Event-related potential correlates of face-emotion processing impairments in bipolar disorder

Bipolar Disorder (BD) is a major psychiatric disorder that primarily encompasses mood dysregulation. Additionally, patients often present with cognitive impairments, including those pertaining to face-emotion processing. Event-related brain potentials (ERPs) index multiple aspects of cognitive impairments; yet, prior BD research has mostly focussed on auditory ERPs. The aim of this thesis was firstly to determine the ERP correlates of face-emotion processing impairments in BD compared with healthy volunteers, through implementation of an emotional go/no-go task employing happy and sad face stimuli. The first analysis revealed increased parieto-occipital P100 amplitudes elicited by happy compared with sad faces in the BD group only, and overall attenuated N170 amplitudes. The second analysis revealed overall prolonged peak latencies of the fronto-central P80 and vertex positive potentials in BD patients. Delayed response inhibition of emotional stimuli in BD was identified in the third analysis. In the second study, a novel experimental task was implemented to investigate the effects of face-emotion on auditory processing. Dual click stimuli following disgust and neutral faces were presented to BD patients and healthy volunteers. The first analysis revealed overall reduced parieto-occipital N170 and P200 responses to faces in BD. The second analysis demonstrated no significant difference between groups for sensory gating of the clicks, across P50, N100 and P200 auditory components measured at the vertex. Furthermore, N100 latency was overall delayed in BD. The third analysis revealed differential correlations between face processing and sensory gating between groups, with a relationship between face-related P200 amplitudes and P200 sensory gating ratios identified in the BD group only. The present studies revealed several novel findings regarding face and face-emotion processing in BD, encompassing early and broad fundamental impairments and anomalous influences on other faculties. These deficits may lead to others downstream, such as social impairments and overall mood symptomatology. Future research is needed to further explore face-emotion processing mechanisms in BD by including a range of emotional stimuli and recruiting patients with different mood states and diagnostic subtypes. This could contribute to the identification of ERP endophenotypes of BD, and ultimately, improved diagnosis and cognitive treatment strategies.

Grantor dc:publisher

UNSW, Sydney

Year dc:date

2012

Author dc:creator

• Degabriele, Racheal

• EEG
• Bipolar disorder
• ERP

Statement dc:rights

• open access
• CC BY-NC-ND 3.0
• free_to_read

Licence

• https://purl.org/coar/access_right/c_abf2
• https://creativecommons.org/licenses/by-nc-nd/3.0/au/

Language dc:language

EN

Identifier

https://doi.org/10.26190/unsworks/15556

OAI identifier oai:identifier

oai:unsworks.library.unsw.edu.au:1959.4/52000