Dynamics of alpha oscillations elucidate facial affect recognition in schizophrenia

Abstract

Impaired facial affect recognition is characteristic of schizophrenia and has been related to impaired social function, but the relevant neural mechanisms have not been fully identified. The present study sought to identify the role of oscillatory alpha activity in that deficit during the process of facial emotion recognition. Neuromagnetic brain activity was monitored while 44 schizophrenia patients and 44 healthy controls viewed 5-s videos showing human faces gradually changing from neutral to fearful or happy expressions or from the neutral face of one poser to the neutral face of another. Recognition performance was determined separately by self-report. Relative to prestimulus baseline, controls exhibited a 10- to 15-Hz power increase prior to full recognition and a 10- to 15-Hz power decrease during the postrecognition phase. These results support recent proposals about the function of alpha-band oscillations in normal stimulus evaluation. The patients failed to show this sequence of alpha power increase and decrease and also showed low 10- to 15-Hz power and high 10- to 15-Hz connectivity during the prestimulus baseline. In light of the proposal that a combination of alpha power increase and functional disconnection facilitates information intake and processing, the finding of an abnormal association of low baseline alpha power and high connectivity in schizophrenia suggests a state of impaired readiness that fosters abnormal dynamics during facial affect recognition.

Reduced frontal theta oscillations indicate altered crossmodal prediction error processing in schizophrenia

“…Recently, Lange et al (2013) found increased theta-band power in the auditory cortex during the processing of incongruent compared with congruent audiovisual speech. Interestingly, altered oscillatory responses in unisensory paradigms have been reported previously in SZP (Grützner et al 2013;Popov et al 2014Popov et al , 2015Uhlhaas and Singer 2010). For example, SZP show altered frontal thetaband power during the processing of color-word incongruence (Popov et al 2015).…”

Oscillations and Neuronal Dynamics in Schizophrenia: The Search for Basic Symptoms and Translational Opportunities

“…In addition to abnormalities of high-frequency oscillations, alterations have also been demonstrated for lower-frequencies in the theta/alpha-frequency range, during sensory processing and working memory tasks [78][79][80]. An important question is whether these abnormalities are secondary to gamma-band dysfunctions or whether they represent independent abnormalities.…”

Changing facial affect recognition in schizophrenia: Effects of training on brain dynamics

“…In the present study, FAT served to examine neural correlates of training targeting facial affect discrimination, which Popov et al (2014) found to be impaired in schizophrenia patients.…”