Dopaminergic and prefrontal contributions to reward-based learning and outcome monitoring during child development and aging

In many instances, children and older adults show similar difficulties in reward-based learning and outcome monitoring. These impairments are most pronounced in situations in which reward is uncertain (e.g., probabilistic reward schedules) and if outcome information is ambiguous (e.g., the relative value of outcomes has to be learned). Furthermore, whereas children show a greater sensitivity to external outcome information, older adults focus less on a rapid differentiation of rewarding outcomes. In this article, we review evidence for the idea that these phenomenologically similar impairments in learning and outcome monitoring in children and older adults can be attributed to deficits in different underlying neurophysiological mechanisms. We propose that in older adults learning impairments are the result of reduced dopaminergic projections to the ventromedial prefrontal cortex, which lead to less differentiated representations of reward value. In contrast, in children, impairments in learning can be primarily attributed to deficits in executive control, which may be due to a protracted development of the dorsal medial and lateral prefrontal cortices. We think that this framework maps well onto recent neurophysiological models of reward processing and is plausible from a broader developmental perspective.     

The effect of cognitive behavior therapy on decision making in adolescents who self-harm: a pilot study

Research shows poor decision making in adolescents who self-harm and a positive correlation between decision-making abilities and duration since last self-harm episode. This exploratory study investigated whether decision making in self-harming adolescents could be improved through treatment with a novel cognitive behavior therapy (CBT). It also investigated whether improvement in decision making following treatment was linked to self-harm cessation. Adolescent self-harmers receiving CBT (n = 24) or no treatment (n = 9) and healthy controls (n = 22) were longitudinally compared on the Iowa gambling task (IGT). Significant IGT improvements were only observed for adolescents who self-harm following CBT. CBT may benefit adolescent self-harmers and generate decision-making improvements.     

It's in the sample: the effects of sample size and sample diversity on the breadth of inductive generalization

Developmental studies have provided mixed evidence with regard to the question of whether children consider sample size and sample diversity in their inductive generalizations. Results from four experiments with 105 undergraduates, 105 school-age children (M = 7.2 years), and 105 preschoolers (M = 4.9 years) showed that preschoolers made a higher rate of projections from large samples than from small samples when samples were diverse (Experiments 1 and 3) but not when samples were homogeneous (Experiment 4) and not when the task required a choice between two samples (Experiment 2). Furthermore, when a property occurred in large and diverse samples, preschoolers exhibited a broad pattern of projection, generalizing the property to items from categories not represented in the evidence. In contrast, adults followed a normative pattern of induction and never attributed properties to items from categories not represented in the evidence. School-age children showed a mixed pattern of results.     

Self-reported experience of bullying of students who stutter: relations with life satisfaction, life orientation, and self-esteem

Self-reported self-esteem, life orientation, satisfaction with life, and bullying were examined in relation to victimization experiences among 54 students who stuttered and 54 students who did not stutter. Those who stuttered reported greater, i.e., clinically significant, victimization (44.4%) than students who did not stutter (9.2%). Significant differences were found between means for self-esteem and life orientation, with students who stuttered reporting lower self-esteem and less optimistic life orientation than those who did not stutter. In both groups of students, high victimization scores had statistically significant negative correlations with optimistic life orientation, high self-esteem, and high satisfaction with life scores. Given the increased likelihood of students who stuttered being bullied, the negative relation of adjustment variables and bullying, and the potentially negative long-term effects of bullying, increased vigilance and early intervention are discussed.     

How to Precisify Quantifiers

I here argue that Ted Sider's indeterminacy argument against vagueness in quantifiers fails. Sider claims that vagueness entails precisifications, but holds that precisifications of quantifiers cannot be coherently described: they will either deliver the wrong logical form to quantified sentences, or involve a presupposition that contradicts the claim that the quantifier is vague. Assuming (as does Sider) that the “connectedness” of objects can be precisely defined, I present a counter-example to Sider's contention, consisting of a partial, implicit definition of the existential quantifier that in effect sets a given degree of connectedness among the putative parts of an object as a condition upon there being something (in the sense in question) with those parts. I then argue that such an implicit definition, taken together with an “auxiliary logic” (e.g., introduction and elimination rules), proves to function as a precisification in just the same way as paradigmatic precisifications of, e.g., “red”. I also argue that with a quantifier that is stipulated as maximally tolerant as to what mereological sums there are, precisifications can be given in the form of truth-conditions of quantified sentences, rather than by implicit definition.     

Stereotype threat in salary negotiations is mediated by reservation salary

Women are stereotypically perceived as worse negotiators than men, which may make them ask for less salary than men when under stereotype threat (Kray et al., 2001). However, the mechanisms of stereotype threat are not yet properly understood. The current study investigated whether stereotype threat effects in salary negotiations can be explained by motivational factors. A total of 116 business students negotiated salary with a confederate and were either told that this was diagnostic of negotiating ability (threat manipulation) or not. Measures of minimum (reservation) and ideal (aspiration) salary goals and regulatory focus were collected. The finding (Kray et al., 2001) that women make lower salary requests than men when under stereotype threat was replicated. Women in the threat condition further reported lower aspiration salary, marginally significantly lower reservation salary and less eagerness/more vigilance than men. Reservation salary mediated the stereotype threat effect, and there was a trend for regulatory focus to mediate the effect. Thus, reservation salary partly explains why women ask for less salary than men under stereotype threat. Female negotiators may benefit from learning that stereotype threat causes sex-differences in motivation.     

Empathy, values, morality and Asperger's syndrome

The aims of this study were, first, to re-address the issue of empathy among people with autism conditions; second, to explore the relationships between empathy and values among autistic populations and controls; and third, to explore the capacity for moral agency among those affected by autism. We compared responses of an Asperger group (N = 41) and a control group (N = 139) to measures of self-reported empathy (Davis's IRI) and value priorities (Schwartz's PVQ). Control group results were largely in line with previous studies, such that empathy subscales of perspective taking and empathic concern showed their strongest positive and negative relations to the Schwartz self-transcendence/self-enhancement dimensions. Results for the Asperger group showed that although on the one hand there were self-reported difficulties in perspective taking and the cognitive recognition of affect, and that on the other hand there were less connections between the empathy and value measures, there was nevertheless a comparable prioritization of moral values. Conclusions suggest that different people may acquire moral values through different mechanisms.     

Relations between timing,position, and grouping in short-term memory

This article is concerned with how information about time and position in a sequence is represented in short-term memory and expressed in the dynamics of serial recall. Temporal-distinctiveness theories of memory predict that isolating a list item in time will improve recall accuracy for that item. Although the majority of research in short-term memory has failed to demonstrate a temporal isolation effect (TIE), there are occasions on which a TIE is observed. The disparity in results has been explained by assuming that participants can adaptively weight temporal and nontemporal information at retrieval, with differences between experiments promoting or discouraging reliance on time as a source of episodic information. A particular focus of the present study is the finding that the TIE is substantially observed in standard serial recall only when participants are instructed to group the list into minisequences. The findings of two experiments using instructed grouping replicated this effect but showed that it is attributable to a longer gap at the group boundary enhancing the positive effect of grouping on recall accuracy. These results show that the hierarchical representations usually associated with temporal grouping are also elicited by instructed grouping but that an additional and nonspecific benefit to recall obtains from lengthening the pause between groups. An additional role for time is identified in the timing of responses: The dynamics of input sequences tend to be mirrored in output sequences for ungrouped lists, whereas the primacy pattern in grouped lists is for a longer duration to speed access to the following group when that duration occurs at an instructed group boundary.