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Stimulus Processing (stimulus + processing)

Distribution by Scientific Domains

Humanities and Social Sciences	40%

Selected Abstracts

Neural correlates of successful and partial inhibitions in children: An ERP study

DEVELOPMENTAL PSYCHOBIOLOGY, Issue 7 2009
Lucy Cragg
Abstract This experiment used event-related potentials (ERPs) to investigate the neural processes underlying the development of response inhibition in a modified version of the go/no-go paradigm [Cragg and Nation [2008] Developmental Science 11(6): 819,827]. N2 and P3 ERP components on correct go trials and partial and successful inhibitions were compared in 7- and 9-year-old children. A larger N2 effect on successful inhibitions was found in 9-year-olds compared to 7-year-olds at fronto-central electrodes. N2 amplitude was positively related to behavioral performance in the 7-year-olds suggesting it may reflect inhibitory processes; however, this relationship was not present in the 9-year-olds. Age differences were also apparent in the go P3, perhaps indicating differences in stimulus processing. The no-go P3 component was larger on successful than partial inhibitions. In contrast, there was no difference in N2 amplitude between partial and successful inhibitions. A significant difference was found in N2 latency however. This suggests that inhibitory processes are similar in both cases but initiated earlier on successful inhibitions. N2 latency was also shorter in 9-year-olds than 7-year-olds supporting an increase in the efficiency of response inhibition with age. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 533,543, 2009. [source]

Perceptual load interacts with stimulus processing across sensory modalities

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 12 2009
J. Klemen
Abstract According to perceptual load theory, processing of task-irrelevant stimuli is limited by the perceptual load of a parallel attended task if both the task and the irrelevant stimuli are presented to the same sensory modality. However, it remains a matter of debate whether the same principles apply to cross-sensory perceptual load and, more generally, what form cross-sensory attentional modulation in early perceptual areas takes in humans. Here we addressed these questions using functional magnetic resonance imaging. Participants undertook an auditory one-back working memory task of low or high perceptual load, while concurrently viewing task-irrelevant images at one of three object visibility levels. The processing of the visual and auditory stimuli was measured in the lateral occipital cortex (LOC) and auditory cortex (AC), respectively. Cross-sensory interference with sensory processing was observed in both the LOC and AC, in accordance with previous results of unisensory perceptual load studies. The present neuroimaging results therefore warrant the extension of perceptual load theory from a unisensory to a cross-sensory context: a validation of this cross-sensory interference effect through behavioural measures would consolidate the findings. [source]

On the positive side of error processing: error-awareness positivity revisited

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2009
Shani Shalgi
Abstract Performance errors are indexed in the brain even if they are not consciously registered, as demonstrated by the error-related negativity (ERN or Ne) event-related potential. It has recently been shown that another response-locked potential, the error positivity (Pe), follows the Ne, but only in those trials in which the participants consciously detect making the error (,Aware Errors'). In the present study we generalize these findings to an auditory task and investigate possible caveats in the interpretation of the Pe as an index of error awareness. In an auditory Go/No-Go error-awareness task (auditory EAT) participants pressed an additional ,fix error' button after noticing that they had made an error. As in visual tasks, the Ne was similar for aware (,fixed') and unaware (,unfixed') errors, while the Pe was enhanced only for Aware Errors. Within subjects, the Ne and Pe behaved in similar fashions for auditory and visual errors. A control condition confirmed that the awareness effect was not due to the requirement to report error awareness. These results reinforce the evidence in favor of the Pe as a correlate of conscious error processing, and imply that this process is not modality-specific. Nevertheless, single-trial analysis suggested that the Pe may be a delayed P3b related to stimulus processing rather than to response monitoring. [source]

Repetition suppression of induced gamma band responses is eliminated by task switching

EUROPEAN JOURNAL OF NEUROSCIENCE, Issue 9 2006
Thomas Gruber
Abstract The formation of cortical object representations requires the activation of cell assemblies, correlated by induced oscillatory bursts of activity >,20 Hz (induced gamma band responses; iGBRs). One marker of the functional dynamics within such cell assemblies is the suppression of iGBRs elicited by repeated stimuli. This effect is commonly interpreted as a signature of ,sharpening' processes within cell-assemblies, which are behaviourally mirrored in repetition priming effects. The present study investigates whether the sharpening of primed objects is an automatic consequence of repeated stimulus processing, or whether it depends on task demands. Participants performed either a ,living/non-living' or a ,bigger/smaller than a shoebox' classification on repeated pictures of everyday objects. We contrasted repetition-related iGBR effects after the same task was used for initial and repeated presentations (no-switch condition) with repetitions after a task-switch occurred (switch condition). Furthermore, we complemented iGBR analysis by examining other brain responses known to be modulated by repetition-related memory processes (evoked gamma oscillations and event-related potentials; ERPs). The results obtained for the ,no-switch' condition replicated previous findings of repetition suppression of iGBRs at 200,300 ms after stimulus onset. Source modelling showed that this effect was distributed over widespread cortical areas. By contrast, after a task-switch no iGBR suppression was found. We concluded that iGBRs reflect the sharpening of a cell assembly only within the same task. After a task switch the complete object representation is reactivated. The ERP (220,380 ms) revealed suppression effects independent of task demands in bilateral posterior areas and might indicate correlates of repetition priming in perceptual structures. [source]

Irrational Wanting and Subrational Liking: How Rudimentary Motivational and Affective Processes Shape Preferences and Choices

POLITICAL PSYCHOLOGY, Issue 4 2003
Piotr Winkielman
People's wanting and liking reactions reflect not only high-level beliefs, but also the operation of rudimentary biopsychological processes. Previous studies suggest that the following wanting and liking processes may be relevant to political behavior: irrational wanting (where wanting is triggered by activation of the brain dopamine system and becomes dissociated from liking); unconscious liking and wanting (where evaluative judgments and behavior are modified without awareness of the eliciting affective stimuli or of the underlying affective response); and fluency-based liking (where preferences are influenced by the ease of stimulus processing). This review suggests how conceptual and methodological tools from affective neuroscience and psychophysiology can refine our understanding of basic affective and motivational processes that shape political attitudes and choices. [source]