摘要:

AbstractFemale Mongolian gerbils were observed in undisturbed conditions and the ultrasounds produced by their pups were monitored. Ultrasound production was less in these conditions than with isolated pups. Correlations between various parameters suggest that nest‐building, sniffing pups, and licking pups are influenced primarily by ultrasounds whereas self‐grooming, feeding, and scratching are influenced primarily by the overall activity of the fem

ISSN:0012-1630    

DOI:10.1002/dev.420120402

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractTwo experiments examining spontaneous alternation in young white Leghorn chicks are reported. In Experiment I chicks (20 per group) run in a T‐maze for 4 trials to social reward displayed alternation of responses, whereas nonrewarded chicks did not alternate. In Experiment II socially rewarded chicks (20 per group) again showed reliable alternation of responses whereas food, water, and nonrewarded chicks did not alternate. These data support the premise that spontaneous alternation behavior has some phyletic generality under optimum conditions, although the mechanisms which control it may differ across specie

ISSN:0012-1630    

DOI:10.1002/dev.420120403

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractForty‐eight kittens were dark reared or light reared from birth for 1 to 8 months and formed 6 age groups. Following rearing the kittens were examined daily in several tasks of visually guided behavior. Compared to younger dark‐reared groups of kittens, older deprived groups showed longer acquisition times for visual placing to a surface, visual tracking, visually guided reaching to a serrated edge and moving object, and visually guided locomotion on elevated platforms. After dark rearing durations of 3 months or longer, deprived groups displayed overall deficiencies in obstacle avoidance during their 1st postdeprivation month. The older dark‐reared groups gave some indication of a direct relationship between duration of dark rearing and both delay in acquisition times for the visually guided behaviors and deficiency in obstacle avoidance. One interpretation of the results is that during dark rearing the kitten may acquire nonvisual behaviors which could interfere with and prolong its development of visually guided behavior subsequent to depriv

ISSN:0012-1630    

DOI:10.1002/dev.420120404

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractTo test the hypothesis that the motivational effects of neonatal undernutrition might conceal the detrimental effects on learning, we tested previously undernourished and normally nourished Sprague‐Dawley rats on learning of a novel maze pattern under either latent learning (nonappetitive) or food‐motivated conditions. Under the nonappetitive conditions, the previously under‐nourished rats learned significantly less than the normal controls, but when motivated for food, the undernourished rats performed as well as the controls. When learning performance measures are sensitive to motivation, differential motivation between undernourished and normal subjects must be controlled or elimi

ISSN:0012-1630    

DOI:10.1002/dev.420120405

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractWe studied 3 parameters affecting average body weight differences between mouse litters and have arrived at an approximation of the contribution that each makes to such differences. These parameters are birth weight, genetically based growth potential variations, and maternal competence. We have developed methods for controlling these parameters and show that through their application we can reduce litter‐average body weight differences from our normal value of more than 24% to about 3%. The vanished 21% consists of 12% due to differences in maternal competence, 6% due to growth potential differences, and 3% due to initial weight difference

ISSN:0012-1630    

DOI:10.1002/dev.420120406

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractTwenty alert 16‐week‐old infants were presented with 20‐sec tones at variable intertrial intervals for 10 trials while beat‐by‐beat heart rate responses were recorded to assess response at offset as well as onset of each stimulus. Consistent with past research, onsets elicited deceleratory responses which habituated and showed some evidence of dishabituation with a change in stimulus frequency on the last 2 trials. Offsets also elicited significant deceleratory responses overall, but inspection of pre‐offset heart rate suggested that deceleration in anticipation of the offset event appeared after a few stimulus repetitions and increased in magnitude over trials. However, individual variability was considerable and although the anticipatory response was significant averaged over all trials, the apparent increase over trials did not reach statistical significance. The evidence clearly indicates infants quickly process and act upon temporal information in

ISSN:0012-1630    

DOI:10.1002/dev.420120407

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractA model depicting 2 horizontally positioned black spots resembling facing eyes, as compared with models depicting other spot arrangements, elicits intense flight activity in young African jewel fish (Hemichromis bimaculatus) under 5 months of age and 7‐month‐old subadults reared apart from conspecifics with eyeless cave fish (Anoptichthys jordani). In contrast, subadults permitted to observe or interact fully with conspecifics during development exhibited attenuated discriminative flight activity. These findings suggest that visual experience with facing conspecifics, irrespective of physical contact, modifies the flight‐eliciting properties of the innate mechanism subserving eye‐schema recognition, but only during later mat

ISSN:0012-1630    

DOI:10.1002/dev.420120408

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractAfrican jewel fish reared with eyeless cave fish, but without visual‐tactile contact with conspecifics, exhibit hyperresponsive behavior after release in community aquaria. Because the optic tectum might be affected by these restraints on visual experience, unreleased members of the same social isolate group were compared histologically with controls reared in community aquaria. Using the rapid Golgi method, we counted dendritic spines and branches on pyriform interneurons between 402 and 529 days of age. As compared with isolates, control group interneurons exhibited significantly more spines and primary branches on apical dendrites in deep tectal layers. Our focus is the relation between experiential differences in rearing conditions and synaptic changes in the deep tectal layer

ISSN:0012-1630    

DOI:10.1002/dev.420120409

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractIndividual components of activity and habituation of activity were determined throughout the 1st month of life in the rat pup. Total activity increased from 25% at 8 days of age to 68% at 22 days before declining to 49% at 26 days. Total slight activity (predominantly sniffing) increased to a maximum of 33% at 15 days whereas total very active behavior (predominantly ambulation) reached its maximum of 38% at 22 days. Habituation of activity expressed as the mean slope of decrement of activity over the 1st 30 min of the observation period was observed in rats as young as 8 days of age. By 12 days, habituation of total activity had increased significantly reflecting a 3‐fold increase in habituation of slight activity, an effect observed at 15 days as well. However, by 19 days the slope of activity decrement had declined to half of its 15‐day value, indicating an impairment of habituation and reflecting the attenuation of very active behavior, predominantly ambulation. This decline in habituation continued through 22 days but by 26 days habituation of activity had increased again reaching a maximum for the 1st month of postnatal life. Our results suggest that the phenomenon of behavioral arousal observed in the developing rat pup 19 days of age reflects an inability of the organism to modulate his activity as effectively as the 15‐day‐ or 26‐day

ISSN:0012-1630    

DOI:10.1002/dev.420120410

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY

摘要:

AbstractTwo types of asphyxia were studied in monkeys, total asphyxia during mid‐pregnancy (94–98 days gestation) and combined partial and total asphyxia at term (165 days gestation). Auditory evoked potentials and the acquisition of 2 auditory discrimination tasks were studied in asphyxiated animals as well as in a group of controls. The brains of all asphyxiates were examined histologically. No auditory discrimination deficit was found in the asphyxiated animals; however, the auditory evoked potentials differentiated between control and asphyxiated animals, especially those with verified inferior colliculus dam

ISSN:0012-1630    

DOI:10.1002/dev.420120411

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1979

数据来源: WILEY