A follow-up developmental study of hypothesis behavior among mentally retarded and nonretarded children

To clarify the roles of IQ and mental age (MA) in hypothesis behavior, MA-matched subjects at three levels of IQ (70, 100, and 130) and three levels of MA ($\text{5}\text{1}\text{2}\text{, 7}\text{1}\text{2}\text{,}\text{and}\text{9}\text{1}\text{2}\text{years}$) received blank-trial discrimination learning problems using procedures designed to discourage position-oriented responding. With position responding discouraged, earlier findings were contradicted in that no hypothesis measure showed a main effect of IQ. This suggest that previously reported IQ group differences in hypothesis behavior may not reflect cognitive deficits inherently linked to low IQ, but instead may reflect the influence of specific methodological factors. The finding and interpretation are consistent with Zigler's (American Journal of Mental Deficiency, 1969, 73, 536–556) “developmental” theory of retardation and inconsistent with the general “difference” position. In additional findings, the predictions that subjects at all three MA levels would use hypotheses, and that retarded children from special-education classes would use hypotheses more often than retarded children “mainstreamed” in classes for the nonretarded were confirmed.     

Normality and impairment following profound early institutional deprivation: a longitudinal follow-up into early adolescence

Longitudinal analyses on normal versus impaired functioning across 7 domains were conducted in children who had experienced profound institutional deprivation up to the age of 42 months and were adopted from Romania into U.K. families. Comparisons were made with noninstitutionalized children adopted from Romania and with nondeprived within-U.K. adoptees placed before the age of 6 months. Specifically, the validity of the assessment, the degree of continuity and change in levels of functioning from 6 to 11 years, and the factors in the pre- and postadoption environment accounting for heterogeneity in outcome were examined. Pervasive impairment was significantly raised in children experiencing institutional deprivation for > or =6 months of life, with a minority within this group showing no impairment. There was no additional significant effect of duration of deprivation beyond the 6-month cutoff, and few other predictors explained outcome. The pattern of normality/impairment was mainly established by 6 years of age, with considerable continuity at the individual level between 6 and 11 years. The findings are discussed in terms of the possibility of a sensitive period for development.     

Electrophysiological evidence of altered memory processing in children experiencing early deprivation

Associations between early deprivation and memory functioning were examined in 9- to 11-year-old children. Children who had experienced prolonged institutional care prior to adoption were compared to children who were adopted early from foster care and children reared in birth families. Measures included the Paired Associates Learning task from the Cambridge Neuropsychological Test and Automated Battery (CANTAB) and a continuous recognition memory task during which ERPs were also recorded. Children who experienced prolonged institutionalization showed deficits in both behavioral memory measures as well as an attenuated P300 parietal memory effect. Results implicate memory function as one of the domains that may be negatively influenced by early deprivation in the form of institutional care.     

Training strategic study time apportionment in educable retarded children

Two groups of educable retarded children differing in functioning level served as subjects. One group, the High group, consisted of 31 children drawn from the upper two classes of a five-class stream. The Low group consisted of 39 children drawn from the lowest two classes. During pretesting, on each trial but the first of a multitrial free recall procedure, subjects were allowed to select half of the to-be-remembered items to see if they would strategically select missed items for extra study. Following pretesting, subjects were divided for training into three groups for which the experimenter selected items for study: in the Standard group, missed items; in the Creeping group, recalled items plus one missed item; and in the Random group, half missed and half recalled items. Children in the High group improved in the Standard condition, and those in the Low group benefited from Creeping training. There was no evidence of maintenance of training in the Low group, but children in the High group given training in the standard strategy selected missed items for recall on the posttests. The results are discussed in terms of the stability of trained strategies in retardates, and the question of what constitutes an optimal strategy is considered.     

Call for a follow-up study of experiments on long-term deprivation of human infants

Three experiments on long-term isolation and educational deprivation of infants were performed 50 years ago by Myrtle McGraw and by Wayne and Marsena Dennis. Current textbooks regularly present these studies incorrectly as supporting the notion that early motor development is unaffected by environment. This presentation is shown to be incorrect by a reanalysis of the studies which indicates severe and far-reaching negative effects of the depriving conditions upon the experimental infants. A follow-up study of the experimental subjects in later years and a publication of McGraw's unreported study are called for.     

Comments on 'Call for a follow-up study of experiments on long-term deprivation of human infants' by Micha Razel

Razel's examination of the early work of McGraw and the Dennises puts a heavy requirement on studies of single subjects and on some possible interpretations for which, unfortunately, documentation is insufficient. Further, the Dennises placed more emphasis on the autotelic quality of motor mastery than Razel notes. Rather than looking for these persons whose behavior was studied long ago, direct study of motor mastery by systematic provision of enrichment conditions during early development is more likely to be instructive and a better use of scientific resources.     

弱智儿童感知动作技能特点的实验研究

本研究以难易程度不同的两个打洞操作作业 ,对弱智儿童和正常儿童的感知 动作技能进行了多种参数的测查。结果发现 :两类儿童在理解操作要点、操作速度、操作动作协调性以及操作正确性等各个方面都有明显的差异。同时通过比较 ,对弱智儿童感知 动作技能的特点 ,从外部肢体动作方式和内部智力动作方式两方面进行了详细的分析 ,并在此基础上对弱智儿童的感知 动作技能的教育与训练提出了建议 ,这对弱智学校改革教学、提高教学质量具有重要意义。     

Control in memory for movement cues by mentally retarded children

The study was designed to determine the desirability of providing external prompts (1) to use a mnemonic to enhance accuracy of recall and (2) to use response 'priming' in memory for spatial location by mentally retarded persons. Two groups of 40 mentally retarded boys and girls and two groups of 40 MA-matched nonretarded children were compared for accuracy in the recall of movement on an arm-positioning task. No differences were found between mentally retarded subjects and MA-matched subjects treated under the same conditions. However, all groups were unable to make spontaneous control adjustments to accommodate the covert manipulations made just prior to recall. By providing response primes, appropriate performance adjustments were made by all groups, resulting in a significant improvement in accuracy of recall. These findings serve to reaffirm earlier reports showing remarkable similarity between the mentally retarded and MA-matched nonretarded subjects.     

Attention in performance of a complex skill by retarded children.

Try materials were used to train 9 retarded children to attend to differences in colors and shapes of objects, and Frostig worksheets were used to train the children to attend to left-to-right directionality. Evidence suggests Ss' ability to attend to these characteristics was generalized to a complex bead-stringing task on which significant gains in performance were found immediately after 15 days of practice with training materials and after a 6-mo. interval of no further training or practice.     

Maintenance and generalization of trained metamnemonic awareness by educable retarded children

The majority of educable retarded children (young group, MA 6; old group, MA 8) required to estimate their memory span was found to be unrealistic estimators. Following training in span estimation the older subjects improved under both explicit and implicit feedback conditions, while younger children only benefited from explicit feedback. Three posttests of the effects of training revealed long-term (1-year) maintenance of training for older subjects but younger subjects showed post-test improvement only on an immediate test. While long-term maintenance was found for older subjects, generalization to similar span-estimation tests was not found. The utility of training metamnemonic knowledge which does not generalize was questioned and alternate training procedures were proposed.