Sensation and Perception Web Quest Go to: http://users.rcn.com/jkimball.ma.ultranet/BiologyPages/V/Vision.html 1.) Define and explain the following parts: a. iris- A ring of muscle tissue that forms the colored portion of the eye around the pupil and controls the size of the pupil opening. Pigmented and responsible for the eye color.
b. pupil- The adjustable opening in the center of the eye through which light enters. It is under the control of the autonomic nervous system[->0]. In dim light or when danger is felt, the pupil opens wider letting more light into the eye. In bright light the pupil closes down. This not only reduces the amount of light entering the eye but also improves its…show more content… Scroll down to “Context” and follow the instructions.
6.) How does context affect our outlook?- What surrounds an object (the “context”) effects what we see and our outlook of the item.
Go To: http://psych.hanover.edu/Krantz/sen_tut.html
7.) What is size constancy? - refers to the fact that our peceptions of the size of objects are relatively constant despite the fact that the size of objects on the retina vary greatly with distance.
8.) What is signal detection theory? - a means to quantify the ability to discern between signal and noise. Go to: http://allpsych.com/psychology101/sensation.html
9.) Define the following concepts: a. Absolute threshold - The absolute threshold is the point where something becomes noticeable to our senses. It is the softest sound we can hear or the slightest touch we can feel. Anything less than this goes unnoticed. The absolute threshold is therefore the point at which a stimuli goes from undetectable to detectable to our senses.
b. Difference threshold - is the amount of change needed for us to recognize that a change has occurred.
c. Just Noticeable Difference - the difference between two stimuli that (under properly controlled experimental conditions) is detected as often as it is undetected.
d. Weber’s Law - states that the change in a stimulus that will be just noticeable is a constant ratio of the original