People find it easier to learn about topics that interest them, but little is known about the mechanisms by which intrinsic motivational states affect learning.
curiosity (intrinsic motivation to learn) influences memory.
In both immediate and one-day-delayed memory tests, participants showed improved memory for information that they were curious about and for incidental material learned during states of high curiosity.
Importantly, individual variability in curiosity-driven memory benefits for incidental material was supported by anticipatory activity in the midbrain and hippocampus and by functional connectivity between these regions.
These findings suggest a link between the mechanisms supporting extrinsic reward motivation and intrinsic curiosity and highlight the importance of stimulating curiosity to create more effective learning experiences.
stimulus-related processing
particular motivational states
memory formation
consolidation processes
In real-life situations, learning is often self-motivated, driven by intrinsic curiosity in a particular topic, rather than by external rewards (Berlyne, 1966; Reeve and Reeve, 1996; Ryan and Deci, 2000).
According to these views, the SN/VTA (particularly, the VTA) modulates learning of salient information in the hippocampus via enhanced dopamine release, whereas the nucleus accumbens incorporates additional information related to novelty and goal-relevance into this functional circuit. Although the hippocampal-VTA loop theory has primarily been used to explain effects of stimulus-related salience on learning, we predicted that the same circuit might also mediate effects of intrinsic motivational states.
curiosity modulates activity in the nucleus accumbens and SN/VTA, along with a possible set of SN/VTA afferents across the striatum and prefrontal cortex.
Activity in the SN/VTA was predictive of successful memory formation in both curiosity conditions
Findings for the hippocampus paralleled those for the nucleus accumbens, exhibiting a trend for a Curiosity x Memory interaction in the right hippocampus
the results indicate that curiosity-driven memory benefits were driven by anticipatory activity, rather than activity elicited during processing of interesting trivia answers
recognition performance was higher for faces that were encoded during states of high curiosity
This small, but significant effect is in line with the idea that a curious state can benefit learning of incidental information.
high curiosity = question-evoked activity
We did not, however, find significant interactions between curiosity and memory or main effects of memory in the ROIs (all F’s≤2.01, p’s≥0.173), possibly due to high inter-subject variability in behavioral effects of curiosity on face encoding. Stimulus-related activity was predictive of successful memory formation, but this effect was independent of whether a face was presented during high or low curiosity states
individual differences in activity in the SN/VTA and hippocampus, and functional connectivity between the two regions accounted for between-individual variability in incidental face encoding during states of high curiosity.
Recall of trivia answers to high curiosity questions was higher than recall of answers to low curiosity questions. Results also replicated the small, but reliable recognition advantage for faces that were presented during high curiosity states, although this finding was specific to confidently recognized faces. The rate of confidently recognized faces was significantly higher for faces encoded during high curiosity states than for faces encoded during low curiosity states
curiosity can influence memory consolidation of interesting material and also incidental material encoded during high curiosity states.
The goal of the present study was to examine how intrinsic motivation benefits learning of interesting and incidental information. Behavioral results from two studies revealed that states of high curiosity enhance not only learning of interesting information, but also learning of incidental material. Imaging results demonstrated that these learning benefits are related to anticipatory brain activity in the mesolimbic dopaminergic circuit including the hippocampus. In particular, curiosity-driven memory benefits for incidental material were supported by activity in the SN/VTA and the hippocampus and by increased midbrain-hippocampus functional connectivity. Importantly, the effects of curiosity on memory for incidental material were correlated with activity in the SN/VTA prior to the encoding event, accounting for more than half of the behavioral variance in incidental encoding during high curiosity states. These findings are consistent with the idea that curiosity enhances learning, at least in part, through increased dopaminergic modulation of hippocampal activity.
Kang et al. investigated how curiosity interacts with prior knowledge, whereas our study investigated how curiosity influences new learning... Thus, our findings speak more to the influences of a curious state on memory, rather than to the phasic reinforcing influence of satisfying one’s curiosity.
Although we cannot make strong conclusions about whether fMRI signals in the midbrain and nucleus accumbens in our study reflect increased release of dopamine, there is reason to believe that dopamine might have played an important role.
It has been shown that dopamine stimulates local protein synthesis in the dendrites of hippocampal neurons, which in turn is necessary for the late phase of LTP
several models (Frey and Morris, 1998; Lisman and Grace, 2005; Lisman et al., 2011; Redondo and Morris, 2011; Shohamy and Adcock, 2010) propose that stabilization of learning-induced hippocampal plasticity depends on dopaminergic neuromodulation, in addition to synaptic activity.
research has indicated that weak learning events can elicit LTP if they are preceded by events that upregulate dopaminergic activity (Wang et al., 2010). Thus, dopaminergic activity might influence encoding “not only of specific salient events, but also the contexts in which they occur” (Shohamy and Adcock, 2010, p. 470).
dopaminergic activity during states of high curiosity might have “rescued” memories for incidentally encoded faces that would otherwise been forgotten (Lisman et al., 2011; Redondo and Morris, 2011).
Collectively, these findings suggest that both intrinsic and extrinsic motivational states can modulate memory formation.
some differences between effects of curiosity on intentional and incidental learning.
Anticipatory activation in the nucleus accumbens predicted later memory performance only for high curiosity trivia answers, whereas activation in the SN/VTA was related to memory for high and low curiosity trivia answers and to faces incidentally encoded during states of high curiosity.
Anticipatory activity in the nucleus accumbens may set the stage for encoding of upcoming information that is goal-relevant. In contrast, anticipatory activity in the midbrain may promote memory for goal-relevant information, temporally contiguous goal-irrelevant information (e.g., faces shown during high curiosity trials), and other information that is somehow salient but irrelevant to current goals (e.g., subsequently remembered answers to low curiosity trivia questions). This account is admittedly speculative, but it aligns with models (Goto and Grace, 2008; Lisman and Grace, 2005; Scimeca and Badre, 2012) proposing that the VTA signals salience, whereas the nucleus accumbens integrates information about salience from the VTA with information about goal-relevance conveyed by the prefrontal cortex.
Further research is needed to explore the relationship between extrinsic and intrinsic motivation. Although there is reason to think that they share common mechanisms, they might also interact in counter-intuitive ways.
For instance, behavioral studies have shown that extrinsic rewards can undermine intrinsic motivation (for a review, see Deci et al., 1999), an effect that has been linked to decreased activation in the striatum and prefrontal cortex (Murayama et al., 2010).
Murayama and Kuhbandner (2011) demonstrated that the effects of extrinsic rewards and curiosity on memory encoding are not additive. In their study, extrinsic rewards were associated with enhanced memory for uninteresting trivia answers, but rewards did not improve memory for answers of questions that participants were highly curious about.
These findings suggest that it would be useful to directly assess interactions between intrinsic and extrinsic motivational processes in relation to dopaminergic activity and learning.