Curiosity

Curiosity-drive theory relates to the undesirable experiences of "uncertainty". The reduction of these unpleasant feelings, in turn, 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, it is curiosity-drive that attempts to gather information and knowledge of the unfamiliar to restore coherent thought processes. Through this theory, the general concept dictates that curiosity is developed strictly out of the desire to make sense of unfamiliar aspects of one's environment through interaction of exploratory behaviors. Once understanding of the unfamiliar has been achieved and coherence has been restored, these behaviors and desires will subside.

Subsets of curiosity-drive theory differ on whether curiosity is a primary or secondary drive and if this curiosity-drive is originated due to one's need to make sense of and regulate their environment or if it is caused by an external stimulus.[10] Causes can range from basic needs that need to be satisfied (e.g. hunger, thirst) to needs in fear induced situations.[10] Each of these subset theories state that whether the need is primary or secondary curiosity is developed from experiences that create a sensation of uncertainty or perceived unpleasantness. Curiosity then acts as a means in which 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.[11] This type of exploratory behavior is common in many species. Take the example of a human toddler who, if bored in his current situation devoid of arousing stimuli, will walk about until something interesting is found. 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 the desire for some to seek out opportunities to engage in exploratory behaviors without the presence of uncertain or ambiguous situations. Optimal-arousal theory attempts to explain this aspect of curiosity by suggesting that one can be motivated to maintain a pleasurable sense of arousal through these exploratory behaviors.

The concept of optimal-arousal of curiosity suggests that there is a tendency to maintain an optimal level of arousal.[8] When a stimulus is encountered that is associated with complexity, uncertainty, conflict, or novelty, this will increase arousal, 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 and exploratory behavior will be engaged in order 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."[12] 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.[6][12][13] This approach puts curiosity in a broader perspective, also involving aggression and fear. That is, 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 is assumed to alter perception by forcefully manipulating it into matching the expected situation, while uninhibited fear results in fleeing, thereby removing the inconsistent stimulus from the perceptual field and resolving the inconsistency.[12]

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 the act of wanting and desiring new information directly involves mesolimbic pathways of the brain that directly account for dopamine activation. The use of these pathways and dopamine activation may account for the assigning of value to new information and then interpreting as reward.[10][14][15] This aspect of neurobiology can accompany curiosity-drive theory in motivating exploratory behavior.

Dopamine pathway in the brain

The drive to learn new information or perform some action is often initiated by the anticipation of reward. In this way, the concepts of motivation and reward are naturally tied to the notion of curiosity.[14]

This idea of reward is defined as the positive reinforcement of an action that encourages a particular behavior by using the emotional sensations of relief, pleasure, and satisfaction that correlate with happiness. Many areas in the brain are used to 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 opioid chemicals.[14]

Dopamine is linked to the process of curiosity, as it is responsible for assigning and retaining reward values of information gained. Research suggests higher amounts of dopamine is released when the reward is unknown and the stimulus is unfamiliar, compared to activation of dopamine when stimulus is familiar.[14]

The nucleus accumbens is a formation of neurons and is important in reward pathway activation. As previously mentioned, the reward pathway is an integral part in the induction of curiosity. 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.

In addition, the sensation pleasure of "liking" can occur when opioids are released by 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.[11][15][17]

The caudate nucleus, is a region of the brain that is highly responsive to dopamine. The caudate nucleus is another component of the reward pathway. Research has suggested that the role of the caudate nucleus is to anticipate the possibility and reward of exploratory behavior and gathered information, thus contributing to factors of curiosity.[17][18]

Regions of the anterior cortices correspond to both conflict and arousal and, as such, seem to reinforce certain exploratory models of curiosity.[19]

Cortisol is a chemical known for its role in stress regulation. However, cortisol may also be associated with curious or exploratory behavior. Findings in recent studies suggesting the role of cortisol with curiosity support the idea of optimal arousal theory. It is suggested the release of a small amount cortisol causing stress encourages curious behavior, while too much stress can initiate a "back away" response.[18][20]

Attention is important to the understanding of curiosity because it directly correlates with one's abilities to selectively focus and concentrate on particular stimuli in the surrounding environment. As there are limited cognitive and sensory resources to understand and evaluate various 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 their energies on stimuli that are particularly stimulating or engaging. Indicating that the more attention a stimulus garners, the more frequent one's energy and focus will be directed towards that stimulus. This idea suggests an individual will focus their attention on new or unfamiliar stimuli in an effort to better understand or make sense of the unknown over the more familiar or repetitive stimuli, creating the idea that curiosity demands attention.[21]

The striatum is a part of the brain which coordinates motivation with body movement. It would seem natural that the striatum plays a role in attention and reward anticipation, both of which are important in the provocation of curiosity.[19]

The precuneus is a region of the brain that is involved in attention, episodic memory, and visuospatial processing. There has been a correlation found between the amount of grey matter in the precuneus and levels of curious and exploratory behaviors; suggesting that the precuneus density has an influence on levels of curiosity.[22]

Memory plays an important role in the understanding of curiosity. If curiosity is the desire to seek out and understand unfamiliar or novel stimuli, one's memory is important in determining if the stimulus is indeed unfamiliar.

Memory is the process by which the brain can store and access information. In order to determine if the stimulus is novel, an individual must remember if the stimulus has been encountered before. Thus, memory plays an integral role in dictating the level of novelty or unfamiliarity, and the level of need for curiosity.

It can also be suggested that curiosity can affect memory. As previously mentioned, 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 instrumental in determining the novelty of various stimuli.[23] Research suggests the hippocampus is involved in generating the underlying motivation to explore for the purpose of learning.[2][24][25]

The parahippocampal gyrus (PHG), the area of grey matter surrounding the hippocampus, has recently been implicated in the process of curiosity. This finding suggests that the PHG may be involved in the amplification of curiosity more so than the primary induction of curiosity.[17]

The amygdala often is associated with emotional processing, particularly for the emotion of fear, as well as memory. It is suggested the amygdala is important in processing emotional reactions towards novel or unexpected stimuli and the induction of exploratory behavior. This implies a potential connection between curiosity levels and the amygdala. However, more research is needed on direct correlation.[26]