摘要:

AbstractEpstein's phrenoblysis states that brain growth and mental growth occur in correlated spurts at 3–10 months and 2–4, 6–8, 10–12 or 13, and 14–16 or 17 years of age. The present study was the first to test statistically such spurts in head‐circumference and mental‐age growth rates and to assess any correspondence in individual differences between spurts in the two variables in a single sample of children measured serially between 2.5 and 17 years of age. While the statistically significant spurts observed in each variable did fall within the hypothesized age periods, the chance rate for such theoretical concordance was high and several hypothesized spurts were not supported. Moreover, no relationship existed within individuals between head‐circumference and mental‐age gro

ISSN:0012-1630    

DOI:10.1002/dev.420160602

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe importance of gut signals for the short‐term and long‐term control of ingestion was investigated using rat pups in the natural suckling situation. Pups at 10 days of age were deprived of milk and their dam for 9 hr. Pyloric ligation, vagotomy, and preloading procedures were performed on the pups shortly before testing began. The initial latency to attach to a nipple and the incidence of attachment were recorded during the 2‐hr suckling period. Milk intake and the weight of gastric contents were measured following the test. Pregastric stimulation together with natural or artificial gastric filling suppressed ingestion. Acute subdiaphragmatic truncal vagotomy enhanced ingestion under these conditions, and vagotomy alone resulted in controlled hyperphagia concomitant with exaggerated gastric filling. The data suggest that the stomach is one site where milk activates a suppression mechanism for ingestion. This mechanism is mediated primarily by the vagus nerve. The importance of nipple‐attachment behavior is discussed in relation to ingestive behavior, and the question of satiety is suckling rats is raised. The chronic effects of truncal vagotomy on rat pups were also investigated, beginning with denervation at 10 days of age. The pups were challenged with deprivation and tested in the natural suckling situation on Day 20. Weaning occurred on Day 22, and the pups were sacrificed on Day 41, followed by measurements of body weight, body length, and gastric contents. The physical and behavioral changes that developed during the chronic phase of vagotomy included (1) permanent gastric distension following the first postsurgical bout of ingestion; (2) reduced intake of milk when the availability of milk was greatest during the suckling test; (3)increased resting behavior regardless of milk letdown conditions during the suckling test; (4) failure to gain weight at a normal rate; and (5) failure to grow at a normal rate.The data indicate that the vagus nerve is necessary for normal internal control of ingestion as well as normal gastric filling and emptying in the suckling rat. The inability of suckling and weanling pups to thrive in the chronic phase of vagotomy indicates that nonvagal internal controls of ingestion and digestion function adequately for survival, but they are not optimal for growth and maintenance of body weight

ISSN:0012-1630    

DOI:10.1002/dev.420160603

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

年代:1983

数据来源: WILEY

摘要:

AbstractHuman parents were asked to identify their infants on the basis of tape‐recorded cries that they had not previously heard. The cries of twenty 30‐day‐old infants were recorded just prior to a feeding, then rerecorded onto a test tape containing cries from three other infants. Eighty percent of mothers were able to recognize their infants's cries, as were 45% of fathers. An additional 140 adults (non‐‐parents) were tested in order to determine if the process of dubbing cries into test tapes had left extraneous auditory cues to infants' identities and if the foil infants were equally discriminable. The results indicated that parents' recognition was not based on extraneous cues and that, overall, the foils were appropriate distractors in the parents' task. Thus, the majority of parents can recognize their 30‐day‐old infants on the sole basis of acoustic cues contained in the infants' cries. The acoustic features that underlie this recognition are now being

ISSN:0012-1630    

DOI:10.1002/dev.420160604

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

年代:1983

数据来源: WILEY

摘要:

AbstractIn order to investigate the development of autonomic control and its relation to postnatal illness, healthy term, healthy preterm, and preterm infants who had recovered from respiratory distress syndrome (RDS) were seen around the expected date of their birth, 40 weeks conceptional age (C.A.), and again at 3 months conceptional age. Three minutes of resting EKG were collected at each age point while the infant was in a quiet, alert state. Measures of resting heart period and heart period variability were derived. Results revealed the influence of maturity and illness on autonomic activity. RDS and healthy preterm infants, at 40 weeks C.A. exhibited a pattern of small heart period compared to healthy term. RDS preterm infants at 40 weeks C.A. exhibited less overall variability than either healthy group and across age displayed less short‐term variability than the healthy infants. The data suggest that autonomic activity during the early months of life may be affected by both pre‐maturity and postnatal illness. The significance of these data in understanding term/preterm differences in the neonatal period is discus

ISSN:0012-1630    

DOI:10.1002/dev.420160605

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

年代:1983

数据来源: WILEY

摘要:

AbstractTwenty‐one monkeys continuously fed one of five diets high in tyrosine, histidine, alanine, glycine, or tryptophan between the ages of 1 and 12 months were compared with 20 controls. Social behavior either (a) while on the diet and tested in familiar groups of four or (b) while on a normal diet and paired with unfamiliar monkeys showed no effects of the high amino acid diets, confirming a previous analysis of learning abilit

ISSN:0012-1630    

DOI:10.1002/dev.420160606

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

年代:1983

数据来源: WILEY

摘要:

AbstractAlthough a number of studies have demonstrated that the relatively rapid rate of forgetting in young rats (i.e., infantile amnesia) can be alleviated by various reminder treatments, the possibility of enhancing retention by other procedures seems largely unexplored. Given the putative importance of contextual cues as sources of memory retrieval, this experiment examined whether the presence of a distinctive pharmacological state at training and testing could override infantile amnesia. Weanling rats were given pentobarbital or saline prior to Pavlovian fear‐conditioning. When tested 1 week later, subjects in the same‐state drug condition showed better retention than the same‐state saline group. This finding extends previous work on memory recovery in young animals by demonstrating alleviation of infantile amnesia without a re‐exposure to the CS or UCS during the retention i

ISSN:0012-1630    

DOI:10.1002/dev.420160607

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

年代:1983

数据来源: WILEY

摘要:

AbstractTen‐day‐old rats sustained bilateral electrolytic lesions of the parabrachial nuclei in the pons (PBN). Growth measures and tests of sensorimotor, feeding and drinking behaviors, sodium appetite, and gustatory capacities were made between age 1 and 150 days. PBN rats displayed a transient period of attentuated suckling, as evidenced by body weight loss. When tested soon after weaning, PBN rats were hyperdipsic in response to cellular dehydration and during food deprivation. This effect, however, was temporary. When tested as adults, PBN rats were hypodipsic in response to extracellular fluid volume depletion, they displayed alterations in sodium appetite, showed “exaggerated” preferences and aversions to saccharin and NaCl solutions, and they displayed attentuated quinine aversions. These results are generally similar to the behaviors of rats sustaining more central gustatory pathway lesions as adults. The functional significance of the PBN in the developing rat for preference/aversion and sodium appetite behaviors are di

ISSN:0012-1630    

DOI:10.1002/dev.420160608

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

年代:1983

数据来源: WILEY

摘要:

AbstractThe effects of two biological insults, hypothyroidism and malnutrition, incurred during pre‐ and postnatal development were compared using a newly developed test of observational learning in rats. Whereas, early hypothyroidism produced a significant impairment in observational learning in recovered rats, no indication of any impairment was observed in rats recovered from early malnutrition. These results are important in that they demonstrate that tests of advantageous learning such as observational learning are sensitive to the kinds of early biological insult that lead to permanent cognitive impairment in humans. Moreover, these data further support the concept that the cognitive impairment observed during periods of malnutrition in humans and animals is not permanen

ISSN:0012-1630    

DOI:10.1002/dev.420160609

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

年代:1983

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420160610

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

年代:1983

数据来源: WILEY

ISSN:0012-1630    

DOI:10.1002/dev.420160611

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

年代:1983

数据来源: WILEY