Brain signature of emotional change: Altered neurophysiological processing after one session of psychotherapy

Objective: Emotional change is crucial for successful psychotherapy, and is assumed to occur on a subjective level, but also on the level of neurophysiological information processing. Little is known about the neurophysiological signature, as psychotherapeutic change is idiosyncratic and difficult to operationalize in a way allowing for neurophysiological investigation. In the present study, we aim at tracking idiosyncratic emotional change with event-related potentials (ERPs).
Methods: A total of 19 persons suffering from long-standing interpersonal pain, also called emotional ‘unfinished business’ (UFB), participated in a one-time psychotherapeutic intervention. Before and after the intervention, the electroencephalogram (EEG) was recorded during a face-viewing task which activated idiosyncratic emotional representations. The individualized face stimuli belonged to different personally known persons: significant others with whom participants had emotional UFB; appreciated persons; and familiar persons. ERPs were calculated and segmented into microstates, i.e., periods of quasi-stable network activation that reflect specific neurophysiological information processing steps. Features of these ERP microstates were compared between the different face conditions and between time points (pre- and post-intervention) with randomization-based statistics.
Results / Discussion: After the psychotherapeutic intervention, participants reported subjective emotional change, i.e., less negative feelings (UFB) towards the significant other. A neurophysiological signature of emotional change was observed around the time window of the P3-ERP-component: From pre- to post-intervention, ERPs in reaction to UFB-faces displayed a more pronounced pre-P3-microstate (200 to 382 ms post-stimulus), probably indicating enhanced novelty processing of the UFB-representations which were targeted during the intervention. The P3-microstate peaking around 500 ms decreased from pre- to post-intervention, but this P3-reduction was less pronounced in reaction to UFB-faces, probably indicating sustained processing of their emotional-motivational salience. Taken together, these results suggest that a one-time psychotherapeutic intervention does not only foster subjectively experienced emotional change, but also neurophysiological change.