Sensation and perception is a concept in psychology that attempts to explain how humans see and perceive their world. In sensation and perception, the former is the raw form in which humans consume their surroundings and the latter is how they digest them. Sensation and perception is a chapter typically covered in psychology 101 classes. Comprehensive notes are extremely encouraged in such courses. The sensation aspect of sensation and perception includes all the information that is immediately available to a person. This covers such things as ambient temperature, light level, random chatter or the strong smell of perfume. One does not, however, notice things like x-rays, radio waves or microscopic parasites. There is a such thing as an absolute threshold, that is, a point when something becomes noticeable. Maybe a person does not notice the radio in the other room, but they do when it gets to a certain volume level. Of course, adaptability allows for all manner of potentially annoying stimuli to become part of one's background noise. For the perception aspect of sensation and perception, it is simply the way one interprets all the sensory stimuli taken in. People tend to group sensations based on similarity, thus the familiar sense of sight, scent, taste, touch and hearing. Some of the basics of sensation and perception that will be covered are as follows. Tastebuds and olfactory cells regrow about every two weeks. The rate of growth declines sharply around age 40. There are 4 separate sensors in the skin that detect pressure, temperature, stretching, and pain. There are no scent categories akin to the taste groups because humans can detect about 350 separate and unique odors. Conversely, lab rats can detect well over 1,000 unique odors. In sensation and perception, scent is the strongest sense tied to memory because olfactory information travels through the brain's memory center. There are such things as "super tasters" as well as people who have very little sense of taste. "Cocktail Party Phenomenon" is an aspect of sensation and perception that refers to one's ability to detect the utterance of their name in a crowded, noisy room. It is somewhat similar to "New Car Psychosis", which occurs in a variety of situations. It's because of the newly-introduced stimulus. A new neural pathway is forged, and the stimulus is literally at the front of the mind. Detecting one's name in a crowded room, however, has more to do with a well-forged neural pathway. After all, what does one hear more in one's life than one's own name? Some popular sensation and perception textbooks include: Alchemy of Mind by Diane Ackerman, Brain States by Tom Kenyon, Cognition and the Visual Arts by Robert L. Solso, Cognition, Brain, and Consciousness by Nichole M. Baars, Color Studies by Edith Anderson Feisner and Consciousness and Behavior by Benjamin Wallace and Leslie Fisher.