author: niplav, created: 2023-04-07, modified: 2023-04-07, language: english, status: in progress, importance: 5, confidence: likely
A bibliography of various methods for meditation enhancements through brain stimulation and feedback, focusing on intracranial ultrasound stimulation.
See Constantin 2023a for a general overview for neuroenhancement and Constantin 2023b for more information on companies working on ultrasound for neuromodulation in particular.
The project follows standard neuroscience research protocols. In the lab, study subjects (novices as well as experienced meditators), don something that looks like a hairnet studded with ultrasonic transducers. Over a period of five or 10 minutes, they receive intermittent pulses of ultrasound energy. Ultrasound frequencies are far above the threshold of human hearing, so the test subjects feel no sensations, and because this is a placebo-controlled study, some people receive no stimulation at all.
Participants may also undergo ultrasound stimulation while lying in an MRI scanner that enables the researchers to gauge how different brain regions respond to the intervention. “The biggest brain and subjective reports are at about 20 minutes post-ultrasound,” Sanguinetti says. “So there’s some change in the way the brain regions are talking to each other.”
The primary target is the posterior cingulate cortex (PCC), a region deep in the brain that is massively connected with other structures and is associated with the default mode network—active during daydreaming and mind-wandering. Young and Sanguinetti theorize that the ultrasound energy mutes activity in the PCC in much the same way meditation tames the “monkey mind.”
Experienced meditators report significant effects after undergoing the ultrasound sessions, Sanguinetti says.
Adds Young, “We get these equanimity-related reports from the participants without prompting. They don’t know that we’re looking into anything related to meditation—we’re just some mad scientists that want to put energy into their brain. They on their own report some very meditation-like things.”
“The general effect was, within the first week, an extreme quieting of both inner and external space. The inner space became much stiller than I was able to accomplish just by sitting for 45 minutes every day. With the PCC ultrasound, it was within the first five minutes.”
—Michael Haederle, “Equanimity On Demand: Can Brain Stimulation Technology Mimic the Effects of Meditation?”, 2021
During the individual's two-month post-completion evaluation, he showed a significant score decrease in mood inventories, with virtually no remaining anxiety or depression. The response pattern observed may demonstrate that fUS [focused ultra-sound] targeting the amygdala produces very specific symptom relief in anxiety, but not in depression and obsessive thinking. In this previously treatment-resistant individual, anxiety may have prevented the therapeutic response to previous treatments for comorbid conditions in these patients. Indeed, extremely high levels of general anxiety are often considered to be markers of non-response to antidepressants, therapy, rTMS and ECT.
—Zielinski et al., A Case Study of Low-Intensity Focused Ultrasound For Treatment-Resistant Generalized Anxiety Disorder and Major Depressive Disorder, 2021