Dissecting the brain's internal clock: how frontal-striatal circuitry keeps time and shifts attention.

The ability of organisms to time and coordinate temporal sequences of events and to select particular aspects of their internal and external environments to which they will attend is vital to the organism's ability to adapt to the world around them. Numerous psychological theories have been proposed that describe how organisms might accomplish such stimulus selection and represent discrete temporal events as well as rhythm production. In addition, a large number of studies have demonstrated that damage to the frontostriatal circuitry appears to compromise the ability of organisms to successfully shift attention and behavior to adapt to changing temporal contexts. This suggests that frontostriatal circuitry is involved in the ability to make such shifts and to process temporal intervals. A selective review is accomplished in this article which focuses upon the specific neural mechanisms that may be involved in interval timing and set shifting. It is concluded that prefrontal cortex, substantia nigra pars compacta, pedunculopontine nucleus, and the direct and indirect pathways from the caudate to the thalamus may provide the neuroanatomical and neurophysiological substrates that underlie the organism's ability to shift its attention from one temporal context to another.     

Women’s Attitudes Toward Testing for Fragile X Carrier Status: A Qualitative Analysis

Fragile X syndrome (FXS) is primarily due to a repeat expansion mutation found in the FMR1 X-linked gene. We have conducted a qualitative analysis of responses from women concerning their attitudes toward testing for carrier status of the fragile X mutation among reproductive-age women. We obtained responses from focus groups including women with and without FXS in their families. We found the following themes: (1) mothers of children with FXS have difficulty formulating their opinions on population screening because of their unique experiences surrounding their own carrier diagnosis and their relationship with their children with FXS, (2) the motivation for carrier testing and need for information differ by family history of FXS and parental status, and (3) the timing of carrier testing with respect to a woman’s life stage dictates whether carrier information will be viewed as beneficial or detrimental. There was evidence that non-carrier women from the general population would be wholly unprepared for positive carrier results. These findings have significant implications for genetic counseling as well as for population screening.     

Sugar ingestion and dichotic listening: Increased perceptual capacity is more than motivation

Participants ingested a sugar drink or a sugar-free drink and then engaged in a pair of dichotic listening tasks. Tasks presented category labels then played a series of word pairs, one in the left ear and one in the right. Participants attempted to identify pairs containing a target category member. Target category words were homonyms. For example, arms appeared as a target in the “body parts” category. Nontargets that played along with targets were related to a category-appropriate version of the target (e.g., sleeves), a category-inappropriate version (e.g., weapons), or were unrelated to either version of the target (e.g., plant). Hence, an effect of nontarget type on number of targets missed was evidence that participants processed nontargets for meaning. In the divided attention task, participants monitored both ears. In the focused attention task, participants monitored the left ear. Half the participants in each group had the divided attention task before the focused attention task; the other half had the focused attention task before the divided attention task. We set task lengths to about 12 min so working on the first task would give sufficient time for metabolizing sugar from the drink before the start of the second task. Nontarget word type significantly affected targets missed in both tasks. Drink type affected performance in the divided attention task only after sufficient time for converting sugar into blood glucose. The result supports an energy model for the effect of sugar ingestion on perceptual tasks rather than a motivational model.     

Just following orders? The rhetorical invocation of ‘obedience’ in Stanley Milgram's post‐experiment interviews

Recent research has begun to challenge the received idea that Milgram's ‘obedience’ experiments are demonstrations of obedience as typically understood (i.e., as social influence elicited in response to direct orders). One key warrant for explaining the studies in terms of obedience has been the post‐experiment interviews conducted with participants. The present study uses data from archived audio recordings of these interviews to highlight the extent to which participants used rhetorical strategies emphasising obedience when pressed by the interviewer to account for their behaviour. Previous research that has used these accounts as reports of underlying processes misses the extent to which they performed particular social actions in the context of their production. It is concluded that the standard social psychological version of ‘obedience’ is present in the experiments after all, but in a rather different way than is typically assumed—rather than an empirical finding, obedience is a participants' resource.     

The influence of aging on preferences for sequences of mixed affective events

Research on preferences among sequences of mixed affective events has mostly used young adults as participants. Given differences due to aging in people's ability to regulate emotion, one could expect differences due to aging in preferences for different sequences. Study 1 demonstrated age‐related differences in how older adults (age 65 and older) versus young adults (age 18–25) choose to order mixed affective events that will occur over time. The tendency to choose sequences in which the final event is positive was greater among older adults versus young adults. And, more so than young adults, older adults preferred that the positive and negative events in a sequence be separated in time by a neutral event. Studies 2–3 investigated age‐related differences in overall retrospective evaluations of presented sequences of mixed affective events. In contrast to young adults, older adults' retrospective evaluations were not affected by: (1) whether the final trend of the sequence improved monotonically; (2) whether the last event in the sequence was positive; or (3) the temporal proximity of positive and negative events in the sequence. Results of Study 3 suggest that these age‐related differences are due to differences in older (vs. young) adults' ability to regulate emotion. Copyright © 2010 John Wiley & Sons, Ltd.     

Idiodynamic Profiles of Cardiovascular Activity: A P-technique Approach

A study was conducted to expand the conventional view of cardiovascular (CV) reactivity by using the idiodynamic paradigm for investigation of individuals. Patterns of autonomic CV regulation were assessed in six subjects across diverse laboratory tasks on three separate occasions. Individual CV profiles were derived from these data with P-technique factor analysis, and then group aggregated with chain P-technique. The composite pattern suggested a three-component solution consisting of cardiac rate, cardiac contractility, and peripheral resistance factors. Individual profiles were compared to the composite pattern; these profiles differed in the number of components derived, percentage variance explained by these components, and relative dominance of specific CV components. A hypothesis that emerged is that the subjects differed in the complexity of CV control. It appears that the idiodynamic framework, combined with novel research designs and statistical methods, may help expand the view of CV reactivity beyond the traditional unitary view as response magnitude.     

Preference Assessment for Dimensions of Reinforcement to Inform Token Economies Targeting Problem Behavior

The purpose of the current two-experiment study was to examine the use of a preference assessment for dimensions of reinforcement to inform an effective token economy arrangement. Three participants diagnosed with developmental disabilities who engaged in negatively reinforced problem behavior participated in this study. During Experiment 1, a preference assessment for four dimensions of reinforcement (i.e., quality, immediacy, magnitude, and rate) occurred to inform a more- and less-preferred token economy arrangement. During Experiment 2, a treatment evaluation compared these two token economy arrangements. Results for all three participants showed lower rates of problem behavior under the more-preferred token economy arrangement compared to the less-preferred token economy arrangement. Rates of task completion were higher under the more-preferred token economy arrangement for one of the three participants. Results are discussed in terms of their practical implications for clinicians and educators implementing token economies to manage problem behavior.