Rotem Leshem

Impulsive Decision-Making: Learning to Gamble Wisely?.

A decade ago, Bechara et al. [Bechara, A., Damasio, A. R., Damasio, H., & Anderson, S. W. (1994). Insensitivity to future consequences following damage to human prefrontal cortex. Cognition, 50, 7-15] published a paper in Cognition, introducing a Gambling Task which was designed to mimic everyday decision-making. Since then, the task has been computerized, its decision-making components have been scrutinized, and it has been employed in various patient groups, such as pathological gamblers, substance abusers, and so forth. Time and again it has been shown that while normal controls perform well on the task, it is the various target populations under scrutiny who exhibit poor performance. Yet, as we show in this paper, a total of 46% of normal individuals exhibited poor performance on the task, indicating a lack of learning. We argue that while so much importance has been placed on contrasting patients with controls, perhaps the real emphasis should lie in distinguishing among different individual profiles of performance on the task, irrespective of clinical classification. Our basic recommendation is to look at the individual data, pool when you can, and only then to contrast groups.

A Critical Look at the Relationship Between Impulsivity and Decision-Making in Adolescents: Are They Related or Separate Factors?

This study examined the relations between impulsivity and decision-making as assessed by the Iowa Gambling Task (IGT). A total of 73 nonclinical adolescents were administered self-report measures for trait impulsivity and the Wisconsin Card Sorting Test (WCST) to assess cognitive impulsivity. We found significant correlations between trait impulsivity and WCST performance among adolescents exhibiting poor performance on the IGT, and no such correlations for those adolescents performing well on the IGT. We recommend that researchers should assess performance on the IGT at the individual level in terms of learning.

Brain Development, Impulsivity, Risky Decision Making, and Cognitive Control: Integrating Cognitive and Socioemotional Processes During Adolescence—An Introduction to the Special Issue

Adolescence is a colorful and versatile period, accompanied by many contradictions and conflicts. Adolescents often desire to be different and unique in their thoughts, behaviors, outward appearanc...

The effects of attention on ear advantages in dichotic listening to words and affects

This study examined the effects of attention on ear advantages using dichotic listening to words and affects, a focused-attention paradigm. We compared the mixed condition, in which attention is switched between the ears in each trial, to the blocked condition, in which attention is directed to one ear for an entire block of trials. Results showed a decreased right ear advantage for word processing only in the mixed condition and an increased left ear advantage for emotion processing in both attention conditions for hits index. The mixed condition showed smaller laterality effects than the blocked condition for words with respect to hits index, while increasing right ear predominance for intrusions. The greater percentage of intrusions in the right ear for the word task and in the mixed condition suggests that the right ear (left hemisphere) is most vulnerable to attention switching. We posit that the attention manipulation has a greater effect on word processing than on emotion processing and propose that ear advantages reflect a combination of the effects of attentional and structural constraints on lateralisation.

The effects of sad prosody on hemispheric specialization for words processing

This study examined the effect of sad prosody on hemispheric specialization for word processing using behavioral and electrophysiological measures. A dichotic listening task combining focused attention and signal-detection methods was conducted to evaluate the detection of a word spoken in neutral or sad prosody. An overall right ear advantage together with leftward lateralization in early (150-170 ms) and late (240-260 ms) processing stages was found for word detection, regardless of prosody. Furthermore, the early stage was most pronounced for words spoken in neutral prosody, showing greater negative activation over the left than the right hemisphere. In contrast, the later stage was most pronounced for words spoken with sad prosody, showing greater positive activation over the left than the right hemisphere. The findings suggest that sad prosody alone was not sufficient to modulate hemispheric asymmetry in word-level processing. We posit that lateralized effects of sad prosody on word processing are largely dependent on the psychoacoustic features of the stimuli as well as on task demands.

Using Dual Process Models to Examine Impulsivity Throughout Neural Maturation

ABSTRACT The multivariate construct of impulsivity is examined through neural systems and connections that comprise the executive functioning system. It is proposed that cognitive and behavioral components of impulsivity can be divided into two distinct groups, mediated by (1) the cognitive control system: deficits in top-down cognitive control processes referred to as action/cognitive impulsivity and (2) the socioemotional system: related to bottom-up affective/motivational processes referred to as affective impulsivity. Examination of impulsivity from a developmental viewpoint can guide future research, potentially enabling the selection of more effective interventions for impulsive individuals, based on the cognitive components requiring improvement.

Reproduction of duration: how should i count the ways?

We take a close look at the task of prospective time reproduction, wherein an individual is aware of the fact that she will subsequently be asked to reproduce a demarked duration. Our participants were either explicitly instructed not to count, or were allowed to count. When participants are allowed to count, their reproductions (R) tend to be a linear function of target duration (D). When instructed not to count, they exhibited a shorter log(R) mean value than those who were allowed to count. Participants not counting are thus less veridical in time estimation. Given that for them β<1, this suggests that subjective time for them is not a linear function of physical time. We further contrast four major indices relating reproduced time to target duration: R/D, D/R, |R−D|, and |R−D|/D. While the D/R ratio score detected the difference between groups; this was not the case for the other measures.

Sensation seeking and risk-taking

Abstract Adolescence is a period that embodies great potential for growth and development, and this is also a period of heightened vulnerability for risky behaviors. There are normative increases in sensation seeking and risk-taking during early adolescence, and peer associations influence the expression of sensation seeking in risk-taking. Emergent models of brain development suggest that changes in relative preferences for immediate versus long-term rewards are mediated by a socioemotional network, which undergoes extensive remodeling early in adolescence. In contrast, changes in impulse control, planning, and other higher-order cognitive functions mediated by the cognitive control system mature more gradually over a longer period of time, into early adulthood. Neurobiological changes during adolescence are likely to play an integral role in the relationship between sensation seeking and adolescent risk-taking exhibited in conduct disorder (CD). High impulsive sensation seeking, coupled with low (neurobiologically-mediated) cognitive control, increases the risk for CD, particularly given a context of affiliation with deviant peers. We describe important future directions and highlight possible intervention and policy implications.