Event-related potential examination of facial affect processing in bipolar disorder and schizophrenia

Abstract

Background Patients with bipolar disorder exhibit consistent deficits in facial affect identification at both behavioral and neural levels. However, little is known about which stages of facial affect processing are dysfunctional. Methods Event-related potentials (ERPs), including amplitude and latency, were used to evaluate two stages of facial affect processing: N170 to examine structural encoding of facial features and N250 to examine decoding of facial features in 57 bipolar disorder patients, 30 schizophrenia patients, and 30 healthy controls. Three conditions were administered: participants were asked to identify the emotion of a face, gender of a face, or whether a building was 1 or 2 stories tall. Results Schizophrenia patients’ emotion identification accuracy was lower than that of bipolar patients and healthy controls. N170 amplitude was significantly smaller in schizophrenia patients compared to bipolar patients and healthy controls, which did not differ from each other. Both patient groups had significantly longer N170 latency compared to healthy controls. For N250, both patient groups showed significantly smaller amplitudes compared with controls, but did not differ from each other. Bipolar patients showed longer N250 latency than healthy controls; patient groups did not differ from each other. Conclusions Bipolar disorder patients have relatively intact structural encoding of faces (N170) but are impaired when decoding facial features for complex judgments about faces (N250 latency and amplitude), such as identifying emotion or gender.

Forming first impressions of others in schizophrenia: Impairments in fast processing and in use of spatial frequency information

“…This is consistent with previous studies showing delays in processing configural aspects of faces (Butler et al, 2008), increased reaction time in making social appraisals (Taylor et al, 2011), impaired early-stage processing of faces in electrophysiological studies (Turetsky et al, 2007; Wynn et al, 2013) that may be related to impaired structural encoding of faces (Turetsky et al, 2007), and possibly impaired time continuity in schizophrenia (Giersch et al, 2013). Thus, impairments in temporal processing also extend to the ability to make a first impression.…”

Changes in event-related potentials in patients with first-episode schizophrenia and their siblings

“…Indeed, the laboratory setting and the measurement devices are factors that render the environment unnatural for these patients, masking some of the effects. Despite normal N170 and N250 amplitude and latency among the three groups in our study, previous research has found that patients with schizophrenia showed significantly longer latency compared to healthy controls [27]. These differences may be due to the small sample size of our study, or reflect the fact that the patients with schizophrenia in our study were very recently diagnosed and so are likely to be in the early stage of the disease.…”

Emotion recognition deficits in schizophrenia-spectrum disorders and psychotic bipolar disorder: Findings from the Bipolar-Schizophrenia Network on Intermediate Phenotypes (B-SNIP) study

“…On the other hand, divergent patterns of neural activation on emotion tasks have primarily been isolated to areas showing higher activation in BD than SCZ in medial temporal lobe structures (e.g., hippocampus, parahippocampal gyrus, and mid-cingulate cortex) (Whalley et al, 2012). Electrophysiological studies also suggest that patients with SCZ and less so BD have deficits in structural encoding of faces, whereas both patient groups may show less efficient decoding of facial affect features (Wynn et al, 2013; Wynn et al, 2008). These neurophysiological findings may partly account for similarities between SCZ and BD-P in recognizing specific facial expressions (e.g., anger, neutral) but greater deficits for SCZ in judging other emotions (e.g., sadness, happiness).…”