5-100 - Chapter 5 sensation and perception 1 2 perception...

Chapter 5, sensation and perception:
1. perception often based on previous experience.
2. our perception of the world is not a camera. We sense, we guess, sometimes get the details
wrong.
Stimuli must be coded to be understood by the brain:
Sensory coding: sensory organs’ translation of stimuli to neural impulses.
Coarse coding: sensory qualities are coded by only a few different types of receptors.
Psychophysics relates stimulus to response:
Psychophysics, a subfield that examines our psychological experiences of physical stimuli. How much
physical energy is required for our sense organs to detect a stimulus.
Absolute threshold: minimum intensity of stimulation that must occur before one experience a
sensation. E.g.: touch, minimum stimulus, a fly’s wing falling on your check from one cm away.
Difference threshold: just noticeable difference between two stimuli- the minimum amount of change
required to detect a difference. Minimum change in volume in tv so that you notice that the show has
changed to commercial.
Weber’s Law: the just noticeable difference between two stimuli is based on a proportion of the
original stimulus rather than on a fixed amount of difference.
Signal detection theory: detecting a stimulus requires making a judgment about its presence or absence.
Response bias: a participant’s tendency to report detecting the signal in an ambiguous trial.
Basic sensory processes
Taste: taste relies on the sense of smell. Taste experience occurs in the brain.
Individual food preferences, culture preferences (begin in the womb).
Smell: ordor- olfactory receptors- olfactory epithelium- olfactory bulb- olfactory nerve- cortex and
amygdale- perception.