Elsevier

Brain Research

Volume 1397, 23 June 2011, Pages 10-18
Brain Research

Research Report
Source localization of late electrocortical positivity during symptom provocation in spider phobia: An sLORETA study

https://doi.org/10.1016/j.brainres.2011.04.018Get rights and content
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Abstract

This symptom provocation study on spider phobia investigated sources of late event-related potentials (ERPs) using sLORETA (standardized low resolution brain electromagnetic tomography). Twenty-five phobic female patients and 20 non-phobic controls were confronted with phobia-relevant, generally fear-inducing, disgust-inducing and affectively neutral pictures while an electroencephalogram was recorded. Mean amplitudes of ERPs were extracted in the time windows 340–500 ms (P300) and 550–770 ms (late positive potential, LPP). Phobics showed enhanced P300 and LPP amplitudes in response to spider pictures relative to controls. Sources were mainly located in areas engaged in visuo-attentional processing (occipital and parietal regions, ventral visual pathway). Moreover, there were sources in areas which are crucial for emotional processing and the representations of aversive bodily states (cingulate cortex, insula). Further sources were located in premotor areas reflecting the priming of flight behaviour. Our findings are in good accordance with existing brain imaging studies and underline that source localization is a useful alternative for identifying phobia-relevant cortical regions.

Research highlights

► Phobics showed enhanced P300 and LPP amplitudes relative to controls. Sources were mainly located in visuo-attentional processing areas. ► Our findings are in good accordance with existing brain imaging studies. ► This study partly overcomes temporal resolution problems of fMRI studies.

Keywords

sLORETA
Spider phobia
Symptom provocation
Source localization
EEG
Parietal cortex
Attention
ERP
Cingulate cortex
Insula
P300
LPP

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