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There is a demand for ways to enhance cognitive flexibility, as it can be a limiting factor for performance in daily life. Video game training has been linked to advantages in cognitive functioning, raising the question if training with video games can promote cognitive flexibility. In the current study, we investigated if game-based computerized cognitive training (GCCT) could enhance cognitive flexibility in a healthy young adult sample (N = 72), as measured by task-switch performance. Three GCCT schedules were contrasted, which targeted: (1) cognitive flexibility and task switching, (2) attention and working memory, or (3) an active control involving basic math games, in twenty 45-min sessions across 4-6 weeks. Performance on an alternating-runs task-switch paradigm during pretest and posttest sessions indicated greater overall reaction time improvements after both flexibility and attention training as compared to control, although not related to local switch cost. Flexibility training enhanced performance in the presence of distractor-related interference. In contrast, attention training was beneficial when low task difficulty undermined sustained selective attention. Furthermore, flexibility training improved response selection as indicated by a larger N2 amplitude after training as compared to control, and more efficient conflict monitoring as indicated by reduced Nc/CRN and larger Pe amplitude after training. These results provide tentative support for the efficacy of GCCT and suggest that an ideal training might include both task switching and attention components, with maximal task diversity both within and between training games.

Behavioral and psychophysiological studies on the Simon effect have demonstrated that stimuli automatically activate spatially corresponding responses, even if their location is irrelevant to the task. Interestingly, this Simon effect is attenuated after stimulus-response incompatible trials (Gratton effect or compatibility-sequence effect), a pattern that has often been attributed to online conflict adaptation, even though an account in terms of episodic binding and retrieval is just as plausible. Here we show that the compatibility-sequence effect can be eliminated and partly reversed by rotating the boxes in which stimuli are presented in between two given trials, a manipulation that is likely to affect episodic representation but not online control. Sequential modulations of electrophysiological indicators of automatic response priming were also eliminated (N2) or even reversed in sign (LRP), suggesting that these effects are due to episodic retrieval of stimulus-response bindings but not, or to only a negligible degree, to online adaptation., (Copyright © 2011 Elsevier B.V. All rights reserved.)

People typically respond faster to a stimulus when it is accompanied by a task-irrelevant accessory stimulus presented in another perceptual modality. However, the mechanisms responsible for this accessory-stimulus effect are still poorly understood. We examined the effects of auditory accessory stimulation on the processing of visual stimuli using scalp electrophysiology (Experiment 1) and a diffusion model analysis (Experiment 2). In accordance with previous studies, lateralized readiness potentials indicated that accessory stimuli do not speed motor execution. Surface Laplacians over the motor cortex, however, revealed a bihemispheric increase in motor activation-an effect predicted by nonspecific arousal models. The diffusion model analysis suggested that accessory stimuli do not affect parameters of the decision process, but expedite only the nondecision component of information processing. Consequently, we conclude that accessory stimuli facilitate stimulus encoding. The visual P1 and N1 amplitudes on accessory-stimulus trials were modulated in a way that is consistent with multisensory energy integration, a possible mechanism for this facilitation.

The primary aim of this study was to examine how response inhibition is reflected in components of the event-related potential (ERP), using the stop-signal paradigm as a tool to manipulate response inhibition processes. Stop signals elicited a sequence of N2/P3 components that partly overlapped with ERP components elicited by the reaction stimulus. N2/P3 components were more pronounced on stop-signal trials than on no-stop-signal trials. At Cz, the stop-signal P3 peaked earlier on successful than on unsuccessful stop trials. This finding extends the horse race model by demonstrating that the internal response to the stop signal (as reflected in stop-signal P3) is not constant, but terminates at different moments in time on successful and unsuccessful stop trials. In addition, topographical distributions and dipole analysis of high density EEG recordings indicated that different cortical generators were involved in P3s elicited on successful and unsuccessful stop-signal trials. The latter results suggest that P3 on successful stop-signal trials not only reflects stop-signal processing per se, but also efficiency of inhibitory control.

This study investigated how the speed-accuracy balance is modulated by changes in the time course of motor activation and inhibition of a primed response. Responses and event-related brain potentials were recorded in a paradigm in which the first stimulus indicated the correct response with 80% validity. The remaining 20% of the trials required no response (no-go) or a response opposite to the cued hand (change trials). Subjects were instructed either to balance speed and accuracy or to emphasize speed at the cost of accuracy. Analyses of error patterns, reaction time distributions and brain potentials show that subjects can modulate the amount of activation of the primed response. More surprisingly, the engagement of inhibition of the response also varied with the speed-accuracy instruction. The results are consistent with a model where the frontothalamic loop actively controls both the activation and the inhibition of responses, depending on the current task requirements.

Traditionally, dual-task interference has been attributed to the consequences of task load exceeding capacity limitations. However, the current study demonstrates that in addition to task load, the mutual compatibility of the concurrent processes modulates whether 2 tasks can be performed in parallel. In 2 psychological refractory period experiments, task load and process compatibility were independently varied. In Experiment 1, participants performed 2 mental rotation tasks. Task load (rotation angle) and between-task compatibility in rotation direction were varied. Results suggest more considerable parallel execution of compatible than of incompatible operations, arguing for the need to attribute dual-task interference not only to structural but also to functional capacity limitations. Experiment 2 tested whether functional capacity limitations to dual-task performance can be caused only by demanding processes or whether they are also induced by relatively automatic processes. Results indicate that an irrelevant circular movement of Stimulus 2 interfered more with mental rotation of Stimulus 1 if the rotation directions were opposite than if they were equal. In conclusion, compatibility of concurrent processes constitutes an indispensable element in explaining dual-task performance. (Contains 4 tables and 7 figures.)

Compared 5-, 8-, and 11-year-olds and young adults on 6 speeded performance tasks, 4 requiring an inhibition of response activation. Analyzed reaction and inhibition times; found support for hypothesis of generalized developmental changes in response activation, but revealed less pronounced development of inhibition. Concluded that a nonselective mechanism of response inhibition seems to be fully developed during early childhood. (Author/KB)

Cognitive demands in response conflict paradigms trigger negative affect and avoidance behavior. However, not all response conflict studies show increases in physiological indices of emotional arousal, such as pupil diameter. In contrast to earlier null-results, this study shows for the first time that small (about 0.02 mm) conflict-related pupil dilation can be observed in a Simon task when stimuli do not introduce a light reflex. Results show that response-conflict in Simon trials induces both pupil dilation and reaction-time costs. Moreover, sequential analyses reveal that pupil dilation mirrors the conflict-adaptation pattern observed in reaction time (RT). Although single-trial regression analyses indicated that pupil dilation is likely to reflect more than one process at the same time, in general our findings imply that pupil dilation can be used as an indirect marker of conflict processing. [ABSTRACT FROM AUTHOR]

In the stop-signal paradigm, subjects perform a standard two-choice reaction task in which, occasionally and unpredictably, a stop-signal is presented requiring the inhibition of the response to the choice signal. The stop-signal paradigm has been successfully applied to assess the ability to inhibit under a wide range of experimental conditions and in various populations. The current study presents a set of evidence-based guidelines for using the stop-signal paradigm. The evidence was derived from a series of simulations aimed at (a) examining the effects of experimental design features on inhibition indices, and (b) testing the assumptions of the horse-race model that underlies the stop-signal paradigm. The simulations indicate that, under most conditions, the latency, but not variability, of response inhibition can be reliably estimated. [Copyright &y& Elsevier]

Examines developmental changes in one's ability to activate and inhibit speeded responses in the Netherlands. Comparison of the speeded task performance of four age groups; Developmental trajectories of the activation and inhibition of processing elements; Generality of inhibitory function; Age trends of stop performance.

Presents a study on reaction times and lateralized readiness potentials to find out whether response preparation begin after mental rotation finishes as assumed by discrete stage models. Disoriented normal or mirror-image characters as stimuli; Three experiments; Study methods; Results.