Implicit long-term memory for duration in young children

The aim of the present study was to investigate young children's ability to maintain in long-term memory a duration of an action they have previously experienced (i.e., implicit long-term memory for duration). Children aged 3 and 5 years were trained to produce an action for 5 s by simultaneous imitation of the experimenter's action. Then, they were tested after a retention interval lasting for 1, 24, or 48 hours (Experiment 1), or 6 days, 6 weeks, or 6 months (Experiment 2). The results showed that the young children remembered the learned duration after 48 hours and 6 months at the age of 3 and 5 years, respectively, although the temporal performance decreased at the 1 hour and the 6 weeks retention intervals for the first and the second age group. These findings are discussed in the framework of a discrepancy in the memory retention of duration as a function of the nature of the memory system, i.e., implicit or explicit.     

Attentional distraction and time perception in children

The purpose of the present study was to test the effect of attentional distraction on temporal bisection performance in 5‐ and 8‐year‐old children. During a first learning phase, children were trained to discriminate on a temporal bisection task a short standard duration (2 sec) from a long one (8 sec), presented as visual stimuli. Later, in a second testing phase, intermediate durations (3, 4, 5, 6, 7 s), including the standard durations, were presented. Children's task still was to report if it was a short standard duration or a long one. In addition, during the non‐standard duration, a distracter either did or did not appear. Results showed increasing proportions of “it is the long standard duration” (response “long”) with increasing stimulus durations in both distracter and non‐distracter conditions. However, psychophysical functions were flatter in the 5‐year‐olds than in the 8‐year‐olds, revealing their lower sensibility to time. Nevertheless, the 5‐year‐olds' proportion of long responses was higher under the distracter than in the non‐distracter condition. Consequently, the point of subjective equality (PSE), corresponding to the stimulus duration to which the subject produced 50% of responses of “long” was lower under the distracter condition as compared to the non‐distracter condition. Conversely, for the 8‐year‐olds, the PSE was significantly higher in the distracter than in the non‐distracter condition. Five‐year old children overestimated the time in the presence of an attentional distracter, whereas 8‐year olds tended to underestimate it. The leftward shift and the rightward shift of the PSE in the 5‐ and the 8‐year‐olds, respectively, were accounted for by limited‐capacity attention in the five‐year olds.     

Emotional Desensitization to Violence Contributes to Adolescents’ Violent Behavior

Many adolescents are exposed to violence in their schools, communities and homes. Exposure to violence at high levels or across multiple contexts has been linked with emotional desensitization, indicated by low levels of internalizing symptoms. However, the long-term consequences of such desensitization are unknown. This study examined emotional desensitization to violence, together with externalizing problems, as mediators of the relationship between exposure to violence in pre-adolescence and violent behavior in late adolescence. A community sample of youth (N?=?704; 48 % female; 76 % African American, 22 % Caucasian) reported on their exposure to violence in multiple settings at ages 11, 13 and 18. Internalizing and externalizing problems were assessed at ages 11 and 13; violent behavior was measured at age 18. Structural Equation Modeling showed that exposure to high levels of violence at age 11 was associated with lower levels of internalizing problems (quadratic effect) at age 13, as was exposure to violence across multiple contexts (linear effect). In turn, fewer internalizing problems and more externalizing problems at age 13 predicted more violent behavior at age 18. The results suggest that emotional desensitization to violence in early adolescence contributes to serious violence in late adolescence.     

Idiosyncratic Deals and Helping Behavior: The Moderating Role of I-deal Opportunity for Co-workers

Purpose

This study draws from social comparison theory to explore why and under which circumstances individuals receiving idiosyncratic deals (i-deals) are likely to help their co-workers.

Design

Data were collected with an alumni association of engineers. Participants completed two questionnaires (N = 182 at Time 2).

Findings

We find that the relationship between i-deals and helping behavior is not direct, but is mediated by organizational-based self-esteem. This relationship is stronger when i-deal recipients believe that their co-workers do not have the opportunity to get i-deals for themselves.

Implications

I-deal recipients are expected to help their colleagues because helping colleagues is consistent with the positive self developed thanks to i-deals. When co-workers have the opportunity to get i-deals for themselves, social comparison between the i-deal recipient and colleagues is likely to be more salient, which strengthen the indirect relationship between i-deal and helping behavior.

Originality

This study tests i-deals from the vantage point of social comparison theory rather than from the perspective of social exchange. We thereby provide a richer account of the complexities involved in helping behavior. By exploring contextual variables that are likely to trigger social comparisons, we also expect to better understand the circumstances under which i-deals are likely to be associated with helping behavior.

     

What is the impact of the explicit knowledge of sequence regularities on both deterministic and probabilistic serial reaction time task performance?

The aim of this study was to explore the role of prior explicit sequence knowledge by comparing its influence on serial reaction time (SRT) performance with either a deterministic or a probabilistic sequence. The results confirm that, with a deterministic sequence, preliminary explicit learning improves SRT performance. On the other hand, with a probabilistic sequence, the results show no advantage for SRT performance in explicit-learning conditions. In addition, by using the process dissociation procedure (Jacoby, 1991), we show that performance on a subsequent generation task was more sustained by controlled processes for participants in the explicit-learning conditions than for those in the incidental condition. On the whole, these results, showing that the influence of explicit knowledge can be suppressed in certain specific conditions, are consistent with the intervention of both implicit and explicit mechanisms in SRT tasks, and the results also show that their relative influence can be modulated by the particular demands of the task.     

Effect of normal aging on the manipulation of information in working memory

The goal of this study is to examine the central executive of working memory in normal aging, specifically focusing on its capacities to manipulate or modify the format of the to-be-recalled material. The central executive was measured with the alphabetical span procedure, during which subjects were asked to recall a random series of words in their alphabetical order. The storage demand was equalized across subjects by adjusting the list lengths according to individual span. Experiments 1, 2, and 3 showed that elderly subjects were not impaired in manipulating information, relative to young controls, even when the difficulty of the task was increased. In Experiment 4, validity was tested by asking young subjects to perform the task under the conditions of full or divided attention. Alphabetical recall was more impaired than direct recall during the divided attention condition, which suggests a larger involvement of the central executive component in the former. These results are discussed in relation to the hypothesis of a central executive impairment being associated with normal aging.     

Time flies with music whatever its emotional valence

The present study used a temporal bisection task to investigate whether music affects time estimation differently from a matched auditory neutral stimulus, and whether the emotional valence of the musical stimuli (i.e., sad vs. happy music) modulates this effect. The results showed that, compared to sine wave control music, music presented in a major (happy) or a minor (sad) key shifted the bisection function toward the right, thus increasing the bisection point value (point of subjective equality). This indicates that the duration of a melody is judged shorter than that of a non-melodic control stimulus, thus confirming that “time flies” when we listen to music. Nevertheless, sensitivity to time was similar for all the auditory stimuli. Furthermore, the temporal bisection functions did not differ as a function of musical mode.     

Yerushalmi in a French Key: (French) History and (French) Memory

This article explores the reception of Yosef Hayim Yerushalmi in France in light of the many and diverse reactions his books and lectures engendered at major conferences and meetings. It describes how the American scholar became one of the leading figures among French intellectuals after the first translation of his book Zakhor in 1984 and his first lecture at the École des Hautes Études en Sciences Sociales in 1987, which resulted in a series of annual lectures over the next ten years. Following the readings of Jacques Derrida, Paul Ric?ur, Pierre Vidal-Naquet, and François Furet, among other intellectuals, the eminent standing achieved by Yerushalmi coincided with a special “moment.” At a time when doubt was cast on the testimonies of living witnesses and when the words of Holocaust deniers and of members of the French Resistance were treated on equal terms, the politics of memory challenged the status of history and historians. This paper aims to recover the atmosphere of these past decades and to elucidate how Yerushalmi’s name has become inseparable from the issues linked with the debates about history and memory.     

Magnitude of force perception errors during static contractions of the knee extensors in healthy young and elderly individuals

The accuracy of force perception during muscular contraction has not been studied extensively, despite its importance in rehabilitation and training. The purpose of this study was to quantify the errors made by healthy young and elderly individuals in their perceptions of force produced at the knee. Four different tasks were used to evaluate the perception of force and the effect of a sensory-motor reference and simultaneous contraction on the accuracy of perception. The absolute errors were similar between groups, with values of 11.9% to 16.3%, depending on the task. The raw perception errors were greater for high levels of force (>50% of the maximal voluntary contraction, or MVC), indicating an overestimation of the forces produced for both groups. At 70% MVC, the sensory-motor reference reduced raw perception errors, and the simultaneous contraction improved the accuracy of force production. Healthy young and elderly individuals had about the same capacity to judge the muscular force of their knee extensors. Therapists involved in the training of active?elderly?individuals should be aware that the accuracy of force perception is not perfect and that these clients have the same ability as young individuals to perceive their knee extension strength.