Unique transitions between stimuli and responses in SRT tasks: Evidence for the primacy of response predictions

The present experiments aimed at separating the impact stimulus and response predictions have on serial learning and performance in SRT tasks. In Experiment 1, a unique transition between two of four responses in an otherwise random response sequence was triggered by ambiguous stimulus transitions, allowing local response predictions but no stimulus predictions. The data indicated explicit transition knowledge and strong performance benefits. In Experiments 2 and 3, unique transitions between two of four stimuli in otherwise random stimulus sequences allowed local stimulus predictions under conditions of ambiguous response transitions. The data indicated fragmentary explicit transition knowledge but no performance effects. Experiments 4a and 4b reveal that the inefficacy of the unique stimulus transitions in Experiments 2 and 3 was presumably due to the fact that the stimuli differed with respect to conjunctions of response relevant and response irrelevant features which participants did not have to attend. However, although in Experiments 4a and 4b unique transitions between response relevant stimuli were applied, substantial explicit transition knowledge but only marginal performance effects resulted. It is argued i) that in SRT tasks learning mechanisms are addressed that primarily strive for reliable predictions of forthcoming responses and ii) that for these mechanisms to work the predictors have to be attended. Response transitions are easily learned and used because both criteria are fulfilled. In contrast, pure stimulus transitions are learned only if the predictive stimuli are attended, and learned stimulus transitions become effective only to the extent that the predicted stimuli specify the required responses.     

Semantic categorization in the human brain: spatiotemporal dynamics revealed by magnetoencephalography

We examined the cortical representation of semantic categorization using magnetic source imaging in a task that revealed both dissociations among superordinate categories and associations among different base-level concepts within these categories. Around 200 ms after stimulus onset, the spatiotemporal correlation of brain activity elicited by base-level concepts was greater within than across superordinate categories in the right temporal lobe. Unsupervised clustering of data showed similar categorization between 210 and 450 ms mainly in the left hemisphere. This pattern suggests that well-defined semantic categories are represented in spatially distinct, macroscopically separable neural networks, independent of physical stimulus properties. In contrast, a broader, task-required categorization (natural/man-made) was not evident in our data. The perceptual dynamics of the categorization process is initially evident in the extrastriate areas of the right hemisphere; this activation is followed by higher-level activity along the ventral processing stream, implicating primarily the left temporal lobe.     

Specialization of the motor system in infancy: from broad tuning to selectively specialized purposeful actions

In executing purposeful actions, adults select sufficient and necessary limbs. But infants often move goal‐irrelevant limbs, suggesting a developmental process of motor specialization. Two experiments with 9‐ and 12‐month‐olds revealed gradual decreases in extraneous movements in non‐acting limbs during unimanual actions. In Experiment 1, 9‐month‐olds produced more extraneous movements in the non‐acting hand/arm and feet/legs than 12‐month‐olds. In Experiment 2, analysis of the spatiotemporal dynamics of infants’ movements revealed developmental declines in the spatiotemporal coupling of movements between acting and non‐acting arms. We also showed that the degree of specialization in infants’ unimanual actions is associated with individual differences in motor experience and visual attention, indicating the experience‐dependent and broad functional nature of these developmental changes. Our study provides important new insights into motor development: as in cognitive domains, motor behaviours are initially broadly tuned to their goal, becoming progressively specialized during the first year of life.     

Discrimination of five-dimensional stimuli by pigeons: Limitations of feature analysis

Pigeons were trained to discriminate between stimuli constructed using five orthogonal two-valued features. The stimuli consisted of stylized monochrome drawings of seeds. Two different training procedures (conditional and simultaneous discrimination) were used. In the first two experiments, the discrimination required was between polymorphous categories, in which a positive stimulus was defined as one in which three or more of the five features took their positive values. Discrimination in both experiments was imperfect; the pigeons' behaviour only came under the control of a subset of the available features (one to three in Experiment 1, three or four in Experiment 2). In Experiment 3, single features had to be discriminated, while the remaining features varied. It was found that all five features of the “seed” stimuli could be discriminated, but one of them was exceptionally difficult. The results show that pigeons do not reliably use all the features available to them when making category discriminations. This casts doubts on feature analysis as a basis for the excellent performance pigeons show when required to discriminate between categories of natural objects.     

But I can’t pass that far! The influence of motor skill on decision making

Objectives

The influence of motor skill on perceptual-cognitive and perceptual-motor decision making has been theorised but not verified empirically.

Method

Expert (n = 19), developmental (n = 20), and lesser-skilled netballers (n = 19) completed tests designed to evaluate three different components of domain-specific expertise: (i) motor skill-execution; (ii) perceptual-cognitive decision making; and (iii) perceptual-motor decision making.

Results

Each of the three measures was found to improve commensurate with domain-specific skill. Decisions requiring movements (perceptual-motor) elicited more accurate decision making than simple verbal responses (perceptual-cognitive), irrespective of participant skill. Although motor skill was found to be related to the successful execution of a most appropriate movement in a game situation, it was not found to limit the nature of the decision made by participants. No evidence was found to support the supposition that lesser-skilled participants bias their perceptual-cognitive decisions towards ones supported by their motor ability.

Conclusions

Results fail to comprehensively support the contemporary models for the development of perceptual-cognitive and perceptual-motor skill in sport.     

Implicit need for affiliation is associated with increased corrugator activity in a non-positive, but not in a positive social interaction

Affective changes in response to motive-relevant stimuli are a defining feature of implicit motives. We therefore expected to find an effect of individual differences in the implicit need for affiliation (nAff) on corrugator supercilii activity, an indicator of affect, when participants were confronted with nonverbal indicators of a conversational partner’s withdrawal. Participants’ nAff was assessed with a Picture Story Exercise (PSE). They were then involved in an interaction with a smiling or a neutral experimenter while their corrugator activity was measured with electromyography (EMG). As expected, we found higher corrugator activity for people high in nAff compared to people low in nAff when the experimenter kept a neutral facial expression throughout the interaction but not when he/she was smiling.     

Unmitigated agency, social support, and psychological adjustment in men with cancer

Unmitigated agency (UA), a gender-linked characteristic, has been associated with poorer cancer adjustment. Support from one's social network typically predicts adjustment but may be poorly matched to UA. The influence of UA on the utility of social support on adjustment over time is examined. Men with cancer (N=55) were assessed initially and 6 months later on three indicators of adjustment. Multilevel modeling analyses varied by adjustment indicator. UA was associated with increased cancer-related psychosocial symptoms but not depressive symptoms or cancer-related thought intrusion. Social support predicted fewer depressive symptoms and less cancer-related thought intrusion. However, a cross-level interaction revealed that the utility of social support on cancer-related thought intrusion was weaker for men with greater levels of UA. Men with cancer likely respond differently to changes in social support depending on their endorsement of UA.     

Reducing Psychotropic Medications in an Intensive Residential Treatment Center

Medication rates in behaviorally disordered children and youth have greatly increased to current high levels and are very controversial. This study examined changes in psychotropic medication use, levels of behavioral disturbance, and use of personal restraint and seclusion in a population of youth with serious behavioral disorders receiving medically directed cognitive-behavioral treatment in an intensive residential setting. The hypothesis was that there would be significant reductions in medication rates, without the unintended consequences of increased rates of problem behavior or offsetting increases in the use of seclusion or personal restraint. Results showed significant reductions in both the number of youth on medication and the average number of psychotropic medications during the residential stay. There were also significant reductions in behavioral disturbance, seclusions, and personal restraints. These results demonstrate that psychotropic medication can be significantly reduced without increases in problem behavior or the use of seclusions or personal restraints. We conclude that it is possible to significantly reduce psychotropic medication rates to far more conservative levels within the context of a clinically directed cognitive-behavioral treatment milieu.     

Psychotropic Medication Management Within Residential Treatment Centers: Physician Opinions About Difficulties and Barriers

Research has shown that between 40 and 98 % of youth entering residential treatment are taking at least one psychotropic medication and that psychotropic medication management is often an integral component of treatment in residential settings. To determine physician opinion about the difficulty of managing psychotropic medications for youth in residential treatment and to determine the resources that are used in the process, a survey study was conducted. Overall, physicians indicated that youth involved in residential settings were much more complex than those in traditional outpatient settings, due to multiple mental health diagnoses, polypharmacy, and unknown treatment histories. They also reported that many existing resources are not applicable to youth, particularly those in residential settings, and that they are difficult to read and interpret.     

Interaction Between the Parenting Alliance and Parent–Child Activities in a Clinic-Referred Sample of 2 to 18-year-olds

Several decades of research have demonstrated a link between marital, parenting, and child domains. The present study examined the nature of these links by testing the moderating effect of the parent–child relationship on the association between the parenting alliance and internalizing and externalizing problems in 324 dual-parent families of 2-to-18-year-old clinic-referred youth. Findings indicated that positive parent–child activities directly related to children’s internalizing and externalizing problems, and modified the nature of the association between the parenting alliance and internalizing problems in families of 6-to-10-year-olds. Interestingly, in families where parents engaged in fewer positive activities with their children, a strong parenting alliance actually related to greater child internalizing problems. Findings support the importance of understanding the interaction between the marital and child domains in order to effectively intervene with families of children experiencing behavior problems.