Aspects of psychology

Running head : SENSORY ADAPTATION

Sensory Adaptation : Texture , Temperature , Taste , and Light

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Sensory Adaptation : Texture , Temperature , Taste , and Light

Adaptation (Campbell , Reece Mitchell , 1999 Davis Palladino , 2006 is a process where over repeated exposure to the same stimulus , the intensity of activation in the sensory receptor cells and in areas of the midbrain or thalamus (Campbell , Reece Mitchell , 1999 ) weakens These areas receive veridical (the same as the sensation ) traces lasting less than about a second from the sensory receptors , traces referred to as the sensory

registers (an iconic register for visual stimuli Sperling , 1960 , an echoic one for auditory stimuli , Darwin , Turvey Crowder , 1972 , a tactile register for touch stimuli , Watkins Watkins 1974 . Perception occurs after sensory information is transmitted to areas of the cerebral cortex

Demonstrations

Sensory vs . perceptual processing . Based on inferences drawn from previous research (as cited in Davis Palladino , 2006 , the demonstrations (described in a course handout ) reported below were expected to result in adaptation . It should be noted that in these demonstrations , findings of adaptation could be attributable to expectancy effects influencing perception , i .e , there is robust evidence that people often perceive what they expect to perceive (Harris , 1991 . Prior to the demonstrations , the class already had learned about adaptation and had expectations . For purposes of this , I ignored both possible expectancy effects and , more importantly that there were no physiological , brain imaging , or brain wave monitoring measures

Texture (an example of touch . I rubbed both index fingers back and forth three times over a sheet of coarse sand and then rated its coarseness a 7 (using a 7-point scale , where 7 very coarse ' though not necessarily the coarsest a stimulus could feel . After 2 m , I rubbed my index fingers back and forth once over the same sand , and rated its coarseness a 5 (meaning it felt moderately coarse . In both cases , mechanoreceptors under the skin that were sensitive to coarseness , different from those sensitive to smoothness , were activated (Hollins Sliman , 2007 , with less intensity after the 2 m delay Awareness of adaptation was a result of processing in the somatosensory association areas of the parietal lobes in each hemisphere of the brain (Campbell , Reece Mitchell , 1999

Water temperature (an example of touch . I simultaneously placed my left and right hands in bowls of hot and cold water respectively . After 3 m , I placed both hands in a middle bowl that was a mixture of water from the other two bowls . The water felt cold on my left hand (though not as cold as my right hand felt when it was in the cold water ) and warm (though not hot ) on my right hand . Adaptation did not occur over the 3 m my hands were in the hot and cold water , but adaptation was reflected as a weakening of activation in the different receptors for hot and cold (Patapoutian , Peier , Story Viswanath , 2003 ) when the coldness and heat felt in the left and right hands respectively when in...