The cognitive and neural foundations of discrete motor sequencing skill:A TMS study

The dual processor model (Verwey, 2001) is a cognitive model that postulates that the production of discrete movement sequences is regulated by a cognitive processor and a motor processor. It assumes that the relative contribution of each of these processors depends on the mode in which sequences are being executed. The present study tested the core assumptions of this model at the behavioral level, and the data supported these assumptions. In a next step, we explored the neural substrate that underlies the various functions of the cognitive processor. Specifically, we targeted the pre-supplementary motor area (pre-SMA) by applying 20 min 1 Hz repetitive transcranial magnetic stimulation before performance in a test phase. We predicted its involvement specifically in the selection and initiation of motor chunks, and explored its involvement in other functions of the cognitive processor. Results demonstrated that rTMS stimulation of the pre-SMA slowed key presses reflecting chunk initiation, indicating that the pre-SMA is involved in the activation of internal sequence representations from long term memory. Pre-SMA was also found to be involved in managing sequence complexity across all key-presses. Overall, then, we provided coherent support for the dual processor model, and for the involvement of pre-SMA in various functions of the cognitive processor

Parent-child interaction therapy for preschool children with disruptive behaviour problems in the Netherlands

Background\ud Persistent high levels of aggressive, oppositional and impulsive behaviours, in the early lives of children, are significant risk factors for adolescent and adult antisocial behaviour and criminal activity. If the disruptive behavioural problems of young children could be prevented or significantly reduced at an early age, the trajectory of these behavioural problems leading to adolescent delinquency and adult antisocial behaviour could be corrected. Parent–Child Interaction Therapy (PCIT) is a short-term, evidence-based, training intervention for parents dealing with preschool children, who exhibit behavioural problems. Recently, PCIT was implemented in a Dutch community mental health setting. This present study aims to examine the short-term effects of PCIT on reducing the frequency of disruptive behaviour in young children. \ud \ud Methods\ud This study is based on the data of 37 referred families. Whereby the results of which are derived from an analysis of parent reports of the Eyberg Child Behavior Inventory (ECBI), obtained during each therapeutic session. Furthermore, demographic information, extracted from client files, was also utilized. However, it must be noted that eleven families (27.5%) dropped out of treatment before the treatment protocol was completed. To investigate the development of disruptive behaviour, a non-clinical comparison group was recruited from primary schools (N = 59). \ud \ud Results\ud The results of this study indicate that PCIT significantly reduces disruptive behaviour in children. Large effect sizes were found for both fathers and mothers reported problems (d = 1.88, d = 1.99, respectively), which is similar to American outcome studies. At post treatment, no differences were found concerning the frequency of behavioural problems of children who completed treatment and those who participated in the non-clinical comparison group. \ud \ud Conclusion\ud The findings of this study suggest that PCIT is potentially an effective intervention strategy for young children and their parents in the Dutch population. However, further research into the evaluation of PCIT using a randomised controlled trial is recommendable\u

The premotor theory of attention and the Simon effect

In the paper by Hommel (2011-this issue), the roles of the theory of event coding (TEC) and the premotor theory of attention (PMTA) for the Simon effect were considered. PMTA was treated by Hommel in terms of the proposal that attentional orienting can be viewed as the preparation of a saccade towards a certain location, and was dismissed as providing no useful contribution for an attentional explanation of the Simon effect. Here we considered a more recent and broader conception of the PMTA, compared this approach with TEC, and confronted both approaches with a few studies focusing on the role of spatial attention for the Simon effect. It was argued that PMTA may account more easily for various studies examining the influence of spatial attention on the Simon effect. We concluded our paper by listing some elements that an overall encompassing theory on the Simon effect should contai

Context-dependent motor skill and the role of practice

Research has shown that retrieval of learned information is better when the original learning context is reinstated during testing than when this context is changed. Recently, such contextual dependencies have also been found for perceptual-motor behavior. The current study investigated the nature of context-dependent learning in the discrete sequence production task, and in addition examined whether the amount of practice affects the extent to which sequences are sensitive to contextual alterations. It was found that changing contextual cues—but not the removal of such cues—had a detrimental effect on performance. Moreover, this effect was observed only after limited practice, but not after extensive practice. Our findings support the notion of a novel type of context-dependent learning during initial motor skill acquisition and demonstrate that this context-dependence reduces with practice. It is proposed that a gradual development with practice from stimulus-driven to representation-driven sequence execution underlies this practice effect

Serial action and perception

The central theme of this dissertation concerns the nature of (implicit) perceptual-motor sequence learning as studied in the serial reaction time (SRT) task. Convincing support exists in the literature for three forms of serial learning: perceptual learning (S-S associations), response-based learning (R-R associations) and response-effect learning (R-S associations). In fact, the strong evidence for these multiple forms of serial learning has gradually caused a shift away from a long held oppositional view (mainly between perceptual and response-based learning), towards the notion that sequence learning in the SRT task is a distributed, multi-level phenomenon. In Chapter 2 of the current dissertation, this multiple level notion was made more explicit by reviewing the relevant literature, and linking the notion to an existing framework for sequence learning that is referred to as the dual system model (Keele, Ivry,Mayr, Hazeltine & Heuer, 2003). Most of the empirical chapters (i.e., Chapters 3-6) were based upon the notion that sequence learning develops also at the stimulus level, either through perceptual (S-S) or response-effect (R-S) associations. In Chapter 3, the effect on sequence performance of changing seemingly task-irrelevant features of the visual display was explored, in order to determine possible context dependencies in sequence learning. Next, it was explored whether sequence learning can be guided by tactile as opposed to visual stimuli (i.e., Chapters 4 and 5), and whether sequence learning benefits from the availability of multiple, congruent response cues (i.e., Chapters 5 and 6). In Chapter 7, the final empirical chapter, the focus shifted from the stimulus to the response selection level of information processing. Through manipulating the stimulus-to-response (S-R) mapping, it aimed at further exploring the involvement of the response selection stage in (implicit) sequence learning. Finally, in chapter 8 it was explored to what extent findings on the SRT task may provide practical recommendations for the optimization of training programs for perceptual-motor skills

Distinct modes of executing movement sequences: Reacting, associating, and chunking

Responding to individual key-specific stimuli in entirely unfamiliar keying sequences is said to involve a reaction mode. With practice, short keying sequences can be executed in the chunking mode. This is indicated by the first stimulus sufficing for rapid execution of the entire sequence. The present study explored whether an associative mode develops also in participants who practice short keying sequences. This associative mode would involve priming by earlier events of responses to external stimuli, and is believed to be responsible for skill in the Serial Reaction Time task. In the present study participants practiced two discrete 6-key sequences. In the ensuing test phase, participants were prevented from using the chunking mode by including two deviant stimuli in most sequences. The results from the remaining – unchanged – familiar sequences confirmed that participants no longer used the chunking mode, but as predicted by associative learning these sequences were executed faster than unfamiliar sequence

Designing training programs for perceptual-motor skills: practical implications from the serial reaction time task = Concevoir des programmes d’entraînement pour l’acquisition d’habiletés...

Within various contexts, such as sports and the military, training programs are being designed to effectively and efficiently guide perceptual-motor skill acquisition. Even though this notion is often underestimated, the design of such training programs may greatly benefit from findings and theories from basic cognitive psychology. One particular basic paradigm that addresses this issue is the serial reaction time task. In the current article, we take on the challenge to review this paradigm from an applied point of view. We highlight a range of themes that have been explored with this paradigm that could have a direct relevance for the process of optimizing training procedures for perceptual-motor skill acquisition

What determines the impact of context on sequential action?

In the current study we build on earlier observations that memory-based sequential action is better in the original learning context than in other contexts. We examined whether changes in the perceptual context have differential impact across distinct processing phases (preparation versus execution of a motor chunk) within an ongoing movement sequence. Participants were trained on two discrete keying sequences, each of which was systematically presented in its own unique color during a practice session with either limited or extended practice. In a subsequent test session, sequences were performed with the same, with reversed, and with completely novel sequence-specific colors. The results confirm context-dependence in sequential action, the relevance of practice for its development, and its selective expression for the preparation but not the execution of highly practiced motor chunks. As such, the current study provides novel insights into the determinants of context-dependent sequential action. We finish by outlining the overall status of context-dependence in sequential motor behavior, and specify a general working mode