Biology subjects

Jahn, C. I.

Publications and source records attributed to Jahn, C. I..

4 recordsLinked to original sources

bioRxiv2023

Learning attentional templates for value-based decision-making

Attention filters sensory inputs to enhance task-relevant information. It is guided by an attentional template that represents the stimulus features that are relevant for the current task. To understand how the brain learns and uses new templates, we trained monkeys to perform a visual search task that required them to repeatedly learn new attentional templates. Neural recordings found templates were represented across prefrontal and parietal cortex in a structured manner, such that perceptually neighboring templates had similar neural representations. When the task changed, a new attentional template was learned by incrementally shifting the template towards rewarded features. Finally, we found attentional templates transformed stimulus features into a common value representation that allowed the same decision-making mechanisms to deploy attention, regardless of the identity of the template. Altogether, our results provide new insight into the neural mechanisms by which the brain learns to control attention and how attention can be flexibly deployed across tasks.

neuroscience↗

bioRxiv2023

Multiplexed Subspaces Route Neural Activity Across Brain-wide Networks

Cognition is flexible. Behaviors can change on a moment-by-moment basis. Such flexibility is thought to rely on the brains ability to route information through different networks of brain regions in order to support different cognitive computations. However, the mechanisms that determine which network of brain regions is engaged are unknown. To address this, we combined cortex-wide calcium imaging with high-density electrophysiological recordings in eight cortical and subcortical regions of mice. Different dimensions within the population activity of each brain region were functionally connected with different cortex-wide subspace networks of regions. These subspace networks were multiplexed, allowing a brain region to simultaneously interact with multiple independent, yet overlapping, networks. Alignment of neural activity within a region to a specific subspace network dimension predicted how neural activity propagated between regions. Thus, changing the geometry of the neural representation within a brain region could be a mechanism to selectively engage different brain-wide networks to support cognitive flexibility.

neuroscience↗

bioRxiv2022

Strategic exploration in the macaque prefrontal cortex

Humans have been shown to strategically explore. They can identify situations in which gathering information about distant and uncertain options is beneficial for the future. Because primates rely on scare resources when they forage, they are also thought to strategically explore, but whether they use the same strategies as humans and the neural bases of strategic exploration in monkeys are largely unknown. We designed a sequential choice task to investigate whether monkeys mobilize strategic exploration based on whether that information can improve subsequent choice, but also to ask the novel question about whether monkeys adjust their exploratory choices based on the contingency between choice and information, by sometimes providing the counterfactual feedback, about the option not chosen. We show that monkeys decreased their reliance on expected value when exploration could be beneficial, but this was not mediated by changes in the effect of uncertainty on choices. We found strategic exploratory signals in anterior and mid-cingulate cortex (ACC/MCC) and dorsolateral prefrontal cortex (dlPFC). This network was most active when a low value option was chosen which suggests a role in counteracting expected value signals, when exploration away from value should to be considered. Such strategic exploration was abolished when the counterfactual feedback was available. Learning from counterfactual outcome was associated with the recruitment of a different circuit centered on the medial orbitofrontal cortex (OFC), where we showed that monkeys represent chosen and unchosen reward prediction errors. Overall, our study shows how ACC/MCC-dlPFC and OFC circuits together could support exploitation of available information to the fullest and drive behavior towards finding more information through exploration when it is beneficial.

neuroscience↗

bioRxiv2017

Independent contributions of noradrenaline to behavioural flexibility and motivation

Among neuromodulatory systems, the noradrenergic system remains one of the least understood. Several theories have pointed out its implication in behavioural flexibility and more recently in motivation, with a strong role in effort processing. Here, we designed a sequential cost/benefit decision task to test the causal role of noradrenaline in these two functions. We manipulated noradrenaline using clonidine, an alpha-2 noradrenergic receptor agonist, which reduces central noradrenaline levels. Clonidine had two distinct effects: it decreased choice volatility (without affecting the cost/benefit trade off) and reduced force production. Because the effects were independent, they cannot be accounted for by a non-specific effect on arousal. Altogether, these results support the global implication of noradrenaline in facing challenging situations in two complementary ways: by modulating behavioural volatility, which would facilitate adaptation depending on the lability of the environment, and by modulating the mobilization of resources to face immediate challenges.

neuroscience↗