The concept of arousal has been a major aspect of many learning theories and is closely related to other important concepts such as anxiety, attention, and motivation.
One of the most important findings with respect to arousal is the so-called Yerkes-Dodson law which predicts a U-shaped function between arousal (motivation) and performance. Across a broad range of experimental settings, it has been shown that both low and high levels of arousal produce minimum performance whereas a moderate level of arousal results in maximum performance in a task. This suggests that too little or too much stimulation tends to be ignored by individuals.
Berlyne (1960) attempted to explain the relationship between arousal and curiosity based upon Hull's drive reduction theory . According to Berlyne, there is an optimal level of arousal for an individual at a given time. If the level of arousal drops below the optimal level, the organism will seek stimulation (i.e., exploratory behavior). Berlyne argued that curiosity was a consequence of "conceptual conflict" that could be caused by: doubt, perplexity, contradiction, incongruity, or irrelevance.
Eysenck (1982) examines the relationship between attention and arousal. He concludes that there are two types of arousal: a passive and general system that can raise or lower the overall level of attention, and a specific, compensatory system that allows attention to be focused on certain task or environmental stimuli. Mandler (1984) argues that arousal is the key element in triggering emotional behavior.
References:
Berlyne, D. (1960). Conflict, Arousal, and Curiosity. New York: McGraw-Hill.
Eysenck, M. (1982). Attention and Arousal. NY: Springer-Verlag.
Mandler, G. (1984). Mind and Body. NY: Norton.