Biology subjects

Gruber, M. J.

Publications and source records attributed to Gruber, M. J..

6 recordsLinked to original sources

bioRxiv2023

Curiosity as an amplifier of reward-related feedback processing

Successful learning depends on various factors such as depth of processing, motivation, or curiosity about information. A strong drive to learn something or the expectation of receiving a reward can be crucial to enhance learning. However, the influence of curiosity on the processing of new information and its similarity with reward processing is not well understood. This study examined whether states of curiosity influence specific event-related-potentials (ERPs) associated with reward processing and whether these ERPs are related with later memory benefits. In an initial screening phase, participants indicated their curiosity and confidence in prior knowledge about answers to various trivia questions. In a subsequent study phase, we targeted different time windows related to reward processing during the presentation of trivia answers containing the Reward-Positivity (RewP; 250 - 350 ms), the P3 (250 - 500 ms), and the Late-Positive-Potential (LPP; 600 - 1000 ms). In a following surprise memory test, we found that participants recalled more high- than low-curiosity answers. The RewP, P3 and LPP showed greater positive mean amplitudes for high compared to low curiosity, reflecting increased reward processing. In addition, we found that the RewP and the P3 showed more positive mean amplitudes for later recalled compared to later forgotten answers, but curiosity did not modulate this encoding-related results. These findings support the view that the satisfaction of curiosity resembles reward processing, indicated by event-related-potentials.

neuroscience↗

bioRxiv2023

Intrinsic functional connections determine how curiosity and prediction errors enhance memory

Individuals differ in the way they seek information, acquire knowledge, and form memories. Neural finger-prints of intrinsic functional connectivity distinguish between individuals and predict inter-individual differences in task performance. Both curiosity - the desire to acquire new information - and information prediction errors (IPEs) - the mismatch between information and previous expectations - enhance memory but differ considerably between individuals. The present study assessed whether inter-individual differences in functional connectivity measured using resting-state fMRI determine the extent to which individuals benefit from memory-enhancing effects of curiosity and IPEs. We found a double dissociation between individual differences in mesolimbic functional connectivity, which accounted for curiosity-driven but not IPE-related memory enhancements, and individual differences in cingulo-hippocampal functional connectivity, which predicted IPE-driven but not curiosity-related memory enhancements. These novel findings on how inter-individual differences in dissociable intrinsic functional networks determine memory enhancements stress the need to account for these differences in theoretical frameworks of curiosity and memory.

neuroscience↗

bioRxiv2022

Curiosity and mesolimbic functional connectivity drive information seeking in real life

Curiosity reflects the intrinsic motivation of an individual to seek information in order to close information gaps. Laboratory-based experiments have shown that both curiosity and information seeking are associated with enhanced neural dynamics in the mesolimbic dopaminergic circuit. However, it is unclear whether curiosity and its associated neural dynamics in the dopaminergic circuit drive information seeking in real life. The present study investigated (i) whether curiosity traits predict different characteristics of real-life information seeking and (ii) whether functional connectivity within the mesolimbic dopaminergic circuit is associated with information seeking outside of the laboratory. Up to 15 month before the COVID-19 pandemic, we conducted curiosity and anxiety questionnaires as well as a 10-minute resting-state fMRI session. In a follow-up survey early during the COVID-19 pandemic, participants repeated the questionnaires and filled out an additional questionnaire about their COVID-19-related information seeking. Curiosity but not anxiety remained stable over time. Individual differences in curiosity were positively associated with the frequency of information-seeking behaviour. Anxiety during the pandemic was not linked to any characteristics of real-life information seeking. Interestingly, the frequency of information seeking was also independently predicted by individual differences in resting-state functional connectivity between the ventral tegmental area and the nucleus accumbens. The present translational study paves the way for future studies on the role of curiosity in real-life information seeking by showing that curiosity drives information seeking in real-life situations and that the curiosity-promoting mesolimbic dopaminergic functional network supports the frequency of real-life information-seeking behaviour. SIGNIFICANCE STATEMENTCuriosity is a key driver of learning and information seeking in everyday life. However, the temporal stability of curiosity traits, their relationship to real-life information seeking, and the associated dopaminergic brain activity are poorly understood. The present study provides evidence that curiosity traits are stable over time - even through a major event, such as the COVID-19 pandemic - and that both curiosity and intrinsic functional connectivity within the mesolimbic dopaminergic circuit are associated with the frequency of real-life information seeking. These findings contribute to a better understanding of cognitive and neural differences that shape how individuals seek out information and may offer the opportunity to help individuals with suboptimal information-seeking behaviour that negatively affects their well-being or mental health.

neuroscience↗

bioRxiv2021

Connectivity between the hippocampus and default mode network during the relief, but not elicitation, of curiositysupports curiosity-enhanced memory enhancements

Consistent with the idea that curiosity enhances information seeking, it has been shown that activity within both the dopaminergic circuit and hippocampus supports curiosity-enhanced learning. However, the role of whole-brain mechanisms involved in cognitive control (fronto-parietal network; FPN) and memory integration (default mode network; DMN) that might underpin curiosity states and their effects on memory remain elusive. We hypothesised that the FPN and DMN should distinguish between high- and low-curiosity conditions and be recruited more heavily for later remembered information associated with high-curiosity. Here, we used functional magnetic resonance imaging whilst participants completed a trivia paradigm, in which we presented trivia questions associated with high- and low-curiosity, followed by the associated answer. After a short delay, we tested memory for trivia answers. We adopted a network-based parcellation of the brain into subnetworks of the FPN and DMN to examine how neural activity within, and functional connectivity between, each subnetwork predicts curiosity-enhanced memory. Across elicitation and relief of curiosity, we found focal recruitment of FPNA and widespread recruitment of DMN subnetworks in support of curiosity and curiosity-enhanced memory. Most importantly, during the elicitation of curiosity, functional subcortical connectivity and across cortical networks, but not subcortical-cortical coupling, correlated with curiosity-enhanced memory. However, during the relief of curiosity, coupling between subcortical regions and DMNA emerged in support of curiosity-enhanced memory. Taken together, our results provide the first evidence about how neuromodulatory mechanisms via the hippocampal-dopaminergic circuit trigger states of curiosity and thereby communicate to higher-order cortical regions to facilitate curiosity-enhanced memory. Significant statementDoes neural activity within, and functional connectivity between, the dopaminergic-hippocampal network, fronto-parietal network (FPN), and default mode network (DMN) underpin curiosity states and their effects on memory? Here, we show how the dopaminergic system together with the hippocampus interact specifically with subnetwork DMNA potentially reflecting how subcortical regions support the enhancement of memory intergration of semantic information associated with curiosity. As DMNA (the core DMN subnetwork) was also functionally coupled with the whole DMN network and the semantic control network (FPNA), these findings provide a plausible neuromodulatory mechanism through which hippocampal-dopaminergic input triggers curiosity and then communicates to higher-order brain regions via DMNA to facilitate curiosity-enhanced memory.

neuroscience↗

bioRxiv2019

Curious connections: white matter pathways supporting individual differences in epistemic and perceptual curiosity

Across the lifespan, curiosity motivates us to learn, yet curiosity varies strikingly between individuals. Such individual differences have been shown for two distinct dimensions of curiosity: epistemic curiosity (EC), the desire to acquire conceptual knowledge, and perceptual curiosity (PC), the desire for sensory information. It is not known, however, whether both dimensions of curiosity depend on different brain networks and whether inter-individual differences in curiosity depend on variation in anatomical connectivity within these networks. Here, we investigated the neuroanatomical connections underpinning individual variation in trait curiosity. Fifty-one female participants underwent a two-shell diffusion MRI sequence and completed questionnaires measuring EC and PC. Using deterministic spherical deconvolution tractography we extracted microstructural metrics (fractional anisotropy (FA) and mean diffusivity (MD)) from two key white matter tracts: the fornix (implicated in novelty processing, exploration, information seeking and episodic memory) and the inferior longitudinal fasciculus (ILF) (implicated in semantic learning and memory). In line with our predictions, we found that EC - but not PC - correlated with ILF microstructure. Fornix microstructure, in contrast, correlated with both EC and PC, with posterior hippocampal fornix fibres - associated with posterior hippocampal network connectivity - linked to PC specifically. These findings suggest that differences in distinct dimensions of curiosity map systematically onto specific white matter tracts underlying well characterized brain networks. Furthermore, the results pave the way to study the anatomical substrates of inter-individual differences in dimensions of trait curiosity that motivate the learning of distinct forms of knowledge and skills.

neuroscience↗

bioRxiv2017

Theta Phase Synchronization Between The Human Hippocampus And The Prefrontal Cortex Supports Learning Of Unexpected Information

Events that violate predictions are thought to not only modulate activity within the hippocampus and prefrontal cortex, but also to enhance communication between the two regions. Several studies in rodents have shown that synchronized theta oscillations facilitate communication between the prefrontal cortex and hippocampus during salient events, but it remains unclear whether similar oscillatory mechanisms support interactions between the two regions in humans. Here, we had the rare opportunity to conduct simultaneous electrophysiological recordings from the human hippocampus and prefrontal cortex from two patients undergoing presurgical evaluation for pharmaco-resistant epilepsy. Recordings were conducted during a task that involved encoding of contextually expected and unexpected visual stimuli. Across both patients, hippocampal-prefrontal theta phase synchronization was significantly higher during encoding of unexpected study items, compared to contextually expected study items. In contrast, we did not find increased theta synchronization between the prefrontal cortex and rhinal cortex. Our findings are consistent with the idea that theta oscillations orchestrate communication between the hippocampus and prefrontal cortex during the processing of contextually salient information.

neuroscience↗