PSYCH 2220 Perception Lecture 11
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Transcript of PSYCH 2220 Perception Lecture 11
PSYCH 2220Perception
Lecture 11
Do we need to LEARN to see?
KEYWORDS for lecture 9
"do we need to learn to see?", empiricists (yes), nativists (no),
innate visual behaviours, dung beetle, chimpanzees and snakes, ducklings and hawks, Molyneux's question ("if a man is given his sight as an adult, could he distinguish a sphere and a cube?"), two patients described, babies, mixed up faces, visual cliff, contrast sensitive function for infants, preferential looking, adaptation (remember that Dalmatian!), inverting prisms, hens show no adaptation, horizontal or vertical rearing
EMPIRICIST(all knowledge comes from experience)
NATIVIST(knowledge is ‘a priori’; you are born with it)
1 animal behaviour
Molyneux’s question:
“could a man born blind distinguish a sphere and a cube by sight alone?”
2 blind people recovering sight
S.B could see with minimal experience
H.D. never could see very well.
3 child development, Fant’z Experiment
4 adaptation
5 controlled rearing
walks activelycarried passively
Animal behavour
Blind people recovering their sight
Babies’ visual development
Adaptation experiments
Controlled rearing experiments
EVIDENCE
……………………. Nativist
… Empiricist & nativist
…………. Empiricist & nativist
…………… Empiricist
……….. Empiricist
INTRODUCTION TO HEARING
pinna(external ear)
malleusincusstapes
little bones
oval windowtympanic membrane (ear drum)
leverage= 1.3 x
this section coiled upin the actual ear (cochlea)
(ossicles)}
areadecrease17 x
}
OUTER EAR MIDDLEEAR
INNER EAR
helicotrema
basilar membrane
top tube
middle tube
bottom tube
tectorial membrane
hair cells
vibrations pass down the top tube to theend (the HELICOTREMA) and thenback down the bottom tube.
helicotremaoval window
vibrates most tohigh frequencies(around 10 kHz)
vibrates most tomiddlefrequencies(around 1 kHz)
vibrates most tolow frequencies(down to around27 Hz)
hairs
hair cell
nucleus
fibre of 8th nerve (auditory nerve)
ACTION POTENTIALS TO BRAIN
Auditory system 13 - 5
10 100 1000 10,000Frequency (Hz)
(high)(low)
020406080
100(loudest)
(quietest)
sound levelin decibels(dB)
can hear
can't hear
this line shows thequietest sounds youcan hear. At soundpressure levels belowthis line you can't hearthe sound.
10 100 1000 10,000Frequency (Hz)
(high)(low)
020406080
100(loudest)
(quietest)
sound levelin decibels(dB)
*
*
*
All points on this curve have the same perceived loudness as the standard (*)
All points on this curve have the same perceived loudness as the standard (*)
All points on this curve have the same perceived loudness as the standard (*)
EQUAL LOUDNESS CURVES
Place theory1 - Travelling wave; stiffness varies2 - one place most active for a given frequency3 - tonotopic code; coded as place
Periodicity theory1 - sound coded as pattern
Hearing thresholdsEqual loudnessMaskingThe case of the missing fundamental
harmonicspitchtimbre
Training a goldfish...
Evidence against place-- Missing fundamental-- which can be masked -- some animals have no basilar membrane
Evidence against periodicity-- cells can’t fire fast enough-- diplacusis
Evidence for place-- physiology
Evidence for periodicity-- multiple cells could do it-- phase locking of cells
Place theorysound coded as place
Periodicity theorysound coded as pattern
Duplicitybelow 1kHz, coded by periodicityabove 1 kHz, coded by place
Auditory localization
1 inter-aural time of arrival differences-- circle of confusion
2 inter-aural intensity differences3 pinnae (up/down front/back etc..)4 head movements
hairs
hair cell
nucleus
fibre of 8th nerve (auditory nerve)
ACTION POTENTIALS TO BRAIN
Auditory system 13 - 5
Auditory cortex
Auditory thalamus
Superior colliculus
Inferior colliculus
cochlea
Cochlear nucleus
Superior olive
The AuditorySystem
The AuditorySystem(cortical route)
Cochlear nucleus
Inferior colliculus
thalamus
cortex
The AuditorySystem(sub-cortical route)
Cochlear nucleus
Superior olive
Inferior colliculus
Superior colliculus
The AuditorySystem
front
back
left right
The SuperiorColliculus
a a
a
b
b
c
c
d
d
f
g
LOCALIZATION OF FUNCTION IN THE CORTEX
Phrenology
Visual cortex.
Motor cortexSomatosensory cortex
Auditory cortex
Olfactory cortex
FRONT
• Stimulation• recording• lesions• anatomy
PARIETAL CORTEX (the"WHERE" system)...
INFEROTEMPORAL CORTEX(the "WHAT" system).
FRONTALCORTEX (involvedin personality)
PARIETAL CORTEX (the"WHERE" system)...
INFEROTEMPORAL CORTEX(the "WHAT" system).
FRONTALCORTEX (involvedin personality)
Phineas Gage
BROCA'S AREA(speech production)
WERNICKE'S AREA(speech comprehension)
corpuscallosum
from above from front
THECORPUSCALLOSUM
RIGHT
FIELDVISUAL
LEFT
FIELDVISUAL
LEFT RIGHTBRAIN BRAIN
left eye sees right eye sees
left hand touches
right handtouches
“SPLIT BRAIN”