Class Notes (1,100,000)
CA (620,000)
UTSC (30,000)
Psychology (8,000)
PSYB51H3 (300)
Lecture 10

PSYB51H3 Lecture Notes - Lecture 10: Single-Photon Emission Computed Tomography, Hird, Stereo Display


Department
Psychology
Course Code
PSYB51H3
Professor
Matthias Niemeier
Lecture
10

This preview shows pages 1-2. to view the full 8 pages of the document.
Lecture 10:
([SODLQWKHWHPSRUDOFRGHRIVRXQGIUHTXHQF\:KDWLVFRGHG"+RZLVLWFRGHGZKDWV
the proper scientific term for it)? What are the limits of temporal coding? How could this
limitation be overcome?
The interoral time difference. This is about what kind of sound it isY its about frequency, it has to do
with high accuracy about processing in a certain time.
Frequency is processed first in the inner ear( cochlea) and we have this organ of coriti that is rolled up
like a snail. And in the organ of corti its like a thin piece of elongated chewing gum and it vibrates
depending on the frequency you have, high frequency will make the organ of coriti vibrate near the
oval window at an earlier time and lower frequencies later.
This is not the temporal code of frequency:
The temporal one is dependent on what piece of the organ of coriti is vibrating by the sound pressure
wave,. You can code each frequency in terms of time. Example: so imagine we have sound waves at a
certain frequency and they stimulate the oran of corti at a certain piece of the choclea so what
happens at this piece of the organ of corti is that you have these hair cells that sit on the basili
membrane and there is another membrane on top that is shifting back and forth and uses shear forces
on the stereocilia of the hair cells. So its brushed in one or and other direction.
^}Z}µZ]oo}vv}Z]vvZ]oovZ[}vv}the axons of the
auditory nerve .
So now say we have pure tone which is a perfect sine wave , it will travel through the hairs and steer
them in certain direction. So there fore, what happens is the hair is more receptive towards one
direction of steering for example: when the sine wave is directed in the way shown in the diagram
below, it stimulates the hair more . at that point in time it will have a burst of action potential
1000 hz is the limit to
measuring frequency because
Z[Z(Z]oov vibrate !
:KDW¶V6SHFLDO$ERXW0XVLF"
±:KDW¶VWKHGLIIHUHQFHEHWZHHQWone height and tone chroma?
±Chords
tMelody
So this is a graph that shows
activation of the action potentials
at a point in time, see how it
correlates with the direction of
the sine wave!
www.notesolution.com

Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

{Dµ]]ÁÇ}ÆZ}µPZvu}]}v
tPythagoras: Numbers and music intervals
tSome clinical psychologists practice music therapy
When we look at brain function its immediately obvious what the purpose is so in term of evolution it
tells us why we evolved.
^}ÁZÇuµ]Á}µoZÀÀ}M/[Po}oZv}uvU}Zµ}u]PZ}uo]}
express emotions.
Dµ][u]u]]v}µv}f events like in movies it might amplify an events( horror movies and
sound effects)
Pythagoras: he also studied music and what he did was pluck a string on a string instrument and what he
observed was that if you dissect a string in certain systematic intervals you get certain increases in
sound tones
0XVLFDOQRWHV
±Sounds of music extend across a frequency range from about 25 to 4500 Hz
tPitch: The psychological aspect of sounds related mainly to the fundamental frequency
We can hear 50-20000 hertz. The hertz of a tone directly indicates the pitch so that the psychological
aspect.
So there are intervals of a harmonic sound and :so the lets say the fundamental frequency of the string
ZÇ}µoµl]îììZÌZvÆ(µvÇZÇ}µ[oou}o]lhear is (2*200) the third is (3*200)
and these are integer steps.
so the piccolo flute has the highest frequency ->
2FWDYH7KHLQWHUYDOEHWZHHQWZRVRXQGIUHTXHQFLHVKDYLQJDUDWLRRI
2:1
± Example: Middle C (C4) has a fundamental frequency of 261.6
Hz; notes that are one octave from middle C are 130.8 Hz (C3)
and 523.2 Hz (C5)
± C3(130.8 Hz) sounds more similar to C4(261.6 Hz) than to
E3(164.8 Hz)
± There is more to musical pitch than just frequency!
7RQHKHLJKW$VRXQGTXDOLW\FRUUHVSRQGLQJWRWKHlevel of pitch. Tone
height is monotonically related to frequency
www.notesolution.com
You're Reading a Preview

Unlock to view full version

Only pages 1-2 are available for preview. Some parts have been intentionally blurred.

7RQHFKURPD$VRXQGTXDOLW\VKDUHGE\WRQHVWKDWKDYHWKHVDPHRFWDYHLQWHUYDO
±Each note on the musical scale (A±G) has a different chroma
So if you organize each different pitch from a going up this sort of helix display occurs. Its
logarithmic but its gradual.
{Dµ]oZo]ÆWvZo}À]µo]Ìuµ]o]Z
Musical instruments: Produce notes below 4 kHz
-Listeners: Great difficulty perceiving octave relationships between tones when one or both
tones are greater than 5 kHz ->temporal frequency coding?
±Chords: Created when three or more notes are played simultaneously
±Consonant: Have simple ratios of note frequencies (3:2, 4:3) tones that are played together
sound good
±Dissonant: Less elegant ratios of note frequencies (16:15, 45:32)tones played together that
sound bad ( people band these tones because they were thought to be devils tone.)
5DWLRVFRXQWFKRUGVDFURVVVHYHUDORFWDYHVSHUFHLYHGDVWKH³VDPH´
Cultural differences
±Some relationships between notes, such as octaves, are universal
±Research on music perception: Western versus Javanese
-DpDQHVHFXOWXUH)HZHUQRWHVZLWKLQDQRFWDYHJUHDWHUYDULDWLRQLQQRWV
acceptable frequencies they have more than 12 notes compared to western
music.
0XVLFLDQHVWLPDWHVRILQWHUYDOVEHWZHHQQRWHVFRUUHVSRQGWRWKHPXVLFVFDOH
from their culture
{/vfants detect inappropriate notes within both scales
Melody: An arrangement of notes or chords in succession
±([DPSOHV³7ZLQNOH7ZLQNOH/LWWOH6WDU´RU³%DD%DD%ODFN6KHHS´ the first
three notes for these songs are the same.
Some people have perfect pitch meaning they can identify most pitches, what
was recently found was that people that speak Chinese or are from that
culture have a higher rate of people that have perfect pitch.
±Defined by relationship between successive notes, not specific sounds
0HORGLHVFDQFKDQJHRFWDYHVRUNH\VDQGVWLOOEHWKHVDPHPHORG\
1RWHVDQGFKRUGVYDU\LQGXUDWLRQ
{du}WdZ perceived speed of the presentation of sounds
Rhythm: Not just in
music
±Lots of activities have rhythm: Walking, waving, finger tapping, etc.
±Bolton (1894) played sounds perfectly spaced in time. Listeners are
predisposed to group sounds into rhythmic patterns
{v]v]
Melodies also have to do with certain tempo and rhythm.
How Do We Perceive Speech?
www.notesolution.com
You're Reading a Preview

Unlock to view full version