Biology subjects

Meliss, S.

Publications and source records attributed to Meliss, S..

4 recordsLinked to original sources

bioRxiv2022

Curiosity-Motivated Incidental Learning With And Without Incentives: Early Consolidation And Midbrain-Hippocampal Resting-State Functional Connectivity

Human memory is selective and not all experiences are remembered. Both monetary rewards/incentives and curiosity have been found to motivate and facilitate learning by dopaminergic midbrain projections to the hippocampus during encoding. In this study, we examined potential brain mechanisms during early consolidation period that jointly or independently contribute to these facilitating effects. Participants (N = 50) watched 36 videos of magic tricks and rated their "subjective feelings of curiosity" while the availability of extrinsic incentives was manipulated between groups. Functional magnetic resonance imaging (fMRI) data were acquired before, during, and after learning, and memory for magic tricks was assessed one week after. Our analysis focused on the change in resting-state functional connectivity (RSFC) between the dopaminergic midbrain and the anterior hippocampus, a dopaminergic consolidation mechanism previously reported in the context of extrinsically motivated learning. Changes in RSFC were correlated with behavioural measures of learning, i.e., the total number of items encoded and the curiosity-driven memory benefit. We found that brain-behaviour correlations differed depending on the availability of extrinsic incentives. More specifically, the correlation between the total number of items encoded and RSFC change was significantly different in the incentivised compared to the control group. The curiosity-driven memory benefit, however, did not correlate with changes in RSFC in either of the groups. In sum, this suggests that curiosity-motivated learning might be supported by different consolidation mechanisms compared to extrinsically motivated learning and that extrinsic incentives influence consolidation mechanisms supporting learning. Key pointsO_LIA new curiosity-motivated incidental encoding paradigm was used to investigate how dopaminergic consolidation mechanisms support learning and whether this is further influenced by the availability of monetary incentives. C_LIO_LIChanges in resting-state functional connectivity between the dopaminergic midbrain and the anterior hippocampus, a dopaminergic consolidation mechanism, predicted learning outcomes significantly differently if monetary incentives were available. C_LIO_LIThese results might suggest that learning motivated by curiosity might rely on different neural mechanisms during early consolidation than learning motivated by monetary incentives. C_LI

neuroscience↗

bioRxiv2022

Broad Brain Networks Support Curiosity-Motivated Incidental Learning Of Naturalistic Dynamic Stimuli With And Without Monetary Incentives

Curiosity - the intrinsic desire to know - is a concept central to the human mind and knowledge acquisition. Experimental studies on information-seeking have found that curiosity facilitates memory encoding and exhibits similar reward,ng properties as extrinsic rewards/incentives by eliciting a dopaminergic response. However, it is not clear whether these findings hold with more naturalistic dynamic stimuli and how the joint effect of curiosity and extrinsic incentive manifests in learning and neural activation patterns. Herein, we presented participants with videos of magic tricks across two behavioural (N1 = 77, N2 = 78) and one fMRI study (N = 50) and asked them to rate subjective feelings of curiosity, while also performing a judgement task that was incentivised for the half of participants. Incidental memory for the magic trick was tested a week later. The integrated results showed that both curiosity and availability of extrinsic incentives enhanced encoding but did not interact with each other. However, exploratory analyses showed that curiosity and monetary incentives were associated with recollection and familiarity differently, suggesting the involvement of different encoding mechanisms. Analysis of the fMRI data using the intersubject synchronisation framework showed that, while the effects of curiosity on memory were located in the hippocampus and dopaminergic brain areas, neither the effects of curiosity nor incentives themselves were found in the often-implicated reward network, but instead were associated with cortical areas involved in processing uncertainly and attention. These results suggest that curiosity recruits broader brain networks than what was implicated in the previous literature when investigated with dynamic stimuli.

neuroscience↗

bioRxiv2020

A 'Naturalistic Neuroimaging Database' for understanding the brain using ecological stimuli

Neuroimaging has advanced our understanding of human psychology using reductionist stimuli that often do not resemble information the brain naturally encounters. It has improved our understanding of the network organization of the brain mostly through analyses of resting-state data for which the functions of networks cannot be verifiably labelled. We make a Naturalistic Neuroimaging Database (NNDb v1.0) publically available to allow for a more complete understanding of the brain under more ecological conditions during which networks can be labelled. Eighty-six participants underwent behavioural testing and watched one of 10 full-length movies while functional magnetic resonance imaging was acquired. Resulting timeseries data are shown to be of high quality, with good signal-to-noise ratio, few outliers and low movement. Data-driven functional analyses provide further evidence of data quality. They also demonstrate accurate timeseries/movie alignment and how movie annotations might be used to label networks. The NNDb can be used to answer questions previously unaddressed with standard neuroimaging approaches, progressing our knowledge of how the brain works in the real world.

neuroscience↗

bioRxiv2019

Motivated for near impossibility: How task type and reward modulates intrinsic motivation and the striatal activation for an extremely difficult task.

Economic and decision-making theories suppose that people would disengage from a task with near zero success probability, because this implicates little normative utility values. However, humans are often motivated for an extremely challenging task, even without any extrinsic incentives. The current study aimed to address the nature of this challenge-based motivation and its neural correlates. We found that, when participants played a skill-based task without extrinsic incentives, their task enjoyment increased as the chance of success decreased, even if the task was almost impossible to achieve. However, such challenge-based motivation was not observed when participants were rewarded for the task or the reward was determined in a probabilistic manner. The activation in the ventral striatum/pallidum tracked the pattern of task enjoyment. These results suggest that people are intrinsically motivated to challenge a nearly impossible task, but only when the task requires certain skills and extrinsic rewards are unavailable.

neuroscience↗