摘要:

AbstractUsing techniques developed by Hall (1975) and modified by Diaz (1991), we maintained rat pups in total social isolation from the time they were 2 or 3 days of age until they were 42 days old. We found that rat pups reared in social isolation exhibited susceptibility to social enhancement of food preference indistinguishable from that exhibited by normally reared rat pups. These data suggest that development of a tendency to use conspecifics as sources of information about what foods to eat does not depend upon previous experience either of interaction with conspecifics or of feeding in social situations.© 1994 John Wiley&Sons, Inc

ISSN:0012-1630    

DOI:10.1002/dev.420270202

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

年代:1994

数据来源: WILEY

摘要:

AbstractThe cardiac orienting response to brief auditory stimuli was measured in preweanling and adult rats. The eliciting stimulus varied in duration (2 or 10 s) and complexity (continuous or pulsing). Stimulus complexity affected response magnitude with the pulsing stimulus eliciting a larger response than the continuous stimulus. Stimulus duration affected response persistence but only when a pulsing stimulus was used. In contrast to recent research with stimuli of much longer duration, age did not significantly affect any aspect of the cardiac response to the novel auditory stimuli in the present study. These results are discussed in terms of (1) the effects of stimulus duration on the heart‐rate component of the orienting response and (2) two‐stage models of attention.© 1994 John Wiley&Sons,

ISSN:0012-1630    

DOI:10.1002/dev.420270203

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

年代:1994

数据来源: WILEY

摘要:

AbstractJimpy (jp/Y) male mice have a sex‐linked mutation which results in dysmyelination throughout the CNS, causing tremors and behavioral abnormalities. These mice rarely live past 30 days of age. Due to the sex‐linked nature of this mutation, both jimpy and normal male pups occur within the same litter. We examined the early behavioral development of these mice by recording their motor behaviors, including slight movement, locomotion and grooming, and their ultrasonic vocalizations (UVs) at 2‐day intervals from 2‐20 days of age. Jimpy males weighed less than their normal littermates and reached developmental milestones at a later age. They produced fewer UVs than their normal male littermates from 2–8 days of age, after which UVs ceased almost completely in both groups of mice. Jimpy mice spent less time engaged in coordinated motor activities (locomotion and grooming) than normal littermates, and more time engaged in slight movement or remaining inactive. On three of the behavioral measures used (UV production, slight movement, and inactivity) differences were evident early in development (Day 2 postpartum), whereas differences on the other measures (locomotion, grooming) were not evident until later in the developmental period. Our results indicate the importance of using multiple behavioral measures when examining the functional effects of myelin deficiency.© 1994 John Wiley

ISSN:0012-1630    

DOI:10.1002/dev.420270204

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

年代:1994

数据来源: WILEY

摘要:

AbstractAfter being nursed just once for 4‐5 min by an artificially scented doe, newborn rabbits show the full pattern of nipple‐search behavior when placed on a fur scented with the same odor as their mother. It was the aim of the present study to test whether such rapid learning is dependent on age. In Experiment 1 in which normally raised pups were nursed by a scented doe either on Days 1, 3 or 5, conditionability was found to decline markedly by postnatal Day 5. In Experiment 2 conditionability was maintained in pups deprived of suckling experience by bottle feeding from Days 1–4, but not in hand‐raised pups allowed to search on a doe for 4 min daily without milk intake. Possible mechanisms underlying the decline in conditionability to suckling odors, as well as the potential functional significance of this early learning for immediate postnatal and later life are discussed.© 1994 John Wiley&S

ISSN:0012-1630    

DOI:10.1002/dev.420270205

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

年代:1994

数据来源: WILEY

摘要:

AbstractThis study describes the orderly changes in manipulation over the first 6 months in capuchin monkeys (Cebus apella). By 6 months of age, all the basic forms of manipulation seen in adults have appeared. Actions that occur frequently in the first 8 weeks are gentle and involve sustained visual orientation and aimed reaching. Later actions are more vigorous, and involve grasping. Large increases in the rate of activity are evident over the period of development studied. The increase from the first 8 weeks to the second may be due to (a) an increase in the amount of time spent alert and active, (b) a decrease in the amount of time spent in a ventral position, (c) improvements in postural control and stamina and (d) the onset of independent locomotion. Changes in form can be attributed primarily to postural factors and to neuromuscular development (precisely aimed and controlled movements appearing in the 5th and 6th months).© 1994 John Wiley&Sons, Inc

ISSN:0012-1630    

DOI:10.1002/dev.420270206

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

年代:1994

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420270201

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

年代:1994

数据来源: WILEY