Investigating the Neural Correlates of Processing Basic Emotions: A Functional Near-Infrared Spectroscopy (fNIRS) Study

Emotion regulation, a fundamental aspect of human functioning, involves the ability to monitor, evaluate, and modify emotional responses. Understanding the neural mechanisms underlying emotion regulation holds significant implications across various disciplines, including psychology, neuroscience, and clinical psychiatry. This study aims to explore the neural correlates of emotion regulation using functional near-infrared spectroscopy (fNIRS) with a specific focus on the prefrontal cortex (PFC). fNIRS, a non-invasive and portable brain imaging technology, offers an excellent opportunity to investigate real-life emotion processing with high temporal resolution. Twenty participants underwent an experimental protocol where they viewed emotional pictures from the International Affective Picture System (IAPS) database, varying in valence (positive and negative) and arousal (high and low). fNIRS data were collected during the picture presentation, and the hemodynamic responses in the PFC were analyzed. The findings demonstrated distinct spatiotemporal patterns of activation associated with different emotional states. Positive valence stimuli elicited higher hemodynamic activation in bilateral dorsolateral prefrontal cortex (DLPFC) and orbitofrontal cortex (OFC) regions when compared to negative valence stimuli. On the other hand, negative valence stimuli induced higher activation in the medial prefrontal cortex (mPFC) when compared to positive valence stimuli. Moreover, high arousal positive valence stimuli evoked higher activation in the left DLPFC region when compared to high arousal negative valence stimuli. These results shed light on the differential neural processing of positive and negative emotions within the PFC, supporting the notion of lateralized emotional processing. The study validates the feasibility of fNIRS for objectively capturing emotion-related neural activity, providing valuable insights for future applications in emotion recognition and affective brain-computer interfaces (BCIs). Understanding the neural basis of emotion regulation has significant implications for designing targeted interventions for individuals experiencing emotion dysregulation disorders. Additionally, the integration of fNIRS technology into affective BCIs may offer new possibilities for real-time emotion detection and communication in populations with communication challenges. ### Competing Interest Statement The authors have declared no competing interest.