Curiosity

Curiosity-drive theory posits undesirable experiences of "uncertainty" and "ambiguity". The reduction of these unpleasant feelings is rewarding. This theory suggests that people desire coherence and understanding in their thought processes. When this coherence is disrupted by something that is unfamiliar, uncertain, or ambiguous, an individual's curiosity-drive causes them to collect information and knowledge of the unfamiliar to restore coherent thought processes. This theory suggests that curiosity is developed out of the desire to make sense of unfamiliar aspects of one's environment through exploratory behaviors. Once understanding of the unfamiliar has been achieved and coherence has been restored, these behaviors and desires subside.[11]

Derivations of curiosity-drive theory differ on whether curiosity is a primary or secondary drive and if this curiosity-drive originates due to one's need to make sense of and regulate one's environment or if it is caused by an external stimulus.[12] Causes can range from basic needs that need to be satisfied (e.g. hunger, thirst) to needs in fear-induced situations.[12] Each of these derived theories state that whether the need is primary or secondary, curiosity develops from experiences that create a sensation of uncertainty or perceived unpleasantness. Curiosity then acts to dispel this uncertainty. By exhibiting curious and exploratory behavior, one is able to gain knowledge of the unfamiliar and thus reduce the state of uncertainty or unpleasantness. This theory, however, does not address the idea that curiosity can often be displayed even in the absence of new or unfamiliar situations.[13] This type of exploratory behavior, too, is common in many species. A human toddler, if bored in his current situation devoid of arousing stimuli, will walk about until he finds something interesting. The observation of curiosity even in the absence of novel stimuli pinpoints one of the major shortcomings in the curiosity-drive model.

Optimal-arousal theory developed out of the need to explain this desire to seek out opportunities to engage in exploratory behaviors without the presence of uncertain or ambiguous situations. Optimal-arousal suggests that one can be motivated to maintain a pleasurable sense of arousal through such exploratory behaviors.[9]

When a stimulus is encountered that is associated with complexity, uncertainty, conflict, or novelty, this increases arousal above the optimal point, and exploratory behavior is employed to learn about that stimulus and thereby reduce arousal again. In contrast, if the environment is boring and lacks excitement, arousal is reduced below the optimal point and exploratory behavior is employed to increase information input and stimulation, and thereby increasing arousal again. This theory addresses both curiosity elicited by uncertain or unfamiliar situations and curiosity elicited in the absence of such situations.

Cognitive-consistency theories assume that "when two or more simultaneously active cognitive structures are logically inconsistent, arousal is increased, which activates processes with the expected consequence of increasing consistency and decreasing arousal."[14] Similar to optimal-arousal theory, cognitive-consistency theory suggests that there is a tendency to maintain arousal at a preferred, or expected, level, but it also explicitly links the amount of arousal to the amount of experienced inconsistency between an expected situation and the actually perceived situation. When this inconsistency is small, exploratory behavior triggered by curiosity is employed to gather information with which expectancy can be updated through learning to match perception, thereby reducing inconsistency.[7][14][15]

This approach associates curiosity with aggression and fear. If the inconsistency is larger, fear or aggressive behavior may be employed to alter the perception in order to make it match expectancy, depending on the size of the inconsistency as well as the specific context. Aggressive behavior alters perception by forcefully manipulating it into matching the expected situation, while fear prompts flight, which removes the inconsistent stimulus from the perceptual field and thus resolves the inconsistency.[14]

Taking into account the shortcomings of both curiosity-drive and optimal-arousal theories, attempts have been made to integrate neurobiological aspects of reward, wanting, and pleasure into a more comprehensive theory for curiosity. Research suggests that desiring new information involves mesolimbic pathways of the brain that account for dopamine activation. The use of these pathways, and dopamine activation, may be how the brain assigns value to new information and interprets this as reward.[12][16][17] This theory from neurobiology can supplement curiosity-drive theory by explaining the motivation of exploratory behavior.

Dopamine pathway in the brain

The drive to learn new information or perform some action may be prompted by the anticipation of reward. So what we learn about motivation and reward may help us to understand curiosity.[16]

Reward is defined as the positive reinforcement of an action, reinforcement that encourages a particular behavior by means of the emotional sensations of relief, pleasure, and satisfaction that correlate with happiness. Many areas in the brain process reward and come together to form what is called the reward pathway. In this pathway many neurotransmitters play a role in the activation of the reward sensation, including dopamine, serotonin, and opioids.[16]

Dopamine is linked to curiosity, as it assigns and retains reward values of information gained. Research suggests higher amounts of dopamine are released when the reward is unknown and the stimulus is unfamiliar, compared to activation of dopamine when stimulus is familiar.[16]

The nucleus accumbens is a formation of neurons that is important in reward pathway activation—such as the release of dopamine in investigating response to novel or exciting stimuli. The fast dopamine release observed during childhood and adolescence is important in development, as curiosity and exploratory behavior are the largest facilitators of learning during early years.

The sensation pleasure of "liking" can occur when opioids are released by the nucleus accumbens. This helps someone evaluate the unfamiliar situation or environment and attach value to the novel object. These processes of both wanting and liking play a role in activating the reward system of the brain, and perhaps in the stimulation of curious or information-seeking tendencies as well.[13][17][19]

The caudate nucleus is a region of the brain that is highly responsive to dopamine, and is another component of the reward pathway. Research suggests that the caudate nucleus anticipates the possibility of and reward of exploratory behavior and gathered information, thus contributing to factors of curiosity.[19][20]

Regions of the anterior insula and anterior cingulate cortex correspond to both conflict and arousal and, as such, seem to reinforce certain exploratory models of curiosity.[21]

Cortisol is a chemical known for its role in stress regulation. However, cortisol may also be associated with curious or exploratory behavior. Studies suggesting a role of cortisol in curiosity support optimal arousal theory. They suggest the release of some cortisol, causing some stress, encourages curious behavior, while too much stress can initiate a "back away" response.[20][22]

Attention is important to curiosity because it allows one to selectively focus and concentrate on particular stimuli in the surrounding environment. As there are limited cognitive and sensory resources to understand and evaluate stimuli, attention allows the brain to better focus on what it perceives to be the most important or relevant of these stimuli. Individuals tend to focus on stimuli that are particularly stimulating or engaging. The more attention a stimulus garners, the more frequent one's energy and focus will be directed towards that stimulus. This suggests an individual will focus on new or unfamiliar stimuli in an effort to better understand or make sense of the unknown, rather than on more familiar or repetitive stimuli.[23]

The striatum is a part of the brain that coordinates motivation with body movement.The striatum likely plays a role in attention and reward anticipation, both of which are important in provoking curiosity.[21]

The precuneus is a region of the brain that is involved in attention, episodic memory, and visuospatial processing. There is a correlation between the amount of grey matter in the precuneus and levels of curious and exploratory behaviors. This suggests that precuneus density has an influence on levels of curiosity.[24]

Memory plays an important role in curiosity. Memory is how the brain stores and accesses stored information. If curiosity is the desire to seek out and understand unfamiliar or novel stimuli, memory helps determine if the stimulus is indeed unfamiliar. In order to determine if a stimulus is novel, an individual must remember if the stimulus has been encountered before.

Curiosity may also affect memory. Stimuli that are novel tend to capture more of our attention. Additionally, novel stimuli usually have a reward value associated with them, the anticipated reward of what learning that new information may bring. With stronger associations and more attention devoted to a stimulus, it is probable that the memory formed from that stimulus will be longer lasting and easier to recall, both of which facilitate better learning.

The hippocampus is important in memory formation and recall and therefore in determining the novelty of various stimuli.[25] Research suggests the hippocampus is involved in generating the motivation to explore for the purpose of learning.[2][26][27]

The parahippocampal gyrus (PHG), an area of grey matter surrounding the hippocampus, has been implicated in the amplification of curiosity.[19]

The amygdala is associated with emotional processing, particularly for the emotion of fear, as well as memory. It is important in processing emotional reactions towards novel or unexpected stimuli and the induction of exploratory behavior. This suggests a connection between curiosity levels and the amygdala. However, more research is needed on direct correlation.[28]