Interoceptive attention task

The dominant neuroimaging paradigm in interoception research, and — until this page — the wiki’s most cited unpaged method. It has been sitting behind claims on farb-2015-interoception-contemplative-health, mindfulness-meditation, interoceptive-training-clinical, helen-weng and a dozen other pages, doing the work of “the study that found insula activation during interoception.”

Created with the Haruki & Ogawa (2023) ingest, which is the first study in raw/ to run the paradigm on two organs at once and therefore the first to expose what it can and cannot deliver.

The design in one line

Show a word naming an organ; ask the person to feel it; subtract a matched exteroceptive attention block.

That is nearly all of it. The sophistication is in the control condition and in what gets contrasted, not in the task.

Why the field uses it

Not because it is a good measure of interoception — it is a fairly poor one — but because the good measures cannot be applied to most of the body.

Mapping visceral cortex properly would mean perturbing a viscus and recording the response: fundus distension by barostat (Lu et al. 2004), bladder infusion (Jarrahi et al. 2015), isoproterenol bolus (Khalsa et al.). Each requires its own apparatus, each is invasive, and no two can be combined in a single session — which means that until this paradigm, a within-subject comparison of two organs was not merely undone but undoable. Perturbation methods also introduce a confound that is fatal for exactly that comparison: the activation includes the participant’s discomfort and alarm, which differ by organ and by how nasty the manipulation is.

The attention paradigm gives that up in exchange for asking almost nothing of the participant and nothing at all of the body.

What it actually measures

In the taxonomies’ vocabulary, this instrument operationalizes attention — Farb et al.’s “attention tendency,” Khalsa et al.’s “attention,” Berntson & Khalsa’s “attention.” It does not measure detection, magnitude, discrimination, accuracy, sensitivity, insight or coherence, because it has no correct answer. There is nothing the participant can get right.

This is worth stating flatly because the paradigm’s papers, including its best ones, routinely title themselves about awareness. Haruki & Ogawa name their conditions “cardiac interoceptive awareness” and “gastric interoceptive awareness” on the strength of an assumption stated once in their introduction: that “interoceptive attention has been found to elicit interoceptive awareness.” Perhaps. The paradigm does not test it, and the wiki’s own evidence that attention and accuracy dissociate — meditators attend more without detecting better (does-mindfulness-enhance-interoceptive-accuracy) — is a reason to keep the two words apart.

The control condition is the measurement

Since the reported map is always a difference, the exteroceptive control determines what the paradigm can see. Haruki & Ogawa’s control is unusually well matched: a word (“TARGET”) in the same position as the organ cues, whose colour fades from black to grey in five imperceptible steps — so all three conditions are “sustain attention to a faint, non-salient signal for ten seconds,” varying only in where the signal is.

Even so, the control turned out to be the most demanding condition: participants rated the visual target as more intense than either bodily sensation, and it produced the study’s largest activations. One consequence, recorded on insular-cortex, is that the right dorsal anterior insula — the wiki’s canonical interoceptive-awareness region — was more active during the exteroceptive control than during interoceptive attention.

A paradigm whose subtrahend engages the region of interest more than the minuend does is a paradigm to read carefully.

What one study got out of it that no other design could

The organ-vs-organ contrast. Because both interoceptive conditions run in the same session with the same instructions and the same control, Haruki & Ogawa could ask which regions prefer the heart to the stomach — and found that the right anterior insula does, that gastric attention recruits visual cortex overlapping the gastric-network, and (by MVPA over anatomical subdivisions) that the left dorsal middle insula carries organ identity in its multivoxel pattern.

None of those questions is answerable with a perturbation method, a heartbeat task, or a questionnaire. That is the case for the paradigm, and it is a good one — provided its output is labelled attention.

Variants worth distinguishing

• Single-organ vs multi-organ. Most studies cue only the heart. Kerr et al. (2016) and Simmons et al. (2013) included stomach blocks but did not contrast the organs against each other, which is why Haruki & Ogawa could claim the comparison as unmade.
• With vs without physiological recording. Farb et al.’s breath-focus work records respiration; Haruki & Ogawa record nothing. The difference determines whether the study can say what the body was doing while it was being attended to.
• Decoding rather than contrasting. Weng’s work trains classifiers to detect interoceptive attention from brain activity, which converts the paradigm from a localizer into a measure of attention that neither asks the participant nor counts heartbeats — see weng-2021-interventions-of-interoception. This is the most promising direction out of the paradigm’s central weakness, since a decoder supplies the verification the instruction cannot.