Biology subjects

Kukkonen, N.

Publications and source records attributed to Kukkonen, N..

3 recordsLinked to original sources

bioRxiv2026

Hippocampal-midbrain interactions link encoding-related pupil response to memory success

Encoding-related pupil responses predict later memory performance, but the neural mechanisms linking these autonomic dynamics to memory formation remain unclear. This study examined whether pupil responses during encoding track activity in the brains memory network and whether they reflect functional interactions between memory-related regions and neural systems involved in pupil control. Participants performed an incidental encoding task involving object stimuli while undergoing simultaneous fMRI and pupillometry; recognition memory was subsequently assessed outside the scanner. Greater pupil constriction during encoding predicted both the strength and quality of later memory. These pupil dynamics correlated with activity in memory-related brain regions, notably the hippocampus and the parahippocampal cortex. Connectivity analyses indicated that encoding-related pupil responses were supported by functional interactions between the hippocampus and the midbrain Edinger-Westphal nucleus, the striatum, and the orbitofrontal cortex. The findings suggest that interactions between memory-related regions and parasympathetic pupil-control systems may modulate encoding efficiency. Together, the results identify encoding-related pupil constriction as a non-invasive marker of memory-network engagement and suggest a hippocampal-midbrain pathway through which autonomic pupil dynamics are coupled with successful memory formation.

neuroscience↗

bioRxiv2026

Parallel control of conjunctive and compositional representations supports dynamic task preparation

People can dynamically and adaptively update task goals in the face of task uncertainty. In this fMRI study, we aimed to investigate the modulation of neural task representations that subserve such flexible task control. On each trial, we asked people to perform one of nine image categorization tasks. During task preparation, participants had to actively infer varying levels of task uncertainty and dynamically modulate their task preparation accordingly. Multivariate pattern analyses demonstrated dissociable uncertainty-driven modulations of conjunctive and compositional task representations in the right frontoparietal network. Specifically, different sub-regions showed diminished conjunctive task representations when task uncertainty increased during task preparation. At the same time, we observed an active maintenance of compositional task representations, suggesting an adaptive cognitive strategy in facilitating compositional task reconfiguration. These findings suggest a mechanism of parallel control on conjunctive and compositional representations that allows for maximizing the advantages of both representational formats, offering new insights into the neural mechanisms underpinning human flexible task preparation.

neuroscience↗

bioRxiv2024

Mind the instructions: reward cues are liked first, wanted later

Current theories propose that mental effort is invested only when the anticipated benefits, such as rewards, outweigh the associated costs, like task difficulty. Yet, it remains unclear whether this motivational and mitigating aspect of reward processing is reflected in the evaluation of reward/difficulty cues as such, and to what extent it depends on task experience. In a pre-registered experiment (N=84), we used the affect misattribution procedure (AMP) to gauge affective evaluations of nonword cues predicting reward and task difficulty levels. Contrary to previous studies, the AMP was administered at the outset, after cue instructions, and after the cues were used in a random dot motion (RDM) task. Compared to baseline, cues predicting a larger reward were evaluated more positively after RDM task experience, and most importantly, already after cue instructions, with no difference between the two phases. This evaluative effect manifested in increased performance after larger reward cues in the RDM task. Our results suggest that AMP effects may generally capture performance expectations which are independent of task experience. Importantly, these instructed expectations of reward and difficulty play a crucial role in the evaluation and subsequent investment of mental effort.

animal behavior and cognition↗