Biology subjects

Barrett, L. F.

Publications and source records attributed to Barrett, L. F..

6 recordsLinked to original sources

bioRxiv2023

Cortical and subcortical mapping of the allostatic-interoceptive system in the human brain: replication and extension with 7 Tesla fMRI

The brain continuously anticipates the energetic needs of the body and prepares to meet those needs before they arise, called allostasis. In support of allostasis, the brain continually models the sensory state of the body, called interoception. We replicated and extended a large-scale system supporting allostasis and interoception in the human brain using ultra-high precision 7 Tesla functional magnetic resonance imaging (fMRI) (N = 90), improving the precision of subgenual and pregenual anterior cingulate topography combined with extensive brainstem nuclei mapping. We observed over 90% of the anatomical connections published in tract-tracing studies in non-human animals. The system also included regions of dense intrinsic connectivity broadly throughout the system, some of which were identified previously as part of the backbone of neural communication across the brain. These results strengthen previous evidence for a whole-brain system supporting the modeling and regulation of the internal milieu of the body.

neuroscience↗

bioRxiv2022

Distinct spatial patterns of neural and physiology-related activity in the human periaqueductal grey during anticipatory social stress.

Periaqueductal gray (PAG) columns mediate affective experience, physiological regulation, and survival-related behavior; yet, only 7T imaging can resolve these small structures in humans. In a social stress task, participants prepared a speech, and we observed (a) bilateral ventrolateral PAG activity, relative to baseline, and (b) distinct spatial patterns of correlation between PAG activity and physiological response (i.e., cardiac interbeat interval, reparation rate, and tonic electrodermal activity).

neuroscience↗

bioRxiv2022

The role of human superior colliculus in affective experiences during visual and somatosensory stimulation

The superior colliculus is often studied for its role in visually guided behaviors, but research in non-human animals indicates it is a midbrain hub for processing sensory information from multiple domains, including interoception (which is associated with affect). We used ultra-high field 7-Tesla fMRI to extend this work to humans, modeling superior colliculus BOLD signal intensity during visual or somatosensory stimulation (N = 40 in each sensory modality), both under aversive and neutral affective intensity. As hypothesized, the superior colliculus showed increased BOLD signal intensity in the dorsal and ventral subregions during visual and somatosensory stimulation, respectively. The entire superior colliculus also showed increased BOLD signal intensity during aversive compared to neural conditions. The superior colliculus BOLD signal intensity also correlated with a preregistered set of brain regions involved in visual, somatosensory, and interoceptive processing.

neuroscience↗

bioRxiv2022

Layer-dependent activity in the human superior colliculus during working memory

We examined the superior colliculus (SC) with ultra-high resolution 7-Tesla fMRI during an N-back working memory task. We observed both increased BOLD signal intensity and functional connectivity that followed a layer-dependent pattern predicted from anatomical connections between SC and other brain structures important for visual processing, motor control, and executive function. Our results highlight a role for the human SC in cognitive functions that usually associated with the cerebral cortex.

neuroscience↗

bioRxiv2018

Preserved functional connectivity in the default mode and salience networks is associated with youthful memory in superaging

'Superagers' are older adults who, despite their advanced age, maintain youthful memory. Previous morphometry studies revealed multiple default mode network (DMN) and salience network (SN) regions whose cortical thickness is preserved in superagers and correlates with memory performance. In this study, we examined the intrinsic functional connectivity within DMN and SN in 41 young (24.5 {+/-} 3.6 years old) and 40 elderly adults (66.9 {+/-} 5.5 years old). As in prior studies, superaging was defined as youthful performance on a memory recall task, the California Verbal Learning Test (CVLT). Participants underwent a resting state fMRI scan and performed a separate visual-verbal recognition memory task. As predicted, within both DMN and SN, superagers had stronger connectivity compared to typical older adults and similar connectivity compared to young adults. Superagers also performed similarly to young adults and better than typical older adults on the recognition task, demonstrating youthful episodic memory that generalized across memory tasks. Stronger connectivity within each network independently predicted better performance on both the CVLT and recognition task in older adults. Variation in intrinsic connectivity explained unique variance in memory performance, above and beyond preserved neuroanatomy. A post-hoc analysis revealed that DMN and SN nodes were more strongly inversely correlated in superagers than in typical older adults but were similarly correlated in superagers and young adults. Stronger between-network inverse correlations also predicted better memory performance in the entire sample of older adults. These results extend our understanding of the neural basis of superaging as a model of successful aging.

neuroscience↗

bioRxiv2017

From affect to control: Functional specialization of the insula in motivation and regulation

The insula plays a key role in a wide range of brain processes, from viscerosensation and pain to motivation, emotion, and cognitive control. While human neuroimaging studies in all these domains report activations in the insula, little systematic attention is paid to anatomical subdivisions that may provide the basis for functional sub-regions. We conducted a meta-analysis of insular tasks across studies in four domains: emotion, pain, attention switching, and working memory. Using a priori subdivision of the insula based on anatomical studies, we provide evidence that different sub-regions are preferentially activated in different tasks. We suggest that the ventral anterior insula is most important for core affect, a term that describes broadly-tuned motivational states (e.g., excitement) with associated subjective feelings. The dorsal anterior insula, by contrast, may be critical for developing and updating motivational states with specific associated actions (i.e., goals). This region is activated by cognitive control tasks, pain, and some tasks that elicit affective processing. The posterior insula, including SII and portions of parietal operculum, is distinctly activated by pain, providing a double dissociation between pain and tasks that elicit emotions.

neuroscience↗