Piaget Reconsidered
Sensation
How do we know the world? Nativists vs. Empiricists
Sensation vs. Perception
Top Down vs. Bottom Up
3 Common Principles across sensory systems
Transduction,
Neural Coding
Interaction
Stage 3--Concrete Operations
Lasts from approx. age 6 or 7 to age 11 or 12.
Harder to point to a single conceptual attainment
Thought becomes more adult like -- more logical.
Begin to understand relational terms
Make greater use of abstract conceptual categories
Stage 4--Formal Operations
From approx. age 11 or 12 on
Adult-like thought
Able to reason logically and abstractly -- to engage in deductive -- if, then sorts of thinking
Egocentrism again
If asked to show mommy a picture, 2 - 3 year olds will turn the picture the correct way.
Conservation again
When children play a game where the "number" determines the winner, they are not thrown off by changes in the spacing.
The nativist (a.k.a. rationalist) position--Much of our knowledge is based on innately given characteristics. From this perspective, sensation and perception should be "hard-wired."
The empiricist position--We are born as blank slates (tabula rasa). Thus, we must learn to sense and perceive.
Sensation--Refers both to the experience associated with a simple
stimulus (i.e., a light, a sound) and to the initial steps the sense
organs and brain take in processing that stimulus.
Perception--Refers to the subsequent organization of sensory information and to the meaningful interpretations extracted from it (e.g., That object is a Diet Coke can).
So...in one sense the difference between sensation and perception is simply one of degree. Perception involves more interpretation and inference.
Bottom-up--To move from the stimulus to the "perception."
Top-down--To move from expectation to the stimulus.
Sight
Audition
Smell
Taste
Kinesthesis
Sense of touch including
Pressure (touch)
Warmth
Cold
Pain
All of the senses must be able to convert physical stimulus energy (e.g., light waves, chemical molecules, air pressure) into electrical changes in the receptor cells. This process is called "transduction."
The stimulus input must be processed and coded for intensity (i.e., strong vs. weak) and qualitative aspects (e.g., red vs. blue, foul vs. pleasant, A flat vs. B sharp).
Typically, much of this coding happens at post-receptor sites.
PUT SUCCINCTLY... What you sense now in any given place depends upon what you sensed a minute ago and what is happening at other receptor sites.
E.G., Sensory adaptation--The change in sensitivity that occurs when a sensory system is either stimulated or not stimulated for a length of time.