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Biomedical subjects

J Kagan

Publications and source records attributed to J Kagan.

At least 145 records · Page 8Linked to original sources
PubMed1982

Canalization of early psychological development.

Recent research on the infant and young child suggests that the maturation of cognitive abilities and biologicaly based temperamental dispositions plays an important role in early psychological development. The enhancement of the cognitive competence of retrieval memory displayed during the end of the first year is a prerequisite for the universal fears of infancy, and the capacities for empathy and inference appear to be necessary for the development of standards on aggression. The temperamental disposition to display inhibition and distress to the unfamiliar appears to be a stable and significant characteristic of children in the second year of life.

Child Behavior↗
PubMed1981

Antigen-induced proliferation of murine T-lymphocytes in vitro. II. The effect of different macrophage populations on the antigen-induced proliferative response.

Various macrophage-containing preparations were tested for their ability to increase the antigen-specific proliferative response of murine T-lymphocytes. The preparations examined included: peritoneal exudate cells (PEC) from mice injected with mineral oil or thioglycolate; fresh bone-marrow cells; bone marrow cells grown in culture for up to 11 days; normal spleen cells, and spleen cells from mice injected with mineral oil. The best proliferative response was obtained when the lymphocytes were supplemented with 30% spleen cells from mice injected with mineral oil. When spleen cells from mineral oil injected mice are compared with those of spleen cells from normal mice, it is evident that mineral oil given i.p. activates the spleen macrophages. Although the number and percentage of macrophages in the spleen does not increase following mineral oil injection, the activities of some of their enzymes (acid phosphatase and beta-glucuronidase) increase while others do not change (Cathepsin D and lysozyme). Furthermore, the Fc-dependent phagocytic activity of spleen macrophages and their spreading on plastic culture dishes is increased after mineral oil treatment. We conclude that the activation of spleen macrophages caused by an i.p. injection of mineral oil also induces the changes in their antigen-presenting apparatus. Consequently, macrophages from spleens of mineral oil-injected mice are most suitable cell preparations for antigen presentation to T-lymphocytes.

Animals↗
PubMed1981

The enhancement of memory in the first year.

Eleven infants were seen longitudinally at one month intervals from six through 11 months of age and administered tasks of recognition memory. The results revealed that the ability to retrieve a memory of an initially unfamiliar event that occurred more than five seconds earlier may be fragile until the child is about 10 months of age.

Discrimination Learning↗
PubMed1980

Antigen-induced proliferation of murine T-lymphocytes in vitro. I. Characterization of the lymphocyte culture system.

The present report describes further improvements in the methodology for antigen-specific T-lymphocyte activation in vitro. Following the experimental protocol, large numbers of enriched T-lymphocytes can be obtained from the draining lymph nodes of immunized mice after purification on a nylon column. These T-cells respond better to stimulation by the soluble immunizing antigen than do unfractionated lymph node cells. The magnitude of response, measured by the incorporation of [3H]thymidine, was dependent on culture conditions and percentage of macrophages added to the column-purified cells. The optimal specific proliferative response was achieved when lymphocytes were incubated with 50% spleen cells and then cultured in RPMI-1640 supplemented with 2-mercaptoethanol (5 x 10(-5) M), sodium pyruvate (1 mM), AB+ human serum (5%) and syngeneic mouse serum (0.5%). Under the optimal culture conditions the lymphocytes undergo two successive cycles of proliferation as a result of antigen or mitogen stimulation. Thus, our studies have defined the culture conditions which can support extensive antigen-induced proliferation of T-cells easily obtained in large numbers. This in vitro system of antigen-specific T-cells from lymph nodes of immunized mice is most suitable for studies on the mode of T-cell activation.

Animals↗
PubMed1980

Children's recognition memory for their drawings.

One hundred preschool boys and girls (2 1/2 and 5 1/2 year old) were asked to recognize four drawings they had made a week earlier. The child's drawing was presented with three foils which varied along the following dimensions: detail, size, and perspective. Chance performance was .25 correct; the group's performance of .34 correct was significantly different from chance (p < .0001); the oldest children's performance was .39 correct (p < .0001). These performances are impressive because of the slight variation between the target and foil drawings. The amount of differentiation in the children's drawings may be a factor in the ease of recognition.

Art↗
PubMed1979

The form of early development. Continuity and discontinuity in emergent competences.

Conceptions of psychological development devised by Western theorists have assumed connectivity of stages, stability of acquired structures, and continuity of process, and have resisted the possibility that some emerging psychological qualities might have relatively short histories. Empirical studies of the first two years of life suggest that the enhancement of retrieval memory at 8 to 10 months of age, the emergence of a linguistic set at 15 to 18 months of age, and sensitivity to standards of competence prior to the second birthday are emergent human competences that may not necessarily have a historical link to the events of early infancy. Developmental theorists should be as receptive to sequences that are relatively discontinuous as they are to those that are gradual and cumulative.

Age Factors↗
PubMed1979

The growth of memory during infancy.

Eight middle class infants were administered a series of tasks over a nine month period from 5 to 14 months of age. Major procedures included object permanence, vacillation, memory for locations and pictures, and reaction to unfamiliar adults and to separation. The results suggested that during the last half of the first year there is a major enhancement in the ability to retrieve a representation of a past event, to compare that representation with present experience, and to tolerate both longer delays between an original and transformed event and greater interference during those delays. It was suggested that many of the diverse phenomena that appear during the last half of the first year are mediated, in part, by an amplification of memorial capacity.

Attention↗
PubMed1979

A cross-cultural study of cognitive development.

This Monograph summarizes a comparative study of recall memory among children from two Guatemalan towns and one American city. The age interval of greatest improvement in serial recall of pictures, words and orientations of dolls varied across settings by as much as 4-6 years, but performance improved with age in all communities. It was suggested that the activation of varied strategies to aid recall memory emerged in all children during the preadolescent years, but environmental factors, as yet unspecified, determined both the slope of the growth function and its asymptotic level.

Adolescent↗
PubMed1978

Psychological factors in the face-hand test.

Young children's failure to report double-simultaneous stimulations of the side of the face and the contralateral hand has been attributed to cerebral deficiencies. When tested under optimal psychological conditions, 3- to 6-year-old children correctly report simultaneous stimulations of the face and contralateral hand. Performance on the face-hand test, which has been used as an index of cerebral functioning, is influenced in a significant way by the child's ease in the testing situation and understanding of the task.

Attention↗
PubMed1978

Successive visual discrimination of forms in 10-month-old infants.

The purpose of this research was to assess the infant's ability to make successive discriminations in the size of a figure. The Ss were 90 10-month-old infants who were habituated to a block figure and dishabituated on different subtle size transformations of that figure. Dishabituation data revealed that the infants were able to detect transformations which increased the area of the habituated figure by 7 percent. There was no evidence of a differentiated sensitivity to detect a change in any special location of the original figure.

Differential Threshold↗
PubMed1978

Infant antecedents of cognitive functioning: a longitudinal study.

A follow-up investigation of 35 boys and 33 girls 10 years old who had been assessed originally at 4, 8, 13, and 27 months old did not reveal strong relations between infant variables such as attentiveness, vocal excitability, irritability or activity, on the one hand, and reflection-implusivity, intelligence quotient, or reading ability at age 10. A suggestive relation was found between assimilative smiling during infancy and a reflective attitude on the Matching Familiar Figures Test and between a slow tempo of play during infancy and longer response time on a specially constructed Embedded Figures Test at age 10. Although attentiveness during infancy predicted IQ and reading ability at age 10, both infancy and childhood variables were positively correlated with social class, suggesting that experiences associated with the social class of the parents, rather than particular infant qualities, were the more important predictors of the cognitive variables at age 10. Children with high EMG levels from the flexor forearm tended to be slightly more impulsive at age 10 and less attentive at 27 months, even when the effect of social class was removed.

Achievement↗
PubMed1977

Relations between nutrition and cognition in rural Guatemala.

The nutritional status of three and four year old children, as measured by height and head circumference, is related to cognitive performance in four rural Guatemalan villages. The relationships persist when social factors are taken into account. Families in two of the villages participate in a voluntary, high protein-calorie supplementation program. In the other two villages, the families receive a vitamin and mineral supplement with one-third of the calories. Although the longitudinal study still is ongoing there is some evidence that the children who receive the higher calorie supplement (or whose mothers received it during pregnancy and lactation) are most likely to score high in cognitive performance. The results support other animal and human studies that report an association between nutrition and cognitive development. The findings, while not diminishing social environmental explantions of differences in cognitive function, suggest the worth of nutrition intervention programs in rural areas of lesser-developed countries.

Child Development↗
PubMed1976

Infant's reaction to changes in orientation of figure and frame.

Five groups of five-month-old infants observed the same horizontal arrangement of a three-element stimulus placed in a rectangular frame during a series of habituating trials. These trials were followed by either (i) additional exposure to the familiarized standard, (ii) a tringular rearrangement of the three stimulus elements, (iii) oblique rotation of the three elements, (iv) oblique rotation of the three elements and the frame, or (v) oblique rotation of the frame alone. The infants were responsive to all changes in the spatial arrangement of the three elements and to the rotation of the frame, but were less responsive to the change in the frame. The two effects were not additive.

Cues↗