Study Guides (258,890)
CA (125,041)
UTSC (8,106)
Psychology (1,886)
PSYA01H3 (210)

Ch. 5 notes

11 Pages
121 Views

Department
Psychology
Course Code
PSYA01H3
Professor
Steve Joordens

This preview shows pages 1-3. Sign up to view the full 11 pages of the document.
Ch. 5 Sensation
- learning: detection by sensory organs nerves
brain
- sensory organs and nerves: provide us w. Useful
info of external world
- differences b/w sources of info in evn =
important consequences for the way the sensory
system prcesses that info
Ex. seeing(rapid scene changes) vs. Hearing
(gradual changes as we move) the world.
Sensory processing
Sensation: detection of simple properties of
stimuli (brightness, colour, warmth, sweetness)
Perception:
- detection of objects (animate, inamiate),
their
- location of objects
- movements of objects
- backgrounds of objects
Before: psychologists... belief: perception
depended on learning, sensation inate
physiological mechanism
- Simple sensations no boundry established
still complex perceptions
TRANSDUCTION*(highlight of chapter)
Brain: cerebrospinal fluid, meninges sheaths,
thick skull, has: only some receptors: detect
temperature, salt [] of blood
1. Sense organs located outside the brain gather
info from the external world, through stimuli:
light, sound, taste, touch
2. Neural impulses (axon potentials) transmit
information of stimuli to brain
Transduction: process: sense organs convert
energy from the environmental events neural
activity
Receptor cells: release neurotransmitters that
stimulate other neurons alter rate of firing of
axons
-Somatosenses (body senses): dendrites of
neurons respond directly to physical stimuli (no
receptor cells)
SENSORY CODING (codes by which brain
transmits info)
Anatomical coding: (location, type of stimulus,
activation of specific nerve fibre of other)
-Johannes Muller: doctrine of specific
energies
-Diff sensory organs send messages to dif
places in the brain
-The way the nervous system represents
information
-Ex. rubbing eye... light receptors
activations... action potentials... see
starts...
-Therefore, sensory coding for the body
surface is anatomical
-Tells where the body is being touched
Temporal coding: (richness in messages due to
pattern of firing)
-A way by which the nervous system codes
information in terms of time
-Simple form of temporal code: time...
rate... light touch = low firing...
-Tells the intensity of touch through the
rate of firing
PSYCHOPHYSICS
Psychodynamics: (physics of the mind)
measure of quantitative relation b/w physical
stimuli and perceptual experience
The principle of just noticeable difference:
(Ernest Weber)
-How do humans discriminate b/w dif
stimuli?
- Measured: jnd (smallest change in
magnitude of a stimulus that a person can
detect)
-Discovery of principle: jnd is directly
related to magnitude of stimulus
www.notesolution.com
-Presented 2 lights... Made one brighter
slowly... you tell him to tell you when he
notices the difference in light
-Jnd is the magnitude of the first point at
which he notices the difference... 0...
0.01.... 0.02.... 1=dif noticed=jnd
-Waber fractions: ratio b/w jnd and the
magnitude of a stimulus (1/40...)
-Ex. start at 40... 40.1.... 4.5... 41 difference
noticed!... 400... 401... 402... 403... 410
difference noticed!
Conclusion (reading graph):
-when looking at a brighter light, you
need more of a difference to see a difference
- Dim light needs less of a difference to
see a But amount more is constant.
-Internal event was reliably measured!...
mind can now be studied.
Signal detection theory: (alternative method
to measure a persons sensitivity to signals
regardless of bias... minimize bias)
Threshold: line b/w not perceiving and
perceiving
Absolute threshold: min value of stimulus that
can be detected
Difference threshold: min detectable diff b/w 2
stimuli (jnd)
Subliminal perception: point where its a little
below the point where person does not process it
but it is in there somewhere.... (used in
marketing)
- psychologists realized: threshold was not a fixed
value
- some participants may see something that
others dont
Convention: threshold = detection 50% of the
time
- activity of the nervous system is variable (non
stimuli avtivation or no activation for very dim
signals)
Jastrows (1897): subliminal perception card
experiment
Signal Detection theory: contd
- a mathematical theory of the detection of
stimuli, which involves discriminating a signal
from the noise in which it is imbedded
- measuring the sensitivity of cognitive system by
minimizing bias
Ex. Sitting in quite room. Flash of light followed
by pop (maybe)
- light followed by pop... yes... yes... yes....
- overtime... pop gets lighter... hard to
detect.
-“yes no is biased
- hits = correct yes when pop is present
- miss =incorrect no when pop is present
- correct negative = correct no when pop
not present
- false alarms = incorrect yes when no
pop is present
- blind, cant perceive anything: hit rate = false
alarm rate
- not blind folded: hit rate > false alarm rate
- false alarm rate is never higher unless some1 is
being silly
- a persons response bias seriously affects an
investigators estimate of the threshold of
detection
- person with a response bias to avoid false
alarm may show a higher sensitivity ...
Solution: set intermediate conditions
- Ex. $1 for every hits, -$0.50 for misses
Receiver operating characteristics curve
(ROC CURVE): Curve: shows performance
when sound difficult to detect
- The concept of threshold is not used in this
method
- Person decides wether a stimulus occurred
- Above horizontal line = null sensitivity...
- hit rate > false alarm... person is
actually percieving
- Theory emphasises: sensory experience involves
factors other than the activity of the sensory
systems (motivation and prior experience)
www.notesolution.com
Vision (most favoured by humnas... long
distance...ability to run... tools... avoid
predation...)
LIGHT(stimulus for visual perception)
- consists of oscillating radiant energy similar to
radio waves
Wavelength (EM): visible light: 380 760 nm
THE EYE AND ITS FUNCTIONS (C-A-P-I-L-L-
O-R-S)
-(Reflexs(eyebrows(bony
socket(eyelid(eyelashes(eye)))))
Cornea: transparent tissue
Aquaous humour: watery fluid behind cornea...
nourishes...
- substitution for capillary to provide
transparency
- glaucoma: extra Aq humour prod... inc.
P... visn dmg
Pupil :
Iris: muscls(gates) in eye... controls size of pupil
Lens: transparent organ behind iris, helps focus
imgs
-Focuses img in the back of the eye
-Transparent, no vessels, dead tissue
Optic disc: spot w no receptors, pasge: nerves
leave eye
Retina: screen light is projected on...
Sclera: tough white layer covering eye
Rich info that distinguishes messages:
Photoreceptors: specialized neurons... light 
neural activity
Rods: dim light, insensitive to colour
Cones: daytime vision, colour perception
Bipolar cells: transmits light:
photoreceptorganglion cells
-Sharpens edges
Ganglion cell: neurons, their axons travel
across retina optic nerves
-Increases/ decreases rate of firing
TRANSDUCTIONS OF LIGHT BY
PHOTORECEPTORS
Photopigment: molecule: transduces energy
neural activity
-Splits when light hits it... gets back in
absence of light
-Rhodopsin: pink photopigment
contained by rods
ADAPTATION TO LIGHT AND DARK
- Extreme light strikes retinas all photopigments
- Rate of regeneration fall behind rate of
bleaching
- All photopigments split bleached
- entering dim room... not enough attached
photopigments
- New photons dont effect already broken
photopigments
- Regeneration of photopigments dark
adaptation
- Light in dark room can be detected again now
EYE MOVEMENTS
Fixation point: where our gaze is fixed
- eyes always make fast jittering movements
Riggs, Ratliff, Cornsweet, Cornsweet:
-Fixed image on one location of eye
-Stabilized images in the retina disappear
-Visual systems dont respond to stable
stumili
3 types of movements:
1. Vergence movements:
- cooperative, both eyes fix on the same
object
2. Saccadic movements:
- Scialfa andJoffe: ^ movement imp. In
searching...
- rapid, stop in between... scanning...
(looking drawer)
- Ross and Ma-Wyatt: ^ helps w spatial
relationships
3. Pursuit movements:
- tracking the object we are following
COLUR VISION
www.notesolution.com

Loved by over 2.2 million students

Over 90% improved by at least one letter grade.

Leah — University of Toronto

OneClass has been such a huge help in my studies at UofT especially since I am a transfer student. OneClass is the study buddy I never had before and definitely gives me the extra push to get from a B to an A!

Leah — University of Toronto
Saarim — University of Michigan

Balancing social life With academics can be difficult, that is why I'm so glad that OneClass is out there where I can find the top notes for all of my classes. Now I can be the all-star student I want to be.

Saarim — University of Michigan
Jenna — University of Wisconsin

As a college student living on a college budget, I love how easy it is to earn gift cards just by submitting my notes.

Jenna — University of Wisconsin
Anne — University of California

OneClass has allowed me to catch up with my most difficult course! #lifesaver

Anne — University of California
Description
-Somatosenses (body senses): dendrites of Ch. 5 Sensation neurons respond directly to physical stimuli (no - learning: detection by sensory organs nerves receptor cells) brain - sensory organs and nerves: provide us w. Useful SENSORY CODING (codes by which brain info of external world - differences bw sourcesof info in evn = transmits info) Anatomical coding: (location, type of stimulus, important consequences for the way the sensory system prcessesthat info activation of specific nerve fibre of other) - Johannes Muller: doctrine of specific Ex. seeing(rapid scene changes) vs. Hearing (gradual changes as we move) the world. energies - Diff sensory organs send messages to dif places in the brain Sensory processing - The way the nervous system represents Sensation: detection of simple properties of information stimuli (brightness, colour, warmth, sweetness) - Ex. rubbing eye... light receptors Perception: activations... action potentials... see - detection of objects (animate, inamiate), starts... their - Therefore, sensory coding for the body - location of objects surface is anatomical - movements of objects - Tells where the body is being touched - backgrounds of objects Temporal coding: (richness in messages due to Before: psychologists... belief: perception pattern of firing) depended on learning, sensation inate - A way by which the nervous system codes physiological mechanism information in terms of time - Simple sensations no boundry established - Simple form of temporal code: time... still complex perceptions rate... light touch = low firing... - Tells the intensity of touch through the TRANSDUCTION*(highlight of chapter) rate of firing Brain: cerebrospinal fluid, meninges sheaths, thick skull, has: only some receptors: detect PSYCHOPHYSICS temperature, salt [] of blood Psychodynamics: (physics of the mind) 1. Sense organs located outside the brain gather measure of quantitative relation bw physical info from the external world, through stimuli: stimuli and perceptual experience light, sound, taste, touch The principle of just noticeable difference: 2. Neural impulses (axon potentials) transmit information of stimuli to brain (Ernest Weber) - How do humans discriminate bw dif Transduction: process: sense organs convert energy from the environmental events neural stimuli? - Measured: jnd (smallest change in activity magnitude of a stimulus that a person can Receptor cells: release neurotransmitters that detect) stimulate other neurons alter rate of firing of - Discovery of principle: jnd is directly axons related to magnitude of stimulus www.notesolution.com - Presented 2 lights... Made one brighter - a mathematical theory of the detection of slowly... you tell him to tell you when he stimuli, which involves discriminating a signal notices the difference in light from the noise in which it is imbedded - Jnd is the magnitude of the first point at - measuring the sensitivity of cognitive system by which he notices the difference... 0... minimizing bias 0.01.... 0.02.... 1=dif noticed=jnd Ex. Sitting in quite room. Flash of light followed - Waber fractions: ratio bw jnd and the by pop (maybe) - light followed by pop... yes... yes... yes.... magnitude of a stimulus (140...) - Ex. start at 40... 40.1.... 4.5... 41 difference - overtime... pop gets lighter... hard to detect. noticed!... 400... 401... 402... 403... 410 differencenoticed! -yes no is biased - hits = correct yes when pop is present Conclusion (reading graph): -when looking at a brighter light, you - miss =incorrect no when pop is present need more of a difference to seea difference - correct negative = correct no when pop - Dim light needs less of a difference to not present seea But amount more is constant. - false alarms = incorrect yes when no - Internal event was reliably measured!... pop is present mind can now be studied. - blind, cant perceive anything: hit rate = false Signal detection theory: (alternative method alarm rate to measure a persons sensitivity to signals - not blind folded: hit rate > false alarm rate regardless of bias... minimize bias) - false alarm rate is never higher unless some1 is Threshold: line bw not perceiving and being silly perceiving - a persons response bias seriously affects an Absolute threshold: min value of stimulus that investigators estimate of the threshold of can be detected detection Difference threshold: min detectable diff bw 2 - person with a response bias to avoid false stimuli (jnd) alarm may show a higher sensitivity ... Subliminal perception: point where its a little Solution: set intermediate conditions below the point where person does not process it - Ex. $1 for every hits, -$0.50 for misses but it is in there somewhere.... (used in Receiver operating characteristics curve marketing) (ROC CURVE): Curve: shows performance - psychologists realized: threshold was not a fixed when sound difficult to detect value - The concept of threshold is not used in this - some participants may seesomething that method others dont - Person decides wether a stimulus occurred Convention: threshold = detection 50% of the - Above horizontal line = null sensitivity... - hit rate > false alarm... person is time - activity of the nervous system is variable (non actually percieving stimuli avtivation or no activation for very dim signals) - Theory emphasises: sensory experience involves factors other than the activity of the sensory Jastrows (1897): subliminal perception card experiment systems (motivation and prior experience) Signal Detection theory: contd www.notesolution.com
More Less
Unlock Document


Only pages 1-3 are available for preview. Some parts have been intentionally blurred.

Unlock Document
You're Reading a Preview

Unlock to view full version

Unlock Document

Log In


OR

Don't have an account?

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit