摘要:

AbstractA Soft grip the size of an adult index finger was placed in the palm of 3‐month‐old human infants during face‐to‐face interaction with their mothers. In a between‐subjects experiment, half the subjects interacted with mother for 3 min with no grip, which was followed by a 3 min interaction with the grip in the left hand; for the other half, the grip was placed in the right hand in the second condition. A within‐subjects experiment compared the grip interaction for 3 min first in one hand and then in the other. The grip did not significantly alter the infant's gaze at mother, smiling, or positive vocalizations. The movements of the hand with the grip were suppressed similarly for left and right hands. Lateral asymmetry was found for looking to the left side when the grip was in the left hand, compared to no lateral preference in looking during any other condition. The results support a model of right‐side dominance for attention contr

ISSN:0012-1630    

DOI:10.1002/dev.420230102

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

年代:1990

数据来源: WILEY

摘要:

AbstractRecent evidence from both altricial and precocial neonates suggests that premature stimulation of a later developing sensory system may alter the functioning of earlier developing sensory systems. The present study examined the influence of prenatal visual stimulation on postnatal auditory functioning in precocial bobwhite quail chicks. Hatchlings that experienced patterned light during the 24–36 hr prior to hatching did not exhibit a naive auditory preference for their species‐specfic maternal call at 24 hr or 48 hr following hatching, a reliable phenomenon in chicks not receiving embryonic visual stimulation. To examine whether this lack of responsiveness resulted from enhanced intersensory functioning, hatchlings were tested for preference for both auditory and visual features of the bobwhite hen. Results indicate that prematurely stimulated chicks require species‐typical auditoryandvisual stimulation earlier in postnatal development than do normally reared chicks to direct their filial behavior. These findings point to the importance of normally occurring developmental limitation of sensory input to early species‐typical sensory/perceptual organ

ISSN:0012-1630    

DOI:10.1002/dev.420230103

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

年代:1990

数据来源: WILEY

摘要:

AbstractWe examined reproductive tracts of 253 female Mongolian gerbils (Meriones unguiculatus) and recorded the uterine locations (relative to siblings of opposite sex) in which 812 male and 823 female fetuses were found. Within‐litter comparisons revealed that sexes were not distributed randomly across uterine horns. The percentage of males in right horns (55.0%) was greater than the percentage of males in left horns (41.8%) and the percentage of females in right horns (45.0%) was significantly less than the percentage of females (58.2%) in left horns. We did not find differences in the total number of fetuses in left and right uterine horns or a sex bias in the total sample of 1635 fetuses. Results were discussed in terms of: (a) effects of sexual segregation of fetuses on expected probabilities of fetuses developing adjacent to 0, 1, or 2 fetuses of opposite sex and (b) consequent alterations in expected frequencies of behavioral phenotypes in populations of gerbil

ISSN:0012-1630    

DOI:10.1002/dev.420230104

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

年代:1990

数据来源: WILEY

摘要:

AbstractWe studied developmental changes in supine head position preference in a group of 14 healthy full‐term infants from age 3 to 18 weeks. The infants assumed an initial head‐right position until 12 weeks. For the maintenace of a head position, a loglinear analysis revealed a developmental trend from and initial head orientation to the right to one with the head in the midline at around 12 weeks. The maintenance of a midline head position was preceded by a marked improvement in postural stabilization, defined as the ability to hold the head upright when seated in an infant chair. The relationship between head position preference and behavioral state changed with age: At 3 weeks all infants maintained the same position regardless of state, but by 18 weeks this situation held for only 64% of those who cried. The implications of these findings for the development of handedness are discus

ISSN:0012-1630    

DOI:10.1002/dev.420230105

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

年代:1990

数据来源: WILEY

摘要:

AbstractDevelopment of eye movements in REM‐sleep was studied in rats during the second and third week of postnatal life. An increased frequency of eye movements was found after eye opening, which was due only to changes in burst activity. Since pups reared in constant darkness showed an increase in eye movement activity similar to that of those exposed to diurnal light‐dark alterations, the change seems to be part of an endogenous developmental timetable rather than due to an increase of visual stimulation by eye open

ISSN:0012-1630    

DOI:10.1002/dev.420230106

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

年代:1990

数据来源: WILEY

摘要:

AbstractGenetics, urinary chemosignals and related social influences, and ambient conditions affect reproduction in female mice. Five experiments tested the effects of environmental stressors on age at first vaginal estrus in female house mice. Environmental disruption in the form of changing the cage bedding and/or nesting material at various prescribed intervals resulted in different degrees of puberty delay relative to non‐disrupted control mice. Disruption in the form of a male chasing the female for one to three 15‐min intervals each day or the female being trapped and held in a live‐trap for one to three 15‐min intervals each day resulted in delays in puberty for treatments involving multiple daily disruptions. Food deprivation, but not water deprivation, influenced the onset of puberty. Variations in temperature and humidity resulted in differences in the age of puberty; low but not high temperatures and extremely low humidity levels delayed sexual mat

ISSN:0012-1630    

DOI:10.1002/dev.420230107

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

年代:1990

数据来源: WILEY

摘要:

AbstractJuvenile rats were trained on a spatial discrimination task (T‐maze) rewarded by the opportunity to play with a conspecific. Neither morphine (MS; 1 mg/kg) nor naloxone (NX; 1 mg/kg) administration affected choice or running time during the acquisition of the task, even though in the goal box. MS‐treated animals played more than and NX‐treated animals less than vehicle‐treated controls. Thus, brain opioid systems seem to influence the expression of play without affecting the apparent appetitive strength of play motivation. When play reward was no longer available in the goal box. Animals that continued to be treated with MS were more resistant to extinction than either vehicle‐or NX‐treated animals. They continued to complete the task more often and in less time than the controls. NX‐treated rats, on the other hand, extinguished faster than controls. The evidence supports the conclusion that opioid systems are important in the maintenance of

ISSN:0012-1630    

DOI:10.1002/dev.420230108

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

年代:1990

数据来源: WILEY

摘要:

AbstractResearch on fetal alcohol syndrome (FAS) has historically held that postnatal deficits result directly from prenatal alcohol exposure. Such exposure may alter infant behavior, and this in turn may affect maternal responsiveness and consequently increase the infant's risk for postnatal deficits. This study examined the effect of prental alcohol exposure on postnatal blood ethanol concentrations, pup development, and the ability of pups to elicit retrieval behaviors from the dam. Dams given access to a 15% ethanol solution throughout gestation and lactation showed blood ethanol concentrations of 0.1% whereas their pups had concentrations below the sensitivity of the test. Prenatal alcohol exposure was shown to have pharmacological effects on the pup's righting reflex and nutritional effects on its rate of weight gain. Control pups were better able to elicit retrieval behavior from control and alcoholic dams than were fetally alcoholic pups. These results indicate that that the condition of the pup can influence maternal responsiveness which, in turn, can influence pup development.

ISSN:0012-1630    

DOI:10.1002/dev.420230109

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

年代:1990

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420230101

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

年代:1990

数据来源: WILEY