The Sympathetic State and Prefrontal Cortex Engagement: Insights from Dr. Stephen Porges

Dr. Stephen Porges’ Polyvagal Theory provides strong evidence for the Autonomic Nervous System (ANS) having 3 major sub-systems: the ventral vagal complex (VVC), the sympathetic nervous system (SNS), and the dorsal vagal complex (DVC). Each system corresponds to distinct behavioural states—social engagement, fight-or-flight, and immobilization, respectively. When organs innervated by the vagal system, such as the heart and lungs, are dominated by a sympathetic state, it significantly impacts the engagement of the prefrontal cortex (PFC), the brain region responsible for appropriate expressions of focus and attention, executive functions like decision-making, problem-solving, and social interaction.

In a sympathetic state, the SNS activates the “fight-or-flight” response, mobilizing the body for immediate action. This involves increased heart rate, vasoconstriction, and the release of stress hormones like adrenaline and cortisol. According to Porges, this state is part of the body’s hierarchical response to perceived threats, where survival mechanisms take precedence over higher-order cognitive processes. The PFC, which is intricately linked to the VVC and the social engagement system, becomes less engaged as resources are redirected. This redirection is evident in the heightened activity in a part of the brain known as the amygdala, which prioritizes threat detection, and the subsequent reduction in blood flow and neural activity in the PFC. As a result, cognitive functions such as attention control and emotional regulation, which rely heavily on the PFC, are diminished.

Porges introduces the concept of “neuroception,” the subconscious process by which the nervous system evaluates environmental safety or danger. In a sympathetic state, neuroception shifts focus toward immediate environmental cues, further reducing the PFC’s role in nuanced social interactions or complex cognitive tasks. Additionally, stress hormones like cortisol can impair PFC function by disrupting neurotransmitter balance, particularly dopamine, which is crucial for cognitive flexibility and working memory. Consequently, the dominance of the Sympathetic Nervous System(SNS) over the Ventral Vagal Complex (VVC) leads to a diminished capacity for social engagement and cognitive processing, as the Prefrontal Cortex (PFC) is sidelined in favour of survival-oriented responses.

In summary, when the brain-body systems described above are working in a manner that is incongruent with the current level of environmental safety, they are said to be in a dysregulated state. A major characteristic of this dysregulation is the loss of prefrontal cortex dominance. This dysregulated state of brain-body operation correlates very highly with (and may be cause of) the symptoms that characterise a range of chronic common mental health conditions. HEG neurofeedback allows a direct intervention that facilitates a re-establishment of Prefrontal Cortex dominance. As the training progresses related subconscious autonomic brain-body neural systems (introduced in the above paragraphs), are trained back into a regulated pattern of functioning. The impact on trainees is that they experience a marked decrease in key symptoms for some of the most common mental health conditions. See the following paragraphs for more detail on this. 

Reestablishing Prefrontal Cortex Dominance: Insights from Dr. Christine Tyrrell Baker’s pIR HEG Neurofeedback Published Paper (2023)

Dr. Christine Tyrrell Baker’s study, “Documenting the Effects of Noninvasive Prefrontal pIR HEG Neurofeedback in the Treatment of Common Mental Health Problems“ (doi: 10.15540/nr.10.3.207), provides compelling evidence for the efficacy of passive infrared hemoencephalography (pIR HEG) neurofeedback in reestablishing PFC dominance. The research was conducted in a mental health private practice setting, involved 66 clients with mixed diagnoses, of mental health conditions. The research collected both qualitative and quantitative data to assess changes in anxiety, depression, limbic overload, and self-efficacy following neurofeedback sessions.

The pIR HEG neurofeedback method involves monitoring cerebral blood flow in the prefrontal cortex using a non-invasive headband, which has two infrared lenses. Heat is a “waste product” of neural activity. The more neural activity, the more heat radiates from the PFC part of the brain through the forehead, and can be detected in less than a second. The infrared lenses enable the headband to pick up fluctuations in heat that are directly reflective of neural activity.

Participants choose from movies that are selected to elicit a sympathetic nervous system (SNS) reaction, thereby decreasing the activity in the PFC. The infrared lenses pick up the drop in temperature in the PFC, which causes the movie to pause. The point being the participant now has the opportunity to learn how to use the states of mind that characterise attention, and intention to particular cues. Attention is drawn to the realtime thermometer, that appears on screen when the movie pauses, and the participant is invited to focus on the intention of lifting the temperature reading.

At the same time direction is given on how to shift particular body symptoms of SNS signalling to the brain, towards a relaxed yet focused state of mind. As this is achieved the PFC is reengaging, and the participant sees the associated temperature increase in real time. Seeing this feedback helps the brain increase activity in the PFC while reducing activity in the limbic system, the emotional centre of the brain.

Baker’s findings indicate that after just five sessions, there were statistically significant improvements in anxiety, depression, limbic overload, and coping self-efficacy. For those who completed 10 or 15 sessions, the results were even more robust, showing enhancements in general self-efficacy and reductions in dissociation.

The study demonstrates that pIR HEG neurofeedback enhances PFC dominance by strengthening neural pathways associated with executive function and emotional regulation. The increased PFC activitycorrelates with improved cognitive control and reduced emotional reactivity, aligning with the goal of rebalancing the autonomic nervous system. This reestablishment of PFC dominance is crucial for mitigating the effects of a sympathetic state, as it allows for better regulation of the limbic system and improved social engagement capabilities. Baker’s work highlights the potential of pIR HEG neurofeedback as a versatile, powerful, and easy-to-implement clinical tool, offering a pathway to restore cognitive and emotional balance in individuals with common mental health challenges.