Real-time fMRI for Insular Cortex Brain State-triggered Experience Sampling

The investigators will develop a new approach called real-time functional MRI (fMRI)-triggered experience-sampling to efficiently sample spontaneous neural events (of a predefined type) and to map those events to specific qualities of self-generated experiences. Within 60 healthy adults, the investigators will use online (real-time) fMRI analysis to detect brain activations and trigger the appearance of visual rating scales so that participants can report their experiences immediately after the occurrence of a neural event of interest. The investigators will develop and validate the approach with a focus on real-time fMRI analysis of the dorsal anterior insular cortex (daIC), a brain region implicated in salience detection that is consistently identified as having aberrant structure, function, and connectivity in psychiatric illness at a transdiagnostic level. Aim 1 is to determine whether spontaneous daIC activation events are time-locked to instances of salient, high-arousal self-generated experience. The investigators will sample self-generated experiences both during instances of daIC activation and during baseline (intermediate daIC activity) events. The investigators hypothesize that daIC activation, relative to baseline events, will be time-locked to self-generated experiences with higher subjective ratings of arousal and vividness (regardless of affective valence). Aim 2 is to determine how distinct instances of daIC activation are coupled to physiological and whole-brain activity. Using a hypothesis-driven approach, the investigators will determine whether spontaneous fMRI activations in the daIC are associated with pupil dilation and activation of the locus coeruleus, a subcortical generator of arousal-related neuromodulation. Additionally, using a more data-driven approach, the investigators will test whether different instances of daIC activation are associated with multiple, distinct whole-brain co-activation patterns, and whether these co-activation patterns are associated with fluctuations in subjective affect (positive vs. negative experiences). If successful, the protocols can later be applied in patients with psychiatric illness and to potentially guide the development of interventions (e.g., neurostimulation, neurofeedback) that aim to target the neural processes that produce self-generated experiences that are core to mental illness.