Farb, Segal & Anderson (2013, SCAN) — Mindfulness meditation training alters cortical representations of interoceptive attention
The training companion the wiki had been promising itself for two ingests. When the raw/papers/Farb/ exclusion lifted, the Cerebral Cortex attention paper (farb-2013-attentional-modulation) came in first, and its disambiguation note ended: “the companion — Farb, Segal & Anderson (2013), SCAN, ‘Mindfulness meditation training alters cortical representations of interoceptive attention’ — is the training paper, and is still pending in the ingest queue.” This is that paper. It is the source of the “mindfulness training increased posterior insula activation” phrasing the wiki inherited secondhand through Weng et al. (2021) and provisionally reattributed on insular-cortex and respiratory-interoception — and reading it first-hand sharpens that claim in two ways the secondhand note got slightly wrong (below).
Norman Farb is this wiki’s author (see norman-farb); recorded as provenance, not weighted as authority, per the convention across the Farb corpus.
The design, and how it differs from its Cerebral Cortex twin
The two 2013 papers share a scanner paradigm — the same Breathe / Maintain / Suppress block design, contrasting interoceptive attention (IA, monitoring the breath without altering it) against exteroceptive attention (EA, a 1-back task and a suppression task on visual trait words) — but they ask different questions of it:
| [[farb-2013-attentional-modulation|Cerebral Cortex 2013]] | SCAN 2013 (this paper) | |
|---|---|---|
| question | does attention (IA vs EA) select which cortex represents the breath? | does training (MBSR vs waitlist) alter that representation? |
| sample | 27 adults, MBSR completion a nuisance covariate | 36 adults split into MT graduates (20) vs untrained waitlist (16) |
| key contrast | IA vs EA, within-subject | MT vs untrained, between-groups, ×(IA vs EA) |
| headline structure | posterior insula, VMpo thalamus, graded posterior→anterior tuning | dorsal anterior insula, DMPFC deactivation, DMPFC–insula connectivity |
The clean disambiguation matters because the wiki’s secondhand summary had merged the two. The insula↔posterior-ventromedial-thalamus (VMpo) connectivity finding belongs to the attention paper, not this one; this paper’s connectivity story is about DMPFC and the putamen, not the thalamic relay. And the “training raised posterior insula” claim is here — but as a practice-dose effect, not the group-level effect, which was in the anterior insula. See the correction filed on insular-cortex and mindfulness-meditation.
The group-level training effect is in the anterior insula
The anatomically partitioned insula ROI analysis (eight gyri per hemisphere, after Craig 2009) gave a three-way interaction (location × attention × group) driven by the MT group responding more to IA in the dorsal anterior insula — the accessory gyrus and anterior short gyrus — where the untrained group was instead more responsive during exteroceptive attention. Farb et al. read this as training recruiting the anterior “dysgranular” insula, where interoceptive afference is integrated with higher-order contextual and external information, rather than the posterior primary map. It fits their broader claim that MBSR develops interoceptive awareness that is integrated with present-moment context rather than bare sensation — the anterior insula doing the binding that the attention paper assigns it (“not an area of pure body awareness”).
The DMPFC is where training shows up most cleanly
In the whole-brain analysis the dorsomedial prefrontal cortex was the only region where attention interacted with group. Untrained participants activated DMPFC equally whether attending in or out; MT participants deactivated it during interoceptive attention (t(19)=6.82, p<0.001). The reading Farb et al. give is continuous with the dual-mode framework their 2007 paper founds: DMPFC deactivation during IA marks a departure from both mind-wandering and effortful focal attention — a shift out of evaluative cortical-midline processing toward an “expansive and diffuse” sensory attention. It is the midline disengagement of the dual-mode story, appearing here for interoceptive attention specifically.
The connectivity analysis makes the DMPFC finding mechanistic. The MT group showed IA-specific negative connectivity between DMPFC and the right posterior insula (t(1,34)=3.45) that the untrained group did not — training builds an interoceptive network in which engaging DMPFC for executive work does not automatically suppress primary interoceptive cortex. Farb et al. propose this as “an emergent prefrontal pathway through which MT alters IA”: whether DMPFC deactivation causes sustained posterior-insula activation or vice versa is left open (PPI is correlational), but the negative coupling is present during IA and absent during EA, so it is context-specific rather than a blanket suppression.
Practice dose, not group membership, moved the posterior insula
This is the finding the wiki most needs stated precisely, because the secondhand version flattened it. The MT-vs-untrained group effect was anterior. The posterior insula — the primary interoceptive cortex of Craig and the attention paper — moved with how much people actually practised. Within the MT group, percentage of prescribed daily MBSR practice completed predicted greater IA-related activation in right sensorimotor cortex and posterior insula, and reduced activation in the left pulvinar/LGN and visual cortex (less recruitment of the visual pathway during body-focus). Interoceptive bias (IA−EA) in the right posterior long gyrus correlated with practice completion at r=0.61. So the training’s effect on primary interoceptive cortex is graded by dose — which is a stronger, more specific claim than “training raised posterior insula,” and the one the wiki should carry.
The distinction Farb et al. draw from it: participating in MBSR at all was enough to raise anterior-insula interoceptive integration (connectivity), but only daily practice raised the amplitude of the primary posterior signal. Integration is cheap; signal gain is earned.
What the wiki gains, and the two corrections
- The training claim is now first-hand and correctly attributed. insular-cortex and respiratory-interoception had held “training raised posterior insula + VMpo connectivity (Farb 2013)” as a Weng-sourced summary, flagged as belonging to “the SCAN companion, still pending.” Read first-hand: the VMpo connectivity is the attention paper, and the posterior-insula training effect is a practice-dose effect, with the group-level effect sitting anteriorly. Both corrections are filed on those pages.
- It supplies the training half of the dual mode’s interoceptive generalization. 2007 showed training decouples the right insula from the vmPFC self-model during self-reference; this shows training decouples (negatively couples) DMPFC from the posterior insula during breath attention, and builds a standing “online” posterior↔middle-insula connectivity the untrained can only voluntarily invoke. Same architecture — training changes the organization and default availability of interoceptive processing, not (as far as this paper can say) raw sensitivity — now demonstrated for interoceptive attention rather than trait self-reference.
Where it sits in the debates
- does-mindfulness-enhance-interoceptive-accuracy. This is the “right construct, wrong metric” pattern in neural form: training demonstrably alters cortical recruitment and connectivity during interoceptive attention, but no accuracy task was run, and the design is cross-sectional. It is evidence that something interoceptive changes with training — attentional integration, network organization, practice-dosed posterior signal — without being evidence of an accuracy gain, exactly the position the Farb side of that debate occupies (and which Eusebio et al. 2022 later complicates by showing self-report doesn’t discriminate under randomization).
- feedforward-vs-predictive-interoception. DMPFC deactivation with negative DMPFC–posterior-insula coupling during IA is naturally read as top-down modulation of a low-level channel — precision-weighting language — but the paper frames it as recruitment/suppression rather than prediction, and cannot adjudicate the architecture.
- is-more-interoceptive-awareness-better / is-interoception-domain-general. More training (and more practice) means more anterior-insula integration and more posterior-insula gain — a “more is better” datum on the wellbeing side — but bounded to the one voluntarily-drivable channel, so its reach to the heart and gut is exactly the open question those pages hold.
Provenance and funding
Zindel Segal (MBCT co-developer) and Adam K. Anderson recur across this group’s work. The paper declares no conflicts; funded by CIHR (#MT81164), NIMH (#MH066992), and a Mind and Life Institute Varela grant.