Prefrontal cortex and action sequences: a review on neural computational models

The prefrontal cortex (PFC) can be considered the central executive of cognitive control, responsible for the flexibility of human behavior. By a switching-mechanism PFC can update rules and goals representations stored in working memory, so as to performance novel task and accomplish complex routines. PFC functional organization and relation with specific subcortical areas give an account of representations active mantainance that allows to achieve a goal through a series of sub-goals. On the basis of the most recent studies, we present a rieview of the theories concerning PFC role and neural computational models. The paper incudes a focus section on models developed to study the role of PFC in action-sequences learning and performin

Postural Sway and Brain Hemispheric Power Spectral Density Under Different Attentional Focus Conditions

The purpose of this study was to determine the differences, if any, in the root mean square error (RMSE) of postural sway and hemispheric power spectral density (PSD) in the alpha and beta bands (8-12Hz and 12-25Hz) during different conditions of attentional focus (i.e., internal focus (IF), and external focus (EF) and a control condition (C)). Previous studies have shown that the adoption of IF and EF significantly alter motor performance and that EF promotes automaticity (Wulf, 2013). Sports performance and balance studies utilizing EEG spectral analyses report increased alpha oscillations during expert performance and stable balance and increased beta oscillations during novice performances and challenging balance tasks. The present study was the first to examine the effects of attentional focus on postural sway and hemispheric PSD of EEG readings. Fifteen participants (N=15) were given instructions (i.e., C, stand still ; IF, keep your feet still ; EF, keep the platform still ) while standing on an unstable, compliant surface. Data were recorded for 3 minutes 45 seconds per condition. Results of the analyses were compared within subject. Postural sway analysis did not reveal differences between conditions but did show higher RMSE values in the anterior-posterior than the medial-lateral directions. The EEG PSD analyses revealed significant Condition x Frequency interaction within the right hemisphere for alpha and beta frequencies. The control condition had more power density than did the external or internal focus conditions. Also, the left hemisphere had more power density in the beta band in the control condition than the other focus conditions. There were not, however, differences between external and internal focus in either hemisphere or frequency band. Possible limitations of the study and suggestions for future inquiries are discussed

A Dual-Pathway Neural Network Model of Control Relinquishment in Motor Skill Learning

Cognitive psychologists have long recognized that the acquisition of a motor skill involves a transition from attention-demanding controlled processing to more fluent automatic processing. Neuroscientific studies suggest that controlled and automatic processing rely on two largely distinct neural pathways. The controlled pathway, which includes the prefrontal cortex, is seen as acquiring declarative representations of skills. In comparison, the automatic pathway is thought to develop procedural representations. Automaticity in motor skill learning involves a reduction in dependence on frontal systems and an increased reliance on the automatic pathway. In this paper, we propose a biologically plausible computational model of motor skill automaticity. This model offers a dual-pathway neurocomputational account of the translation of declarative knowledge into procedural knowledge during motor learning. In support of the model, we review some previously reported human experimental results involving the learning of a sequential key pressing task, and we demonstrate, through simulation, how the model provides a parsimonious explanation for these results.