Experimental Psychology PSY 433 Chapter 10 Memory.

Experimental PsychologyPSY 433

Chapter 10

Memory

What is Plagiarism?

http://www.indiana.edu/~wts/pamphlets/plagiarism.shtml#plagiarized

Samples from Past Student Papers

The participants will report to a specified lab room in building 5. Participants will be greeted and asked to quietly take a seat at a computer station.

Subjects will report to a specified lab room in building 5. Upon entering the lab subjects will be greeted and asked to quietly take a seat.

This is Unacceptable

Another Unacceptable Example

Using a bivalent within-subjects design, we will be measuring the affect…

Using a bivalent within-subjects design, we will measure the participant’s correct responses.

We will be using a bivalent within-subjects design measuring both the affects of the sex…

Using a bivalent design, the correct responses of the participants will be measured…

One More Unacceptable Example

Data was analyzed using SPSS a statistics software program produced by IBM. A 0.05 significance level was used.

Information was collected from the participants’ responses and was evaluated at the .05 level of significance using SPSS known as a statistical software developed by IBM.

One student clearly used a group member’s paper as a template for writing the Results.

Ebbinghaus’s Techniques

Nonsense syllables – controls for prior experience and knowledge of meanings.

Trials to criterion – keep practicing until the words are perfectly learned, count trials needed.

Savings score – percentage of trials saved in relearning a list, relative to original trials needed. Example: 10 – 5 / 10 x 100% = 50% 10 original learning (OL), 5 relearning (RL)

Varieties of Memory

Short-term vs long-term memory Atkinson & Shiffrin’s 3-stage model

Procedural vs declarative (semantic) Memory for doing things vs knowledge of facts

Explicit (episodic & semantic) vs implicit memory Tulving’s idea that consciousness makes a

difference. Implicit includes procedural memory but also

priming

Name the Seven Dwarfs

Is it easier with the picture?

A Recognition Task

Which of the following are names of the Seven Dwarfs?

Goofy Bashful

Sleepy Meanie

Smarty Doc

Scaredy Happy

Dopey Angry

Grumpy Sneezy

Wheezy Crazy

Dependent Variables

Recall -- % or proportion remembered Serial recall Free recall Paired-associates recall

Recognition -- % or proportion remembered Yes/No Forced choice (multiple choice)

Primed recognition– e.g., stem completion

Independent Variables

The kind of material to be remembered: Letters, digits, nonsense syllables, words,

phrases, sentences, paragraphs, passages of prose.

Retention interval – how fast does forgetting occur?

Modality of presentation – visual vs verbal. Encoding strategies Type of test – recall vs recognition.

Control Variables

Amount and type of material presented. Concreteness vs abstractness of words.

Rate of presentation. Modality of presentation – eyes, ears. Each of these could also be an IV – but do

not vary everything in the same experiment. Whatever is varied, the other aspects should

be controlled.

Scale Attenuation Effects

Memory experiments are especially sensitive to difficulty of the task: Ceiling effects occur when the task is too easy

and everything gets nearly 100% correct. Floor effects occur when the task is too

difficult and few people get any questions correct.

Aim for 80% correct in the control group. Test your items before manipulating the IV.

Scarborough’s Experiment

Used the Brown-Peterson technique to measure short-term memory: A trigram is followed by distractor task after a

certain number of seconds. Percentage correct is measured

Proactive interference makes the task difficult: trigrams seen on previous tasks interfere with

remembering subsequent trigrams.

Scarborough’s Design

Do we remember info better if we see it or hear it – does modality of presentation matter?

IV 1 – Presentation modality: Visual Only group saw the trigrams Auditory Only group heard the trigrams read

aloud Both group saw and heard the trigrams.

IV 2 – Retention interval: 0, 3, 6, 9, 12, 18 sec

DV – Proportion correctly recalled.

Which condition did better?

Scarborough’s Results

Subjects who only saw the trigrams did as well as subjects who both saw and heard the trigrams.

Subjects who only heard the trigrams did worse than those who saw or both saw and heard them.

Seeing produces better retention than hearing.

Different Rates of Forgetting?

Decline in retention appears steeper for those who only heard the trigrams. Does this mean auditory presentation results

in faster forgetting? A ceiling effect complicates this interpretation.

All three modalities are at 100% at 0 sec. With a higher ceiling, the decline for visual

modality might have shown the same slope as for auditory.

Weight Loss Example

Two men make a bet about who can lose the most weight.

They weigh themselves on a scale that tops out at 300 lbs. Both weigh 300 lbs on the scale, although one

actually weighs 350 while the other truly weighs 300.

Both lose 100 lbs, so one now weighs 200 while the other weighs 250. Who won the bet?

Pilot Studies are Important!

Avoid extremes of performance (high or low) by testing materials on pilot subjects.

Make the task more difficult by increasing the amount of material to be remembered, presenting it faster, testing after a longer time interval, etc.

Make the task easier by decreasing material, slowing down presentation rate, etc.