Sequential congruency effects in implicit sequence learning

We deal with situations incongruent with our automatic response tendencies much better right after having done so on a previous trial than after having reacted to a congruent trial. The nature of the mechanisms responsible for these sequential congruency effects is currently a hot topic of debate. According to the conflict monitoring model these effects depend on the adjustment of control triggered by the detection of conflict on the preceding situation. We tested whether these conflict monitoring processes can operate implicitly in an implicit learning procedure, modulating the expression of knowledge of which participants are not aware. We reanalyze recently published data, and present an experiment with a probabilistic sequence learning procedure, both showing consistent effects of implicit sequence learning. Despite being implicit, the expression of learning was reduced or completely eliminated right after trials incongruent with the learned sequence, thus showing that sequential congruency effects can be obtained even when the source of congruency itself remains implicit.     

Inaction inertia

Inaction inertia occurs when bypassing an initial action opportunity has the effect of decreasing the likelihood that subsequent similar action opportunities will be taken. This overview of the inaction inertia literature demonstrates the impact of inaction inertia on decision making. Based on research on the causes of inaction inertia, we show that it is a multi-determined phenomenon, explained by both valuation and regret considerations. Moreover, we demonstrate how a sour grapes explanation of inaction inertia might integrate these two accounts. Furthermore, we explain when inaction inertia is most likely to occur and how it can be prevented. We conclude that the inaction inertia literature does not only add to our understanding of this intriguing phenomenon, but also contributes to related social psychological phenomena, such as the sunk cost effect, sequential decision making, decision avoidance (e.g., choice deferral, status quo bias, decisional conflict), and procrastination.     

Numerical representation: Abstract or nonabstract?

Until now it has been a commonly held view that numbers are represented abstractly in the human brain. However, a recent imaging study challenged the existence of an abstract representation at least of digits and number words, at the brain level, and argued that previous studies and paradigms were not sensitive enough to detect deviations from abstract representation at the behavioural level. The current study addressed this issue with an analysis of distance and sequential effects in magnitude classification. Previous studies that used this paradigm did not find deviation from abstract representation for digits and number words (e.g., Dehaene, 1996 Dehaene, S. 1996. The organization of brain activations in number comparison: Event-related potentials and the additive-factors method. Journal of Cognitive Neuroscience, 8: 47–68. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]; Schwarz & Ischebeck, 2000 Schwarz, W. and Ischebeck, A. 2000. Sequential effects in number comparison. Journal of Experimental Psychology: Human Perception and Performance, 26: 1606–1621. [Crossref], [PubMed], [Web of Science ®] , [Google Scholar]). However, in the current study a short stimulus–response interval was used, which reduced subjective expectancy and increased automatic processing. The current results showed deviation from abstract representation in both reaction time and accuracy and therefore support the idea that nonabstract representations of numbers do exist.     

A tutorial on adaptive design optimization

Experimentation is ubiquitous in the field of psychology and fundamental to the advancement of its science, and one of the biggest challenges for researchers is designing experiments that can conclusively discriminate the theoretical hypotheses or models under investigation. The recognition of this challenge has led to the development of sophisticated statistical methods that aid in the design of experiments and that are within the reach of everyday experimental scientists. This tutorial paper introduces the reader to an implementable experimentation methodology, dubbed Adaptive Design Optimization, that can help scientists to conduct “smart” experiments that are maximally informative and highly efficient, which in turn should accelerate scientific discovery in psychology and beyond.     

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 model.     

Sequential difficulty effects during execution of memory strategies in young and older adults

This study aimed at uncovering factors influencing execution of memory strategies and at furthering our understanding of ageing effects on memory performance. To achieve this end, we investigated strategy sequential difficulty (SSD) effects recently demonstrated by Uittenhove and Lemaire in the domain of problem solving. We found that both young and older participants correctly recalled more words using a sentence-construction strategy when this strategy followed an easier strategy (i.e., repetition strategy) or a harder strategy (i.e., mental-image strategy). These SSD effects were of equal magnitude in young and older adults, correlated significantly with Stroop performance in both young and older adults and correlated with N-back performance only in young adults. These findings have important implications for furthering our understanding of memory strategy execution and age-related variations in memory performance, as well for understanding mechanisms underlying SSD effects.     

Examining age-related movement representations for sequential (fine-motor) finger movements

Theory suggests that imagined and executed movement planning relies on internal models for action. Using a chronometry paradigm to compare the movement duration of imagined and executed movements, we tested children aged 7-11 years and adults on their ability to perform sequential finger movements. Underscoring this tactic was our desire to gain a better understanding of the age-related ability to create internal models for action requiring fine-motor movements. The task required number recognition and ordering and was presented in three levels of complexity. Results for movement duration indicated that 7-year-olds and adults were different from the other groups with no statistical distinction between 9- and 11-year-olds. Correlation analysis indicated a significant relationship between imagined and executed actions. These results are the first to document the increasing convergence between imagined and executed movements in the context of fine-motor behavior; a finding that adds to our understanding of action representation in children.     

Temporal preparation,response inhibition and impulsivity

Temporal preparation and impulsivity involve overlapping neural structures (prefrontal cortex) and cognitive functions (response inhibition and time perception), however, their interrelations had not been investigated. We studied such interrelations by comparing the performance of groups with low vs. high non-clinical trait impulsivity during a temporal preparation go no-go task. This task measured, in less than 10 min, how response inhibition was influenced both by temporal orienting of attention (guided by predictive temporal cues) and by sequential effects (produced by repetition/alternation of the duration of preparatory intervals in consecutive trials). The results showed that sequential effects produced dissociable patterns of temporal preparation as a function of impulsivity. Sequential effects facilitated both response speed (reaction times – RTs – to the go condition) and response inhibition (false alarms to the no-go condition) selectively in the low impulsivity group. In the high impulsivity group, in contrast, sequential effects only improved RTs but not response inhibition. We concluded that both excitatory and inhibitory processing may be enhanced concurrently by sequential effects, which enables the temporal preparation of fast and controlled responses. Impulsivity could hence be related to less efficient temporal preparation of that inhibitory processing.