PSY 105 Lecture Notes - Lecture 6: Gustav Fechner, Ambiguous Image, Psychophysics
27 Apr 2018
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Week 5 (Psychophysics & Illusions)
Midterm 2 starts from here
White/gold vs black/blue dress
- Dress is actually black/blue (which is what i see)
- Our brains have been programmed over time to see colours
- Light changes the strength of colours and those that see it as white/gold have
overtuned the colours
Reversible figures
- Looks like 2 different shades of grey because of the shading
- We cut off
Stimulus coming in aren’t exactly the same as what we perceive it as
Main focus is on optical illusions
The senses will only be those that are taught in the lectures
Psychophysics
- The study of how physical stimuli are translated into psychological experience
Sensation and perception: the distinction
- Sensation: the detection of physical energy by the sense organs
- 5 senses: sight, touch, hearing, taste, smell
- Perception:
- The brain's interpretation of raw sensory data
Transduction
- The process of converting an external stimulus into electrical signals within neurons
When senses meet the brain
- After being transduced our brains then organize the sensory data into meaningful
concepts
- Our brains piece together
- What's in our sensory field
- What was there moments ago
- What we remember from our past
Psychophysics: the basic concepts
- Sensation begins with a detectable stimulus
- What we can detect 50% of the time
- Takes on the shape of an S-curve
- When we hit the 50% mark that’s where we start getting more accurate
- But what counts as detectable depends on whom or what is doing the detecting
- Gustav Fechner (1860) questioned, for any given sense, what is the weakest detectable
stimulus
- The concept of the threshold
- A dividing point between energy levels that do and do not have a detectable
effect
- Example: automatic lights turn on when a threshold is reached
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Dress is actually black/blue (which is what i see) Our brains have been programmed over time to see colours. Light changes the strength of colours and those that see it as white/gold have overtuned the colours. Looks like 2 different shades of grey because of the shading. Stimulus coming in aren"t exactly the same as what we perceive it as. The senses will only be those that are taught in the lectures. The study of how physical stimuli are translated into psychological experience. Sensation: the detection of physical energy by the sense organs. 5 senses: sight, touch, hearing, taste, smell. The brain"s interpretation of raw sensory data. The process of converting an external stimulus into electrical signals within neurons. After being transduced our brains then organize the sensory data into meaningful concepts. What we can detect 50% of the time. Takes on the shape of an s-curve. When we hit the 50% mark that"s where we start getting more accurate.
