摘要:

AbstractPolygraphic recordings of sleep and wakefulness were obtained over 4‐hr periods from infant opossums, aged 48–79 days, while they were in the mothers' pouches. Concurrent body temperature measurements were obtained from littermates held at ambient temperatures of 25 and 30°C. The ontogenesis of sleep was similar to that of placental mammals: quiet sleep increased from 13% sleep time at 48 days to 55% at 79 days; conversely, active sleep decreased from 87% to 45%, respectively. The amplitude of the electroencephalogram (EEG) during quiet sleep increased with age and quiet sleep could be categorized as slow wave sleep at 75 days. Active sleep could be identified as rapid eye movement sleep at the same age. Temperature measurements revealed that thermogenesis appeared at approximately 55 days and the 1st signs of thermoregulation were apparent at 67 days. Near‐adult thermoregulatory capabilities were present by 79 days. Increases in percent time spent in quiet sleep corresponded with increases in percent adult thermogenesis. The appearance of slow wave EEG activity coincided with the onset of thermoregulatory capabilities. We suggest that lowered metabolism associated with slow wave sleep is adaptive in offsetting the increased energy demands of thermog

ISSN:0012-1630    

DOI:10.1002/dev.420130502

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

年代:1980

数据来源: WILEY

摘要:

AbstractStrychnine (STR), glycine (GLY), and γ‐aminobutyric acid (GABA) were injected intravenously into 6‐ and 7‐day chick embryos and subsequent effects upon spontaneous motility were observed. In 7‐day embryos STR alone increased motility and when injected simultaneously with GLY antagonized the GLY‐induced motility decrements; STR did not antagonize GABA‐induced motility decrements. In 6‐day embryos STR injected alone had no effect on motility, but did antagonize motility decrements induced by the simultaneous injection of GLY; again STR did not antagonize GABA‐induced mot

ISSN:0012-1630    

DOI:10.1002/dev.420130503

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

年代:1980

数据来源: WILEY

摘要:

AbstractThis experiment concerns 2 issues: the time of onset of the process of social attachment in the dog, and the nature of the interaction between the emotion of separation distress and that caused by discomfort. The subjects were 48 puppies from 4 genetic backgrounds: beagles, Telomians, and their reciprocal F1hybrids. Puppies were divided into 4 groups and isolated for short periods under comfortable and uncomfortable conditions beginning at 3, 11, 17, and 25 days from birth. The dependent variable was distress vocalization during a 10‐min period. Separation distress did not occur before 11 days and remained at a low level until 21 days, when it rose rapidly. The process of attachment is thus initiated in the transition period but does not reach a high level until some 2 weeks later. Interaction between the 2 kinds of affect is compatible and additiv

ISSN:0012-1630    

DOI:10.1002/dev.420130504

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

年代:1980

数据来源: WILEY

摘要:

AbstractTwo experiments were performed to determine whether or not persistence acquired under reinforcement conditions of infancy can be retained and transferred to adult reinforcing conditions. In Experiment I 2 groups of rats 14–15 days of age were trained in a runway under a partial (PRF) or continuous (CRF) schedule of milk‐suckling reinforcement. A 3rd group was trained under continuous nonreinforcement (NRF) conditions. The PRF and CRF groups acquired the approach response about equally, and the NRF showed a very small increase in speed. In immediate extinction, the PRF group was more resistant to extinction than its CRF counterpart. For the NRF group “extinction” produced a continuation of the low‐level “acquisition” performance. Experiment II showed that persistence acquired at 14–15 days with milk‐suckling reinforcement can be sustained through a 2‐week retention period including a phase of CRF

ISSN:0012-1630    

DOI:10.1002/dev.420130505

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

年代:1980

数据来源: WILEY

摘要:

AbstractIn 2 experiments using milk‐suckling from an anesthetized dam as the reinforcer, evidence is presented that the transitional age in rat pups for learning of persistence as a result of appetitive partial reinforcement is between 11 and 12 days of age. In Experiment I, pups 12–13 days of age showed the partial reinforcement extinction effect (PREE) whereas 10–11‐day olds did not. In Experiment II, pups trained at 11–12 days and tested at Day 13 did show a PREE at Day 13 but those trained at 10–11 d

ISSN:0012-1630    

DOI:10.1002/dev.420130506

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

年代:1980

数据来源: WILEY

摘要:

AbstractThis study was designed to assess the separate effects of inbreeding the mother and the pups on behavioral development in the mouse. The pups were tested on a standardized developmental rating scale at 32 days gestational age. The results indicated that maternal inbreeding retarded development by 1.5 days and that inbreeding the pups retarded development by .7 days.

ISSN:0012-1630    

DOI:10.1002/dev.420130507

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe cardiac orienting response to species‐specific songs was measured in young swamp sparrows and song sparrows. Swamp sparrows respond with significantly greater deceleration to conspecific songs than to songs of the sympatric song sparrow. This discriminatory ability is operating during the sensitive period for song learning and is evident upon initial exposures to conspecific song. These results are the 1st direct evidence for a sensory component in the process of selective vocal learning in bird

ISSN:0012-1630    

DOI:10.1002/dev.420130508

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

年代:1980

数据来源: WILEY

摘要:

AbstractHorenstein (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 discusse

ISSN:0012-1630    

DOI:10.1002/dev.420130509

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

年代:1980

数据来源: WILEY

摘要:

AbstractA step‐through locomotor passive avoidance task is described requiring the suppression of a spontaneous escape reaction from a cool toward a warm compartment in order to avoid an electric shock delivered in the warm side. We observed no learning of this task at 9 days of age, a very low but significant level of acquisition at 11 days, a slow but progressive improvement of avoidance from the 13th until the 17th day when the adult capacity was achieved, and a marked increase in the rate between 17–20 d

ISSN:0012-1630    

DOI:10.1002/dev.420130510

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

年代:1980

数据来源: WILEY

摘要:

AbstractThe development of memory of a conditioned response was examined in London black rats between 0 and 4 days of age. For the conditioning, a vibrotactile stimulus paired with an electric shock was presented to the animal 80 times with an interval of 2000 msec between stimuli. The animals were retested at retention intervals of 3 min or 24 hr. The results showed that 0‐, 2‐, 3‐, and 4‐day‐old rats possess a retention capacity of at least 24 hr and suggest that the emergence of memory may be task

ISSN:0012-1630    

DOI:10.1002/dev.420130511

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

年代:1980

数据来源: WILEY