The neuroanatomical organization of interoceptive dimensions: Multimodal evidence from neurodegeneration and stroke

GARCIA CORDERO, INDIRA; SEDEÑO LUCAS; FITTIPALDI SOL; IBAÑEZ AGUSTIN

Congreso; 18th International Organization of Psychophysiology (IOP) World Congress; 2016

Interoception is a complex process encompassing multipledimensions, such as accuracy, learning, and awareness. Here weexamined whether each of those dimensions relies on specializedneural hubs distributed throughout the vast interoceptive network. Tothis end, we obtained relevant measures of cardiac interoception inhealthy subjects and patients offering contrastive models of neurodegenerationand focal brain damage: behavioral variant frontotemporaldementia (bvFTD), Alzheimer?s disease (AD), and fronto-insular stroke.Neural correlates of the three dimensions were examined throughstructural and functional resting-state imaging and online measurementsof the heart-evoked potential (HEP). The three patient groupspresented deficits in interoceptive accuracy, associated to insulardamage, connectivity alterations, and abnormal HEP modulations.Interoceptive learning was differentially impaired in AD patients,suggesting a key role of memory networks in this skill. Interoceptiveawareness results showed that bvFTD and AD patients overestimatedtheir performance; this pattern was associated with abnormalities inanterior regions and associated networks subserving metacognitiveprocesses, and probably related to well-established insight deficits indementia. Our findings specify how damage to specific hubs in a broadfronto-temporo-insular network differentially compromises interoceptivedimensions, and how such disturbances affect widespread connections beyond those critical hubs. This is the first study in which amultiple lesion model reveals fine-grained alterations of body sensing,offering new theoretical insights into neuroanatomical foundations ofinteroceptive dimensions (This work was partially supported by grantsfrom CONICET; CONICYT/FONDECYT Regular 1130920 and 1140114;FONCyT-PICT 2012-0412, FONCyT-PICT 2012-1309; FONDAP 15150012;and the INECO Foundation).