Attention, in and Out: Scalp-Level and Intracranial EEG Correlates of Interoception and Exteroception

GARCÍA-CORDERO, INDIRA; ESTEVES, SOL; MIKULAN, EZEQUIEL P.; HESSE, EUGENIA; BAGLIVO, FABRICIO H.; SILVA, WALTER; GARCÍA, MARÍA DEL CARMEN; VAUCHERET, ESTEBAN; CIRAOLO, CARLOS; GARCÍA, HERNANDO S.; ADOLFI, FEDERICO; PIETTO, MARCOS; HERRERA, EDUAR; LEGAZ, AGUSTINA; MANES, FACUNDO; GARCÍA, ADOLFO M.; SIGMAN, MARIANO; BEKINSCHTEIN, TRISTÁN A.; IBÁÑEZ, AGUSTÍN; SEDEÑO, LUCAS

Frontiers in Neuroscience

Frontiers

Lugar: Lausanne; Año: 2017 vol. 11

Interoception, themonitoring of visceral signals, is often presumed to engageattentional mechanisms specifically devoted to inner bodily sensing.In fact, most standardized interoceptive tasks require directingattention to internal signals. However, most studies in the fieldhave failed to compare attentional modulations between internally-and externally-driven processes, thus probing blind to thespecificity of the former. Here we address this issue through amultidimensional approach combining behavioral measures, analyses ofevent-related potentials and functional connectivityvia high-densityelectroencephalography, and intracranial recordings. In Study 1, 50healthy volunteers performed a heartbeat detection task as werecorded modulations of the heartbeat-evoked potential (HEP) in threeconditions: exteroception, basalinteroception (also termedinteroceptive accuracy), and post-feedback interoception (sometimescalled interoceptive learning). In Study 2, to evaluate whether keyinteroceptive areas (posterior insula, inferior frontal gyrus,amygdala, and somatosensory cortex) were differentially modulated byexternally- and internally-driven processes, we analyzed humanintracranial recordings with depth electrodes in these regions. Thisunique technique provides a very fine grained spatio-temporalresolution compared to other techniques, such as EEG or fMRI. Wefound that both interoceptive conditions in Study 1 yielded greaterHEP amplitudes than the exteroceptive one. In addition, connectivityanalysis showed that post-feedback interoception, relative to basalinteroception, involved enhanced long-distance connections linkingfrontal and posterior regions. Moreover, results from Study 2 showeda differentiation between oscillations during basal interoception(broadband: 35?110 Hz) and exteroception (1?35 Hz) in the insula,the amygdala, the somatosensory cortex, and the inferior frontalgyrus. In sum, this work provides convergent evidence for thespecificity and dynamics of attentional mechanisms involved ininteroception.p { margin-bottom: 0.25cm; line-height: 120%; }