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.     

We Agree: Fat IS a Feminist Issue! Response to Commentators

In our review of the literature on women and weight bias (Fikkan and Rothblum 2011), we attempted to cull findings from multiple disciplines that demonstrate the impact (social, educational, and financial) of the stigma of women’s weight. We undertook this for two purposes: the first was to address a gap in the weight bias literature, which tends to make only a side note mention that fat women suffer worse penalties than do fat men; the second, to raise the point that feminist scholars, though highly attuned to pressures on women to be thin, have spent less time discussing the disparate impact for women of being fat, despite the mounting evidence of how much weight bias impacts women. We offered some of our own thoughts on the persisting neglect of this topic among feminist writers, despite previous calls to action (Rothblum 1992, 1994). Given the dearth of attention to what has become one of the most frequent types of discrimination against women (Puhl et al. 2008), we asked: “is fat a feminist issue?” We were delighted with the response from the commentators and the thoughtful exploration they devoted to our question and to this issue within feminist scholarship. Here, we briefly summarize some of the main themes identified by these writers, offer our own thoughts on these themes and repeat their call to action for further study of this important area of women’s lives.     

Did the Chinese Have a Change of Heart?

In their "The Prevalence of Mind-Body Dualism in Early China," Slingerland and Chudek use a statistical analysis of the early Chinese corpus to argue for Weak Folk Dualism (WFD). We raise three methodological objections to their analysis. First, the change over time that they find is largely driven by genre. Second, the operationalization of WFD is potentially misleading. And, third, dating the texts they use is extremely controversial. We conclude with some positive remarks.     

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.     

Switching in the cocktail party: exploring intentional control of auditory selective attention

Using a novel variant of dichotic selective listening, we examined the control of auditory selective attention. In our task, subjects had to respond selectively to one of two simultaneously presented auditory stimuli (number words), always spoken by a female and a male speaker, by performing a numerical size categorization. The gender of the task-relevant speaker could change, as indicated by a visual cue prior to auditory stimulus onset. Three experiments show clear performance costs with instructed attention switches. Experiment 2 varied the cuing interval to examine advance preparation for an attention switch. Experiment 3 additionally isolated auditory switch costs from visual cue priming by using two cues for each gender, so that gender repetition could be indicated by a changed cue. Experiment 2 showed that switch costs decreased with prolonged cuing intervals, but Experiment 3 revealed that preparation did not affect auditory switch costs but only visual cue priming. Moreover, incongruent numerical categories in competing auditory stimuli produced interference and substantially increased error rates, suggesting continued processing of task-relevant information that often leads to responding to the incorrect auditory source. Together, the data show clear limitations in advance preparation of auditory attention switches and suggest a considerable degree of inertia in intentional control of auditory selection criteria.     

Representational momentum in aviation

The purpose of this study was to examine the effects of expertise on motion anticipation. We conducted 2 experiments in which novices and expert pilots viewed simulated aircraft landing scenes. The scenes were interrupted by the display of a black screen and then started again after a forward or backward shift. The participant's task was to determine whether the moving scene had been shifted forward or backward. A forward misjudgment of the final position of the moving scene was interpreted as a representational momentum (RM) effect. Experiment 1 showed that an RM effect was detected only for experts. The lack of motion anticipation on the part of novices is a surprising result for the RM literature. It could be related to scene unfamiliarity, encoding time, or shift size. Experiment 2 was run with novices only. It was aimed at testing the potential impact of 2 factors on the RM effect: scene encoding time and shift size. As a whole, the results showed that encoding time and shift size are important factors in anticipation processes in realistic dynamic situations.     

The cultural narratives of Francophone and Anglophone Quebecers: using a historical perspective to explore the relationships among collective relative deprivation, in-group entitativity, and collective esteem

Responding to calls to contextualize social psychological variables in history, the present research examines the relationship between collective relative deprivation and collective esteem using a historical perspective. We hypothesized that collective relative deprivation perceived to be experienced during an important low-point in a group's history serves to define the group's current collective identity, which is in turn associated with collective esteem. In Study 1, cultural narrative interviews were conducted with Francophone and Anglophone Quebecers in order to identify key historical chapters for these groups and to examine the extent to which historical low-points were identity-defining features of their narratives. In Study 2, using the information obtained from these narratives, collective relative deprivation was explored across group members' perceived histories and related to current in-group entitativity and collective esteem. The relationship between collective relative deprivation thought to be experienced by one's group during a historical low-point and collective esteem was positive for both Anglophone and Francophone Quebecers and was mediated by in-group entitativity. Collective relative deprivation perceived to be experienced during a historical low-point serves to define one's collective identity, which is in turn associated with greater collective esteem.     

Maternal sensitivity during distressing tasks: a unique predictor of attachment security

The extent to which maternal sensitivity during a non-arousing free play task and during distressing tasks at 6 months predicted infant-mother attachment security was examined. When considered simultaneously, only maternal sensitivity during distressing tasks predicted subsequent attachment security. Infant temperament was unrelated to attachment security.     

Diagnosing fatigue in gait patterns by support vector machines and self-organizing maps

The aim of the study was to train and test support vector machines (SVM) and self-organizing maps (SOM) to correctly classify gait patterns before, during and after complete leg exhaustion by isokinetic leg exercises. Ground reaction forces were derived for 18 gait cycles on 9 adult participants. Immediately before the trials 7–12, participants were required to completely exhaust their calves with the aid of additional weights (44.4 ± 8.8 kg). Data were analyzed using: (a) the time courses directly and (b) only the deviations from each individual’s calculated average gait pattern. On an inter-individual level the person recognition of the gait patterns was 100% realizable. Fatigue recognition was also highly probable at 98.1%. Additionally, applied SOMs allowed an alternative visualization of the development of fatigue in the gait patterns over the progressive fatiguing exercise regimen.