Biology subjects

Mullins, T. S.

Publications and source records attributed to Mullins, T. S..

3 recordsLinked to original sources

bioRxiv2026

Protracted prediction: Neurodevelopment of reward processing in the adolescent cerebellum.

Adolescence is characterized by heightened reward sensitivity and risky decision-making. Prevailing neurodevelopmental frameworks attribute these behavioral trends to a maturational imbalance between rapidly developing motivational brain regions, and slower-maturing prefrontal cognitive control circuitry. However, these models overlook the cerebellum-a structure that demonstrates protracted development across adolescence and reciprocal connectivity with both striatum and prefrontal cortex. Here, we conducted a systematic literature search and activation likelihood estimation (ALE) meta-analysis of functional magnetic resonance imaging (fMRI) studies examining reward anticipation and feedback processing in healthy adolescents (19 studies; 55 cerebellar peaks). In adults, a recent ALE analysis found a diffuse set of cognitive and affective cerebellar regions is recruited during reward anticipation, while feedback-locked activation is circumscribed and mostly restricted to the Vermis (Kruithof et al., 2023). In adolescents, we found evidence for a reward phase-specific spatial dissociation relative to adults. In adolescents, reward anticipation-locked activity is restricted to regions of the Vermis that are functionally connected to occipital and salience networks. Conversely, feedback processing elicits diffuse activation across bilateral Crus I/II regions that are connected to frontoparietal, default-mode, and limbic networks. These results suggest a proactive engagement of cortico-cerebellar networks during reward anticipation in adults, and a reactive recruitment of cortico-cerebellar networks post-feedback in adolescents. Adolescents may have less mature internal models for optimizing decision-making, and as a result they may require more widespread recruitment of cortico-cerebellar cognitive and affective circuitry post-feedback. Prevailing maturational imbalance models of youth decision-making should be expanded to incorporate developmental changes in cerebellar reward processing.

neuroscience↗

bioRxiv2021

The neurocomputational architecture of explore-exploit decision making

Humans and other animals often make the difficult decision to try new options (exploration) and forego immediate rewards (exploitation). Novelty-seeking is an adaptive solution to this explore-exploit dilemma, but our understanding of the neural computations supporting novelty-seeking in humans is limited. Here, we presented the same explore-exploit decision making task to monkeys and humans and found evidence that the computational basis for novelty-seeking is conserved across primate species. Critically, through computational model-based decomposition of event-related functional magnetic resonance imaging (fMRI) in humans, these findings reveal a previously unidentified cortico-subcortical architecture mediating explore-exploit behavior in humans.

neuroscience↗

bioRxiv2019

Spatiotemporal patterns of transcranial electrical stimulation can strengthen the metamemory of individual episodic memories in humans

Targeted memory reactivation (TMR) during slow-wave oscillations (SWOs) in non-rapid eye movement (NREM) sleep has been demonstrated with sensory cues to achieve about 5-12% improvement in post-nap memory performance on simple laboratory tasks. But prior work has neither addressed the one-shot aspect of episodic memory acquisition, nor dealt with the presence of interference from ambient environmental cues in real-world settings for the sensory cues. Moreover, TMR with sensory cues may not be scalable to the multitude of experiences over ones lifetime. We designed a novel non-invasive paradigm that tags one-shot experiences of minute-long naturalistic episodes within immersive virtual reality (VR) with unique spatiotemporal amplitude-modulated patterns (STAMPs) of transcranial electrical stimulation (tES) and cues them during SWOs. In particular, we demonstrate that these STAMPs can be re-applied as brief pulses to temporally coincide with UP states of SWOs (0.4167 - 1 s) on two consecutive nights to achieve about 20% improvement in the metamemory of targeted episodes at 48 hours after the one-shot viewing, compared to the control episodes. Post-sleep metamemory of the targeted episodes was driven by an interaction between their pre-sleep metamemory and the number of STAMP applications for those episodes during sleep. Overnight metamemory improvements were mediated by spectral power increases from 6.18 to 6.7 s following the offset of STAMPs in the slow-spindle band (9-12 Hz) for left temporal areas in the scalp electroencephalography (EEG) during sleep. These results prescribe an optimal strategy to leverage STAMPs for boosting metamemory and suggest that real-world episodic memories can be modulated in a targeted manner even with coarser, non-invasive spatiotemporal stimulation.

neuroscience↗