus making these animals useful as models when this non-invasive measure of autonomic nervous system activation would be appropriate. Such studies have included those of stress, the action of psychopharmacologica1 agents, and physiological assessment of stimulus perception. Landis and DeWick (1929) have cited the response in cats, dogs, horses, toads and monkeys, and Wang (1957-58) has also cited research on the phenomenon utilizing animals. Recently the response has been detected in the rat (Vernet, 1970) and as a means of studying psychdeptic drug action in the mouse (Marcy & Quermonne, 1974). The availability of the electrodermal response as a parameter in some species of monkeys has allowed for expansion of the areas of primate research to include autonomic nervous system monitoring experimentation of the type currently involving humans, with the ability for diverse types of manipulations. Electrodermal response of the usual conductance or resistance type has been observed in rhesus monkeys ( M a c ~ c . r trzlc1'rtt.r) (Bagshaw. Kimble, & Pribram, 1965; Downer & Thompson, 1972; Grueninger, Kimble, Grueninger, & Levine, 1965; Kimble, Bagshaw, & Pribram, 1965), baboons ( P ~ p i opapio j (Downer & Thompson, 1972) and infant chimpanzees ( P d n troglodytes) (Berkson, 1963). Also, the electrophysiological evoked skin potential response T h i s study was partly supported by National Aeronautics and Space Administration Contract NAS9-14546 and National Institutes of Health Grant NS-10940. A portion of this study was presented at the annual meeting of the Associat~on for Research In Otolaryn~oloEyI; October, 1976. %epartment of Psychology, Rice Universiry, Houston, Texas 77001 (Advisor: Dr. W. C. ?well). Request reprints from: Dr. M. Igarashi, Department of Otorhinolaryngology and Communicative Sc~ences,Baylor College of Medicine, Houston, Texas 77030. 'Neurophys~ology, Space Research and Operations Division, NASA-Johnson Space Center, Houston, Texas 77058.
'
944
J. K. LEVY, ET AL.
was found in the rhesus monkey, and it was concluded that these potentials correspond to the effect of presentation of psychological stimuli to the primate subject (Yamazaki, Tajimi, Okuda, & Niimi, 1972). The squirrel monkey (Saimiri scj:jrerrs) is a widely used primate model, attractive due to its size, cost, and comparable physiological systems (Beischer & Furry, 1964; Hanson, 1968; Herd, Morse, Kelleher, & Jones, 1968; Igarashi, McLeod, & Graybiel, 1966; Igarashi, Graybiel, & Deane, 1968; Malinow, Maruffo, & Perley, 1966; Meek, Graybiel, Beischer, & Riopelle, 1962; Middleton, Clarkson, Lofland, & Prichard. 1964). Three studies (Igarashi, et dl., 1966; Igarashi, et al., 1968; Meek, et al., 1963) concerned the production of motion sickness-like syndrome in Saimiri, the observations based on overt, visible responses, such as emesis. Further application of this primate model to investigation of motion sickness-like responses was intended; however, a more direct, electrophysiologically monitorable, yet non-invasive technique was needed. The autonomic nervous system parameter of the electrodermal response was proposed as a measure. A concerted search for the existence of this activity in Sainriri did not yield a study in which this measure had been used. Downer and Thompson (1972) reported slow resistance changes, yet none of the typical smooth transients characterized as electrodermal response (EDR) or galvanic skin response (GSR). Insofar as anatomical considerations apply, Machida, Perkins, and Hu (1967) found eccrine glands on the palmar and plantar surfaces with histochemical confirmation of acetylcholinesterase about the secretory innervation, suggesting a mechanism at least analogous to the sympathetic sweat system in humans. Sympathetic autonomic morphology on a gross lwel has been reported (Prejzner-Morawska, 1965), but no conclusions were drawn as to functional implication. Johnson and Elizondo ( 1974) discussed eccrine distribution in New World primates with an acknowledgment of limited thermoregulatory capability and a proposed tactile sensitivity enhancement. As electrodermal response is thought to arise from the activity of the eccrine system (Edelberg, 1967; Venables & Martin, 1967), monitoring of electrodermal response to novel, startle, or haptic stimuli was attempted through use of the direct skin conductance method in Saimiri.
METHOD Subjects Subjects were ten randomly selected, healthy, female, wild-born squirrel monkeys (Sairniri scizrreus), 1% to 3 yr. old on entry to our colony. They were obtained from importers who gathered the animals in Bolivia. They weighed on average from 500 to 700 gm and were maintained on an ad lib. eating and drinking schedule including commercially produced primate biscuits and supplementary fresh fruit. Housing quarters' temperature was regulated
ELECTRODERMAL RESPONSE IN THE SQUIRREL MONKEY
945
to approximately 26' C with supplementary humidification. A daily 12-hr. light-dark cycle of illumination was automatically imposed. The squirrel monkeys received antihelminthic treatment on arrival and also were periodically tuberculin tested.
Apparatus During the test session, the subject was placed in a laboratory-built restraining chair, with a bite bar and occiput braces to immobilize the head. Velcro straps (self-adhering cloth fasteners) were fastened around the arms and trunk to secure them, and leg braces immobilized the lower limbs. A laboratory-built electrode holder containing two chlorided Beckman 807-214410 pure silver cup electrodes (each filled with Grass Type EC2 electrode cream) was applied to the subject's right plantar surface. The dimensions of the Plexiglas base upon which the cup electrodes were dental cemented were 7.0 cm X 4.0 cm X 0.5 un. Interelectrode distance was 2.5 cm. The electrodes were 1.0 cm in diameter each (approximately 0.79 c m v l a t surface area). Output of the electrodes was fed into a Beckman Type 9844 skin conductance coupler in a Beckman Type R dynograph. In preparation for recording the animal was manually fixed into a laboratory-built restraining chair. The animal's lower limbs were immobilized by taping them to angle leg splints which were affixed to the base of the chair. The animal's plantar surfaces were washed with warm water and antiseptic soap, briskly toweled dry, and rubbed with a gauze saturated with ether. The electrode assembly was taped to the foot and then was taped to the leg brace to minimize any movement artifacts which would be exhibited as short duration transients compared to the smoother, longer duration GSR. The coupling to the animal's foot was not so tight as to compromise circulation. Recordings were routinely continued for 20 min. This time period, according to various sources on this parameter, is necessary not only for the stabilization of the electrodes but also to allow the subject to calm down after the stressful process of being physically restrained. From our experiences with restraining primates for nystagrnus testing, the 20-min. period was short enough to expect that fatigue from restraint would not be so great as to influence the results. Following this period subjects were stimulated by tapping of the leg, tail, or head, or by loud sounds such as tapping on the table, or by placing a light proof cap over the subject's head to eliminate its vision. Subjects were tested no more than once per week. Room temperature was maintained at 22' to 25' C and tests were conducted in areas shielded from direct air currents associated with the laboratory air conditioning system to avoid evaporative cooling effects.
J. K. LEVY, ET AL.
946
Data, from the pen records of the physiograph system, were analyzed qualitatively by visual inspection for changes in conductance level following the onset of stimuli and quantitatively by getting a value of conductance in pmhos from the calibrated pen position to get a skin conductance level.
RESULTSAND DISCUSSION Findings from the pen records of skin conductance measure indicated a definite monophasic, psychogalvanic or electrodermal response to novel or startle stimuli. These responses seemed to resemble human electrodermal response in wave form and latency to onset, approximately 1-2 sec. Fig. 1 illustrates representative traces of the responses to such novel stimuli. Additionally, a stabilized, tonic skin conductance average for squirrel monkey subjects from 44 test sessions was determined at 5.02 pmhos with a standard error of the mean of 0.334. 18444
$CREASE IN CONDUCTANCE
tv
tV
8
tw
I-
B
C
t A
-
H
1 sec
I05lrmto
A : Subject struggling
: Auditory stimulus : Toclile stimulus D : Vision blocking cop added, removed
8
C
FIG.1. Representative pen records of electrodermal response to novel or startle stimuli
Qualitatively the findings from this New World primate model were somewhat similar to those previously found in studies with humans, except that the values were lower, both for tonic level and the response. The presence of the traditional type of "galvanic skin response" was found in the squirrel monkey. The negative findings previously reported might have reflected differences in methodology. The use of skin conductance as a parameter of sweating activity was selected on the basis of its parallel relation to sudomotor response. Darrow (1934, 1964) pointed out the linear relationship of conductance measure, the reciprocal of the resistance value to sweat as measured by other means. The measure i s convenient in that it allows standardization of response value over a wide range of skin resistance levels (Lykken & Venables, 1971). This method
ELECTRODERMAL RESPONSE IN THE SQUIRREL
MONKEY
947
also permits the direct recording of the response in pmhos, which is the unit of measure commonly reported. . Given the present findings indicating the presence of electrodermal response in the squirrel monkey, this primate model seems to have an added dimension, a parameter useful in psychophysiological study to supplement the other physiological and behavioral capabilities that have typified this species' contribution to previous research efforts. REFERENCES
BAGSHAW, M. H., KIMBLE, D. P., & PRIBRAM, K. H. The GSR of monkeys during orienting and habituation and after ablation of the amygdala, hippocampus and inferotemporal cortex. Neuropsychologia, 1965, 3, 111-120. BEISCHER, D. E., & FURRY, D. E. Saimiri sciurrus as an experimental animal. Anatomical Record, 1964, 148, 615-624. BERKSON, G. Stimuli affectin vocalization and basal skin resistance of neonate chirnpanzees. Perceptual a n f Motor Skills, 1963, 17, 871-874. DARROW, C. W . The significance of the galvanic skin reflex in the light of its relation to quantitative measurements of perspiration. Psychological Bulletin, 1934, 31, 697-698. DARROW, C. W. The rationale for treating the change in galvanic skin response as a change in conductance. Psychophysiology, 1964, 1, 31-38. DOWNER, T. B., & THOMPSON, W. B. Test of the law of initial values in four species of primates. Psychological Reports, 1972, 30, 191-195. EDELBERG, R. Electrical properties of the skin. In C. C. Brown (Ed.), Methods in psychophysiology. Baltimore: Williams & Wilkins, 1967. Pp. 1-53. GRUENINGER, W. E., KIMBLE, D. P., GRUENINGER, J., & LEVINE, S. GSR and corticosteroid response in monkeys with frontal ablations. Neuropsychologia, 1965, 3, 205-216. HANSON,H. M. Use of the squirrel monkey in pharmacology. In L. A. Rosenblum & R. W. Cooper (Eds.), T h e squirrel monkey. New York: Academic Press, 1968. Pp. 365-392. HERD,J. A., MORSE,W. H., KELLEHER, R. T., & JONES,L. G. Arterial blodd pressure in the squirrel monkey during behavioral experiments. Federation Proceedkgs, 1968, 27, 743. IGARASHI, M., GRAYBIEL, A., & DEANE,F. R. Screening of squirrel monkeys (Saimiri sciweus) for vestibular function studies. NASA-Navy Joint Report, NAMI1042, Pensacola, Fla.: Naval Aerospace Medical Institute, 1968. IGARASHI, M., MCLEOD,M. E., & GRAYBIEL, A. Clinical pathological correlations in squirrel monkeys after suppression of semicircular canal function by streptomycin sulfate. Achz Otolaryngologica, Supplcmentum, 1966, 21(1, 1.28. JOHNSON, G. S., & ELIZONDO, R. S. Eccrine sweat gland in Maraca mulatta: histochemistry, and distribution. journal o f Applied Physiology, 1974, !,hi?t.ls"%: KIMBLE, D. P., BAGSHAW, M. H., & PRIBRAM, K. H. The GSR in monkeys d u r ~ n gorienting and habituation after selective partial ablations of the cingulate and frontal cortex. Neuropsychologia, 1965, 3, 121-128. LANDIS, C., & DEWICK,H. N. The electrical phenomena of the skin (psychogalvanic reflex). Psychologica1 Bulletin, 1939, 26, 64-119. LYKKEN, D. T., & VENABLES, P. H. Direct measurement of skin conductance: a proposal , 8, 656-672. for standardization. P s y c h ~ p h y s i o l o ~ y1971, WCHIDA, H , PERKINS, E., & Hu, F. The skin of primates: XXXV. The skin of the squirrel monkey (Saimiri sciureus) . American Journal of Physical Anthropology, N e w Series, 1967, 26, 45-54. MALINOW, M. R., MARUFPO, G. A,, & PERLEY,A. M. Experimental atherosclerosis in squirrel monkeys (Saimiri sciusea) . ]otrrnal o f Pathology and Bacteriology, 1966: 92, 491-510.
948
J. K. LEVY, ET AL.
MARCY,R., & QUERMONNE, M. A. An improved method for studying the psychogalvanic reaction in mice and its inhibition by psycholeptic d r u s, comparison with the effects of other pharmacological agents. Psychopharmacokgra, 1974, 34, 335-349. MEEK, J. C., GRAYBIEL,A., BEISCHER,D. E., & RIOPELLE,A. J. Observations of canal sickness and adaptation in chimpanzees and squirrel monkeys in a "slow rotation room." Aerospace Medicine, 1962, 33, 571-578. MIDDLETON,C. C., CLARKSON,T. B., LOFLAND,H. G., & PRICHARD,R. W. Atherosclerosis in the squirrel monkey. Archiz~es of Pathology, 1964, 78, 16-23. PREJZNER-MORAWSKA, A. Gan lia of the lumbar portion of the sympathetic uunk in ~ 1965, 24, 401-406. platyrrhine monkeys. F O Morphologica, VENABLES,P. H., & MARTIN, I. (Eds.) A manual o f p s y ~ h o p h ~ ~ i o l o g i cmethods. al Amsterdam: North-Holland, 1967. Pp. 53-102. VERNETET MAURY, E. R6ponses 6lectrodermale.s chez le rat aux stimulations visuelles, auditives, et olfactives [Electrodermal responses in the rat to visual, audito and olfactory stimuli]. Journd d e Phyriologie, Supplemenrum 1 , 1970, 225-?2?. WANG,G. H. The alvanic skin reflex, a review of old and recent works from a physiologic point of view. Ammican Jorrrnal of Physical Medicine, Part I . 1957, 36, 295-320; Part 11. 1958, 37, 35-57. YAMAZAKT, K.,-TAJIMI, T.,OK&A, K., & NIIMI, Y. PS chophysiological significance of skin potential activity in monkeys. ~ s y c h o ~ h y s i o l o1972, ~ ~ , 9, 620-623.
Accepted September 9,1977.
ELECTRODERMAL RESPONSE I N THE SQUIRREL MONKEY1 JOEL K. LEVY MAKOTO IGARASH13 JOHN C. LEDET Department o f Otorhinol~ryngologyand Communirariz~eScicnces Baylor College of Mediiint? MILLARD F. RESCHKE4 NASA-Johnson Space Center
Summary.-An effort to find evidence of electrodermal response in the squirrel monkey (Saimiri sriureus), as found in man, some infra-human genera of Simiae, and some lower mammals and amphibians, failed to locate an example. Given anatomical considerations, the availability of this response in Sairniri was suspected. In this study, using the skin conductance (constant voltage) method, monophasic electrodermal response as a result of novel or startle stimuli presentation was detected and a range of skin conductance level for test cases was determined.
Some subhuman species have been found to exhibit electrodermal activity, thus making these animals useful as models when this non-invasive measure of autonomic nervous system activation would be appropriate. Such studies have included those of stress, the action of psychopharmacologica1 agents, and physiological assessment of stimulus perception. Landis and DeWick (1929) have cited the response in cats, dogs, horses, toads and monkeys, and Wang (1957-58) has also cited research on the phenomenon utilizing animals. Recently the response has been detected in the rat (Vernet, 1970) and as a means of studying psychdeptic drug action in the mouse (Marcy & Quermonne, 1974). The availability of the electrodermal response as a parameter in some species of monkeys has allowed for expansion of the areas of primate research to include autonomic nervous system monitoring experimentation of the type currently involving humans, with the ability for diverse types of manipulations. Electrodermal response of the usual conductance or resistance type has been observed in rhesus monkeys ( M a c ~ c . r trzlc1'rtt.r) (Bagshaw. Kimble, & Pribram, 1965; Downer & Thompson, 1972; Grueninger, Kimble, Grueninger, & Levine, 1965; Kimble, Bagshaw, & Pribram, 1965), baboons ( P ~ p i opapio j (Downer & Thompson, 1972) and infant chimpanzees ( P d n troglodytes) (Berkson, 1963). Also, the electrophysiological evoked skin potential response T h i s study was partly supported by National Aeronautics and Space Administration Contract NAS9-14546 and National Institutes of Health Grant NS-10940. A portion of this study was presented at the annual meeting of the Associat~on for Research In Otolaryn~oloEyI; October, 1976. %epartment of Psychology, Rice Universiry, Houston, Texas 77001 (Advisor: Dr. W. C. ?well). Request reprints from: Dr. M. Igarashi, Department of Otorhinolaryngology and Communicative Sc~ences,Baylor College of Medicine, Houston, Texas 77030. 'Neurophys~ology, Space Research and Operations Division, NASA-Johnson Space Center, Houston, Texas 77058.
'
944
J. K. LEVY, ET AL.
was found in the rhesus monkey, and it was concluded that these potentials correspond to the effect of presentation of psychological stimuli to the primate subject (Yamazaki, Tajimi, Okuda, & Niimi, 1972). The squirrel monkey (Saimiri scj:jrerrs) is a widely used primate model, attractive due to its size, cost, and comparable physiological systems (Beischer & Furry, 1964; Hanson, 1968; Herd, Morse, Kelleher, & Jones, 1968; Igarashi, McLeod, & Graybiel, 1966; Igarashi, Graybiel, & Deane, 1968; Malinow, Maruffo, & Perley, 1966; Meek, Graybiel, Beischer, & Riopelle, 1962; Middleton, Clarkson, Lofland, & Prichard. 1964). Three studies (Igarashi, et dl., 1966; Igarashi, et al., 1968; Meek, et al., 1963) concerned the production of motion sickness-like syndrome in Saimiri, the observations based on overt, visible responses, such as emesis. Further application of this primate model to investigation of motion sickness-like responses was intended; however, a more direct, electrophysiologically monitorable, yet non-invasive technique was needed. The autonomic nervous system parameter of the electrodermal response was proposed as a measure. A concerted search for the existence of this activity in Sainriri did not yield a study in which this measure had been used. Downer and Thompson (1972) reported slow resistance changes, yet none of the typical smooth transients characterized as electrodermal response (EDR) or galvanic skin response (GSR). Insofar as anatomical considerations apply, Machida, Perkins, and Hu (1967) found eccrine glands on the palmar and plantar surfaces with histochemical confirmation of acetylcholinesterase about the secretory innervation, suggesting a mechanism at least analogous to the sympathetic sweat system in humans. Sympathetic autonomic morphology on a gross lwel has been reported (Prejzner-Morawska, 1965), but no conclusions were drawn as to functional implication. Johnson and Elizondo ( 1974) discussed eccrine distribution in New World primates with an acknowledgment of limited thermoregulatory capability and a proposed tactile sensitivity enhancement. As electrodermal response is thought to arise from the activity of the eccrine system (Edelberg, 1967; Venables & Martin, 1967), monitoring of electrodermal response to novel, startle, or haptic stimuli was attempted through use of the direct skin conductance method in Saimiri.
METHOD Subjects Subjects were ten randomly selected, healthy, female, wild-born squirrel monkeys (Sairniri scizrreus), 1% to 3 yr. old on entry to our colony. They were obtained from importers who gathered the animals in Bolivia. They weighed on average from 500 to 700 gm and were maintained on an ad lib. eating and drinking schedule including commercially produced primate biscuits and supplementary fresh fruit. Housing quarters' temperature was regulated
ELECTRODERMAL RESPONSE IN THE SQUIRREL MONKEY
945
to approximately 26' C with supplementary humidification. A daily 12-hr. light-dark cycle of illumination was automatically imposed. The squirrel monkeys received antihelminthic treatment on arrival and also were periodically tuberculin tested.
Apparatus During the test session, the subject was placed in a laboratory-built restraining chair, with a bite bar and occiput braces to immobilize the head. Velcro straps (self-adhering cloth fasteners) were fastened around the arms and trunk to secure them, and leg braces immobilized the lower limbs. A laboratory-built electrode holder containing two chlorided Beckman 807-214410 pure silver cup electrodes (each filled with Grass Type EC2 electrode cream) was applied to the subject's right plantar surface. The dimensions of the Plexiglas base upon which the cup electrodes were dental cemented were 7.0 cm X 4.0 cm X 0.5 un. Interelectrode distance was 2.5 cm. The electrodes were 1.0 cm in diameter each (approximately 0.79 c m v l a t surface area). Output of the electrodes was fed into a Beckman Type 9844 skin conductance coupler in a Beckman Type R dynograph. In preparation for recording the animal was manually fixed into a laboratory-built restraining chair. The animal's lower limbs were immobilized by taping them to angle leg splints which were affixed to the base of the chair. The animal's plantar surfaces were washed with warm water and antiseptic soap, briskly toweled dry, and rubbed with a gauze saturated with ether. The electrode assembly was taped to the foot and then was taped to the leg brace to minimize any movement artifacts which would be exhibited as short duration transients compared to the smoother, longer duration GSR. The coupling to the animal's foot was not so tight as to compromise circulation. Recordings were routinely continued for 20 min. This time period, according to various sources on this parameter, is necessary not only for the stabilization of the electrodes but also to allow the subject to calm down after the stressful process of being physically restrained. From our experiences with restraining primates for nystagrnus testing, the 20-min. period was short enough to expect that fatigue from restraint would not be so great as to influence the results. Following this period subjects were stimulated by tapping of the leg, tail, or head, or by loud sounds such as tapping on the table, or by placing a light proof cap over the subject's head to eliminate its vision. Subjects were tested no more than once per week. Room temperature was maintained at 22' to 25' C and tests were conducted in areas shielded from direct air currents associated with the laboratory air conditioning system to avoid evaporative cooling effects.
J. K. LEVY, ET AL.
946
Data, from the pen records of the physiograph system, were analyzed qualitatively by visual inspection for changes in conductance level following the onset of stimuli and quantitatively by getting a value of conductance in pmhos from the calibrated pen position to get a skin conductance level.
RESULTSAND DISCUSSION Findings from the pen records of skin conductance measure indicated a definite monophasic, psychogalvanic or electrodermal response to novel or startle stimuli. These responses seemed to resemble human electrodermal response in wave form and latency to onset, approximately 1-2 sec. Fig. 1 illustrates representative traces of the responses to such novel stimuli. Additionally, a stabilized, tonic skin conductance average for squirrel monkey subjects from 44 test sessions was determined at 5.02 pmhos with a standard error of the mean of 0.334. 18444
$CREASE IN CONDUCTANCE
tv
tV
8
tw
I-
B
C
t A
-
H
1 sec
I05lrmto
A : Subject struggling
: Auditory stimulus : Toclile stimulus D : Vision blocking cop added, removed
8
C
FIG.1. Representative pen records of electrodermal response to novel or startle stimuli
Qualitatively the findings from this New World primate model were somewhat similar to those previously found in studies with humans, except that the values were lower, both for tonic level and the response. The presence of the traditional type of "galvanic skin response" was found in the squirrel monkey. The negative findings previously reported might have reflected differences in methodology. The use of skin conductance as a parameter of sweating activity was selected on the basis of its parallel relation to sudomotor response. Darrow (1934, 1964) pointed out the linear relationship of conductance measure, the reciprocal of the resistance value to sweat as measured by other means. The measure i s convenient in that it allows standardization of response value over a wide range of skin resistance levels (Lykken & Venables, 1971). This method
ELECTRODERMAL RESPONSE IN THE SQUIRREL
MONKEY
947
also permits the direct recording of the response in pmhos, which is the unit of measure commonly reported. . Given the present findings indicating the presence of electrodermal response in the squirrel monkey, this primate model seems to have an added dimension, a parameter useful in psychophysiological study to supplement the other physiological and behavioral capabilities that have typified this species' contribution to previous research efforts. REFERENCES
BAGSHAW, M. H., KIMBLE, D. P., & PRIBRAM, K. H. The GSR of monkeys during orienting and habituation and after ablation of the amygdala, hippocampus and inferotemporal cortex. Neuropsychologia, 1965, 3, 111-120. BEISCHER, D. E., & FURRY, D. E. Saimiri sciurrus as an experimental animal. Anatomical Record, 1964, 148, 615-624. BERKSON, G. Stimuli affectin vocalization and basal skin resistance of neonate chirnpanzees. Perceptual a n f Motor Skills, 1963, 17, 871-874. DARROW, C. W . The significance of the galvanic skin reflex in the light of its relation to quantitative measurements of perspiration. Psychological Bulletin, 1934, 31, 697-698. DARROW, C. W. The rationale for treating the change in galvanic skin response as a change in conductance. Psychophysiology, 1964, 1, 31-38. DOWNER, T. B., & THOMPSON, W. B. Test of the law of initial values in four species of primates. Psychological Reports, 1972, 30, 191-195. EDELBERG, R. Electrical properties of the skin. In C. C. Brown (Ed.), Methods in psychophysiology. Baltimore: Williams & Wilkins, 1967. Pp. 1-53. GRUENINGER, W. E., KIMBLE, D. P., GRUENINGER, J., & LEVINE, S. GSR and corticosteroid response in monkeys with frontal ablations. Neuropsychologia, 1965, 3, 205-216. HANSON,H. M. Use of the squirrel monkey in pharmacology. In L. A. Rosenblum & R. W. Cooper (Eds.), T h e squirrel monkey. New York: Academic Press, 1968. Pp. 365-392. HERD,J. A., MORSE,W. H., KELLEHER, R. T., & JONES,L. G. Arterial blodd pressure in the squirrel monkey during behavioral experiments. Federation Proceedkgs, 1968, 27, 743. IGARASHI, M., GRAYBIEL, A., & DEANE,F. R. Screening of squirrel monkeys (Saimiri sciweus) for vestibular function studies. NASA-Navy Joint Report, NAMI1042, Pensacola, Fla.: Naval Aerospace Medical Institute, 1968. IGARASHI, M., MCLEOD,M. E., & GRAYBIEL, A. Clinical pathological correlations in squirrel monkeys after suppression of semicircular canal function by streptomycin sulfate. Achz Otolaryngologica, Supplcmentum, 1966, 21(1, 1.28. JOHNSON, G. S., & ELIZONDO, R. S. Eccrine sweat gland in Maraca mulatta: histochemistry, and distribution. journal o f Applied Physiology, 1974, !,hi?t.ls"%: KIMBLE, D. P., BAGSHAW, M. H., & PRIBRAM, K. H. The GSR in monkeys d u r ~ n gorienting and habituation after selective partial ablations of the cingulate and frontal cortex. Neuropsychologia, 1965, 3, 121-128. LANDIS, C., & DEWICK,H. N. The electrical phenomena of the skin (psychogalvanic reflex). Psychologica1 Bulletin, 1939, 26, 64-119. LYKKEN, D. T., & VENABLES, P. H. Direct measurement of skin conductance: a proposal , 8, 656-672. for standardization. P s y c h ~ p h y s i o l o ~ y1971, WCHIDA, H , PERKINS, E., & Hu, F. The skin of primates: XXXV. The skin of the squirrel monkey (Saimiri sciureus) . American Journal of Physical Anthropology, N e w Series, 1967, 26, 45-54. MALINOW, M. R., MARUFPO, G. A,, & PERLEY,A. M. Experimental atherosclerosis in squirrel monkeys (Saimiri sciusea) . ]otrrnal o f Pathology and Bacteriology, 1966: 92, 491-510.
948
J. K. LEVY, ET AL.
MARCY,R., & QUERMONNE, M. A. An improved method for studying the psychogalvanic reaction in mice and its inhibition by psycholeptic d r u s, comparison with the effects of other pharmacological agents. Psychopharmacokgra, 1974, 34, 335-349. MEEK, J. C., GRAYBIEL,A., BEISCHER,D. E., & RIOPELLE,A. J. Observations of canal sickness and adaptation in chimpanzees and squirrel monkeys in a "slow rotation room." Aerospace Medicine, 1962, 33, 571-578. MIDDLETON,C. C., CLARKSON,T. B., LOFLAND,H. G., & PRICHARD,R. W. Atherosclerosis in the squirrel monkey. Archiz~es of Pathology, 1964, 78, 16-23. PREJZNER-MORAWSKA, A. Gan lia of the lumbar portion of the sympathetic uunk in ~ 1965, 24, 401-406. platyrrhine monkeys. F O Morphologica, VENABLES,P. H., & MARTIN, I. (Eds.) A manual o f p s y ~ h o p h ~ ~ i o l o g i cmethods. al Amsterdam: North-Holland, 1967. Pp. 53-102. VERNETET MAURY, E. R6ponses 6lectrodermale.s chez le rat aux stimulations visuelles, auditives, et olfactives [Electrodermal responses in the rat to visual, audito and olfactory stimuli]. Journd d e Phyriologie, Supplemenrum 1 , 1970, 225-?2?. WANG,G. H. The alvanic skin reflex, a review of old and recent works from a physiologic point of view. Ammican Jorrrnal of Physical Medicine, Part I . 1957, 36, 295-320; Part 11. 1958, 37, 35-57. YAMAZAKT, K.,-TAJIMI, T.,OK&A, K., & NIIMI, Y. PS chophysiological significance of skin potential activity in monkeys. ~ s y c h o ~ h y s i o l o1972, ~ ~ , 9, 620-623.
Accepted September 9,1977.
