Biology subjects

Davranche, K.

Publications and source records attributed to Davranche, K..

6 recordsLinked to original sources

bioRxiv2023

Action monitoring boosts perceptual confidence

Dominant models of metacognition suggest that sensory information quality determines perceptual confidence, but recent accounts propose that motor signals also affect confidence judgments. In this study, we investigated the impact of motor planning of perceptual responses on decision confidence, testing two hypotheses. The "fluency hypothesis" suggests that ease of motor response selection and preparation enhances confidence. In contrast, the "monitoring hypothesis" posits that increased action monitoring during response selection boosts confidence, potentially counteracting response fluency. In three pre-registered experiments, participants reported the orientation of a stimulus and indicated their confidence in their response. A cue induced action planning that was either congruent or incongruent with the response side used to report the stimulus orientation. Across experiments, we consistently observed higher confidence when participants prepared spatially incongruent actions compared to congruent ones, regardless of response accuracy. In the third experiment, electroencephalography (EEG) revealed an increased fronto-central P2 amplitude for incongruent actions, suggesting that incongruent action planning heightened early attentional resources needed to resolve response conflict. Incongruent action plans also modulated post-response ERPs at centro-parietal channels (e.g., Pz), typically linked to confidence and error monitoring. These findings align with the "monitoring hypothesis" suggesting that the degree of action monitoring during response selection modulates retrospective decision confidence. Public Significance StatementWhile virtually every decision we make leads to an action, the role of motor processes in decision making has been largely neglected. Our results show that retrospective confidence in a perceptual discrimination task is boosted when the motor execution is spatially incongruent with motor preparation, independently of the correctness of the response. Electroencephalography recordings indicate that this effect could be explained by a larger involvement of early attentional resources related to action monitoring, which has an impact on confidence computations. Taken together, these results suggest that action planning information might trigger monitoring mechanisms susceptible to alter retrospective confidence in our decisions, implying that motor processes are not only the output, but also an input of the decision mechanisms.

neuroscience↗

bioRxiv2023

High-intensity physical activity enhances cognitive decision processes

This study investigates the acute impact of high-intensity activity on perceptual decision-making, using computational modeling to assess changes during and after physical activity. Participants performed a two-alternative forced choice perceptual decision-making task at rest (pre- and post-exercise) and during six of eight 5-minute cycling bouts (totaling 47 minutes) under dual-task condition, while maintaining an average intensity of 86 {+/-} 7% of their maximum heart rate. Drift diffusion modeling was applied to accuracy and reaction time data to estimate changes in evidence accumulation (drift rate), decision threshold (boundary separation), and non-decision processes (ter). Results revealed improved post-exercise performance, characterized by shorter non-decision time, potentially reflecting a transient improvement in motor or perceptual efficiency. During ongoing physical activity, results indicate that exercise is associated with a decrease in non-decision time and an increase in the efficiency of evidence accumulation, while response caution remains stable. These findings provide novel insights into how sustained high-intensity exercise modulates perceptual decision-making dynamics under physiological stress.

neuroscience↗

bioRxiv2021

Peer presence and familiarity as key factors to reduce cocaine intake: an effect mediated by the Subthalamic Nucleus

Stimulant use, including cocaine, often occurs in a social context whose influence is important to understand to decrease intake and reduce associated harms. Given the regulatory role of the subthalamic nucleus (STN) on cocaine intake and emotions, we investigate its role on such influence of social context on cocaine intake. We explored the influence of peer presence and familiarity on the frequency of self-administered cocaine and its neurobiological basis. We first compared cocaine intake in various conditions (alone or with peers with different characteristics: observing or self-administering, familiar or not, cocaine-naive or not, dominant or subordinate) in rats (n=90). The risk of drug consumption was reduced when a peer was present, observing or self-administering as well, and further diminished when the peer was unfamiliar (vs familiar). The presence of a cocaine-naive peer further decreased cocaine consumption. The presence of a non-familiar and drug-naive peer represents thus key conditions to diminish cocaine intake. We tested the effects of STN lesions in these various conditions and also conducted social experiments to validate the role of STN in social cognition. The STN lesion by itself reduced cocaine intake to the level reached in presence of a stranger naive peer and affected social cognition, positioning the STN as one neurobiological substrate of social influence on drug intake. Finally, with a translational research approach, we compared the drug intake in these conditions in human drug users (n=77). This human study confirmed the beneficial effect of social presence, especially of strangers. Our results indirectly support the use of social interventions and harm reduction strategies, in particular supervised consumption rooms for stimulant users.

neuroscience↗

bioRxiv2018

Impact of Physical and Cognitive Exertion on Cognitive Control

In a recent study, the differential effects of prolonged physiologically challenging 4 exercise upon two executive processes (cognitive control and working memory) have been 5 investigated. However, the impact of exercise on the selective inhibition task remained debatable and needed further analysis to dissociate the effects induced by exercise intensity from those induced by the time spent on task upon cognitive control outcomes. In this study we propose a thorough analysis of these data, using a generalized mixed model on a trial-by-9 trial basis and a new measure of the strength of the automatic response based on reaction time distribution, to disentangle the effect of physical fatigue from cognitive fatigue. Despite the prolonged duration of exercise, no decline in cognitive performance was found in response to physical fatigue. The only change observed over the 60-min exercise was an acceleration of the correct trials and an increase of errors for incompatible trials. This pattern, similar in both exercise conditions, supports the occurrence of cognitive fatigue induced by the repetition of the cognitive tasks over time.

neuroscience↗

bioRxiv2018

Revealing subthreshold motor contributions to perceptual confidence

Established models of perceptual metacognition, the ability to evaluate our perceptual judgments, posit that perceptual confidence depends on the strength or quality of feedforward sensory evidence. However, alternative theoretical accounts suggest the entire perception-action cycle, and not only variation in sensory evidence, is monitored when evaluating confidence in ones percepts. Such models lead to the counterintuitive prediction that perceptual confidence should be directly modulated by features of motor output. To evaluate this proposal here we recorded electromyographic (EMG) activity of motor effectors while subjects performed a near-threshold perceptual discrimination task and reported their confidence in each response. A subset of trials exhibited sub-threshold EMG activity in response effectors before a decision was made. Strikingly, trial-by-trial analysis showed that confidence, but not accuracy, was significantly higher on trials with subthreshold motor activation. These findings support a hypothesis that preparatory motor activity impacts upon confidence over and above performance, consistent with models in which perceptual metacognition integrates information across the perception-action cycle.

neuroscience↗

bioRxiv2018

Of Rats And Men: Peer Presence And Familiarity Are Key Factors Which Modulate Drug Intake

Social environment influences drug consumption, its persistence and evolution. Little is known regarding the influence of the presence of a peer during drug consumption and especially how the relationship between peers (familiarity and dominance) can influence drug consumption. We used here a translational and transdisciplinary approach to explore the influence of peer presence and peer familiarity in rats and humans that self-administer stimulants. In rats, cocaine intake was compared when rats were alone with intake when peers with different characteristics (familiar or not, cocaine naive or not, dominant or subordinate) were present. In humans, 77 cocaine and/or methylphenidate users were asked to detail their most recent drug use episodes and their relationship with peers present at consumption. The results show that in both humans and rats, the risk of cocaine/stimulant consumption was significantly reduced by 37% and 32%, respectively, when a peer was present. Moreover, the lowest risk of consumption was consistently observed when the peer was unfamiliar (vs familiar) with a further 38% and 17% risk reduction, respectively. In rats, a decreased risk of consumption was greater when the peer was cocaine naive (vs non-cocaine naive).\n\nThe presence of a non-familiar and possibly drug-naive peer is the most efficient condition to diminish stimulant intake. Our results indirectly support the use of harm reduction strategies, in particular supervised consumption rooms for stimulant users.

neuroscience↗