Effects of Different Types of Neurofeedback on Emotional Arousal: A Pilot Study

Physiological activation, known as arousal, may fluctuate based on our biological needs, such as oxygen demands, or based on our emotions. Physiological arousal related to our emotional states is known as emotional arousal, and it can help or hinder our daily functioning. For example, high physiological arousal prepares our bodies for movement, which may occur if we feel threatened and must run away. High arousal may also improve performance on cognitive tasks to a certain point, but past that point, it may be excessive and impair performance and comfort. When functioning properly, emotional arousal typically fluctuates naturally based on our emotional state to meet our current needs. Despite its importance for our daily functioning, we do not fully understand the neurobiological mechanisms of functional emotional arousal and its regulation. As such, our understanding of the neurobiological mechanisms of dysfunctional arousal commonly associated with several mental health disorders, such as post-traumatic stress disorder, is also lacking. The neurophysiological underpinnings related to emotional arousal and its regulation can be measured with electroencephalography (EEG). Furthermore, the relationships between emotional arousal and EEG activity may be tested by manipulating EEG activity through EEG-based biofeedback, also known as neurofeedback (NF). NF incorporates recording EEG activity and providing comprehensible feedback of this activity in real time via brain-computer interface devices. Through operant conditioning, people can learn to regulate their EEG activity related to their emotional arousal. Previous studies have found several EEG-based brain activation patterns that may be related to emotional arousal, which may be used as the basis for NF. Such brain activation patterns include the Emotional Arousal Pattern (EMAP), which was derived from the EEG activity of healthy people, and a clinically-based EEG pattern that was derived from people with PTSD. In this randomized, double-blind study, we sought to determine whether healthy participants could upregulate relevant EEG activity via NF based on these two EEG patterns and a pre-recorded “sham” feedback control and, if so, what effects this training might have on emotional arousal and emotion processing. We measured alterations in emotional arousal over time through changes in EEG activity, peripheral physiology, self-report measures, and performance on an arousal-sensitive cognitive task. Due to COVID-19-related suspension of the data collection, only 13 people took part in this study. We did not find any significant changes in any measures of emotional arousal by group. From our pilot data, we were unable to determine the effectiveness of the emotional arousal-increasing NF. However, the descriptive trends in EEG power indicated that a full-scale NF study is merited. A full-scale NF study could improve our understanding of the neurobiological mechanisms of functional emotional arousal and how it may affect emotion processing. It would also support emotional arousal-based NF as a potential individualized treatment intervention for those with disorders related to arousal-regulation difficulties, such as PTSD.