Biology subjects

Schueller, C. B.

Publications and source records attributed to Schueller, C. B..

2 recordsLinked to original sources

bioRxiv2020

Chronic deep brain stimulation of the human nucleus accumbens region disrupts the stability of inter-temporal preferences.

When choosing between rewards that differ in temporal proximity (inter-temporal choice), human preferences are typically stable, constituting a clinically-relevant transdiagnostic trait. Here we show in patients undergoing deep brain stimulation (DBS) of the anterior limb of the internal capsule / nucleus accumbens region for treatment-resistant obsessivecompulsive disorder (OCD), that long-term chronic (but not phasic) DBS disrupts inter-temporal preferences. Hierarchical Bayesian modeling accounting for temporal discounting behavior across multiple time points allowed us to assess both short-term and long-term reliability of inter-temporal choice. In controls, temporal discounting was highly reliable, both long-term (6 months) and short-term (1 week). In contrast, in patients undergoing DBS, short-term reliability was high, but long-term reliability (6 months) was severely disrupted. Control analyses confirmed that this effect was not due to range restriction, the presence of OCD symptoms or group differences in choice stochasticity. Model-agnostic between- and within-subject analyses confirmed this effect. These findings provide initial evidence for long-term modulation of cognitive function via DBS and highlight a potential contribution of the human nucleus accumbens region to inter-temporal preference stability over time. Significance StatementChoosing between rewards that differ in temporal proximity is in part a stable trait with relevance for many mental disorders, and depends on prefrontal regions and regions of the dopamine system. Here we show that chronic deep brain stimulation (DBS) of the human anterior limb of the internal capsule / nucleus accumbens region for treatment-resistant obsessive compulsive disorder disrupts the stability of inter-temporal preferences. These findings show that chronic stimulation of one of the brains central motivational hubs can disrupt preferences thought to depend on this circuit.

neuroscience↗

bioRxiv2020

Temporal discounting in adolescents and adults with Tourette syndrome

BackgroundTourette syndrome is a neurodevelopmental disorder with the clinical hallmarks of motor and phonic tics which are associated with hyperactivity in dopaminergic networks. Dopaminergic hyperactivity in the basal ganglia has previously been linked to increased sensitivity to positive reinforcement and increases in choice impulsivity. ObjectiveWe address whether this extends to changes in temporal discounting, where impulsivity is operationalized as an increased preference to choose smaller-but-sooner over larger-but-later rewards. Results are discussed with respect to neural models of temporal discounting, dopaminergic alterations in Tourette syndrome and the developmental trajectory of temporal discounting. MethodsIn the first study we included nineteen adolescent patients with Tourette syndrome and nineteen age- and education matched controls. In the second study, we compared twenty-five adult patients with Tourette syndrome and twenty-five age- and education-matched controls. ResultsIn the light of the dopaminergic hyperactivity model, we predicted differences in temporal discounting in patients with Tourette syndrome. However, computational modeling of choice behavior using hierarchical Bayesian parameter estimation revealed reduced impulsive choice in adolescent patients, and no group differences in adults. ConclusionWe speculate that adolescents might show reduced discounting due to improved inhibitory functions that also affect choice impulsivity and/or the developmental trajectory of executive control functions. The absence of an effect in adults might be due to differences in the clinical population (e.g. patients who acquired successful tic inhibition during adolescence might have gone into remission). Future studies would benefit from adopting longitudinal approaches to further elucidate the developmental trajectory of these effects.

neuroscience↗