bluuebunny/crossref_metadata_2025 huggingface dataset:
Adult responsiveness to ultrasonic signals from gerbils of varying ages: Parity, gender, and housing effects
Authors: Kleese Deborah , Hull Elaine
Published: January 2005

Groups of adult gerbils differing by gender, parity, and presence or absence of young in the nest were exposed to taped ultrasonic distress calls of male and female pups on postnatal Days 3, 8, and 13. Frequency and time spent performing several behavioral items as well as frequency and time spent in the compartment housing the recorded tapes were assessed in the adult groups. Adult groups differed in rates and durations of certain behavioral items only during playback, with females with young in the home nest exhibiting the highest frequency of nest building in the test apparatus. However, all groups spent more time in the arm from which calls of Day‐8 pups were played. Calls of Day‐3 and Day‐13 pups did not produce significant differences in adult responsiveness. These results reveal significant characteristics of the ultrasounds for each group which parallel certain morphological and behavioral changes.
Dietary and metabolic effects on rhesus social behavior: Phenylalanine‐related dietary alterations
Authors: Chamove A. S.
Published: January 2005

Infant rhesus monkeys were (a) fed a diet high in phenylalanine or (b) fed a diet high in p‐chlorophenylalanine for the 1st 12 months of life, (c) selected from mothers fed a diet high in phenylalanine during pregnancy, (d) fed a diet low in phenylalanine, (e) maintained as controls, or (f) maintained as pair‐fed controls. Tested during the 1st year of life with familiar peers, during the 2nd year with unfamiliar stimulus animals and with a movie film, the 3 groups of phenylketonuric monkeys showed less play and other positive social behavior and more withdrawal and more aggressive behavior than did the 2 control groups. The results support learning data suggesting that phenylketonuric monkeys are more emotionally reactive.
Early social isolation of the domestic cat: Responses to separation from social and nonsocial rearing stimuli
Authors: Guyot Gary W. , Cross Henry A. , Bennett Thomas L.
Published: January 2005

The relative contributions of social‐rearing stimuli (a mother and/or a littermate) and nonsocial‐rearing stimuli (a brooder) to the formation and decline of infant kitten attachments were assessed by counting the frequency of distress cries produced by separation from the following rearing conditions: (1) mother‐littermate; (2) mother‐only; (3) brooder‐littermate; and (4) brooder‐only. Four male and 4 female kittens were reared in each condition. Each kitten was separated from its rearing condition once a week, from 2 until 5 weeks of age, and placed in open field for 15 min. The frequency of distress cries in both littermate‐reared groups did not significantly differ throughout the experiment. The frequency was consistently high until 5 weeks of age when distress cries were significantly reduced. The frequency of distress cries consistently increased in the mother‐only‐reared kittens with repeated separations, but consistently decreased in the brooder‐only‐reared kittens. The results were interpreted as being commensurate with the social conditions at the time of separation.
Ontogeny of passive avoidance: Role of task demands and development of species‐typical behaviors
Authors: Stehouwer Donald J. , Campbell Byron A.
Published: January 2005

Preweanling rats 10 to 15 days of age were given passive avoidance training in a circular chamber in which the floor comprised one shock electrode and the wall the other. All ages showed acquisition of the response, but both rate of learning and asymptotic performance increased with age. Yoked‐shock controls, adaption controls, and naive controls did not demonstrate passive avoidance on subsequent test trials, ruling out alternative interpretations based on sensitization to shock, fatigue, familiarity with the apparatus, and handling. From 10 to 15 days of age, improved performance was due in part to the transition from stereotyped shock‐elicited behavior in the younger pups to discrete withdrawal from shock in the older pups. A paradoxical deterioration of performance was observed from 20 to 25 days of age, attributable to the development of species‐typical defense reactions which were incompatible with the avoidance response. Retention of the avoidance response was found to increase from about 6 hr in the 10‐day‐old to at least 5 days in the 15‐day‐old. The data suggest that maturation of storage and/or retrieval mechanisms, rather than perceptual or experiential changes induced by development, is responsible for improved retention during ontogeny.
Child abuse: Evidence from nonhuman primates
Authors: Nadler Ronald D.
Published: January 2005

Horenstein (1977) recently examined laboratory research on infant abuse among rhesus monkeys for implications regarding the related problem in our own species. His analysis supported a psychiatric interpretation of human child abuse, for which specific measures at rehabilitation of both the parent and the child were proposed. In this paper, additional evidence regarding infant abuse in nonhuman primates is presented and implications of a social‐psychological interpretation of the problem are discussed.
Age differences in the duration of mating periods of female rhesus monkeys
Authors: Wilson Mark E. , Gordon Thomas P.
Published: January 2005

Examination of the patterns of mating behavior exhibited by 27 sexually‐mature female rhesus monkeys housed in a social group in an outdoor compound revealed that younger animals (3.5–4.5 years) exhibited significantly longer periods of sexual activity than did older animals (5.5 years and older). Observed sexual activity in all age groups was largely confined to discrete periods associated with an ovulatory cycle and typically resulted in pregnancy. Related findings suggest that differences in patterns of sexual behavior may be related to variations in estrogen secretion or sensitivity to estrogen, both of which show age‐related changes. Additionally, these findings underscore the importance of documenting behavioral and endocrine changes in reproductive function across the full life span of the mature subject.
Fertility, maternal care, and offspring behavior in mice prenatally treated with tobacco smoke
Authors: Baer Darius S. , McClearn Gerald E. , Wilson James R.
Published: January 2005

Female mice from lines selectivity bred for differences in open‐field activity were exposed to tobacco smoke during gestation. Smoke‐treated females were less likely than controls to have produced litters by 23 days after observation of a vaginal plug. Within the high‐active line, fewer pups of smoke‐treated dams survived to weaning. Regardless of treatment, fewer high‐active than low‐active offspring survived to weaning. Results of a 4‐day series of open‐field activity tests administered to offspring beginning at 28 days of age indicated that tobacco smoke administered prenatally and/or during testing depresses open‐field activity in both lines. Other activity tests administered at 50 days of age gave similar results. Tissue nicotine levels after nicotine injection tended to be higher in high‐active and control groups than in low‐active and smoke‐treated groups, respectively. Liver weight expressed as percentage of body weight was 11.9% greater in smoke‐treated animals than in controls.
Attachment in chicks: Effects of companion species on social preferences
Authors: Hindman Joanne Lucas
Published: January 2005

Social preference was assessed across 9 weeks in domestic chicks which were either living with a live companion (another chick or a guinea pig) or in isolation. Experimental chicks lived for 3‐week periods with the original companion, with an alternate companion of a different species, and again with the original companion. Control subjects lived continuously with their original companion or in isolation. Weekly preference tests initially indicated strong preference for the original companion, regardless of the biological appropriateness of the species of the companion, although controls living in isolation tended to prefer the chick. Preference waned but did not reverse for experimental chicks living with the alternate companion during the 2nd period, whereas original preference continued for controls. Returning the subjects to the original companion in the 3rd period did not reestablish the original preference.
The effects of age on the kindling phenomenon
Authors: Moshé Solomon L.
Published: January 2005

Repeated unilateral electrical stimulation of the amygdala in adult rats produces generalized seizures (kindling). New data indicate that kindling can be induced in both suckling rats between 15 and 18 days old and in rats, 34 to 72 days old. However, the expression of kindling differs in the suckling rats, but not in the 34‐day‐old rat, perhaps as a result of the immaturity of the central nervous system.
Responses of juvenile bonnet macaques to social stimuli presented through color videotapes
Authors: Plimpton Edward H. , Swartz Karyl B. , Rosenblum Leonard A.
Published: January 2005

Twelve juvenile bonnet macaques (Macaca radiata), 6 males and 6 females, were presented with color videotape recordings of 3 types of social stimuli. The stimulus animals, all unfamiliar adult conspecifics, consisted of a passive female, a passive male, and a threatening male. Subjects were observed in the presence of their mother and 1 other juvenile‐mother dyad. The juveniles showed the highest scores for contact with mother when presented with the threatening male stimulus. Similarly, subjects lipsmacked significantly more to the threatening male stimulus than to either the passive male or female. The female stimulus was approached significantly more than either the passive or threatening male. Results suggest that juvenile macaques will respond to social stimuli presented through color video recordings in a socially appropriate manner. This technique provides a new tool in the investigation of social perception in nonhuman primates.
Ontogeny of control over the acoustic startle reflex by visual prestimulation in the rat
Authors: Parisi Thomas , Ison James R.
Published: January 2005

In Experiment I, rats 13–35 days of age were presented with acoustic startle stimuli in conjunction with light flashes or noise bursts at 4–320 msee lead times. Inhibition of the startle reflex by leading noise bursts was present on Days 13–15, whereas light flashes were not effective until Days 21–23. In Experiment II, 3 intensities of noise and 3 intensities of light preceded the reflex‐eliciting stimuli on Days 16 and 35. All intensities of noise were effective on Day 16, whereas no visual stimuli were. On Day 35, all stimuli were effective. These data reveal that intrinsic visual structures and/or connections between these structures and reflex‐control mechanisms mature relatively late in the rat.
Fluoxymesterone and the development of sexual behavior in the golden hamster
Authors: Vomachka Archie J. , Clemens Lynwood G.
Published: January 2005

Male hamsters castrated at birth and female hamsters were treated on postnatal Days 2–4 with 100 μg of testosterone, 100 μg of fluoxymesterone, or the hormone vehicle. As adults, mounting behavior and lordosis were measured following exogenous hormone treatment. Although the degree of penile or clitoral virilization did not appear to differ between testosterone‐ and fluoxymesterone‐treated animals, behavioral differences occurred. Neonatal treatment with fluoxymesterone failed to “masculinize” or “defeminize” behavior; neonatal testosterone treatment induced mounting in males and females and intromission in males. These results, along with those of others, indicate that fluoxymesterone has little or no central neural effect on sexual behavior in the hamster.
Wing‐flapping develops in chickens made flightless by feather mutations
Authors: Provine Robert R.
Published: January 2005

Two lines of mutant, domestic chickens (scaleless and delayed feathering), flightless because they lack flight feathers, were used to evaluate the influence of flight‐related experience and adaptation on the development of wing‐flapping. Most testing was at 13 days because normally feathered control chicks of this age flap at adult rates and can fly. By 13 days, the wing‐flapping rates of the flightless, mutant chicks and the normally feathered and flight‐competent control chicks were similar. Therefore, normal adult rates of wing‐flapping developed in the absence of flight‐related behavioral consequences. Drop‐evoked wing‐flapping was probably initiated by vestibular mechanisms: feather‐related mechanoreceptor and visual cues were not necessary because flapping was initiated by naked, scaleless chicks which were deprived of visual input by masking their eyes or by testing in a darkened room. The possible role of feather mutations in the evolution of avian flightlessness is also considered.
Regulation of visual attention in offspring of female monkeys treated chronically with Δ9‐tetrahydrocannabinol
Authors: Golub Mari S. , Sassenrath E. N. , Chapman Loring F.
Published: January 2005

Visual attention was studied in a group of rhesus monkey infants whose mothers received daily oral treatment with low levels of δ9‐tetrahydrocannabinol (THC, 2.4 mg/kg/day) prior to and during pregnancy and throughout lactation (3.5 postnatal months). Attention was measured at 1 and 2 years of age in a standardized test situation in which animals looked at projected slides. In comparison with controls (offspring of untreated mothers), THC offspring directed more attention at slides on the 1st trial of session. The THC offspring also engaged in relatively longer individual periods of attention on the 1st vs 2nd trials of the session and during the 1st vs 2nd session in which a given slide was presented. Further experiments varying novelty and complexity of visual stimuli suggested that changes in visual attention of THC offspring can be characterized as a failure to limit the response to novel stimuli.
Effect of surrogate–administered punishment on surrogate contact in infant squirrel monkeys
Authors: Kaplan Joel N.
Published: January 2005

Three experiments were conducted in which surrogate‐reared infant squirrel monkeys were exposed to punishment in the form of pressurized air emitted from the bodies of the surrogates. Punishment was administered irregularly during the day between the ages of 6 and 34 weeks, under different schedules of random presentation and at different parameters of the airblast stimulus. Physical contact with the surrogate was recorded separately for day and night activity. The results of all experiments were consistent in showing that punished infants spent less time than did nonpunished controls in contacting their surrogates during the daytime throughout the entire period of study. Nighttime scores were less consistent, but showed the same trend in 2 of the experiments. The results also suggested that different subtypes of squirrel monkeys are inherently different in their degree of surrogate contact, with monkeys of the Bolivian type spending more time in contact than those of either Peruvian or Colombian descent.
Early social deprivation and the ontogeny of unrestricted social behavior in the laboratory rat
Authors: Day H. D. , Seay Billy M. , Hale Penny , Hendricks Dan
Published: January 2005

The unrestricted adult social and nonsocial behavior of albino rats isolated from 21 to 70 days of age was compared with the behavior of rats receiving normal social experience. Isolated animals exhibited aberrant self‐manipulative behaviors during the period of isolation, and both isolate‐reared males and females were more aggressive than their group‐reared counterparts. The hypothesis that females are buffered against the effects of social isolation received little support. Numerous gender differences and differences in the gender of the objects of social response were found for both isolate‐ and group‐reared rats. Gender and Rearing Conditions were relatively independent influences on behavior with few Gender X Treatment interactions reaching significance.
Environmental effects on the ontogeny of exploratory and escape behaviors of mongolian gerbils
Authors: Clark Mertice M. , Galef Bennett G.
Published: January 2005

Mongolian gerbils reared in standard laboratory cages and gerbils reared in cages containing a burrowlike shelter did not differ in their rate of development of escape responses to sudden visual stimulation. The presence of shelter in the rearing environment did, however, markedly slow the development of adult‐like patterns of exploration. Reduced exposure to illumination, experienced by shelter‐reared subjects, proved responsible for this retardation of development. The effect of shelter‐rearing on the development of exploratory behavior is interpreted as demonstrating an environmentally induced maintenance of an adaptive juvenile pattern of behavior.
The lactation–blocking drug bromocriptine and its application to studies of weaning and behavioral development
Authors: Martin Paul , Bateson Patrick
Published: January 2005

An experimental method for blocking maternal lactation is reviewed and the possible application of this technique for experimentally manipulating weaning is considered. Maternal milk production can be inhibited using the prolactin‐suppressing drug bromocriptine. The suitability of bromocriptine for use in behavioral experiments is considered. The pharmacology of bromocriptine (CB 154) is briefly outlined and a compilation of the reported lactation‐inhibiting doses for various species is presented. The possible endocrine and behavioral side‐effects and the toxicity of the drug are discussed. It is concluded that, in most species studied so far, the drug is relatively free from significant side‐effects at the low doses needed to suppress lactation. Guidelines for the practical use of bromocriptine are suggested. Finally, some ideas about the possible applications of the drug to the study of behavioral development and parent–offspring relationships are discussed.
Preflight development of bilateral wing coordination in the chick (Gallus domesticus): Effects of induced bilateral wing asymmetry
Authors: Provine Robert R.
Published: January 2005

The performance of bilaterally synchronous wing‐flapping by chick hatchlings suggests but does not prove the existence of a bilateral coordinating mechanism. The present research tests for bilateral coordination by using the technique of induced asymmetry. The onset of bilateral wing coordination was defined as the age when induced bilateral asymmetry produced by right wing amputation, immobilization, or weighting influenced the drop‐evoked flapping rate of the left wing. Unilateral right wing immobilization or weighting immediately before testing reduced the flapping rate of the contralateral left wing of 3–5‐day chicks, the youngest examined. Weighted and unweighted wings flapped synchronously. Therefore, a mechanism which acts across the body midline to synchronize wing‐flapping by slowing the rate of the more rapidly flapping wing to match that of its slower contralateral partner was present by 3–5 days. This is several days before the onset of flight. The flapping rate of the left wing of chicks that had their right wing amputated on Day 1 was similar in rate to that of intact chicks when tested at 7 and 13 days. “Wing‐flapping” on the amputated side of some unilateral amputees was made visible by a prosthesis attached to the stump of the amputated wing. Bilaterally coordinated flapping in the unilateral amputees indicated that the sensory and trophic periphery of a given wing and flight‐related adaptive significance are not necessary for the postnatal production of bilaterally synchronized wing‐flapping. However, the slowed flapping produced by unilateral wing weighting or immobilization indicates that wing‐flapping rate is modulated by sensory feedback, even at preflight stages.
Contact‐promoting behavior, social development, and relationship with parents in sibling juvenile degus (Octodon Degus)
Authors: Wilson Susan C.
Published: January 2005

This study describes infant socialization in captive parent‐young units of the caviomorph rodent Octodon degus. Types of parent‐young contact (huddling or squatting) and social interaction (body nosing and accompanying behaviors) are described and their ontogenetic trends examined between postnatal Days 1 and 46. Fathers spent less time than mothers in contact with the young. Mother‐young contact decreased postnatally, whereas the amounts of mother‐young and father‐young social interaction, measured in terms of body‐nosing exchanges, showed a continuous increase postnatally; sibling interactions also showed a continuous increase. Father‐young interactions tended to be dominated by the father. Young reared with the father cohabiting huddled less with their mother, and engaged in less body‐nosing, than young reared in the father's absence. Observations suggested that paternal control of the young may curb juvenile interactions. Young observed without their parents in an unfamiliar enclosure did not groom or “play” as in their home cage with parents present, but engaged in relatively more vocalizing, neck‐nosing and forepaw‐clasping.
Different outcomes of synergy between song production and song perception in the same subspecies (Molothrus ater ater)
Authors: King Andrew P. , West Meredith J.
Published: January 2005

Here we report data requiring a reinterpretation of published results on the female cowbird's (Molothrus ater ater) ability to identify male song (King, A. P., and West, M. J. (1983). Female perception of cowbird song: A closed developmental program. Dev. Psychobiol., 16:335–342). Previously we stated that naive females, given extensive social experience with males from a distant cowbird subspecies, showed the same degree of preference for native song as did naive females reared with local males: extensive experience with another subspecies produced no evidence of postnatal modifiability. The procedure used to probe for modifiability did not, however, expose the different groups of females to comparable levels of stimulation because the females differentially affected the behavior of their male companions. We must therefore amend our conclusion about the modifiability of females. In addition, we report data on populational differences within the M.a. ater subspecies in the female's ability to influence heterosubspecific males, but data that are consistent with the more general pattern of synergistic effects during song development.
Early handling and latent inhibition in the conditioned suppression paradigm
Authors: Weiner I. , Feldon J. , Ziv‐Harris D.
Published: January 2005

Latent inhibition (LI) is a behavioral paradigm in which repeated exposure to stimuli not followed by meaningful consequences renders these stimuli ineffective for subsequent learning. The development of LI is considered to reflect learning not to attend, to ignore, or tune out irrelevant stimuli. The present study investigated the differences in the development of LI between handled and nonhandled males and females. Infantile handled (days 1–22) and nonhandled, male and female Wistar rats were tested in maturity in the LI paradigm, using a conditioned emotional response (CER) procedure. The procedure consisted of three stages: preexposure, in which the to‐be‐conditioned stimulus, tone, was presented without being followed by reinforcement; acquisition, in which the preexposed tone was paired with shock; and test, in which LI was indexed by animals' suppression of licking during tone presentation. Handled animals exhibited less conditioned suppression as compared to nonhandled animals. LI was obtained in both the handled and the nonhandled females, but only the handled males showed the LI effect. Nonhandled males failed to develop LI. These results replicate our previous findings on LI in conditioned avoidance in demonstrating that: (a) the effects of handling are evident in learning tasks that do not involve motivational‐emotional variables, i.e., learning to ignore irrelevant stimuli; (b) handling differentially affects males and females; (c) the nonhandling procedure has deleterious consequences on adult behavior.
Iris pigmentation and behavioral inhibition
Authors: Rosenberg Allison , Kagan Jerome
Published: January 2005

Two independent investigations of the association between the temperamental dimensions of inhibition and lack of inhibition to the unfamiliar, on the one hand, and the degree of pigmentation of the iris, on the other, revealed a statistically significant relation in Caucasian children between behavioral inhibition to the unfamiliar and blue irises and uninhibited behavior and brown irises. Several biochemical interpretations of this association were discussed and it was suggested that these behavioral styles might be influenced by biological factors that are partially marked by eye color in Caucasian populations.
Early‐life malnutrition selectively retards the development of distal‐ but not proximal‐cue navigation
Authors: Castro Carl Andrew , Rudy Jerry W.
Published: January 2005

The effects of early‐life malnutrition on the distal‐cue and proximal‐cue versions of the Morris (1981) water maze were studied with different‐aged rats. Consistent with the existing literature, malnutrition only mildly influenced the distal‐cue navigation of relatively old pups (30 day olds). Pups 20–27 days old, however, displayed no evidence of distal‐cue navigation if they had been malnourished previously. Malnutrition had no effect on proximal‐cue based navigation by pups at any age. The effect of malnutrition on distal‐cue performance could not be attributed to any general debilitating effects, sensory, motor, or motivational deficits. Instead, it appears to selectively influence the development of the neural system (perhaps the hippocampus and related structures) more directly involved in learning to utilize distal cues.
Physical stimulation reduces the body temperature of infant rats
Authors: Sullivan Regina M. , Shokrai Neda , Leon Michael
Published: January 2005

Physical stimulation of rat pups, of the type normally received from the mother, has been shown to regulate several behavioral and physiological systems in the young. The present paper describes a possible role of physical stimulation in an additional physiological system; the thermoregulatory system. Within a thermoneutral environment, physical stimulation produces a decrease in rectal temperature (Expt. 1). Even in an environment of increasing temperature, similar to that pups experience when in contact with the dam, physical stimulation attenuates an increase in rectal temperature (Expt. 2). The physiological mechanism of heat loss appears to involve ventilatory heat exchange resulting in convective and evaporative heat loss (Expts. 3, 4). Furthermore, physical stimulation continues to produce a decrease in rectal temperature throughout the preweanling period (Expt. 5). These results suggest that pups may not always have to resort to behavioral thermoregulatory mechanisms which require them to separate themselves from their mother. Rather, pups may be cooled, or at least a heat gain attenuated, by physical stimulation from the dam while maintaining contact with her.
Thirst‐induced anorexias and the ontogeny of thirst in the rat
Authors: Leshem Micah , Epstein Alan N.
Published: January 2005

In previous work (Leshem, M., Boggan, B., and Epstein, A.N. (1988). The ontogeny of drinking evoked by activation of brain angiotensin in the rat pup. Dev. Psychobiol. Vol. 21, pp. 63–75) we showed that thirst elicited by activation of the brain's renin‐angiotensin system in the suckling becomes specific to water after 16 days of age. However, in the suckling, we did not find the anorexia that reportedly accompanies angiotensin‐induced thirst in the adult. This suggests the existence of a further stage in the ontogeny of thirst. Therefore, the present study pursued the ontogeny of thirst and its effects on milk intake through prepubescence into aduthood. Experiment 1 revealed that intracranial renin does not cause an anorexia to milk in prepubescent or adult rats. Experiment 2 showed that the absence of anorexia is true of thirst induced by renin but not by cellular dehydration, although both dipsogens suppressed milk intake when rats also had water available. Experiment 3 confirmed that the preweanling shows anorexia to solid food, as does the adult. Together with other work, these findings suggest that the ontogeny of the thirsts aroused by renin or intracellular dehydration is complete before weaning.
Amount of training and retention by infants
Authors: Ohr Phyllis S. , Fagen Jeffrey W. , Rovee‐Collier Carolyn , Hayne Harlene , Vander Linde Eleanor
Published: January 2005

In studies of animals and adult humans, more training typically leads to better retention. The generality of this finding was assessed in two studies with human infants in which amount of training was manipulated in two different ways. In the first study, 3‐month‐olds were trained for either 1, 2, or 3 sessions, each 9 min long; in the second, they were trained for a single session that was either 6, 9, 12, or 18 min long. Retention of independent groups was measured after delays ranging from 1 to 21 days. In both studies, different amounts of training did not yield group differences on any of the standard measures of acquisition or after a retention interval of 1 day. After intervals of a week or longer, however, more training led to better retention. Across studies, the long‐term retention of groups that were trained for the same amount of time differed. We speculate that subjects learn different things in these two training regimens.
Ontogeny of conditioned inhibition of conditioned respiratory suppression in kittens
Authors: Dess Nancy K. , Soltysik S. Stefan
Published: January 2005

Excitatory and inhibitory classical conditioning were examined in 4‐week‐old, 8‐week‐old, and 12‐week‐old kittens. Conditioned respiratory suppression (CRS) was a measure of conditioned fear. The inhibitory conditioning procedure was designed to model the schedule of events that normally accompanies successful coping behavior: The safety signal predicted the cancellation of shock that would otherwise follow the danger singal, rather than simply the absence of shock. Before training, the stimuli elicited small unconditioned respiratory suppression in the 4‐week‐old and 8‐week‐old kittens, but not in the juvenile, 12‐week‐old kittens. During training, danger signals came to elicit robust CRS after 3–4 sessions (20–30 trials) in every age group. Acquisition of inhibition of CRS was also observed within 2–3 days (20–30 trials). The effectiveness of inhibitory stimuli improved significantly with age. The safety signal also inhibited fear (CRS) elicited by a second danger signal. Thus, the kittens learned inhibition to the safety signal per se, rather than having learned to discriminate some nonreinforced configured cue from the danger signal presented alone.
Development of antipredator responses in snakes: IV. Interspecific and intraspecific differences in habituation of defensive behavior
Authors: Herzog Harold A. , Bowers Bonnie Bailey , Burghardt Gordon M.
Published: January 2005

Habituation of defensive attacks directed toward a threatening stimulus was investigated in neonatal garter snakes. The focus of the experiments was on differential effects of a simple experiential process in relation to species, litter, sex, and individual. In Experiment 1 newborn Thamnophis melanogaster from four litters and newborn Thamnophis butleri from three litterswere given daily tests in which snakes were confronted with a nonmoving and moving human hand. Over five successive test days the T. melanogaster neonates showed a decline in number of strikes directed toward the stimuli. When retested 10–13 days later the animals showed significant response recovery. Although some of the T. butleri newborns demonstrated significant habituation, there was no overall habituation of strike scores in this species. The T. melanogaster had high strike scores, more rapid habituation to moving than nonmoving stimuli, and significant litter differences in habituation rates. The T. melanogaster, but not the T. butleri neonates, showed significant habituation of flight responses over the five tests. In T. butleri, but not T. melanogaster, males were more prone to attack than were females. In bath species there were large differences in both overall strike scores and habituation rates of individual newborn animals. In Experiment 2, T, melanogaster, 2‐months old, were tested for short‐term habituation to either a moving or nonmoving stimulus for 10 successive tests on one day. Habituation of strikes was similar to both stimuli, but more animals confronted with the moving stimulus showed an initial increase in strikes, lending support to the dual‐prccess theory of habituation. As in Experiment 1, there were large individual differences in habituation rates. The results are discussed in terms of the ecological and methodological implications for developmental studies.
Pubertal‐related changes influence the development of environment‐related social interaction in the male rat
Authors: Primus Renee J. , Kellogg Carol K.
Published: January 2005

The influence of pubertal age on the differential effect of a familiar versus an unfamiliar environment on social interaction (SI) in pairs of male rats was evaluated. The decrease in SI induced by the unfamiliar environment in adult rats is considered an anxiety‐related response. Intact male rats and male rats castrated at 19 days were tested for SI at 28, 35, and 60 days of age. The results revealed that in the intact rats, decreased SI in an unfamiliar environment was evident at 35 and 60 days but not at 28 days. The behavioral composition of the environment‐induced response at 35 days was different from that measured at 60 days. Prepubertal castration prevented the decrease in SI in the unfamiliar environment at both 35 and 60 days. This study demonstrated the emergence with the onset of puberty of a specific behavioral response to an anxiogenic condition. Furthermore, the development of this environment‐related behavioral response was influenced by gonadal secretion(s), suggesting the importance of gonadal function to the emergence of this response.
Early experience and cross‐generational continuity of mother‐infant contact in vervet monkeys
Authors: Fairbanks Lynn A.
Published: January 2005

This report presents evidence that suggests that spontaneously‐occurring variation in early mother‐infant experience within the normal range can influence primate mothering behavior in the next generation. Longitudinal observations of vervet monkeys (Cercopithecus aethiops sabaeus) living in naturally composed captive social groups demonstrated that the average amount of contact that mothers maintained with their infants in the first six months of life could be predicted by the amount of mother‐infant contact the females had experienced as infants. A female's early experience in infancy was a better predictor of adult mothering behavior than variables measuring social learning as a juvenile, shared circumstances, and average similarity between mothers and daughters.
Conspecific screams and laughter: Cardiac and behavioral reactions of infant chimpanzees
Authors: Berntson Gary G. , Boysen Sarah T. , Bauer Harold R. , Torello Michael S.
Published: January 2005

The present study examined cardiac and behavioral reactions of infant chimpanzees to white noise and to conspecific screams and laughter. Chimpanzee screams evoked typical deceleratory cardiac orienting responses. Analysis of stimulus‐evoked changes in respiratory sinus arrhythmia suggested that this cardiac deceleration arose from an increase in parasympathetic activity. In contrast, chimpanzee laughter evoked notable cardiac acceleration. Laughter also evoked vocalizations from the infant subjects, which were reminiscent of adult threat‐barks. Analysis of respiratory sinus arrhythmia suggested that the cardioacceleratory response likely resulted from sympathetic activation, and was not associated with an inhibition of parasympathetic activity. The autonomic and vocal responses to laughter emerged early in development, were minimally dependent on social contact with adults, and declined in magnitude with increasing age. A consideration of the phylogeny of laughter raised the possibility that the functional reaction to this vocalization may be related to its origin in more primitive agonistic facio‐vocal signals.
Mother and sibling discrimination at a distance by three‐ to seven‐day‐old lambs
Authors: Nowak R.
Published: January 2005

This study examined some aspects of the developmental phase of social bonding in newborn lambs. In Experiment 1, 3‐day‐old Merino lambs (singles and twins) were tested in a 2‐choice situation for mother discrimination at a distance. In Experiment 2, the ability of twins to discriminate their siblings at a distance was studied 3 and 7 days after birth. When released at 9m from two postparturient ewes after a latency of 30 s, which allowed the lambs to hear and to see both animals, most lambs chose to run and to stay with their own mothers before the end of the 2‐min test (Experiment 1). There was no difference between singles and twins, nor between males and females in their distant discriminative ability. However, twins were initially undecided, slower to reach their mothers, and spent significantly less time with them. When the same testing procedure was used for sibling discrimination, most 3‐day‐old twins went to a lamb, but the proportion of lambs reaching the sibling first did not differ significantly from random, and the time spent near either lamb was similar (Experiment 2). During these tests, female lambs performed better than males. When tested 7 days after birth, all twins reached a lamb and a high proportion of them chose to go to the sibling first. They also spent most of the time near it. These results demonstrate that mother discrimination from a distance is well established in 3‐day‐old lambs and sibling discrimination takes longer to develop but has occurred by 7 days of age.
An ecological approach to language development: An alternative functionalism
Authors: Dent Cathy H.
Published: January 2005

I argue for a new functionalist approach to language development, an ecological approach. A realist orientation is used that locates the causes of language development neither in the child nor in the language environment but in the functioning of perceptual systems that detect language‐world relationship and use them to guide attention and action. The theory requires no concept of innateness, thus avoiding problems inherent in either the innate ideas or the genes‐as‐causal‐programs explanations of the source of structure in language. An ecological explanation of language is discussed in relation to concepts and language, language as representation, problems in early word learning, metaphor, and syntactic development. Finally, problems incurred in using the idea of innateness are summarized: History prior to the chosen beginning point is ignored, data on organism‐environment mutuality are not collected, and the explanation claims no effects of learning, which cannot be tested empirically.
Development of coordinated movement in chicks: I. Temporal analysis of hindlimb muscle synergies at embryonic days 9 and 10
Authors: Bradley Nina S. , Bekoff Anne
Published: January 2005

In this study, we examined electromyographic activity for an ensemble of hindlimb muscles during spontaneous activity in chick embryos to advance understanding of early motor coordination and its relationship to later emerging behaviors. Four‐channel recordings were obtained from 6 muscles in ovo at embryonic Days 9 and 10. Analyses indicated that when muscles are repetitively active, patterns during embryonic motility are distinct from those for other behaviors. For example, unlike the muscle patterns for locomotion, extensor muscles and flexor muscles are synchronously activated at 50% of the extensor cycle period. Furthermore, flexor and extensor bursts are similar in duration and show little correlation with extensor cycle period. Finally, our data sugest that the ensemble of muscles active can vary from cycle to cycle. This study provides the basis for future studies that will examine neural and biomechanical interactions underlying the development of coordinated movement.
An examination of the intramodal and intermodal behavioral consequences of long‐term vibrissae removal in rats
Authors: Symons Lawrence A. , Tees Richard C.
Published: January 2005

An assessment was made of the effects of long‐term tactile restriction by bilateral removal of the mystacial vibrissae from an early age on the subsequent somatosensory capacities of rats (i.e., the intramodal consequences) as well as its effects on visual and spatial capacities (i.e., the intermodal consequences). Rearing environment (enriched vs. normal) and method of vibrissae removal (cauterization of follicles vs. plucking) were examined to determine specific factors that might influence the effect of vibrissae removal. Early, long‐term tactile restriction had significant intramodal and intermodal consequences. Dewhiskered rats showed attenuated orientation to tactile stimuli presented to their mystacial pads and enriched‐reared rats whose vibrissae follicles had been cauterized showed increased orientation to visual stimuli. Manipulation of early somatosensory signals had no impact on the development of certain spatial and precise manipulatory skills. These data provide limited evidence for theories of modality interdependence and yield basic information concerning the role of the mystacial vibrissae in the behavior of the rat.
Ontogeny of sexually dimorphic ultrasonic vocalizations in mongolian gerbils
Authors: Holman S. D. , Seale W. T. C.
Published: January 2005

Sexual differentiation of emission rates (Experiment 1) and physical structure of ultrasonic vocalizations (Experiment 2) were investigated in Mongolian gerbils between 17 and 85 days of age. Animals from different litters were allowed to interact in iso‐and heterosexual pairs. Vocalization rates increased in all groups, reaching a plateau at approximately day 56. Female pups had significantly higher rates of all vocalizations than male pairs before the plateau stage. Five stereotypic categories of physical structure were easily distinguished and confirmed by sound spectrographic analysis. Only mid‐range frequencies of vocalizations appeared to decline throughout the juveniles' lives: this change may communicate the animal's age. Two male and one female categories were sexually dimorphic and similar in structure to those made during courtship interactions. Rates of male‐type vocalizations appear to increase as testicular androgens start rising.
Preferred tastes and opioid‐modulated behaviors in neonatal rats
Authors: Kehoe Priscilla , Sakurai Sharin
Published: January 2005

Ten‐day‐old rats were given various tastants to ingest, independent of mother and suckling. Relative to water, the pups ingested significantly more saccharin (0.5%) and NaCl (2.5%) and less quinine (0.4%). Pretreatment with the opiate antagonist, naltrexone, had no effect on water or quinine intake but significantly reduced that of saccharin and NaCl. Furthermore, the preferred solutions of saccharin and NaCl given intraorally caused a decrease in ultrasonic vocalizations of isolated pups and in a separate experiment caused an analgesic response to heat. Both phenomena were reversible with naltrexone administration, suggesting that preferred tastes elicit an endogenous opioid response significantly affecting behaviors seen during isolation.
The early presence of food‐oriented appetitive behavior in developing rats
Authors: Phifer C. B. , Denzinger Annette , Hall W. G.
Published: January 2005

The appetitive behavior of 3‐ to 6‐day‐old rat pups was studied by testing their ability to direct their ingestive behavior to a restricted food source. We found that, from 3 days of age, pups were able to feed efficiently from such a source. More specifically, pups that were deprived of nutrition but not of maternal care as well as pups that were dehydrated ingested significantly more than nondeprived animals, and did so whether liquid diet was spread over the entire floor surface beneath them or restricted to a fraction of the floor surface. However, pups that had been nutritionally and maternally deprived were not able to direct their feeding. The general locomotor activation of pups in this latter group appeared to interfere with their ability to direct their behavior to the restricted source. These results indicate that from early ages, developing rats possess the appetitive competence to guide their behavior and suggest that previous findings of poorly directed behavior were a confound of the behavioral activation shown by pups tested in a state of maternal deprivation.
Behavioral and physiological responses of mother and infant squirrel monkeys to fearful stimuli
Authors: Wiener Sandra G. , Levine Seymour
Published: January 2005

The behavioral and adrenocortical responses of feral squirrel monkey mothers and their laboratory‐born infants were measured following exposure to a live snake and to a flying predator model (hawk). The dyads were either socially or individually housed. The different stimuli were presented above the home cage for 1 hr; behaviors were observed during this period. Blood samples were obtained at the end of the test session and assayed for cortisol. The results indicated that individually housed dyads markedly increased their time spent in contact and their avoidance of the stimuli, and showed increased levels of cortisol when exposed to the snake or hawk model. Socially reared monkeys responded only to the snake. Thus, the presence of social partners ameliorated the response to the hawk model. The marked increase in contact during the presentation of the fear‐eliciting stimuli may be partly responsible for the infants' response. © 1992 Wiley & sons. Inc.
The effect of the neurotoxin DSP4 on the development of a predisposition in the domestic chick
Authors: Davies D. C. , Johnson M. H. , Horn G.
Published: January 2005

Under certain conditions, dark‐reared chicks preferentially approach objects resembling conspecifics. In the current study we investigated the effect of the catecholaminergic neurotoxin DSP4 on this predisposition. After hatching, chicks received an intraperitoneal injection of either DSP4 or vehicle (controls). The chicks were individually placed in running wheels for 2 × 1 hr, 24 hr before testing. The chicks were maintained in darkness until given a preference test, which involved the simultaneous presentation of an illuminated red box and a stuffed fowl at 36, 48, 60, 66, or 72 hr after hatching. The approach of each chick toward the two objects was recorded over 5 min and a preference score calculated. Control chicks placed in the running wheels at 24 and 36 hr posthatch and tested 24 hr later showed a significant preference for the fowl compared to the red box. In contrast, DSP4‐treated chicks did not show such a preference at corresponding ages, but did express a greater preference for the fowl when placed in the running wheels at 42 and 48 hr posthatch and tested 24 hr later. These results suggest that experience of the running wheel or of associated factors, e.g., handling, must occur during a restricted period of time to influence the emergence of the predisposition to approach the stuffed fowl. DSP4 treatment delays the onset of this period. © John Wiley & Sons, Inc.