The roles of order,distance, and interstitial items in temporal visual statistical learning

Humans are adept at learning regularities in a visual environment, even without explicit cues to structure and in the absence of instruction—this has been termed “visual statistical learning” (VSL). The nature of the representations resulting from VSL are still poorly understood. In five experiments, we examined the specificity of temporal VSL representations. In Experiments 1A, 1B, and 2, we compared recognition rates of triplets and all embedded pairs to chance. Robust learning of all structures was evident, and even pairs of non-adjacent items in a sequentially presented triplet (AC extracted from a triplet composed of ABC) were recognized at above-chance levels. In Experiment 3, we asked whether people could recognize rearranged pairs to examine the flexibility of learned representations. Recognition of all possible orders of target triplets and pairs was significantly higher than chance, and there were no differences between canonical orderings and their corresponding randomized orderings, suggesting that learners were not dependent upon originally experienced stimulus orderings to recognize co-occurrence. Experiment 4 demonstrates the essential role of an interstitial item in VSL representations. By comparing the learning of quadruplet sets (e.g., ABCD) and triplet sets (e.g., ABC), we found learning of AC and BD in ABCD (quadruplet) sets were better than the learning of AC in ABC (triplet) sets. This pattern of results might result from the critical role of interstitial items in statistical learning. In short, our work supports the idea of generalized representation in VSL and provides evidence about how this representation is structured.     

Force and Directional Force Modulation Effects on Accuracy and Variability in Low-Level Pinch Force Tracking

The authors investigated how varying the required low-level forces and the direction of force change affect accuracy and variability of force production in a cyclic isometric pinch force tracking task. Eighteen healthy right-handed adult volunteers performed the tracking task over 3 different force ranges. Root mean square error and coefficient of variation were higher at lower force levels and during minimum reversals compared with maximum reversals. Overall, the thumb showed greater root mean square error and coefficient of variation scores than did the index finger during maximum reversals, but not during minimum reversals. The observed impaired performance during minimum reversals might originate from history-dependent mechanisms of force production and highly coupled 2-digit performance.     

Helping Peers Seek Professional Treatment for Depression Among Young South Koreans: An Application of the Theory of Planned Behavior

This study examined the applicability of the theory of planned behavior to understand factors that influence whether young South Koreans help peers with depression to seek professional counseling services. The structural equation modeling on the survey data collected from 191 South Korean students suggests that subjective norms and behavioral control could be salient factors for young South Koreans to take initiative and assist their peers in need of counseling services. Este estudio examinó la aplicabilidad de la teoría del comportamiento planificado para comprender factores que influyen sobre la decisión de jóvenes surcoreanos de ayudar a sus compañeros que sufren de depresión a buscar ayuda profesional a través de servicios de consejería. El modelo de ecuación estructural de los datos de la encuesta recogidos de 191 estudiantes surcoreanos sugiere que las normas subjetivas y el control del comportamiento podrían ser factores destacados para los jóvenes surcoreanos a la hora de tomar la iniciativa y ayudar a sus compañeros que necesitan servicios de consejería.     

The Rhythm Method: A New Method for Measuring Cognitive Load—An Experimental Dual‐Task Study

The present study joins a series of studies that used the dual‐task paradigm to measure cognitive load while learning with multimedia instruction. The goal of the current work was to develop a secondary task, to measure cognitive load in a direct and continuous way using intra‐individual, behavioral measures. The new task is achieved by utilizing internalized cues. More specifically, a previously practiced rhythm is executed continuously by foot tapping (secondary task) while learning (primary task). Precision of the executed rhythm was used as indicator for cognitive load—the higher the precision, the lower cognitive load. The suitability of this method was examined by two multimedia experiments (n₁ = 30; n₂ = 50). Cognitive load was manipulated by seductive details (Experiment 1: with vs. without) and modality (Experiment 2: on‐screen text vs. narration). Learners who learned under low cognitive load conditions (Experiment 1: without seductive details; Experiment 2: narration) showed significantly higher rhythm precision. These results provide evidence that rhythm precision allows for a precise and continuous measurement of cognitive load during learning. Copyright © 2014 John Wiley & Sons, Ltd.     

Models of recognition: A review of arguments in favor of a dual-process account

The majority of computationally specified models of recognition memory have been based on a single-process interpretation, claiming that familiarity is the only influence on recognition. There is increasing evidence that recognition is, in fact, based on two processes: recollection and familiarity. This article reviews the current state of the evidence for dual-process models, including the usefulness of the remember/know paradigm, and interprets the relevant results in terms of the source of activation confusion (SAC) model of memory. We argue that the evidence from each of the areas we discuss, when combined, presents a strong case that inclusion of a recollection process is necessary. Given this conclusion, we also argue that the dual-process claim that the recollection process is always available is, in fact, more parsimonious than the single-process claim that the recollection process is used only in certain paradigms. The value of a well-specified process model such as the SAC model is discussed with regard to other types of dual-process models.     

The adrenergic receptor α-2A gene (ADRA2A) and neuropsychological executive functions as putative endophenotypes for childhood ADHD

There is resurgent interest in the psychiatric literature in endophenotypes, variables thought to more strongly reflect the effects of candidate genes than do manifest disorders. In a sample of 176 children with attention deficit hyperactivity disorder (ADHD) and 52 of their siblings, we examined the validity of several putative endophenotypes for ADHD that represent commonly used clinical measures of multiple cognitive/neuropsychological domains of executive functions (EFs). We review their distributional normality, their relations to ADHD symptoms in probands and unaffected siblings relative to nonADHD controls, and their correlation in siblings. We also tested the EF measures’ associations with the ADRA2A gene and whether they mediated or moderated the associations between ADHD and ADRA2A. Several EF measures showed association with ADRA2A, as well as moderation, but not mediation, of its association with ADHD. Implications of the results for evaluating the validity and utility of putative endophenotype measures and for finding candidate gene effects on ADHD are discussed.     

Cultural differences in neural function associated with object processing

Behavioral research suggests that Westerners focus more on objects, whereas East Asians attend more to relationships and contexts. We evaluated the neural basis for these cultural differences in an event-related fMRI study. East Asian and American participants incidentally encoded pictures of (1) a target object alone, (2) a background scene with no discernable target object, and (3) a distinct target object against a meaningful background. Americans, relative to East Asians, activated more regions implicated in object processing, including bilateral middle temporal gyrus, left superior parietal/angular gyrus, and right superior temporal/supramarginal gyrus. In contrast to the cultural differences in object-processing areas, few differences emerged in background-processing regions. These results suggest that cultural experiences subtly direct neural activity, particularly for focal objects, at an early stage of scene encoding.     

Environmental coupling modulates the attractors of rhythmic coordination

A simple instance of coupling behavior to the environment is oscillating the hands in pace with metronome beats. This environmental coupling can be weaker (1 beat per cycle) or stronger (2 beats per cycle). The authors examined whether strength of environmental coupling enhanced the stability of in-phase bimanual coordination. Detuning by manipulanda that produced different left and right eigenfrequencies shifted the relative phase angle from 0 degrees, with the size of the shift larger for higher movement frequencies. Stronger environmental coupling was found to decrease this relative-phase shift, with accompanying increase and reduction, respectively, in recurrence quantification measures related to coordination stability and coordination noise. Stronger environmental coupling also increased oscillation amplitude. Results are considered from the perspective of parametric stabilization.