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[21] Involuntary processing of facial emotions studied with ERPs in anxious participants


[21] Involuntary processing of facial emotions studied with ERPs in anxious participants



Wioleta Walentowska1 & Eligiusz Wronka1

1 Psychophysiology Laboratory, Institute of Psychology, Jagiellonian University, Krakow, Poland

There is a common suggestion that trait anxiety can influence the processing of threat-related information even without reaching the level of conscious awareness. To test this hypothesis, ERPs were recorded in response to subliminally presented and backward masked faces (fearful and neutral) and non-faces in the preselected low- and high-anxious individuals. The N170 amplitude was found to be larger when elicited by faces in comparison to non-faces, however it was not found to be emotion-sensitive or modulated by the level of anxiety. Interestingly, early differences between low- and high-anxious individuals appeared within the latency of P1 component irrespective of the stimulus content. At later stages, within the EPN component, stronger negativity specific for fearful faces was recorded exclusively in the low-anxious participants. These findings indicate that anxiety level can modulate early stages of information processing (P1 component), which leads to the anxiety-related differences in involuntary emotional expression detection at later stages (EPN component).

[22]

A matter of matching: how goals and primes affect experiences of self-agency.



Anouk van der Weiden1, Henk Aarts1, & Kirsten I. Ruys2

1 Utrecht University; 2 University of Tilburg

The experience of causing action-outcomes, also referred to as the sense of self-agency, is a pervasive experience that people infer from their actions and the outcomes they produce. Recent research suggests that self-agency inferences arise from an explicit goal-directed process as well as an implicit outcome-priming process. Two experiments examined potential differences between these two processes. In these experiments, participants had the goal to produce an outcome or were primed with the outcome. Next, they performed an action in an agency-ambiguous situation, followed by an outcome that either matched or mismatched the goal or prime. After observing each outcome, participants indicated experienced self-agency over the action-outcome. Results showed that goals and outcome-primes equally enhanced self-agency overmatching outcomes. Furthermore, goals reduce self-agency over mismatching outcomes. However, outcome-primes did not affect self-agency over mismatching outcomes, and even enhanced self-agency over mismatching proximate outcomes. The differences in how goals and primes affect experienced self-agency over mismatching outcomes are explained in terms of cognitive control processes and spreading of activation. Our findings provide novel evidence that self-agency experiences result from two distinct inferential routes, and that goals and primes differentially affect the perception of our own behavior.

[23] Two ways to miss your target in Attentional Blink conditions



Chie Nakatani1 & Cees van Leeuwen1

1 KU Leuven, Belgium

We typically perceive some, but not all of the things that occur in our visual field. Certain events are missed, even when a perceiver is alert, attentive, and knows what to look for. Some of these effects are systematic. Amongst these perceptual blindness phenomena, the Attentional Blink (AB) is probably the one most widely explored. To explain the AB, several neuro-computational models have been proposed. The most recent of these, the Visual Selection and Awareness model (ViSA, Simione et al., in press) predicts the timing of certain task-relevant neural activities, such as the onset of inhibition among adjacent target and non-target items, a fast build-up of activity in visual cortices to sustain target information, and a slower, large-scale activity to consolidate target information in working memory. In particular, ViSA predicts that the onset of consolidation would be delayed in AB compared to non-AB conditions. The onsets of the predicted activities were estimated from human EEG data recordings from an Attentioanl Blink task. The analyses confirmed the model predictions. Moreover, they showed two distinct AB scenarios: failure of sustained target activation versus premature onset of consolidation activity.

[24] Disruptive and facilitative effects of consciously and unconsciously perceived rewards on cognitive performance



Claire M. Zedelius1, Harm Veling1, & Henk Aarts1

1 Utrecht University

Rewards are an effective tool to improve cognitive performance. Interestingly, recent research has shown that unconsciously perceived (i.e., subliminally presented) reward cues can improve cognitive performance just as consciously perceived reward cues do. This finding raises the question whether conscious perception of rewards adds something unique to the control over cognitive performance. Our answer is that it does. However, the capacity to consciously reflect on rewards can lead to disruptive as well as facilitative effects on performance depending on the context.

In Study 1, we established that both supraliminally as well as subliminally presented monetary rewards improved performance on a subsequent working memory task. Study 2 showed that when rewards were presented during the execution of the task, subliminal rewards still improved performance, whereas supraliminal rewards impaired performance. These findings suggest that conscious reflection on rewards can distract from ongoing cognitive processes and interfere with performance.

Study 3 demonstrated that conscious awareness of rewards can be beneficial for efficient effort investment when facing unattainable rewards. When participants were confronted with unattainable rewards, subliminally presented high vs. low rewards still improved performance, but supraliminal rewards did not. This finding suggests that consciousness helps to integrate rewards with contextual (i.e., attainability) information.

[25] Delta plots reveal the role of response inhibition in lying



Evelyne Debey1, Bruno Verschuere2, Richard Ridderinkhof2, & Jan De Houwer1

1 Ghent University, 2 University of Amsterdam

Previous research has shown that lying is accompanied by longer reaction times than truth telling. Since lying involves withholding the truth, this ‘lie effect’ (lie – truth) may be due to the time-consuming process of response inhibition. We investigated this response inhibition hypothesis on lying using the delta-plot method, in which condition differences are mapped as a function of reaction time. Delta plots prototypically have a positive slope. However, if the conditions differ in the amount of inhibition that is applied, a gradually developing inhibition process makes delta plots level off for slow responses. This leveling-off has shown to be more pronounced in people with better inhibitory control (Ridderinkhof, 2002). In two experiments, we let participants perform a reaction time task in which they alternately lied and told the truth on autobiographical questions. We hypothesized (1) that the delta plot of the lie effect would level off for slow responses and (2) that this leveling-off would be more pronounced in participants with better inhibition skills (i.e., smaller lie effects). The results of both experiments verified these predictions. Our experiments therefore support the hypothesis that response inhibition may be crucially involved in lying. Theoretical and practical implications are discussed.

[26] Analysis of the unconscious context effects



Goultchira Chakirova1,2

1 Department of Psychiatry, the University of Edinburgh, Edinburgh, UK; 2 The Human Brain Research Foundation

A significant part of perceived information is processed outside of conscious awareness. This includes not only lower level of analysis such as sensory analysis but also complex cognitive processing. Some of the consciously processed information might become unconscious (through some protective psychological defence mechanisms, for example repression or suppression). However, this information does not disappear but rather is stored even if it is believed to be forgotten, and could be retrieved. This storage of information consists of primitive instinctive impulses, desires, emotions and memories that sometimes are too stressful if they are accessed consciously. Such repressed information, however, influences human behaviour and decisions. Moreover, life scenario could be created on the basis of this repressed information. Retrieved life scenario information in four volunteers demonstrated that those scenarios were created during early childhood and were realised later. At least one of those scenarios consisted of the entire life plan including an approximate date of death. This preliminary data indicates a vital importance of understanding of the relationship between conscious and unconscious processing and provided an insight on the degree to which unconscious processes might influence our behaviour and decisions.

Poster Session II: Tuesday 4 December 12.20-14.20

[27] Sequence learning under different practice schedules in the Serial Reaction Time paradigm



Koen Homblé1 & Natacha Deroost1

1 Department of Psychology, Vrije Universiteit Brussel, Belgium

Both laboratory and field studies on motor learning have demonstrated that the organization of training can have a large influence on the acquisition of procedural skills. In general, using highly variable practice schedules is found to be more advantageous than using more structured training schedules. We investigated whether similar effects also apply for sequential learning in a Serial Reaction Time (SRT) task. Two groups of participants performed an SRT task with the same sequence under either fragmented or blocked practice conditions. Both indirect and direct measurements of implicit and explicit sequential knowledge were administered afterwards. Contrary to our expectations, the blocked practice group showed a larger implicit sequential learning effect as compared to the fragmented practice group. No differences in explicit knowledge were found between conditions. We propose that the use of different processing strategies in the SRT task might explain these results.

[28] Cognitive control, response inhibition and error detection of children with ADHD in the Stop-Signal Task: An event-related potentials study.



Magdalena Senderecka1, Jakub Szewczyk2, Krzysztof Gerc3, Roman Chmylak4, & Anna Grabowska5

1 Cognitive Science Unit, Institute of Philosophy, Jagiellonian University, Cracow, Poland; 2 Psychophysiology Laboratory, Institute of Psychology, Jagiellonian University, Cracow, Poland; 3 The Department of Developmental and Health Psychology, Institute of Applied Psychology, Jagiellonian University, Cracow, Poland; 4 NZOZ EEG-GRAF, EEG Laboratory, Cracow, Poland; 5 Nencki Institute of Experimental Biology, Warsaw, Poland

The first aim of the study was to determine whether deficient inhibitory control distinguishes children with a diagnosis of ADHD combined type from normally developing children. The second aim was to investigate error processing in ADHD children. 40 right-handed children aged between 6.9 and 12.3 years participated in the study, with 16 boys and 4 girls in each groups. Participants performed a standard Stop-Signal Task. Relative to controls, the go stimulus reaction time and the stop-signal reaction time were prolonged in ADHD children. They showed reduced P2, enhanced, delayed N2, and reduced P3 component to auditory stop-signal compared with controls in successful stop-signal trials. Additionally, the amplitude of response-locked event-related potentials, containing the ERN-Pe complex, was smaller in ADHD children. These results support the hypothesis of a complex deficit of inhibitory control, conflict monitoring, and error recognition mechanisms in ADHD. Reduced amplitude of the P2 reflects an early orienting deficit. Enhanced amplitude and delayed latency of the N2 are associated with inability to activate an urgent inhibitory process. Reduced amplitude of the P3 reflects a deficit in cognitive control operations affecting overall performance monitoring. Finally, reduced amplitude of the ERN-Pe complex is associated with impaired error detection and evaluation.

[29] The neural correlates of stimulus-driven and intentional inhibition: a comparison



Margot A. Schel1,2, Simone Kühn3, Marcel Brass3, Patrick Haggard4, & Eveline A. Crone1,2,5

1 Institute of Psychology, Leiden University, the Netherlands; 2 Leiden Institute for Brain and Cognition (LIBC), the Netherlands; 3 Department of Experimental Psychology, Ghent University, Belgium; 4 Institute of Cognitive Neuroscience, University College London, United Kingdom; 5 Department of Psychology, University of Amsterdam, the Netherlands

Response inhibition can be both externally driven, such as when a traffic light turns red, and internally driven, such as when one decides not to take another biscuit from the biscuit box. Until now the concepts of external stimulus-driven inhibition and internal intentional inhibition have never been compared in one study. The present study was set out to compare the neural correlates of these two forms of response inhibition. A group of adults (N=24, aged 18-26) performed two response inhibition tasks while lying in the scanner. Stimulus-driven inhibition was measured by a stop-signal task in which participants had to inhibit an already initiated motor-response when a stop-signal was presented. Intentional inhibition was measured by the marble task, in which participants are instructed to freely decide between acting on and inhibiting a prepotent response triggered by a rolling marble. Results showed that during both stimulus-driven and intentional inhibition a similar neural network, consisting of lateral prefrontal cortex, lateral parietal cortex and anterior cingulate cortex / presupplementary motor area, was recruited. The same neural network was also activated during intentional action. Together these results indicate that the same decision-making network is involved in stimulus-driven inhibition, intentional inhibition, and intentional action.

[30] Modulating effect of COMT genotype on the brain regions underlying proactive control process



Mathieu Jaspar1,2, Julien Grandjean1,2, Eric Salmon1, Pierre Maquet1, & Fabienne Collette1,2

1 Cyclotron Research Centre; 2 Department of Psychology: Cognition and Behavior, University of Liège, Liège, Belgium

Catechol-O-methyltransferase (COMT) is an important enzyme which degrades catecholamines, such dopamine, notably in the prefrontal cortex [1]. A large number of studies reported an effect on executive functioning of COMT genotype [2], each genotype being associated with a different COMT enzymatic activity [3].

In an event-related fMRI study, a modified form of the Stroop task was administered to three groups of 15 young adults according to their COMT val158met genotype (VV, VM and MM). Based on the theory of dual mechanisms of control [4], the Stroop task has been built to induce proactive or reactive control processes according to the task context.

Behavioral results did not show significant group differences for reaction times. However, fMRI results revealed that proactive control is specifically associated with increased activity in the anterior cingulate cortex in MM and VM groups by comparison to VV, but also with increased activity in the middle frontal gyrus in the VV and VM groups by comparison to MM.

These observations, paralleling to the higher cortical dopamine level in MM individuals, confirms our expectation of a COMT Val158Met genotype modulation of the brain regions underlying proactive control, especially in frontal areas as suggested by Braver & al. [4].
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