The Seba library treats Parietal Deafferentation in 9 passages, across 3 authors (including Mohandas, E., Gallagher, Shaun, Yaden, David Bryce).
meditation results in an activation of the prefrontal cortex, activation of the thalamus and the inhibitory thalamic reticular nucleus and a resultant functional deafferentation of the parietal lobe.
Mohandas identifies functional parietal deafferentation, mediated by thalamic reticular inhibition during meditation, as the central neural mechanism linking contemplative practice to altered states of consciousness.
, Neurobiology of Spirituality, 2008thesis
of the posterior superior parietal lobule (PSPL) in spirituality
Mohandas situates the posterior superior parietal lobule as the specific anatomical locus whose deafferentation underlies the dissolution of self-world boundaries in spiritual experience, corroborated by a range of neuroimaging studies on meditation.
, Neurobiology of Spirituality, 2008supporting
deafferentation25, 42-55
Gallagher’s index entry for deafferentation signals that the concept receives sustained, chapter-length treatment in his phenomenological analysis of body schema and embodied agency.
, How the Body Shapes the Mind, 2005supporting
Ian, not unlike Dennett’s agent, seemingly represents the precise counter-example to the necessary conditions for intentional action claimed by both these theorists.
Gallagher uses the case of Ian Waterman — whose peripheral deafferentation eliminates proprioceptive and tactile feedback — to challenge philosophical accounts that make direct bodily awareness a necessary condition of intentional action.
, How the Body Shapes the Mind, 2005supporting
the conscious control of movement becomes less exacting with practice … walking over a flat, well-lit surface takes about 50-70 per cent of his attention
Gallagher documents how deafferented subjects must substitute conscious attentional resources for the automatic proprioceptive regulation normally handled subpersonally by the body schema.
, How the Body Shapes the Mind, 2005supporting
CF, who suffered a similar deafferentation as Ian Waterman, but relatively later in life, is confined to a wheelchair and has much greater difficulty
Gallagher extends the deafferentation analysis to a second case, noting that the timing of sensory loss relative to developmental stage significantly affects the degree of functional compensation achievable.
, How the Body Shapes the Mind, 2005supporting
distortions or disruptions of body image coexisting with normally functioning body schemas can be found in other types of disorders, some of which have etiologies very different from neglect.
Gallagher argues that deafferentation-related disorders reveal a fundamental dissociation between body image and body schema, each susceptible to independent disruption.
, How the Body Shapes the Mind, 2005supporting
the annhilational component may reduce negative aspects of excessive self-focus while the relational component likely
Yaden’s account of self-transcendent experience identifies an ‘annihilational component’ — the fading of bodily and social boundaries — that maps conceptually onto the phenomenological correlates attributed to parietal deafferentation in meditative states.
, The Varieties of Self-Transcendent Experience, 2017aside
transient hypofrontality is the unifying feature of all these altered states and that the phenomenological uniqueness of each state is the result of the differential viability of various frontal circuits
Mohandas situates parietal deafferentation within the broader framework of transient hypofrontality, suggesting that prefrontal deregulation and parietal uncoupling work in concert to produce altered states.
, Neurobiology of Spirituality, 2008aside