Bottom-Up Neurotech: Harnessing Sensation for Transformation & Treatment
“We’re seeing converging evidence that not having access to sensation is often a predictor of poor mental health vulnerability. Maintaining access to sensation in the face of distress is a really nice indicator that you’re going to be dynamic and resilient.”
—Norman Farb, Ph.D.
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What I am about to lay out is, by definition, speculative. It is my intuition and understanding based on my reading of several different but related lines of research. I believe it is directionally accurate, and where it is wrong, it is wrong in an interesting and informative way.
If you have thoughts, comments, suggestions, or criticism, hit reply and let me know!
Here is the TL;DR
Neuroticism is a common transdiagnostic factor and predictor of psychopathology. People high in neuroticism expect the worst, see danger even in harmless situations, and have difficulty managing their emotions, which are often negatively valenced.
Through the lens of Predictive Processing, neuroticism is understood as an information processing strategy called “Better Safe Than Sorry,” which tends to be low on sensory-perceptual detail, thus allowing threat-expecting beliefs to dominate the conscious experience.
This strategy creates a self-fulfilling prophecy because perceived stress shuts down our ability to take in sensory information, which does not allow for belief updating, thereby trapping an individual in a neurotic schema.
Overcoming this detrimental strategy requires intentional exposure to perhaps threatening sensory data in a safe, supported, and trusted environment, such that the fear and reflexive discounting can be overturned and sensory data can be allowed to update one’s model.
Bottom-up neurotechnologies—which include light, sound, haptic, thermal, and interoceptive sensory stimulation—offer a promising tool for updating this maladaptive information processing strategy.
Bottom-Up Neurotech: Harnessing Sensation to Treat Psychopathology
In the fourth segment in our Clinic of the Future Series, we looked at “Emergent Neurotechnologies,” which focused on transcranial-focused ultrasound (tFUS), one of the more exciting non-invasive neurotechnologies en route to the clinic for various conditions.
The idea with tFUS and other neurostimulatory technologies that “zap” the brain with magnetic fields, electricity, soundwaves, or other forms of energy is that they can modulate specific brain structures involved in psychopathology, like addiction or depression.
Modulating simply means upregulating or downregulating the neural activity of a specific brain region.
Let’s call this approach Top-Down Neuromodulation.
It’s top-down not just because the brain is in the head and the head is at the top of the human body but also because the emerging view of the brain as the organ of prediction and the constructor of experience is referred to as the “top-down” aspect of experience.
In contrast, incoming sensory information—like sight, sound, touch, and interoception—is bottom-up.
This naturally leads to the question, “Is there such a thing as Bottom-Up Neuromodulation?”
In today’s dispatch, I want to share what I have been learning about Bottom-Up Neurotech and why I think it is an exciting and promising class of intervention for treating psychopathology.
The Predictive Brain and Psychopathology
Previously, in Human Flourishing in the Age of Computational Neuroscience, we noted a few essential features of an emerging theory of the brain to recall for today’s discussion:
The brain is the organ of prediction and protection—it constantly generates models of the world based on past experiences. It uses these models to predict incoming sensory information, with survival (not accuracy) being the highest value.
Our perception is an actively created model known as the generative model.
Rather than passively receiving information, our brains actively shape our experiences by comparing predictions based on past experiences with incoming (bottom-up) sensory data.
If the generative model accurately predicts the incoming sensory data, it reinforces the existing world model. However, if there's a mismatch—a prediction error—the brain revises its model to better reflect the sensory data.
In short, in this understanding—known as the Predictive Processing Framework—what we perceive (sight, sound, touch, hunger, thirst, fear, pain, etc.) is the output of our brain’s predictions about the world checked against incoming sense data.
The predictive model updates through the process of prediction error minimization by comparing incoming sensory data against the predictive model.
Importantly, a faulty process of updating the generative model in response to prediction errors is the basis of psychopathology.
This is the basis of a compelling 2020 paper titled Better Safe Than Sorry: A Common Signature Of General Vulnerability For Psychopathology, which posits that the common trait among all psychopathologies is the inability of the brain to update its generative model in response to new evidence.
Better Safe Than Sorry (BSTS)
It has long been established that neuroticism is a significant transdiagnostic factor in both causing and sustaining psychopathology.
Neuroticism is a common transdiagnostic factor because it is a core vulnerability underlying a wide range of psychological disorders.
It refers to a tendency toward negative emotionality, including anxiety, mood instability, and sensitivity to perceived stress.
People high in neuroticism are more likely to experience intense and frequent negative emotions, such as fear, sadness, and anger, and often have difficulty regulating these emotions.
As a result, neuroticism is a common factor in depression, anxiety, PTSD, addictions, and other conditions.
The authors of BSTS note:
“…one psychobiological dimension that increases the risk for psychopathology and stated that “negative emotionality (neuroticism) lies at the heart of the general factor of psychopathology”
In the language of predictive processing, neuroticism is the inability for the generative model to update in response to prediction errors:
Again, from the BSTS paper:
“This implies information processing that tends to be low on sensory-perceptual detail, giving room to threat-related categorical priors to dominate conscious experience and to chronic uncertainty/surprise due to a stagnated error reduction process. This common information processing strategy has beneficial effects on the short term, but important costs on the longer term.”
In other words, we can understand neuroticism—the common factor in all psychopathology—as an information-processing strategy that ignores sensory information because the default assumption is that it is threatening.
From an evolutionary perspective, neuroticism as a trait can be understood as an adaptive response to repeated threatening experiences.
From the predictive processing perspective, this involves a lowering of the threshold for threat detection, and as a result, innocuous, non-threatening sensory experiences become perceived as threatening and thus avoided.
Sensory Exposure & Sense Foraging
The authors of BSTS offer a solution:
“The critical element advanced here—releasing stagnated error reduction by helping individuals to disengage from defensive-action tendencies during processing of aversive information—involves a fundamental change in psychophysiological response set to process potentially threatening information.
…we suggest that a critical element in all treatment approaches is some kind of exposure, defined as an attentive, open, and nondefensive way of processing threat-relevant information.”
I know what you’re thinking: Exposure Therapy—the therapeutic approach in which patients, with the help of a therapist, relive traumatic events and memories to reduce avoidance and anxiety responses.
However, the challenge of this approach is the high dropout rate, duration, and potential for making things worse.
An alternative approach was recently developed by University of Toronto Neuroscientist Norman Farb, which he calls “Sense Foraging.”
Sense Foraging
Sense foraging is the intentional exploration and engagement with sensory experiences.
The practice involves actively seeking out and attending to various sensory inputs, from the subtle sensation of breath to the complex interplay of environmental stimuli.
Sense foraging serves as a direct counterforce to the BSTS strategy by encouraging active engagement with sensory information rather than its automatic dismissal.
The practice of sense foraging experiences can help individuals rebuild trust in their sensory processing systems, develop finer discrimination of sensory signals, reduce automatic threat responses to neutral sensory input, and strengthen the brain's capacity for accurate sensory prediction.
Supercharged Sense Foraging with Bottom-Up Neurotech
Bottom-up neurotech represents a novel class of therapeutic technologies that work by providing programmatically tailored sensory experiences to recalibrate maladaptive information processing patterns.
Unlike top-down approaches that directly modulate neural activity through external energy, bottom-up neurotech harnesses the brain's natural capacity for sensory processing and belief updating.
These technologies include:
Multi-sensory virtual reality environments
Programmable light and sound experiences
Haptic feedback systems
Thermal stimulation devices
Interoceptive awareness tools
The therapeutic potential of bottom-up neurotech lies in its ability to address the BSTS information processing strategy characteristic of neuroticism.
By providing carefully calibrated sensory experiences in safe, controlled environments, these technologies can help individuals overcome their reflexive discounting of sensory information.
Consider someone with anxiety who categorically interprets bodily sensations as threatening. A bottom-up neurotech intervention might use haptic feedback to generate similar sensations while providing a safe context that allows for new interpretations. Over time, this exposure helps update the brain’s predictive models, reducing the automatic threat response.
The theoretical advantage of this approach over traditional exposure therapy is its precision and scalability. Bottom-up neurotech can deliver consistent, measurable sensory experiences that can be carefully titrated to match an individual's therapeutic needs. This allows for gradual exposure that builds confidence in processing sensory information without overwhelming the system.
Most importantly, bottom-up neurotech offers a path to updating maladaptive predictive models without requiring direct engagement with traumatic memories or situations. By providing novel sensory experiences in safe contexts, these technologies can help break the self-reinforcing cycle of the BSTS strategy, allowing individuals to develop more adaptive ways of processing and interpreting sensory information.
The Promise of Bottom-Up Neuromodulation
Bottom-up neurotech represents a paradigm shift in treating psychopathology.
By combining the intuitive wisdom of sense foraging with precise technological control, it may be possible to offer systematic pathways for updating maladaptive predictive models. This approach, in theory, addresses the core information processing dysfunction that underlies various psychological conditions.
As these technologies mature, they may offer a gentler, more effective way to help individuals trapped in neurotic processing patterns rediscover trust in their sensory experience and develop more adaptive ways of engaging with the world.
In the evolving landscape of mental health treatment, bottom-up neurotech emerges not just as a novel therapeutic tool but as a bridge between our understanding of the predictive brain and practical interventions for psychological well-being.
Fascinating! This is why suppressing our authenticity makes us unwell.