Simulation map

Introduced in Farb et al. (2015) as an analog of Damasio’s “as-if” body representation (Damasio 2003a; Seth & Critchley 2013), and the working construct through which the paper operationalizes interoceptive-inference for contemplative and clinical purposes.

Structure

The simulation map is layered: lowest layers sit closest to raw sensory afferents from the body; higher layers aggregate this information into representations potentially accessible to consciousness. It is computationally the ongoing selection of encoded body states into a working-memory buffer — the best current approximation of body state, informed by prior learned states.

Not the same as current sensation

Critically, the simulation map is not raw current sensation. Current sensation is the immediate set of afferent inputs (nucleus of the solitary tract, thalamus, posterior insula, somatosensory cortices). The simulation map is a filtered, interpreted signal — an integration of sensation with priors. Only a subset of simulation-map layers are consciously accessible; the “phenomenal map” (what one is aware of) is a subset of the broader simulation map, which itself is only partially accessible to introspection. This has a methodological consequence: subjective report cannot fully capture simulation-map composition, motivating neuroscientific (rather than purely self-report) approaches to studying it.

Function

The simulation map is proposed to explain how visceral feeling promotes action: emotional valence is attached to simulation-map states, motivating allostasis (physiological/behavioral change to maintain adaptive homeostatic ranges) — though not all motivated behavior is allostatic (hedonic/pragmatic goals can override balance). Regulation of the map proceeds via two routes, active-inference and perceptual-inference, and the map is the substrate proposed for presence-and-agency.

Relation to the contemplative “subtle body”

Farb et al. explicitly propose the simulation map as the scientific counterpart to the Asian contemplative subtle-body (channels, chi/ch’i/prāṇa, energy centers) — while flagging that how these traditional constructs map onto the neuroscientific model “is currently unclear.”