Lecture 12

Sensation

1. Sensation & Perception
1. Three Component Processes
2. Adaptive Senses
3. Sensation Sans Perception
2. Perception
1. Bottom Up
2. Top Down
3. Visual Search
3. Psychophysics
1. Absolute Thresholds
2. Just Noticeable Difference
3. Weber's Law

Overview

Because the nervous system evolved to help animals react to the external world, sensing external stimuli is a fundamental psychological phenomenon. Perception is a bit different, as it involves a (more or less) conscious awareness of what we have sensed and the meaning we attach to sensory experience. All animals have senses, but not all perceive.

We began this lecture by discussing the processes involved in sensation and perception. Next, we considered why we have the senses that we do, and discussed situations in which animals sense without perceiving. We then considered the nature of visual search. Finally, we discussed the field of psychophysics, which models the relation between physical stimuli and psychological perception.

Specifics

1. Distinguish sensation, transduction, and perception
2. Distinguish bottom-up and top-down processes of perception
3. Describe Hubel and Wiesel's (1962) findings and know why their findings are important.
4. Describe the two-stage model of feature detection, and distinguish automatic, parallel processing from effortful, serial processing.
5. Know what the following terms refer to, and how they relate to the two-stage model of feature detection: Pop out Effect ¡X a Distractor Size Effect.
6. Define the absolute threshold, the just noticeable difference, and the terms that comprise Weber's Law.