bluuebunny/crossref_metadata_2025_split huggingface dataset:
Activity level and auditory responsiveness in neonatal chickens
Authors: Gray Lincoln 
Published: January 2005

AbstractThe effects of prestimulus activity levels on auditory responsiveness were evaluated in newborn chickens. Rates of peeping were used as measures of prestimulus activity, and delays in the otherwise ongoing vocalizations were used as measures of responsiveness. Results show increased responsiveness to pure tones at intermediate levels of prestimulus activity. Responsiveness is reduced during periods of high and low activity. The effect is strongest just prior to the stimulus. Similar analyses could be useful in other studies that depend on the changing rate of repetitive responses, such as gross body movements, head turning, heart rate, and perhaps neural potentials. Some of the variability in the responses of young subjects can be controlled by measuring the subject's activity at the time a stimulus is presented.
Endocrine responses to mother‐infant separation in developing rats
Authors: Kuhn Cynthia M. , Pauk John , Schanberg Saul M. 
Published: January 2005

AbstractSeparation of neonatal rat pups from the dam have been reported to elicit two endocrine responses in the pup: a fall in growth hormone secretion and a rise in corticosterone secretion. However, the temporal, ontogenetic, and behavioral determinants of these responses have not been compared. In the present study, we report that these two responses can be differentiated on each of these criteria. Growth hormone secretion falls repidly immediately upon separation of pups from the dam, while robust rises in corticosterone secretion are delayed for many hours. In addition, growth hormone responses are observed earlier in ontogeny. Finally, active maternal behavior is required for normal growth hormone secretion in 10‐day‐old rat pups, while passive sensory stimuli associated with the dam can significantly reduce the corticosterone response to separation.
The effect of multiple reminders on long‐term retention in human infants
Authors: Hayne Harlene 
Published: January 2005

AbstractThe present series of experiments compared the effects of single‐ and multiple‐reminder procedures on the long‐term memory of 3‐month‐old human infants. Subjects were trained in the mobile conjugate reinforcement paradigm, and the reminder treatment was a brief, noncontingent exposure to the moving mobile. In Experiment I, independent groups received one or two reminder treatments during the 3 weeks following the conclusion of training. Independent groups were tested 1, 3, 7, 14, or 22 days following the last (or only) reminder (i.e., 21–42 days after the end of training). Although retention was equivalent 1 day after one or two reminder treatments, subsequent retention was significantly prolonged by the second reminder treatment; infants receiving a single reminder treatment demonstrated no evidence of retention 7 days after the reminder, but infants receiving two reminder treatment demonstrated perfect retention as long as 14 days later. In Experiment 2, retention was observed 14 days after two reminder treatments irrespective of whether the treatments were presented during the first and second or the third and fourth weeks following the conclusion of training. In Experiment 3, the effect of three reminder treatments on retention was examined. Although retention was excellent when infants were tested 1 day after the third reminder, retention after longer intervals was no better than that observed after a single reminder treatment.
Communicating about communicating: When innate is not enough
Authors: West Meredith J. , King Andrew P. , Duff Michele A. 
Published: January 2005

AbstractThe cowbird is a brood parasite, providing no parental care to its offspring. The species has often been cited as a model of the usefulness of the construct of innate behavior, as an explanation of how young cowbirds develop species‐typical behavior. Here we evaluate the adequacy of this perspective. We show that although it is difficult to explain ontogenetic beginnings without recourse to the concept of innate behaviors, ontogenetic outcomes are less easily accommodated. Constraints on the explanatory power of innateness as an ontogenetic concept are demonstrated with data from the development of singing in cowbirds and the development of babbling in human infants.
Innateness and maturation in linguistic development
Authors: Wexler Kenneth 
Published: January 2005

AbstractLanguage is species‐specific, species‐wide, and highly structured. Its principles (Universal Grammar) are innate (genetically determined) in the child, although some linguistic capacity is subject to a maturational schedule, examples of which are given. Some particular aspects of language are learned, in a way driven by Universal Grammar. However, empiricist “learning theories” of all types are far too weak to be useful in explaining either the final adult language or the precise timing of developmental processes. The assumption of Universal Grammar is, in fact, crucial in explaining what kind of learning actually takes place.
Voluntary and involuntary maternal separation in guinea pig pups with mothers required to forage
Authors: Hennessy Michael B. , Sharp Kevin 
Published: January 2005

AbstractLactating guinea pigs required to leave a nest box to obtai food were observed to be separated from their pups almost 10% of the time on Days 13–15 postpartum. The duration of separation was greater in the dark than in the light, and was not different for mother/litters exposed to low (LFD) versus high (HFD) foraging demand. Subsequently, LFD and HFD pups as well as pups reared under standard laboratory conditions (SLC) all exhibited vocalization and plasma cortisol responses to involuntary maternal separation. However, several effects of rearing were also observed. HFD pups vocalized less during separation and had higher resting cortisol levels than did SLC pups: LFD and HFD males spent less time in contact with the mother in a test cage than did SLC males. These effects are discussed in terms of the importance of the physical environment in shaping infant‐mother interactions and the infant's perception of control.
Infant rats depleted of brain dopamine as neonates exhibit normal independent ingestion
Authors: Potter Beth M. , Bruno John P. 
Published: January 2005

AbstractWeanling or adult rats that have sustained near‐total depletions of striatal dopamine (DA) on postnatal Day 3 do not exhibit the severe ingestive deficits seen in comparably depleted adults. The present experiments demonstrated that these animals are capable of ingesting independently, via an intraoral cannula, as early as three days after the depletion. Both activational and ingestive responses to maternal deprivation and intracellular dehydration were virtually identical to the responses of control pups. However, these responses may not be entirely dopaminergically mediated at Day 6 since administration of haloperidol failed to attenuate these behaviors in normal pups. When tested on Day 12, DA‐depleted pups continued to exhibit normal ingestive and activational behaviors, despite the fact that haloperidol now suppressed these behaviors in both groups of 12‐day‐old pups. These findings demonstrate that there is a developmental progression of dopaminergic involvement in the control of independent ingestion and the associated activational responses, yet a near‐total depletion of striatal DA is not sufficient to impair the expression of these behaviors.
The properties of V̂ in newborns across repeated measures
Authors: Arendt Robert E. , Halpern Leslie F. , MaClean William E. , Youngquist Grant A. 
Published: January 2005

AbstractIt has been argued that a recently developed measure, vagal tone (V̂), is a significant advancement over other existing methods of assessing the periodic variation in heart rate associated with respiration (respiratory sinus arrhythmia). It has been further suggested that, as a noninvasive measure of vagal nerve efferent activity, V̂ may facilitate the early identification of infants at risk for developmental disabilities. This study addressed the relationship between V̂ and other measures of cardiac activity and behaviroal state and the stability of V̂ across repeated measures. Twelve samples of cardiac activity were collected from each of 20 full term infants, 6 samples on each of two consecutive days. V̂ values were derived using a spectral analysis program comparable to Porges' patented MXedit process. Measures of behavioral states were collected by continuous observation. Heart period and heart period variability were highly correlated with V̂. Variation in V̂ between behavioral states was also detected. Repeated assessments revealed that average V̂ values collected in the same state were not significantly correlated across successive days. This short‐term variability both between and within individuals does not support the notion that a single assessment of V̂ can, by itself, be used to identify at‐risk infants or predict developmental outcome.
Multiple functions of context during conditioning: A developmental analysis
Authors: Carew Maura B. , Rudy Jerry W. 
Published: January 2005

AbstractContextual stimuli may influence conditioned behavior in at least two ways (e.g. Bouton & Bolles, 1985). By becoming associated with the unconditioned stimulus (US), context cues can acquire excitatory strength that facilitates responding to a phasic conditioned stimulus (CS). The context also function to clarify the meaning of an ambiguous CS. Data obtained with an appetitive Pavlovian conditioning paradigm suggest that the processes mediating these two influences of context are dissoci‐ during development. Evidence of context‐US associations was observed in rats that began training Postnatal Day 17, but no evidence for a disambiguation function was found until pups were 20‐ to days‐old. Evidence for a context‐US association was obtained by demonstrating that US alone presentations in the training context restored conditioned responding to an extinguished CS. Evidence disambiguation function was obtained by demonstrating that a context shift, concurrent with extinction of responding to a phasic CS, preserved responding to the CS when the subjects were subsequently tested in the training context. These findings were discussed in relation to (a) the development of the rat's ability to use relational representations, and (b) Nadel and Zola‐Morgan's (1984) hypothesis linking hippocampal maturation to the role of context during development.
Cross‐modal associative transfer of response sensitization in infants
Authors: Kaplan Peter S. , Fox Karen B. 
Published: January 2005

AbstractThe effects on visual fixation of a forward pairing relation between a visual stimulus and a tone were investigated. Forward pairings of an adult female smiling face and the 1000 Hz 75 dB tone resulted in increases in the attentional response to the face, while Backward pairings of face and tone led to response decrements. Forward pairings of the face and the 75 dB tone elicited more fixation than did Forward pairings of the face and a 1000 Hz, 65 dB tone, and also more fixation than that elicited by the face alone. These findings demonstrate rapid associative learning in human infants, possibly mediated by the transfer of response sensitizing properties from tone to visual stimulus.
Development of stress‐induced responses in preweanling rats
Authors: Takahashi Lorey K. , Turner Joel G. , Kalin Ned H. 
Published: January 2005

AbstractThis study examined in postnatal Days 7, 14, and 21 male rats the effects of social isolation and social isolation with administration of brief foot shocks on the development of stress‐induced behavioral and pituitary‐adrenal hormone responses. Day 21 rats appeared similar to adult rats in their responses to the two test conditions. That is, exposure to either isolation or to shock increased both pituitaryadrenal hormone secretion and tail‐flick latencies but only administration of shock potentiated freezing and ultrasonic vocalizations. Younger rats differed from Day 21 rats in their responses to the two test conditions. In both tests, Day 7 rats produced the highest number of ultrasounds, which may be due to a significant decrease in body temperature. In contrast, in Day 14 pups, exposure to shock significantly reduced isolation‐induced ultrasonic vocalizations. Additional age‐dependent differences were found in the analgesic responses of Days 7 and 14 rats. Day 7 rats exposed to stress became consistently hyperalgesic whereas Day 14 rats showed only a short‐lasting analgesic response. Although in Days 7 and 14 rats exposure to the two stress conditions produced significant elevations in pituitary‐adrenal hormone concentrations, plasma levels were lower than those measured in Day 21 rats. To summarize, preweanling rats exhibit varied age‐dependent responses when exposed to different stress environments.
The effects of intrauterine position on the degree of corpus callosum deficiency in two substrains of BALB/c mice
Authors: Bulman‐Fleming Barbara , Wahlsten Douglas 
Published: January 2005

AbstractMeasures of several intrauterine position variables as well as an index of abnormality of fetal commissure development (z score) were obtained for fetuses of two substrains of BALB mice, BALB/c Wah 1 and BALB/c Wah2, known to differ as adults in the proportion of animals exhibiting deficient corpus callosum (about 55% & 20% respectively). The extent of midline commissure development at embryonic Day 17.5 for most strain 1 fetuses was significantly reduced compared to strain 2 fetuses of the same chronological age. The two substrains also differed with respect to mean litter size and mean body weight (strain 2 > strain 1 for both measures). The ovarian and cervical positions for strain 2 uteri were found to be the most favorable for body and placental growth; no such differences were evident in strain 1. In strain 2, fetuses in the left uterine horns showed lower z scores (more retardation) than littermates on the right side, but this difference was not evident in strain 1; no other right/left differences were found in strain 2 which could help to explain the right side advantage. None of the other position variables either separately or in combination was found to be important in predicting the z score index. Tests for randomness failed to provide evidence for nonrandom distribution of severely affected fetuses. We suggest that nongenetic variability resulting from stochastic events early in development and intrinsic to the fetus may be responsible for only certain BALB fetuses within a litter exhibiting the callosal anomaly.
Anxiety in rhesus monkey infants in relation to interactions with their mother and other social companions
Authors: Maestripieri D. , Martel F. L. , Nevison C. M. , Simpson M. J. A. , Keverne E. B. 
Published: January 2005

AbstractIn this study the anxiety‐related components of rhesus monkey infant behavior at an early stage of social development were examined. Eight rhesus infants (age 30‐40 weeks) belonging to 3 captive groups were administered with an anxiogenic drug (β‐CCE;0.2 mg/kg) and an anxiolytic drug (midazolam; 0.2 mg/kg). Saline solution was used as placebo. All infants were tested twice with each drug (four times with placebo) and their behavioral interactions with their mother and other social companions were recorded in 1‐hr observation sessions. No convulsant or sedative effects of the drugs were observed. β‐CCE was associated with an increase in time spent by the infant with its mother and a concomitant reduction in proximity with other individuals and in social play. Midazolam did not affect the mother‐infant interaction but increased the infant's locomotor activity away from the mother and its proximity and social play with juveniles and subadults when compared to peers. These results suggest that, although infant anxiety can be experimentally induced, it is not a major component of the mother‐infant relationship. Infant anxiety, however, might affect the formation of other social bonds and play a part in the development of avoidance responses toward other individuals.
Development of antipredator responses in snakes: V. Species differences in ontogenetic trajectories
Authors: Herzog Harold A. , Bowers Bonnie B. , Burghardt Gordon M. 
Published: January 2005

AbstractThe ontogeny of antipredator responses in five species of Natricine snakes was examined. In a split‐litter experiment, neonates were given a standardized defensive behavior test at 1 and/or 20 days of age. Thamnophis sirtalis and Thamnophis melanogaster showed a significant increase in both striking and fleeing from a threatening stimulus. Thamnophis butleri was not reactive in terms of striking at either age but did flee frequently at both ages. Thamnophis radix showed low rates of striking and high rates of fleeing; only fleeing increased significantly between the two tests. Nerodia rhombifer exhibited moderate rates of both striking and fleeing at both ages with no developmental effects. Subsets of most of these species tested at 40 or 60 days of age found no further developmental changes. © 1992 Wiley & sons. Inc.
Development of the ability to detect visual motion in infant macaque monkeys
Authors: Mikami Akichika , Fujita Kazuo 
Published: January 2005

AbstractA preferential looking technique was used to measure detection of visual motion by 12 infant macaque monkeys (10 Macaca fuscatta and 2 Macaca mulatta at ages between 1 and 100 days). A 0.25 cycles/deg square‐wave grating was presented at speeds from 40 to 0.4 deg/s. The threshold was determined by a two‐alternative forced‐choice preferential looking method, in conjunction with a staircase procedure. The threshold for detection of visual motion decreased exponentially with age over the first 100 days of life. At each age there was substantial variability among the individual infants tested, but each monkey's ability to detect visual motion improved with age © 1992 John Wiley & Sons, Inc.
Prenatal stress exposure alters postnatal behavioral expression under conditions of novelty challenge in rhesus monkey infants
Authors: Schneider Mary L. 
Published: January 2005

AbstractThis prospective study investigated whether mild maternal stress during pregnancy could alter the behavioral and affective responses in rhesus monkey infants in a complex, novel environment. Twenty‐four rhesus monkey infants were tested on three occasions at 6 months of age in a novel environment. Twelve infants were derived from mothers exposed to a daily 10‐min mild stressor from Day 90 to Day 145 postconception, while 12 were derived from mothers undisturbed during pregnancy. Prenatally stressed infants demonstrated more disturbance behavior, and lower levels of gross motor/exploratory behavior. Moreover, half of the prenatally stresed infants showed an abnormal response, falling asleep, while none of the control infants displayed this behavior. Males exhibited more clinging to surrogates, while females spent more time in gross motor/exploratory behaviors, with prenatally stressed males tending to spend the least time in gross motor/exploratory activity. © 1992 Wiley & sons. Inc.
Effects of early and delayed visual experience on intersensory development in bobwhite quail chicks
Authors: Banker Heather , Lickliter Robert 
Published: January 2005

AbstractThe relative impact of early versus delayed visual experience on intersensory development was studied by manipulating the timing of visual experience of bobwhite quail (Colinus virginianus) embryos and hatchlings. Previous studies with quail chicks have revealed that: (1) Socially reared chicks require only maternal auditory cues to direct their social preferences in the first 2 days following hatching; (2) by 3 days following hatching chicks require both auditory and visual maternal cues to direct their social preferences; (3) chicks which have received unusually early visual experience as embryos require both auditory and visual cues by 24 hr following hatching, indicating an accelerated pattern of the emergence of intersensory functioning; and (4) chicks reared under conditions of attenuated social and visual experience continue to rely on matenal auditory cues alone at 4 days following hatching, indicating a decelerated pattern of early intersensory functioning. In the present study, quail chicks that received both early visual experience as embryos and delayed visual experience as hatchlings exhibited a pattern of both auditory and visual responsiveness like that seen in normally reared chicks. These results indicate that, at least under the present experimental conditions, the influence of early and delayed visual experience on perinatal perceptual development appears to be relatively comparable in effect © 1993 John Wiley & Sons, Inc.
Social grouping tendencies and separation‐induced distress in juvenile sheep and goats
Authors: Lyons David M. , Price Edward O. , Moberg Gary P. 
Published: January 2005

AbstractSocial affinities in juvenile sheep and goats were compared by measuring grouping tendencies and separation‐induced distress during experimental encounters with a person in either the presence or the absence of juvenile pen‐mates. When tested with pen‐mates, sheep spent more time near penmates than did goats. When separated from pen‐mates, locomotor activity and plasma corticosteroid titers were higher in sheep, whereas vocal rates were higher in goats. Proximity to pen‐mate scores were not correlated with either vocal rates, r = 0.20, or locomotion scores, r = 0.21, recorded when juveniles were tested alone. Proximity to pen‐mate scores were correlated with posttest corticosteroid titers, r = 0.70; juvenile sheep spent more time near pen‐mates and showed greater adrenocortical responses when temporarily separated from juvenile pen‐mates. These findings support the possibility that interspecies differences in emotional reactivity contribute to the differences in grouping tendencies these ungulates display in natural or relatively unrestricted social groups. © 1993 Wiley & sons. Inc.
Spontaneous motility in premature infants: Features of behavioral activity and rhythmic organization
Authors: Hayes Marie J. , Plante Lonnie , Kumar Savitri P. , Delivoria‐Papadopoulos Maria 
Published: January 2005

AbstractThe spontaneous motor activity of clinically stable premature infants, 26–36 weeks gestational age, was investigated. Movements were recorded using a pressure‐sensitive transducer positioned below the infant's head and torso. Behavior samples were digitized every 0.5 s during 2 and 3‐hr continuous recording sessions. Time‐series analyses revealed prominent motility cycles of circa 80 min and circa 30 min. These results are consistent with periodicities in motility and REM activation observed in full‐term neonates. The longer rhythms of 70–100 min of motility found in this study establish that these periods are present at this stage of development independent of maternal zeitgebers. Developmental changes in motility rhythms and movement burst durations were also observed. Bout durations became somewhat longer in older ( > 30 weeks) infants, but the relative time devoted to movement per session was comparable in older and younger (≤ 30 weeks) infants. © 1993 Wiley & sons. Inc.