0) Discuss Self Hypnosis Class When We Do the Consciousness Chapter

Sensation-Perception2008.doc

0) Discuss self hypnosis class—when we do the consciousness chapter

* 2) Do Color vision test --- PSEUDO-ISOCHROMATIC PLATES

3) The rough draft of the paper is due on October THIRD

-- Remember—Don’t plagiarize! – Also don’t uses quotes – Instead, extract the relevant information for your paper, describe the concept using your OWN WORDS, and cite the source. For example:

Colored text was more easily recalled than black and white text (Jones, E.A., 2008).

You need to cite the source for anything that is not “common knowledge.”

Check the grading criteria information found at http://www.New-Hampshire.net\

Have you gotten your “ticket” for the rough draft from the writing center yet? You need to attach it to the front of your paper.

3) Lecture

SENSATION & PERCEPTION

(ch. 4, 2008

The next chapter will be chapter 5 MEMORY

TOPIC:

Definition: Psychophysics is the study of the quantitative relationship between physical stimuli (such as light, touch, or sound,) and the accompanying sensation.

Refs. SS Stevens Handbook of Experimental Psychology

E.G. Boring – Sensation and Perception in the History of Experimental Psychology

Allport– Theories of Perception and the Concept of Structure

Sub-Topic: BASIC TOOLS OF PSYCHOPHYSICS

Definition: A.L. (Absolute Limen = Reiz limen = R.L.)= Absolute Threshold = The minimum stimulus energy under specified conditions which, on the average, is reliably distinguishable from other stimuli.

Definition: D.L. (Difference Limen) Difference Threshold = the j.n.d. = just noticeable difference =

the minimum stimulus energy necessary to tell two stimuli apart.

Operational Definition: A description of a term assumed for a particular purpose for use at a particular time , which may or may not be equivalent to the general definition of that term.

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Sub-Topic: Ernst Heinrich Weber (1834) Weber’s Law — The first quantitative attempt to make a mathematical expression of man’s ability to judge small differences between stimuli.

dI/I = k where dI is the increment of stimulation necessary to be added in order that a just noticeable difference (j.n.d.) will be experienced. I = The stimulus magnitude to which the increment is added.

brief aside:

DEF. Independent variable = the condition manipulated by the experimenter.

DEF. Dependent variable = the relevant quantifiable output of the subject..

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Example:

Ind/ Variable Dep. Variable DI/I DI/I expressed as a

Controlled by E DI Percentage

100 g 5 5/100=.05 5

200 g 10 10/200=.05 5

300 g 15 15/300=.05 5

400 g 20 20/400=.05 5

500 g 25 25/500=.05 5

graph

25 *

.10

20 *

.08

15 * Weber

dI DI/I Fraction .06

10 * * * * * *

.04

5  *

.02

0______

100 500 ______

Intensity in grams 100 500

Intensity in grams

Weber’s Law only holds true for stimuli of mid-range intensity.

Human beings tend to be non-linear perceivers. The stimuli of mid-range intensity tend to be linearly perceived as is shown with Weber’s law . However, Fechner, after doing experiments with sensory perception utilizing Weber’s law that Weber’s approach did not work for the extremes situation of very weak or very strong stimuli.

So, if we take weights that are very light all the way through very heavy, the following occurs.

But this is only the beginning – About 30 years later Gustav Fechner (G.T. Fechner 1860) noted the discrepancy of data in Weber’s law for data that was near the sensory extremes.

.50

weber .45

fraction .40

.35

.30

.25

.20

.15

.10

.05

0 .1 1 10 100 1000 1k 100k Etc..

Log intensity in Grams

DEFINITION: j.n.d. (Just noticeable difference) = The smallest difference between stimuli that can be reliably detected.

Fechner’s law was better able to fit empirical data which was obtained than was true for Weber’s law. However, Weber’s law is correct for stimuli of mid-range intensity and is still used where appropriate.

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Topic: Signal Detection theory (Tanner and Swets about 1960)

Basic concept: The likelihood of a signal’s being perceived is a function of the ratio of signal to noise. Any signal also contains some noise.

Example: Morse code operator tries to hear the signal but misinterprets some of the message due to white noise and competing signals.

Example. Radar operator at airport gives instructions to pilots that desire to land. Weather is rainy with thunder and lightning. There is much clutter on the screen and the operator has trouble seeing “blips” of aircraft.

The population of noise and the population of signal plus noise vary in strength. The difficulty of making a decision that a “target is present” is variable. Also the criteria of the operator varies depending on the importance of making a false alarm or, perhaps, missing the detection of a target.

Thus, Everything you perceive is a combination of SIGNAL + NOISE. Your ability to discriminate signal from noise and your ability to adjust your criteria for perceiving the presence of a signal determines your ability to correctly detect stimuli.

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DECISION MATRIX

Go to the Sensation-perception program and select chapter 2 signal detection and demo the interactive relationship between signal and noise.

Various visuals (.mov & other)

Perception

Perception: The process of integrating sensation with rapid access memory to produce a

near instantaneous understanding of stimuli.

Some types of memory

Very short term memory (iconic or acoustic memory) — time base is less than a second

Short term memory (time base is about 20 seconds)

Long term memory (permanent memory associated with permanent brain changes).

TOPIC: Gestalt Psychology (1880-1960)

Wertheimer

Koffka

Kohler

– The School of Psychology associated with the study of the relationship

between FIGURE and GROUND.

Founder of the school was Max Wertheimer (1880-1943)

The Gestalt Principles of organization Describe Each

Closure

Proximity

Continuation

Common fate

Similarity

Pragnanz

Gestalt psychologists also looked at issues such as the means by which we perceived

depth in an image.

MONOCULAR & BINOCULAR DEPTH CUES

The MAIN BINOCULAR cue to depth is RETINAL DISPARITY

def. RETINAL DISPARITY: The image of an object sent to one eye is different from the image sent to the other eye since there is an angular difference in the view of the object.

BINOCULAR Parallax (the pointing of each eye at the same target but the eye position for

the whole scene provides a dynamic measure of depth.)

MONOCULAR Depth cues

Texture Gradient (most primitive cue –( mention Gibson’s visual cliff research)

Relative Size

Superposition

Height in field of view

Linear Perspective.

TOPIC: Some Motion Illusions (bring in Spiral AE machine)

Phi Phenomenon – The apparent motion of an apparent single light due to the onset and offset of a light followed be a brief delay and the onset and offset of another light that is nearby the first.

Autokinetic effect – The apparent motion of a point source of light caused by the

random movements of the body and the eye in an environment where the point

source of light has no surrounding imagery.

Spiral Aftereffect —Staring of an inwardly rotating spiral causes the apparent outward motion of the spiral when the spiral movement stops.

McCullough Effect — Alternating presentation of Green vertical bars on a black background and red horizontal bars on a black background for about 20 minutes results in perception of red vertical bars and green horizontal bars when the actual stimulus is either black and white vertical or horizontal bars. –

BRIEF TOPIC:BASIC LEVELS OF IMAGE RECOGNITION:

1) Detection – I see something

2) General classification – I see an airplane

3) Identification –I see a Canadian Regional Jet (also known as an RJ)

TOPIC: KINESTHESIA and Perception

Kinesthesis is the Perception of your bodily movement and position in space using tendons,

muscles and joints.

Proprioception is the process of perception of your bodily movement and position in space

using ANY sensory cues.

Example — Hitting a baseball

steering a car

Putting hand to head in position for holding telephone.

Many researchers in developmental psychology maintain that kinesthesis and proprioception

are more basic (pre-wired) in infants and are a “bootstrap” that enable infants to gain an

understanding of external reality

Philosophical issue — If you were a brain that never had a body except for eye and ears, could

you understand the outside (exterior) world?

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CHAPTER 5 Memory