Executive control
Saturday, October 01st, 2011 [17:20 - 19:20]
PS_2.032 - Gender differences in inhibitory control induced by erotic pictures
Juan, C. . 1, 2 , Yu, J. 1, 2, 3 , Tseng, L. 1, 2, 3 , Muggleton, N. 1, 2, 4 , Tzeng, O. J. 1, 2, 3 & Hung, D. 1, 2, 3
1 Institute of Cognitive Neuroscience, National Central University, Jhongli, Taiwan
2 Laboratories for Cognitive Neuroscience, National Yang-Ming University, Taipei, Taiwan
3 Institute of Neuroscience, National Yang-Ming University, Taipei, Taiwan.
4 Institute of Cognitive Neuroscience, University College London, London, UK
The executive control of voluntary action involves not only choosing from a range of possible actions but also the inhibition of responses as circumstances demand. Think of driving toward a crossroads (the light is amber), do you brake or continue to accelerate? A rapid decision which may have severe consequences is required. A recent study has shown that emotional stimuli can effectively alter inhibitory control. However, whether gender may play an important role on modulating the effects of emotional stimuli in inhibitory control is unclear. The present study employed the stop signal paradigm with presentation of erotic pictures to investigate how gender differences modulate the effects of emotion on inhibitory control. Twenty-eight subjects participated in the study and the pattern of results demonstrated that only males’ inhibitory control was deteriorated by the erotic pictures by increasing their stop signal reaction times. In contrast, the erotic pictures did not affect females’ performance on the task. To our knowledge, this is the first study to demonstrate how erotic pictures affect inhibitory control and to examine the differences of the effects between genders. This study highlights the specificity of the effects of emotional stimuli in the modulation of inhibitory control.
PS_2.033 - A new method to dissociate cognitive control mechanisms
Torres-Quesada, M. , Funes , M. J. & Lupiáñez, J.
Department of Experimental Psychology and Behavioural Physiology. University of Granada. Granada.Spain
In the study of cognitive control, a debated question is whether our system counts with several control mechanisms or with a single general one. In an attempt to answer it, previous studies dissociated two well known effects related to cognitive control, conflict adaptation and proportion congruent effects, based on their ease to generalize across conflict types (Funes et al. 2010b; Torres-Quesada et al., under review). In the present experiment, we tried to dissociate both mechanisms in a more direct manner, by testing whether proportion congruent effects can still be present under conditions where conflict adaptation effects are prevented. We presented two types of conflict (Simon and Spatial Stroop) and a proportion congruent manipulation only affecting one conflict type. Our results showed that both proportion congruent and conflict adaptation effects were conflict type specific. Nevertheless, proportion congruent effects were present even in the conflict type alternation condition, that is, on the condition where conflict adaptation effects were prevented. In conclusion, we can say that proportion congruent and conflict adaptation effects can be measured independently of each other, even if both might have similar consequences on performance (both can be conflict type specific).
PS_2.034 - Voluntary task switching versus explicit task-cuing procedure in the Prader-Willi Syndrome
Postal, V. 1 , Copet, P. 2 , Jauregi, J. 3 & Thuilleaux, D. 2
1 Université Bordeaux Segalen, France.
2 Hôpital Marin AP-AH, Hendaye, France
3 University of the Basque Country Psikologia Fakultatea, Donostia, Spain.
Task-switching paradigms are widely used to study executive control. However, standard paradigms may not require active control to switch tasks. We examined voluntary task switching by having subjects choose which task to perform on a series of bivalent stimuli. Instructions were to perform the two tasks equally often and in a random order. The response-to stimulus interval (RSI) was either 100 or 1,000 ms, manipulated between blocks. The aim of this study was to compared this task with the explicit task-cuing procedure on a population presented as having some executive deficit : participants with Prader-Willi Syndrome (SPW).The results showed that the SPW have no deficit on the standard paradigm (except a cognitive slowing) but have performed less well on the voluntary task. The results are interpreted in term of a selective deficit of the switching processes, more precisely as an impairment of the top-down processes and a maintenance of the bottom-up processes.
PS_2.035 - Influence of motivational states on conflict control and error processing
Nigbur, R. & Stürmer, B.
Humboldt-Universität zu Berlin
It is still open whether improvements in cognitive control and performance monitoring are induced by positive or negative emotional states. Here, we investigated effects of appetitive and aversive motivation on the control of cognitive conflicts and error processing. We combined a Simon response conflict task in two different blocks with monetary gains and losses that were related to behavioral performance - so either the 25 % fastest responses were rewarded (reward block) or the 25 % slowest responses were penalized (punishment block). Feedback-related potential amplitudes confirmed appropriate processing of the feedback signal. To quantify selective inhibitory control of response conflict we analyzed block differences in performance via reaction time distributions. Enhanced online inhibitory control was observed in the reward but not in the punishment block. To assess error related block differences we analyzed the error-related negativity (ERN) and post-error-slowing (PES) which mirrors a shift of response threshold. ERN amplitude as well as PES were enhanced in the reward block compared to the punishment block. Our error-related results suggest that the recent reinforcement history determines current expectancy and modulates online performance monitoring. Furthermore, our results indicate that cognitive control is more flexible in positive contexts as compared to negative contexts.
PS_2.036 - Formation and maintenance of task models in a goal-neglect task: Influence of instructions and task experiences
Honma, R. , Shiozaki, M. , Utsumi, K. , Goto, T. & Saito, S.
Kyoto University
A mental model created by participants after receiving experimental instructions is referred to as a task model. It has been established that the complexity of the task model, rather than the complexity of the task itself, affects performance of the task. In this study, we examined whether different instructions for a task would generate different task models and whether the experiences during the task would modify these task models during the experimental session. Our goal-neglect task consisted of a combination of decisions about living/non-living phenomena and a target-detection task. Results indicated that two different instructions led to differential rates of goal neglect (i.e., missing targets) in the target-detection task, but that the response times for the living/non-living and the target-detection tasks did not differ as a function of different instructions. This effect was observed throughout the experimental session, suggesting that participants formed task models on the basis of verbal instructions only, irrespective of task experience, and maintained these models throughout the experimental session.
PS_2.037 - Cognitive functions among khat users
Ruiz Muñoz, M. J. 1, 2 , Colzato, L. 2 , Bajo, M. T. 1 , van den Wildenberg, W. P. 3 & Hommel, B. 2
1 Department of Psychology. Granada University. Granada, Spain
2 Cognitive Psychology Unit, and Leiden Institute for Brain and Cognition. Leiden University. Leiden, The Netherlands
3 Amsterdam Center for the Study of Adaptative Control in Brain and Behaviour, Department of Psychology. University of Amsterdam. Amsterdam, The Netherlands
Catha Edulis is a plant grown in the countries around the Red sea and Eastern Africa. Its leaves are chewed by local people for their stimulant properties. Khat leaves contains alkaloids called cathine and cathinone. These active ingredients are similar in pharmacological activity and structure to amphetamines. We investigated whether khat users show detrimental performance in updating of Working Memory, Inhibitory control and Mental Flexibility as measured by N-back task, Stop Signal task and Global-Local task respectively. We found khat users showed longer SSRTs in the Stop-Signal task than khat-free participants reflecting general slowing of inhibitory processes and indicating lower levels of inhibitory efficiency. Similarly, regular users showed a significant increase in the error rates of the N-back task, suggesting that long-term regular khat use is associated with impairments in WM updating. So this result shows an impairment in monitoring of information. This deficit in monitoring could be decisive to adapt and update the cognitive system in response to changing environments. Finally, Khat users had increased switching costs in the Global-local task, suggesting that recreational use is associated with impaired cognitive flexibility.
PS_2.038 - Response conflict as a negative learning signal
Schouppe, N. 1 , Ridderinkhof, K. R. 2 , De Houwer, J. 3 , Verguts, T. 1 & Notebaert, W. 1
1 Experimental Psychology. Ghent University. Ghent, Belgium
2 Developmental Psychology. University of Amsterdam. Amsterdam, The Netherlands
3 Experimental Clinical and Health Psychology. Ghent University. Ghent, Belgium
Recent cognitive control theories proposed that conflict is a learning signal driving behavioural adaptations. Its nature has remained unclear, however. Verguts and Notebaert (2009) proposed that conflict is an arousal signal; Botvinick (2007) conceptualized conflict as inherently aversive; and recent data suggest that conflict may act as a positive signal (Braem, Verguts, & Notebaert, in press). Here, we focus on the valence dimension of conflict. We used a preference judgement paradigm to investigate whether response conflict is associated with a positive or negative valence. Participants had to choose whether they preferred a trial from one of two categories (low- or high conflict category). Results showed a higher preference for the low-conflict category, indicating conflict avoidance. This was elaborated in a second study, using an approach-avoidance paradigm. Participants were instructed to move a manikin towards (approach) or away from (avoidance) Stroop stimuli based on the colour of the word. They were significantly faster on compatible trials (approach congruent stimuli; avoid incongruent stimuli) than on incompatible trials (approach incongruent stimuli; avoid congruent stimuli). Together, these findings suggest that response conflict is a negative learning signal resulting in avoidance behaviour.
PS_2.039 - Does inter-stimulus interval impact the strength of the stroop effect?
Galer, S. 1, 2 , Schmitz, R. 2 , De Tiège, X. 1 , Van Bogaert, P. 1 & Peigneux, P. 2, 3
1 LCFC - Laboratoire de Cartographie Fonctionnelle du Cerveau, Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium
2 UR2NF - Neuropsychology and Functional Neuroimaging Research Unit, Université Libre de Bruxelles, Brussels, Belgium
3 CRC - Cyclotron Research Center, University of Liège, Liège, Belgium
In the Stroop task, an interference effect between reading a word naming a color and its printed color is a robust phenomenon. Here we tested whether within-task variations in the interstimulus interval (ISI) may impact on this interference. Twelve healthy young adults performed a modified version of the Stroop task, where they responded by pressing buttons to the color of a color-word stimuli when the two sources of information were congruent (e.g., “red” printed in red) or incongruent (e.g., “red” printed in blue). Control stimuli, i.e. neutral words matched with each color were interspersed to annihiliate undesirable effects. Within the task, ISI was pseudo-randomly manipulated so that stimuli within each category were displayed after 1000, 1500 or 3000 msec. A repeated measures ANOVA with interval and condition as within-subject factors was computed on mean reaction times for correct responses . Results disclosed higher RTs for incongruent than congruent stimuli (p < 0.01), and than control items (p < 0.01). The main effect of the interval (p > 0.05) and the interaction between interval and category (p > 0.05) were non-significant. These results indicate that interference effects in the Stroop task are not influenced by ISI variations within this time range.