Instrumental Learning of Anterior Insular Cortex Activity with Real-time fMRI in Autism Spectrum Disorders.
Final Report Abstract
The long-term perspective of the studies carried out in this project was to assess (and manipulate) cortico-subcortical brain interactions in ASD and neurotypical (NT) individuals in order to establish an association between their possible alterations in ASD and the observed impairment in socioemotional behavior. In a first investigation in NT individuals, we observed differential mesocorticolimbic patterns of interactions during the up and down regulation of emotion. In particular, during up regulation, functional integration among salience network (SN) nodes suggest the reactivation of interoceptive and peripheral body signals related to emotional response. On the other hand, the dissociation between SN activity and activity in the frontoparietal control network/default mode network (FPCN/DMN) resulting from reduced activity of the orbitofrontal cortex and medial prefrontal cortex concurrent to increased SN activation, suggested a reduced activity of top-down inhibitory mechanisms facilitating a more intense emotional expression. During down regulation of emotion, the anticorrelation between SN and FPCN/DMN activity, resulting from increased FPCN involvement upon SN activation, might instead permit appropriate control of the emotional response through specific attention- and monitoring-related processes. Overall these results in NT individuals suggest that functional connections within dopaminergic mesocorticolimbic networks essentially contribute to emotion regulatory processes. They are thus highly relevant for the comprehension of emotional disorders characterized by maladaptive emotion regulation strategies such as ASD. Following these findings, we are now conducting resting fMRI connectivity analysis within the mesocorticolimbic network in (adult) ASD individuals (Caria et al. In preparation). In the second parallel branch of the project, which explored sleep and sleep spindle characteristics - a biological indicator of thalamocortical oscillations - in adult individuals with ASD, we observed an alteration of spindle density, in relation to the topography of the slow and fast spindles, with reference to adult NT (Ciringione et al. 2019). Notably, in a complementary study assessing ASD and NT children, we observed no difference of sleep spindles characteristics. This result might suggest a later alteration onset, possibly related to persistent maladaptive behavior during development interacting with maturational processes. In fact, sleep spindles in children appear to differ from those in adults, frontal spindles between 11 to 12.5 Hz significantly decrease in power and stabilize with development, whereas centroparietal spindles, between 12.5 to 14.5 Hz, undergo rather small variations. A number of studies have indicated a correlation between cortical sleep spindles and hippocampus-dependent episodic memory formation. Sleep spindles are assumed to significantly contribute to the strengthening of central emotional information, and some previous studies also suggested a potential role for emotional memory processing, for instance by mediating suppression of non-salient neutral information. Impaired and reduced suppression of task-irrelevant and distractor perceptual information has been often reported in ASD and associated with increased emotional arousal. In consideration of these previous indications along with our preliminary results, our ongoing research is now aiming to clarify a possible relationship between sleep spindles characteristics and altered socioemotional behavior of ASD.
Publications
- (2019) Midbrain involvement in anterior insula-mediated emotion regulation. Organization for Human Brain Mapping Conference OHBM, Rome 9-13.06.2019
Carìa, A., Ciringione, L.
- (2019) Sleep spindles characteristics in adults with Autism Spectrum Disorder and Typical Development. Organization for Human Brain Mapping Conference, OHBM, Rome 9-13.06.2019
Ciringione, L, Cellini, N., Mazzoni, N., De Falco, S., Venuti, P., Zinke, K., Born, J., Carìa A.
- (2020) Mesocorticolimbic Interactions Mediate fMRI-Guided Regulation of Self-Generated Affective States. Brain Sci. 10, 223
Caria, A.
(See online at https://doi.org/10.3390/brainsci10040223)
