A pilot study of neurofeedback intervention modulates cortical activity during emotional experience in schizophrenic patients: fNIRS and EEG data

Reviews and recent evidence have demonstrated the frequency, type, and clinical significance of brain dysfunction in Schizophrenia (S). Neuroimaging measures and electroencephalographic (EEG) data, in fact, suggest anomalies in brain responsiveness in patients. Moreover, empirical evidence suggests that the disturbances in emotional functioning are a major cause of persistent functional disability in S. However, no integration of these methods is usually applied to test and to clarify what specific aspects of emotional functioning are impaired in S. In this current pilot study the aim was to investigate the behavioral and neural correlates of emotional attribution in patients with S and to train these patients to restore the “unbalance cortical activity” through Electroencephalography (EEG-based) Neurofeedback (NF) technique in response to emotional cues. These evaluation procedures were conducted through a “multimethod” approach with functional Near-Infrared Spectroscopy (fNIRS) and EEG in three times: (a) the initial (T0) assessment of prefrontal activity while viewing standardized visual stimuli (positive, negative and neutral) selected from the International Affective Picture System (IAPS). After the emotional picture task, the patients was asked to rate the pictures on the Self-Assessment Manikin (SAM) dimensions of valence and arousal; (b) the NF application during a training protocol of five weeks (T1); (c) the assessment of NF efficacy that revealed a balanced cortical activity after the treatment (T2). 8 patients have been randomly assigned to either control (3 patients, C), or neurofeedback group (5 patients, N). Results showed that in T0 an unbalanced prefrontal activity was present within the left/right hemisphere (higher delta). Nonetheless, no anomalous behavior was observed in S about the explicit evaluation about stimuli emotional valence (SAM ratings). Moreover, the NF treatment effect in T2 was observed for N group in comparison with C group: indeed in T2 the anomalous responsiveness to emotional cues was modulated as shown by both EEG and fNIRS measures. These results suggest that the integration of fNIRS and the EEG measures may be considered a valid method to be used to test the efficacy of clinical treatment (NF) by contemporarily elucidating the cortical oscillation and the hemodynamic effects obtained within the PFC. Finally, these findings underline the potential relevance of NF assisted EEG band modulation to a wide scope of optimal performance applications within and beyond the clinical realm.