ISSN:0012-1630    

DOI:10.1002/dev.420060102

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

年代:1973

数据来源: WILEY

摘要:

AbstractIn previous reports exposure to 80 or 90 days of environmental complexity induced a significant increase in the length of the rat cerebrum, whereas 30 days' exposure induced changes which failed to reach significant levels. In the present study after 30 days of differential rearing, cerebral length was 1.2% (p<.005) greater in brains from the enriched animals; the region contributing to this increase lay between the anterior pole and the point of greatest cerebral width. Measurements of cerebral width and brain weight failed to show any significant change, but the body and adrenal weights of the isolated rats were 19.9% (p≤ .02) greater, respectively, than those of their littermates reared in environmental complexity. However, the ratios of adrenal weight to body weight did not differ significantly between group

ISSN:0012-1630    

DOI:10.1002/dev.420060103

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

年代:1973

数据来源: WILEY

摘要:

AbstractThe relationship of state to HR and behavioral responding to white noise stimulation was investigated in 2‐week old infants. Results indicated that state is a potent determinant of various behavioral and HR phenomena. State was related to prestimulus HR levels. Cardiac responses elicited in active sleep were larger than those elicited in quite awake, even after prestimulus effects on responding were partialled out. Infants who were asleep throughout testing (group I) showed rapid behavioral and large HR response decrement. Infants whose state changed from active sleep to awake (group II), from quiet awake to asleep (group III), and from quiet awake to crying (group IV), showed significantly slower behavioral response decrement than those in group I, but behavioral response decrement was nevertheless evident in all groups. Cardiac response over trials also was examined in these 4 group

ISSN:0012-1630    

DOI:10.1002/dev.420060104

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

年代:1973

数据来源: WILEY

摘要:

AbstractThe hybrid offspring of reciprocal crosses between C57BL/10J and Swiss Albino mice were fostered at birth to Swiss Albino mouse mothers or to Purdue‐Wistar rat mothers.Measures were taken of incidence of survival, body weight, open‐field performance, passive avoidance learning, and fighting. As compared to mice reared by mouse mothers after birth, mice reared by rat mothers (a) had a lower incidence of survival at weaning; (b) weighed more; (c) were less active in the open field, defecated less in the field, and had a greater latency to initiate movement in the field; and (d) had poorer passive learning scores. The findings indicate that the postnatal maternal environment has pervasive effects upon a number of behavioral and morphological characters, but reveal a minimal effect of the prenatal environment. Moreover, they indicate that the absence of differences in fighting scores among the 4 groups may be caused by dominant ge

ISSN:0012-1630    

DOI:10.1002/dev.420060105

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

年代:1973

数据来源: WILEY

摘要:

AbstractThe effect of early protein‐calorie malnutrition on the development of social behavior was studied during the first weeks of postnatal life. Activity and social interaction were recorded in groups of young rats either in the rearing cage or in a novel enviornment. The malnourished group had a delayed development of social behavior and smaller number of social contacts in all tests. During the suckling period, the nutritionally deprived pups were also more dependent on the mother, showed no social grooming, but were also more aggressive. On the 49th day, the normal rats showed increased exploration of the social stimulus whereas the malnourished rats were markedly inhibited. Apparently, early nutritional deficiency altered the social structure of the litter and of all individuals from the beginning by disturbing behavior and interactions of all members of the “fami

ISSN:0012-1630    

DOI:10.1002/dev.420060106

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

年代:1973

数据来源: WILEY

摘要:

AbstractNon‐nutritive sucking in human infants aged 9–13 weeks produces buffering by reducing visual scanning movements in the presence of movement‐invoking cinematic visual displays of both representational and abstract types. Scanning is correlated with movement in a display without the presence of sucking to buff

ISSN:0012-1630    

DOI:10.1002/dev.420060107

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

年代:1973

数据来源: WILEY

摘要:

AbstractThe effects of various egg‐opening techniques, including the Kuo Vaseline technique, upon survival, hatchability, and embryonic behavior have been experimentally evaluated in the present study. The major aim was to develop a technique that could be used for long term behavioral studies throughout most of incubation. The Kuo Vaseline technique was found to provide the poorest results in terms of survival and hatchability: none of the embryos in eggs opened by this technique hatched. Two techniques, however, did provide adequate survival and hatchability such that they could easily be used for behavioral observation of the chick embryo from the 2nd day of incubation until hatching. These latter techniques involved partial removal of the inner shell membrane in the air‐space; or the placement of a lateral window over the embryo along the side of the egg. Of all the techniques evaluated only the Vaseline technique resulted in a significant modification of the embryos' moveme

ISSN:0012-1630    

DOI:10.1002/dev.420060108

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

年代:1973

数据来源: WILEY

摘要:

AbstractKittens reared with their mother under constant illumination from birth to 8 months were compared electrophysiologically, physically, and behaviorally with normally reared kittens. Initial components of visual electrocortical responses recorded from the light‐reared kittens in an awake state were of considerably greater magnitude in contrast to control kittens and adults. The light‐reared kittens also differed significantly in terms of minimal eye blink responses to light and to an approaching object and initially displayed continuous mydriasis independent of light‐dark conditions. The kittens did not differ in orientation to objects, following objects, visual placing, and visual cliff respo

ISSN:0012-1630    

DOI:10.1002/dev.420060109

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

年代:1973

数据来源: WILEY

摘要:

AbstractIn two separate studies, newborn infants' responses to sleep stage deprivation were investigated. In the first study, neonates were selectively awakened from either REM or NREM sleep during 1 interfeeding sleep period and allowed to recover in an undistrubed second. In the 2nd study, infants were kept totally awake for 1 interfeeding period and allowed to sleep undisturbed during the next. The results indicate that selective sleep stage deprivation by manual awakenings was impossible to achieve during the newborn period. Rather, the infants were partially sleep deprived (both stages of sleep were reduced) with increased amounts of wakefulness. During the disturbance the interrupted sleep stage demonstrated considerable “tenacity.” During undisturbed recovery sleep, in both studies, total sleep time was markedly increased. NREM sleep demonstrated a greater tendency for preferential recovery than REM sl

ISSN:0012-1630    

DOI:10.1002/dev.420060110

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

年代:1973

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420060101

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

年代:1973

数据来源: WILEY