Interoceptive awareness and its relationship to hippocampal dependent processes

- fMRI finds that the insula and anterior cingulate cortex support interoception.
- In contrast human brain damage and animal lesion data indicate the hippocampus.
- In healthy adults we tested for links between hippocampal function and interoception.
- Interoceptive awareness was related to hippocampal function in 2 out of 3 tests.
- We discuss why hippocampal activation may not be observed in fMRI studies.

Many neuropsychological and animal lesion studies point to the hippocampus as being critical for mediating interoceptive awareness, while neuroimaging studies have been used to argue for the importance of the insula and anterior cingulate cortex. Here, using healthy young adults - as with the neuroimaging data - we tested for an association between performance on a hippocampal dependent learning and memory (HDLM) measure (logical memory percent retention) and interoceptive awareness assessed on three tasks - heart rate tracking, water loading and the Multidimensional Assessment of Interoceptive Awareness questionnaire (MAIA). After controlling for other relevant potentially confounding variables, we found significant associations between both the water loading and MAIA measures (which were both correlated) and HDLM performance. These findings imply that hippocampal dependent processes are involved in interoceptive awareness in healthy young adults. More tentatively, they suggest that medial temporal lobe structures may mediate interoceptive tasks that involve ingestion and/or integration of past and current state-based information.