Memory Models Studies

Peterson and Peterson

-Trigram (XJD)

- P's asked to count back in 3's to stop them from rehursing.

- Intervals for counting back in 3's varied.

- P's asked to stop counting and recall back the trigram.

-Results showed: longer the P's had to remember the trigram the less likely they were to remember.

Strength - High in internal validity

Weaknesses - cannot be generalised. Low ecological validity. - Capacity of their memory could effect their duration. 

Bahrick et al (1975)

-Tested 392 graduates - Using two types of tests:

-Recall - P's shows pictures and asked to name them.

-Recognition - P's shown pictures and given a list of names.

P's performed well up to 34 years, performance declined after 47 years.

Strengths - High in external validity.

Weaknesses - Low in internal validity (may still have contact e.c.t.)

Conrad (1964)

Showed P's a list of 6 consonants, each was shown for less than a second.

P's then wrote down what they had seen.

Conrad found that most mistakes were accoustic confusions (letters that sounded simiar B/B)

Baddeley (1966)

Found a similar thing to Cin==onrad (STM encoding) but he found that when encoding info into the LTM the meaning of the words get confused.

Stength:

KF Shallice & Warrington (1970) 

Motor Cycle incident, left him with normal functioning LTM, but problems with STM. He forgot words and sounds more than visual stimuli. 

Weakness:

Elsinger & Damasio (1985)

Case study of a man with brain damage - good reasoning skills and a high IQ. But desition making skills were very poor.