How to Interpret Resting-State fMRI: Ask Your Participants

Abstract

Resting-state fMRI (rsfMRI) reveals brain dynamics in a task-unconstrained environment as subjects let their minds wander freely. Consequently, resting subjects navigate a rich space of cognitive and perceptual states (i.e., ongoing experience). How this ongoing experience shapes rsfMRI summary metrics (e.g., functional connectivity) is unknown, yet likely to contribute uniquely to within- and between-subject differences. Here we argue that understanding the role of ongoing experience in rsfMRI requires access to standardized, temporally resolved, scientifically validated first-person descriptions of those experiences. We suggest best practices for obtaining those descriptions via introspective methods appropriately adapted for use in fMRI research. We conclude with a set of guidelines for fusing these two data types to answer pressing questions about the etiology of rsfMRI.

Keywords: coactivation patterns; consciousness; fMRI; introspection; ongoing experience; resting-state.

Figure 1.

Schematic representation of the main premise of this work. A, Subjects have rich ongoing experiences characterized by a succession of cognitive, emotional, and perceptual processes unique to each scan. B, Those experiences manifest in rsfMRI data in the form of short bursts of distributed neuronal activity (i.e., coactivation events). C, Coactivation events, in turn, drive estimates of functional connectivity.

Figure 2.

A, Retrospective introspection relies on thought probes/surveys that take place at the conclusion of a scan and gather information about the overall ongoing experience of subjects during the entirety of the resting-state scan. B, In-the-moment introspection presents thought probes at pseudo-random times during the resting-state scan. Each of those probes is aimed at obtaining a characterization of the ongoing experience unfolding right before the probe was presented (e.g., it gathers information about a short, i.e., few seconds, period of time).