Poster #: 20
Topic: Clinical applications (incl. consciousness)
Thursday, Sep 10, 2015
Intact pre-attentive processing of sound intensity in depression as revealed by mismatch negativity
1Psychology, University of Jyväskylä, Jyväskylä, Finland
2Department of Psychology, University of Jyväskylä, Jyväskylä, Finland
Depression is associated with abnormal cognitive processing of emotional information which has also been shown in mismatch negativity (MMN) studies to both visual and auditory emotional stimuli. Recent research suggests that this processing bias occurs already at the basic visual feature processing level as indexed by visual mismatch negativity. In the auditory modality there is some evidence that the loudness dependence of the auditory evoked potentials would be associated with depression. However, there are no reports of studies applying intensity mismatch negativity paradigm in depressed participants. To that end we compared event-related potentials elicited in oddball condition for sound intensity changes in depressed and non-depressed participants. In one stimulus block the standard sound was 60 dB and the deviant sound 80 dB and in the other stimulus block the assignment was reversed. Differential responses were extracted from two time windows for the analysis: at 90-140 ms (N1) and at 150-200 ms (MMN) post-stimulus interval. At the earlier time window the loud stimulus as a deviant stimulus elicited larger negative amplitudes than the silent standard stimulus. When sound intensities for the standard and the deviant stimuli were reversed, no differential response was elicited. At the later time window negative-polarity differential response was elicited similarly in both stimulus blocks. There were no group differences in the brain responses and they showed no correlations with BDI-score. The results suggest that change detection of basic auditory processing of intensity is intact in depression.