Verbal neuromodulation: old wine in a new bottle

Neuromodulation is a hotly studied field.  Research groups worldwide are exploring genetic and epigenetic modulators, inflammatory processes, optogenetics, dietary effects, and other modalities.  Although neuromodulation can influence many non-psychiatric conditions, one tantalizing hope is that by modifying critical brain physiology and the connectome we may someday attack the root causes of mental illness, a global scourge of human suffering.

It may surprise the reader to learn that this tantalizing promise is, right now, an under-appreciated reality.

Neuromodulation is not a new idea; it has progressed over many decades with advances in medicine and technology.  Thanks to expenditures of many millions of dollars and fervent international effort, brain research now produces complex genetic maps and colorful three-dimensional depictions of metabolic activity known as functional brain imaging.  These visually engaging results suggest that we are closing in on the cellular substrate of the psyche.  Yet the linking of bench research to actual patient outcomes remains elusive.  When it come to psychological suffering, translational medicine seems so close and yet so far.

Oddly neglected in this juggernaut of neurobiological research is verbal neuromodulation.  Transmitted via phylogenetically primitive afferent auditory pathways, verbal signals enter along the eighth cranial nerves, then stimulate limbic and cortical brain centers in highly complex ways.  Simpler (nonverbal) auditory neuromodulation has been used successfully in treating tinnitus, i.e., ringing in the ears, and preliminary research has found that ultrasound can affect intact brain circuits.  But the neurobiological implications of higher-level auditory interventions have been overlooked — perhaps even denigrated — in a field beholden to high-tech reductionism.

In contrast to most neuromodulatory techniques, the verbal variety, historically known as “psychotherapy,” boasts a low-tech high-touch interface similar to everyday dialog.  Most human subjects have conversed since childhood and find the experience somewhat familiar and relatively non-invasive.  Generally well-tolerated and with a good safety record, psychotherapy has been shown to alter functional brain imaging and even brain microstructure, reflecting improved signaling in essential brain pathways.  Moreover, verbal neuromodulation is both “precision medicine” and “patient-centered,” concepts currently deemed crucial to patient care, not to mention academic advancement and publication in peer-reviewed journals.

While verbal neuromodulation has been shown to be highly effective in numerous studies, its mechanism of action is still not well understood.  At the neurostructural level, dialogic reflection may enhance bidirectional signal transduction between the limbic system, which mediates emotion, and cortical areas, which mediate cognition and self-awareness.  By bringing limbic and cortical centers into greater synchrony, the entire brain may work more harmoniously to realize its goals.  This synchronization is presumably mediated by enhanced dendritic arborization, resulting in a fuller connectome, and/or neuronal protein synthesis, allowing the consolidation of new memories.  Further research is surely warranted to delineate the fundamental mechanisms at play.

Verbal strategies to affect emotional well-being are not new.  Friends, family, clergy, counselors, and psychotherapists have conducted such interventions for generations.  Yet, in the 21^st century, the “talking cure” has been supplanted by empty promises from neurobiology, while sufferers make do with dubious symptomatic treatments and quick-fix smartphone apps.  Re-casting dowdy, outmoded “psychotherapy” as verbal neuromodulation optimizes research grant support and may spark excitement in the public.  It may encourage more sufferers to reap the benefits of a brain-modifying treatment that long ago made the leap from theory to evidence-based practice.

Those of us who offer verbal neuromodulation should legitimately present it as the leading technology to target and modify specific brain activity in the service of relieving emotional suffering.  Of course, outside the earshot of pundits, academics, and a public entranced by high-tech, we may still call it psychotherapy.  Just as long as no one hears us.

Graphic courtesy of geralt at pixabay.com