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OS_31. Executive control

Sunday, October 02nd,   2011 [11:30 - 13:10]


OS_31.1 - Is response inhibition attention-demanding?

Suarez , I. C. , Burle, B. , Vidal, F. & Casini, L.

Laboratoire de Neurobiologie de la Cognition,Universite de Provence,Marseille

This study was aimed at investigating whether inhibition of inappropriate response elicited by irrelevant information needs attention to be implemented. A conflict task, the Simon reaction time (RT) task, was performed either as a single task or concurrently to a secondary task (dual-task condition, DT). In Simon RT task, it is classically observed that RTs are shorter for congruent stimulus-response associations than for incongruent stimulus-response associations. Nowadays, one admits that in the incongruent stimulus-response association, the non-required response automatically activated must be inhibited and the attention refocus on the relevant response to be implemented. Interestingly, the efficiency of selective response suppression can be evaluated through the analysis of RT distribution. In Experiment 1, the secondary task was a temporal task known to be very attention demanding. RT distribution analysis revealed that the DT did not alter the inhibition process. In Experiment 2, the secondary task was a visual tracking task involving more motor control. Results showed that the DT impaired the efficiency of inhibition, suggesting that the inhibitory processes do require attentional resources but drawn from motor resources rather than perceptual ones.

OS_31.2 - Now you see it, now you don't: Controlling for contingencies and stimulus bindings eliminates the Gratton effect

Schmidt, J. & De Houwer, J.

Ghent University

The Gratton (or sequential congruency) effect is the finding that conflict effects (e.g., the Stroop and Eriksen flanker effects) are larger following congruent trials relative to incongruent trials. The standard account given for this is that a cognitive control mechanism detects conflict when it occurs and adapts to this conflict on the following trial. Others, however, have questioned the conflict adaptation account and suggested that sequential biases might account for the Gratton effect. In two experiments, contingency biases were removed from the task and stimulus repetitions were deleted to control for stimulus bindings. This eliminated the Gratton effect in the response times in both experiments, supporting a non-conflict explanation of the Gratton effect. A Gratton effect did persist in the errors of Experiment 1; however, analyses supported the hypothesis that congruency switch costs accounted for this result. In all, the conflict adaptation account faired poorly in explaining any of the reported data. Implications for future work on cognitive control are discussed.

OS_31.3 - Speed-accuracy trade-offs in response times: Better use deadlines or response signals?

Dambacher, M. 1, 2 & Hübner, R. 1

1 Cognitive Psychology, University of Konstanz, Germany
2 Zukunftskolleg, University of Konstanz, Germany

Deadlines (DL) and response signals (RS) are two well-established tools for the investigation of speed-accuracy trade-offs (SATs). While DL require responses before a pre-specified period has elapsed, responses to RS must be made immediately after an explicit signal. Thus, the detection of an additional signal in RS paradigms potentially reduces performance in the main task. Here, we compared the two techniques in a flanker task where participants indicated the parity of target digits in the presence of neutral or response-incompatible flankers. Five response intervals with upper limits from 375 to 750 ms were used in separate DL and RS sessions. Both methods yielded robust SAT functions, i.e., faster and less accurate responses for shorter intervals. Overall, the range of response times was more extended with RS. Yet, response times for late RS showed a bimodal distribution, and the flanker effect, as indicated by faster and more accurate responses for neutral than for incompatible stimuli, was smaller with RS than with DL. The data suggest that responses to RS are not a pure measure of the current state of stimulus processing but partly reflect waiting periods for the signal, potentially limiting RS-based inferences about evidence accumulation.

OS_31.4 - Towards a functional view on cognitive control areas in task-switching: adaptation of different task set components

De Baene, W. 1, 2 , Albers, A. M. 1, 2 & Brass, M. 1, 2

1 Department of Experimental Psychology, Ghent University, Belgium
2 Ghent Institute for Functional and Metabolic Imaging, Ghent University, Belgium

Although there is general agreement on which brain areas are involved in task-switching, little is known about the functional role of these cognitive control areas in different sub-processes involved in task-switching. In the present study, we used an adaptation approach to differentiate the brain areas selectively representing one of two task set components involved in task preparation: goal setting and activation of the relevant stimulus-response mapping (S-R). When selectively repeating the task goal without repeating the S-R mappings, adaptation was found in left LPFC, IPS, precuneus and posterior cingulum. These areas showed no adaptation when the S-R mappings were repeated, suggesting that these areas exclusively encode task goal information. Selectively repeating the S-R mappings, by contrast, resulted in adaptation in bilateral motor-related areas (such as pre-PMd and M1). These motor-related areas encode primarily, but not exclusively information on the S-R mappings: also repetition of the task goal led to adaptation in these areas. Adaptation to both task goal and S-R mappings was found in left SPL, IFJ and pre-SMA.

OS_31.5 - The hot hand fallacy in cognitive control

Duthoo, W. 1 , Wühr, P. 2 & Notebaert, W. 1

1 Department of Experimental Psychology. Ghent University. Ghent, Belgium.
2 Institut für Psychologie. Technische Universität Dortmund. Dortmund, Germany.

In two series of studies, the role of expectations in cognitive control was put to the test. Going back to the original interpretation of the congruency sequence effect (Gratton, Coles, & Donchin, 1992), we sought evidence for a congruency repetition bias steering attentional control. In a first experiment, we investigated how participants’ explicit predictions influenced subsequent Stroop performance. Similar to the fallacious hot hand belief in gambling, subjects overpredicted repeating stimulus events. Moreover, behavioural adjustments (i.e., a Gratton effect) were only found when subjects predicted a congruency repetition, whereas alternation predictions did not impact the Stroop effect. In a following series of studies, we manipulated expectations more implicitly. Therefore, we compared two Stroop conditions in which the amount of either congruency repetitions or congruency alternations was raised. Only in the repetition condition a Gratton effect was found, which disappeared completely when alternations outnumbered repetitions. Taken together, these findings point out the importance and validity of expectancy-based proactive control. Therefore, we propose that repetition expectancy is a variable that should be given more attention in current theorizing and modelling of cognitive control, which is characterized by an emphasis on reactive, conflict-induced control adjustments.

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