GASB05H3 Chapter Notes - Chapter 1: Propylthiouracil, Receiver Operating Characteristic, Olfactory Bulb
Chapter 1: Introduction
Sensation: the ability to detect a stimulus and, to perhaps, turn that detection into a private experience
Perception: the act of giving meaning to a detected sensation
- Hand running one’s back
oGesture of affection
oSecurity checkpoint at the airport
oThe way situations are perceived depend on external stimuli and the environment
Etienne Bonnet de Condillac (French philosopher):
- Talk about the mental life of a statue
- Then man demz was like “open the statue’s nose and give it a whiff of the scent of a rose:
oThen believed that the entire mental life of the statue would consist of the essence of a
rose
- Therefore, a real mental life of an individual would develop with experiences
- This idea draws upon the fact that the study of senses is within the science of human behaviour
and human mental life
oNot entirely true; studies of sensation and perception is done through various fields (ex.
Biology, computer science, medicine, etc.)
- It is concluding, however, that the study of perception and sensation NEEDS scientific methods!!
Methods Used To Study the Senses:
Method 1: Thresholds:
- A specific limit the human body can endure without experiencing damage
- Ex. Listening to loud music extensively will damage auditory system
oCausing one to not be able to hear the faintest sounds
- That change in thresholds is measured
Method 2: Scaling – Measuring Private Experience
- Qualia: private conscious experiences of sensations or perceptions
- Is one person’s qualia the same as another’s?
- No way of putting/making one person’s experience into another person’s perception
- It can be demonstrated that different people, in some cases, inhibit different sensory worlds
Method 3: Signal Detection Theory – Measuring Difficult Decisions
- Calling the shots in a difficult situation
oThis can be studied scientifically
- Ex. Radiologist analyzing a mammogram and sees an unclear sign of cancer
oOption 1: ignore it=patient might die the if the unclear sign turns out to be cancer
oOption 2: say it is cancer = patient might go through w/ surgery when there was no
cancer
oBoth options result in negative consequences
Method 4: Sensory Neuroscience:
- Ways in which sensory receptors and nerves undergrid your perceptual experience
- Ex. Smelling grilled peppers with a smokiness appeal
oWhen bit into, one will experience a burning feeling
oThe tongue is not physically warmer than before and the mouth did not change
temperature
oHow did the nervous system get fooled into thinking one’s tongue is “on fire”?
Method 5: Neuroimaging – An Image of the Mind
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- Modern brain-imaging techniques help one see traces of experiences as they take place in the
brain
Thresholds and the Dawn of Psychophysics:
- Gustav Fechner
oDualism: the idea that the mind has an existence separate from the material world of
the body
oMaterialism: the idea that the only thing that exists is matter, and that all things,
including the mind and consciousness, are the results of interaction between bits of
matter
The mind is what the brain does
The mind is not separate
oPanpsychism: the idea that the mind exists as a property of all matter – that is, that all
matter has consciousness
Including plants
oPsychophysics: science of defining quantitative relationships between physical and
psychological (subjective) events
- Ernst Weber
oTested accuracy of touch
oTwo-point threshold: the minimum distance at which 2 stimuli (2 simultaneous touches)
are perceptible as separate
oJudgment of weights:
to see the difference between standard and comparison weight, the
dependence was on the weight of the standard weight
The higher the standard weight, the higher the comparison weight should be
Difference threshold OR just noticeable difference (JND): the smallest
detectable difference between 2 stimuli
Constant ration between the change and what was being changed could
describe the threshold of detectable change quite well
True until the intensities are close to the min/max points of our senses
Weber fraction: the constant of proportionality in Weber’s law
Weber’s Law: the size of the detectable difference (Delta I) is a
constant proportion (K) of the level of the stimuli (I)
Weber’s Law was extended mathematically to the
Fechner’s law
Fechner’s Law: A principle describing the relationship between stimulus and
resulting sensation that says the magnitude of subjective sensation increases
proportionally to the logarithm of the stimulus intensity S= k log R
S = psychological sensation
Log R= logarithm of the physical stimulus level
k = constant
psyche and physics relationship is demonstrated
describes that our psychological experience of the intensity of light,
sound, smell, taste, or touch increases less quickly than the physical
stimulus
Comparing Einstein and Fechner:
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- Einstein and Fechner both equated energy and mass
- Nothing else, they both equated factors that were once deemed not equivalent
- Idk why this author of this fucking book gave a separate section for this information
- Fechner invented many ways to measure what people see, hear, and feel
oAbsolute threshold: the
minimum intensity of a
stimulus that can be
detected
oThe graph on the right shows
that as stimulus intensity
grows larger, larger changes
are required for the changes
to be detected by a perceiver
oVision: stars at night, or a
candle flame 30 miles away
on a dark, clear night
oHearing: ticking watch 20
feet away, with no noises
oVestibular: a tilt of less than half a minute on a clock fire
oTaste: a teaspoon of sugar in 2 gallons of water
oSmell: a drop of perfume in 3 rooms
oTouch: wing of a fly falling on someone’s cheek from a height of 3 inches
- “I hear it/ I don’t hear it” graph: expected to have a sharp threshold change
oCan’t hear to always hear, never in between
oGraph 1 is what is expected! Not what happens
- Graph 2: experiments measuring absolute threshold produce shallower functions relating
stimulus to response
oArbitrary point on the curve, sometimes 50% detection=threshold
oGraph 2 represents reality
Psychological Methods:
-Method of constant stimuli: creating many stimuli w/ different intensities to find the tiniest
intensity that can be detected
oEx. Loudness of phone ringer, person says yes OR no depending on if they heard it or not
oEx. Hearing test
Various intensities of tones are played (not too low/high where your threshold
is expected to be
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find more resources at oneclass.com
Document Summary
Sensation: the ability to detect a stimulus and, to perhaps, turn that detection into a private experience. Perception: the act of giving meaning to a detected sensation. Hand running one"s back: gesture of affection, security checkpoint at the airport, the way situations are perceived depend on external stimuli and the environment. Talk about the mental life of a statue. Then man demz was like open the statue"s nose and give it a whiff of the scent of a rose: then believed that the entire mental life of the statue would consist of the essence of a rose. Therefore, a real mental life of an individual would develop with experiences. This idea draws upon the fact that the study of senses is within the science of human behaviour and human mental life: not entirely true; studies of sensation and perception is done through various fields (ex. It is concluding, however, that the study of perception and sensation needs scientific methods!
