Deck 4: A: Sensation and Perception

Question 1

Distinguish between sensation and perception and explain the nature of transduction (with visual and auditory examples).

Answer 1

Answers will vary but should include the general points mentioned below for full credit.
--Sensation refers to the detection of physical energy by the senses;perception represents the brain's interpretation of those sensory inputs.
--Transduction involves the translation of sensory input into a neural code that the brain can understand.For example,if you see a red ball,the sensory receptors in the eye send a message to the brain indicating the presence of that particular wavelength of light.Alternatively,if you hear the high frequency from a soprano solo,the sensory receptors send a message along the auditory nerve to the brain where it is perceived as a high sound.

Question 2

Discuss the evidence for vision being the most important of our senses.

Answer 2

Answers will vary but should contain at least three of the following points with supporting discussion to earn full credit.
--Light is fundamental to our biology and culture.Without vision,we couldn't sense or perceive much of anything about light other than the heat produced.
--We would miss most of the experiences that occur around us;think of all of the times that we've told someone "watch me/this," "look over here," "are you watching,Mommy/Daddy?"
--The Gestalt principles and the majority of the illusions mentioned in the text are applicable to vision (and in some instances hearing).
--Dizziness and nausea result when our vestibular and visual inputs are not synchronized.

Question 3

Explain how the gate control model of pain perception relates to people's ability to withstand excruciating pain and how distraction and placebos relate to the gate control model.

Answer 3

Answers will vary but should contain the following points with supporting discussion to earn full credit.
-- Pain is physiological and emotional in nature,involving structures in the limbic system as well as basic somatosensory activity.
-- The gate control model (Melzack & Wall)proposes that intense pain can be blocked in circumstances (i.e. ,birthing,skin grafts,combat injuries)from consciousness because neural mechanisms in the spinal cord function as a "gate" to control the flow of sensory input to the CNS.
-- Using things like distraction and placebos are a way of dividing attention away from pain and permitting less focus on the pain itself (like a gate).