Hermann Ebbinghaus ( )

Experiments on Memory First half of 20th century Methods based on associationism Strength of associations Forgetting Second half of 20th century Information processing (based on computer model) Memory systems (iconic, working, long-term memory)

Storage (Maintain in memory) Retrieval (Recover from memory) Encoding (Code and put into memory) Basic Memory Processes

COMPUTER VS. HUMAN MEMORY COMPUTER HUMAN PERMANENT X PERFECT X PARTIALX VARIES WITH TIMEX LOCALIZED X UNLIMITED CAPACITYX INFLUENCED BY MEANINGX

Chinese Room Problem Chinese text Man in room is a fluent Chinese-English interpreter English text Chinese text Man in room full of Chinese-English translation books. Man knows no Chinese. English text Do both men know Chinese?

Three Types of Memory Iconic (Sensory) Memory: msec. Short Term (Working) Memory: 1-30 sec. Long Term Memory: > 2 min.

INFORMATION PROCESSING MODEL OF MEMORY

Serial Position Curve

Contribution of Rehearsal to Serial Position Effect

Effect of Rate Presentation on Serial Position Effect

Manipulating the Recency Effect

“Shallow”Are these words in the same typeface? “HOUSE-trick” “Medium”Do these words rhyme? “BALL-TALL” “Deep”Are these words synonyms? “CAR-AUTOMOBILE” Different Levels of Processing in Working Memory

Which is the Real Penny?

Maintenance Rehearsal –sheer repetition –mechanical –no attention to meaning –little effort Elaborative rehearsal –focus on meaning –relations between items –organization

B K V J

M YES NO

S B

B YES NO

C K W N T L

T YES NO

L D Z

N YES NO

9 D 4 8 C 5 B X K 8

6 YES NO

Parallel Processing All items perceived simultaneously. Reaction time is not influenced by # of items.

Serial Processing Items perceived successively. Reaction time is influenced by # of items.

Serial Processing Self-terminating search Items perceived successively. Reaction time on “no” trials should be twice as long as on “yes” trials.

Serial Processing Serial exhaustive search Items perceived successively. Reaction time on “yes” trials should be same as on “no” trials.

Two Types of Amnesia

HM A 29 year old motor-winder who had been rendered incapable of work by his frequent severe seizures. Because of his desperate condition, Dr. Scoville carried out a radical bilateral medial temporal-lobe resection on Sept 1, He knew that he had had a brain operation, but I think only because the possibility had been entertained for so many years before the operation was finally performed. He kept saying, “It is as though I am just waking up from a dream; it seems as though it has just happened.”

As far as we can tell this man has retained little if anything of the events subsequent to operation, although his IQ rating is actually slightly higher than before. Ten months before I examined him his family had moved from their old house to a new one a few blocks away on the same street. He still has not learned the new address, though remembering the old one perfectly nor can he be trusted to find his way home alone. He does not know where objects constantly in use are kept; for example, his mother still has to tell him where to find the lawnmower, even though he may have been using it only the day before. She also states that he will do the same jigsaw puzzles day after day without showing any practice effect and that he will read the same magazines over and over without finding their contents familiar. [Milner, 1959, p. 49]

Serial Position Effect in Amnesics

Priming

Pursuit Motor Task

Mirror Drawing Task

Patient HM Severe anterograde amnesia Normal STM Normal LTM (for events prior to surgery) Problem: transfer from STM to LTM Could not consolidate new declarative knowledge Capable of acquiring implicit knowledge

Declarative Memory Conscious recollection Knowing That Episodic (autobiographical knowledge) Semantic (general knowledge) Experiments on free recall, recognition

Procedural Memory Knowing how Unconscious Implicit memory Experiments on priming, conditioning & skill learning

TYPES OF MEMORY Sensory Memory Short-term (Secondary, Working) Long-term (Primary) Declarative (knowing what) Procedural (knowing how) Episodic Generic Semantic Generic non-verbal