Early Development of Empathy in Toddlers: Effects of Daily Parent–Child Interaction and Home‐Rearing Environment

The purpose of this exploratory study was to examine the effects of (a) parent–child interaction and (b) home environment on the early development of empathy in toddlers. A total of 176 Japanese families (both young children and their parents) were enrolled in this study. Laboratory assessment of children's empathy development and caregiver's rearing competence was made during a controlled observation of parent–child interaction. The results of this study suggest that of all the factors examined, the degree of parent–child interaction, the stability of long‐term parenting practices, parental attitude, and mother's mental health status were correlated with development of empathy in children. These findings provide new indicators for the development of individualized intervention methods for use in clinical practice.     

Effects of study time and meaningfulness on environmental context-dependent recognition

In two experiments, we examined whether the size of place-context-dependent recognition decreased with study time and with the meaningfulness of the to-be-remembered materials. A group of 80 undergraduates intentionally studied a list of words in a short (1.5?s per item) or a long (4.0?s per item) study-time condition (Exp. 1). Another 40 undergraduates studied lists consisting of words and nonwords in the long-study-time condition (Exp. 2). After a short retention interval, recognition for the targets was tested in the same or in a different context. Context was manipulated by means of the combination of place, subsidiary task, and experimenter. Significant context-dependent recognition discrimination was found for words in the short-study-time condition (Exp. 1), but not in the long-study-time condition (Exps. 1 and 2). Significant effects were found as well for nonwords, even in the long-study-time condition (Exp. 2). These results are explained well by an outshining account: that is, by principles of outshining and encoding specificity.     

Active maintenance of semantic representations

In research on verbal working memory, articulatory rehearsal, a maintenance mechanism for phonological representations, has undergone intensive and excellent study. Possible mechanisms for semantic representation have received less attention. However, several studies have reported a double dissociation in types of memory deficits (semantic memory difficulties vs. phonological memory difficulties). This suggests the separability of two maintenance mechanisms. The present study focused on this separability in individuals with normal memory abilities, using a dual-task interference paradigm. The results indicate a crossover interaction between memory and interference task effects: Preventing articulatory rehearsal more strongly disrupted the phonological memory task, whereas performing a tapping task that interfered with attentional control more strongly disrupted semantic memory. These results suggest that semantic representations are actively maintained by a mechanism other than phonological maintenance.     

Context-dependent effects of background colour in free recall with spatially grouped words

Three experiments investigated context-dependent effects of background colour in free recall with groups of items. Undergraduates (N=113) intentionally studied 24 words presented in blocks of 6 on a computer screen with two different background colours. The two background colours were changed screen-by-screen randomly (random condition) or alternately (alternation condition) during the study period. A 30-second filled retention interval was imposed before an oral free-recall test. A signal for free recall was presented throughout the test on one of the colour background screens presented at study. Recalled words were classified as same- or different-context words according to whether the background colours at study and test were the same or different. The random condition produced significant context-dependent effects, whereas the alternation condition showed no context-dependent effects, regardless of whether the words were presented once or twice. Furthermore, the words presented on the same screen were clustered in recall, whereas the words presented against the same background colour but on different screens were not clustered. The present results imply: (1) background colours can cue spatially massed words; (2) background colours act as temporally local context; and (3) predictability of the next background colour modulates the context-dependent effect.     

Association of maternal smoking during pregnancy and infant neurobehavioral status

The association of maternal smoking during pregnancy with neurobehavioral status was examined in 344 Japanese infants. Based on a questionnaire, their mothers were classified into three groups, Nonsmokers, Exsmokers, and Smokers. The Neonatal Behavioral Assessment Scale was administered three days after birth. Among the three groups, on the seven clusters and their 28 behavioral subscales there were no significant differences. The infants of Smokers had lower scores than those of Exsmokers and Nonsmokers on two behavioral items, general tone and peak of excitement. General tone remained significant after adjustment for covariates.     

Development of a Japanese version of the Positive and Negative Affect Schedule for Children

In this paper, the Positive and Negative Affect Schedule for Children originally developed in 1999 by Laurent, et al. was adapted for use in Japan. In Study 1, a total of 763 children in Grades 4 to 6 completed this Schedule, and 103 of them completed it again about three months later. Principal factor analysis with promax rotation identified two factors, positive and negative affect, in the Japanese version, whose alphas (over .80) and test-retest correlations (over .50) were sufficient to indicate internal consistency and stability over time. In Study 2, a total of 328 children completed the Japanese version, the Depression Self-rating Scale for Children, and the Trait Form of the State-Trait Anxiety Inventory for Children. Intercorrelations showed convergent and discriminant validity using these self-report measures of depression and anxiety. Overall these data support the reliability and validity of this Japanese version.     

Cortical activation during rhythmic hand movements performed under three types of control: an fMRI study

Echoplanar fMRI was used to measure changes in cortical activation during the performance of a simple hand movement task under three types of voluntary control. Each of three imaging series alternated a task with rest: passive (in which the experimenter moved the hand), voluntary against low resistance, and voluntary against higher resistance. Contralateral activation was observed in the supplementary motor area (SMA), the primary motor cortex (M1), and the somatosensory cortex (S1) in all three tasks in each subject, whereas ipsilateral activation differed in each cortical region for each task. SMA had the widest prevalence of ipsilateral activation in all three tasks. In the M1, ipsilateral activation was observed in all but 1 subject in the two voluntary tasks but in only a few subjects in the S1 in any of the tasks. Quantitative changes in signal intensity and spatial extent of activation differentiated the voluntary tasks from the passive task and were most pronounced in the S1.     

The effects of phrase-length order and scrambling in the processing of visually presented Japanese sentences

The present study investigated the effects of phrase length and scrambling in the processing of Japanese sentences. Reading times of short phrases, long phrases, verbs, and whole sentences, measured by the method of self-paced reading, did not differ in terms of phrase-length order and scrambling. In addition, four types of sentences constructed on the basis of phrase-length order and scrambling did not affect duration times of correctness decision-making for sentences. However, error rates differed between canonical and scrambled sentences regardless of phrase-length order. This result implies that scrambled sentences were harder to judge as correct sentences than canonical sentences. Thus, scrambling affects the appropriate integration of information, whereas phrase-length order is simply an indication of preference and not of cognitive processing. To explain the present result, the authors propose the configurational structure without movement, which predicts no difference in speed between the processing of canonical and scrambled sentences, apart from error rates.     

Bilateral lesions of the insular cortex or of the prefrontal cortex block the association between taste and odor in the rat

The neural basis for the association between taste and odor was investigated in the rat. First, behavioral procedures to study the mechanisms underlying the association between qualitative aspects of the odor and taste in rats were developed. Rats were presented with several pairings of the 0.3 mol/L NaCl solution and a flavor, and pairings of distilled water and another flavor. Then the rats received an IP injection of a furosemide to develop sodium deficiency. On the next day, the rats were presented with either of two types of odor-flavored water: water in which the flavor had been paired with NaCl, or water in which the flavor (grape or coffee) had been paired with distilled water. Normal rats avoided ingesting the water flavored with the odor previously paired with NaCl. Sodium-deprived rats, however, ingested the water flavored with that odor. Rats with lesions in either the insular cortex or in the prefrontal cortex neither preferred nor avoided the water flavored with the odor paired with NaCl. It was concluded that rats acquire association between taste and odor, and that the insular and the prefrontal cortices of the rats were involved in this association.