Exploring the role of primary and supplementary motor areas in simple motor tasks with fNIRS

Studies employing functional magnetic resonance imaging (fMRI) have highlighted a covariation between the amplitude of hemodynamic responses recorded in primary and supplementary motor areas (M1 and SMA) and the duration of a motor task. A subset of these studies have hinted to a possible functional dissociation between processing carried out in these areas, with SMA primarily involved in action preparation, while M1 involved in action execution. This proposed functional dissociation was explored in the present study using a different technique—functional near-infrared spectroscopy—which enabled a finer-grained monitoring of the temporal characteristics of the hemodynamic response compared to fMRI. Here, hemodynamic responses in M1 and SMA were recorded in 7 participants during a right-finger-tapping task of short (1 s) or long (3 s) duration. Hemodynamic responses of larger amplitude were recorded from both contralateral M1 and SMA during long-duration than short-duration tapping. Furthermore, the analysis of the temporal profiles of these responses revealed a more sustained and prolonged activity for long-duration versus short-duration tapping in M1, but not in SMA. Rather than functionally dissociable areas, the present results are more compatible with the hypothesis that M1 and SMA subserve different, though strongly interacting, functional subroutines subtended in motor task preparation and execution.     

Exploring actor-partner interdependence in family therapy: whose view (parent or adolescent) best predicts treatment progress?

Predictions of family therapy outcome consistently vary depending on which client rates the alliance. We used the actor-partner interdependence model (Kenny, Kashy, & Cook, 2006) to test the interdependence of parents' and adolescents' ratings of alliance, session depth/value, and improvement-so-far after Sessions 3, 6, and 9. Initial analyses found trivial between-therapists variance; therefore, a 3-level hierarchical model partitioned the variance in these variables into between families, between family members, and between session components. For alliance and session depth, results showed a significant parent actor effect and a significant adolescent partner effect. Specifically, when parents saw a stronger alliance, they also saw the session as more valuable, but when adolescents saw a stronger alliance, their parents saw the session as less valuable. Both the parents' and the adolescents' improvement scores showed significant linear growth over time, and adolescents' alliance ratings were positively associated with their own and their parents' views of therapeutic progress.     

Diversifying experiences enhance cognitive flexibility

Past research has linked creativity to unusual and unexpected experiences, such as early parental loss or living abroad. However, few studies have investigated the underlying cognitive processes. We propose that these experiences have in common a “diversifying” aspect and an active involvement, which together enhance cognitive flexibility (i.e., creative cognitive processing). In the first experiment, participants experienced complex unusual and unexpected events happening in a virtual reality. In the second experiment, participants were confronted with schema-violations. In both experiments, comparisons with various control groups showed that a diversifying experience – defined as the active (but not vicarious) involvement in an unusual event – increased cognitive flexibility more than active (or vicarious) involvement in normal experiences. Our findings bridge several lines of research and shed light on a basic cognitive mechanism responsible for creativity.     

A diffusion model analysis of task interference effects in prospective memory

Holding an intention often interferes with other ongoing activities, indicating that resource-demanding processes are involved in maintaining the intention and noticing the appropriate event to fulfill it. Little is known, however, about the nature of the processes underlying this task interference effect. The goal of the present research was to decompose the processes contributing to the task interference effect by applying the diffusion model (Ratcliff, Psychological Review 85:59–108, 1978) to an event-based prospective memory task. In the first experiment, we validated the interpretation of the response criterion parameter (a) of the diffusion model as reflecting strategies to cope with the anticipated demands of a prospective memory task in the context of the ongoing task. The second experiment served to investigate which underlying processes contribute to the task interference often found with prospective memory tasks. Diffusion model analyses revealed that the task interference effect was due to (1) less efficient processing in the more demanding than in the less demanding prospective memory task and (2) a more conservative response criterion. We suggest that the anticipated demands and the additional processing demands of the prospective memory task jointly contribute to the task interference effect.     

The paradox of the question

What is the best question to ask an omniscient being? The question is intriguing; is it also paradoxical? We discuss several versions of what Ned Markosian calls “the paradox of the question” and suggest solutions to each of those puzzles. We then offer some practical advice about what do if you ever have the opportunity to query an omniscient being.     

Overshadowing between landmarks on the touchscreen and in arena with pigeons

The role of generalization decrement in spatial overshadowing was evaluated using a landmark-based spatial search task in both a touchscreen preparation (Experiment 1a) and in an Automated Remote Environmental Navigation Apparatus (ARENA, Experiment 1b). A landmark appeared as a colored circle among a row of eight (touchscreen) or six (ARENA) potential locations. On overshadowing trials, Landmark X was located two positions away from a hidden goal, while another landmark, A, was in the position between X and the goal. On control trials, Landmark Y was positioned two locations away from the goal but without a closer landmark. All subjects were then tested with separate trials of A, X, Y, and BY. Testing revealed poor spatial control by X relative to A and Y, thereby replicating the spatial overshadowing effect. Spatial control by Y was similar when tested in compound with novel landmark (BY) and on trials of Y alone. Thus, overshadowing in a small-scale environment does not appear to be due to a process of generalization decrement between training and testing.     

The Suppositional Ramsey Test and Decision-Instability

I analyse the relationship between the Ramsey Test (RT) for the acceptance of indicative conditionals and the so-called problem of decision-instability. In particular, I argue that the situations which allegedly bring about this problem are troublesome just in case the relevant conditionals are evaluated by non-suppositional versions, e.g. causal/evidential, of the test. In contrast, a suppositional RT, by highlighting the metacognitive nature of the evaluation of indicative conditionals, allows an agent to run a simulation of such evaluation, without yet committing her to the acceptance of such conditionals. I conclude that a suppositional interpretation of RT is superior to its non-suppositional counterparts and by briefly showing that a suppositional RT is compatible with a deliberational decision theory.     

Motor execution affects action prediction

Previous studies provided evidence of the claim that the prediction of occluded action involves real-time simulation. We report two experiments that aimed to study how real-time simulation is affected by simultaneous action execution under conditions of full, partial or no overlap between observed and executed actions. This overlap was analysed by comparing the body sides and the movement kinematics involved in the observed and the executed action. While performing actions, participants observed point-light (PL) actions that were interrupted by an occluder, followed by a test pose. The task was to judge whether the test pose depicted a continuation of the occluded action in the same depth angle. Using a paradigm proposed by Graf et al., we independently manipulated the duration of the occluder and the temporal advance of the test pose relative to occlusion onset (occluder time and pose time, respectively). This paradigm allows the assessment of real-time simulation, based on prediction performance across different occluder time/pose time combinations (i.e., improved task performance with decreasing time distance between occluder time and pose time is taken to reflect real-time simulation). The PL actor could be perceived as from the front or back, as indicated by task instructions. In Experiment 1 (front view instructions), evidence of action simulation was obtained for partial overlap (i.e., observed and performed action corresponded either in body side or movement kinematics), but not for full or no overlap conditions. The same pattern was obtained in Experiment 2 (back view instructions), ruling out a spatial compatibility explanation for the real-time pattern observed. Our results suggest that motor processes affect action prediction and real-time simulation. The strength of their impact varies as a function of the overlap between observed and executed actions.     

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.