PSY 369: Psycholinguistics Cognitive Psychology
Cognitive Psychology • It is the body of psychological experimentation that deals with issues of human memory, language use, problem solving, decision making, and reasoning. “Cognitive Psychology refers to all processes by which the sensory input is transformed, reduced, elaborated, stored, recovered, and used.” Ulric Neisser (1967)
Mind as computer analogy • Limitations of the analogy Computers • fast • serial (mostly) • digital • few connections Minds (Brains??) • slow • parallel • analog • trillions of connections
Computational theory of mind • Brains and computers embody intelligence for some of the same reasons • The Demands of an Architecture of (Human) Cognition • Behave flexibly as a function of the environment • Exhibit adaptive (rational goal directed) behavior • Operate in real time • Operate in a rich detailed complex environment • Perceive an immense amount of changing detail • Use vast amounts of knowledge • Control a motor system • Use symbol systems • Use language (both natural and artificial) • Learn from the environment and experience • Acquire capabilities through development
The ‘standard model’ Information ‘flows’ from one memory buffer to the next
The sensory store George Sperling (1960) • Full Report: • I'm going to show you a bunch of letters, then I'll cue you to recall as many of letters as you can.
Partial Report • I'm going to show you a bunch of letters, then I'll cue you (with a blue arrow) as to which row of letters I'd like you to recall. Immediately following the cue, write down as many letters as you can from that row.
The sensory store • Typically the result of this experiment is: • Full report: can report about 4.5 letters on average • Partial report: can typically report 4 letters (that's100%) • The partial report results suggest that all of the information is there, the 4.5 average seen in the full report condition reflects the extremely rapid decay of the Sensory Store.
The sensory store • Further support of this comes from a delay manipulation. • In this case you manipulate how much time passes between the stimuli and the recall cue. • If you delay by about 1/4 to 1/2 a second, the average reported drops to about 4.5, the same rate as in the Full report task.
The sensory store • Properties • sensory specific - one for vision, one for audition, etc. • high capacity • extremely fast decay
Short term memory • I’ll read a list of words and ask you to recall them • Okay, now recall as many of the items as you can • Here is the list: • CAT, SHACK, BOAT, CAR, PICTURE, ELEPHANT, MAP, SWING, TACK, BEAR, BOX, DOOR, CHURCH, TREE, DOG, DENTIST, TRAIN, SNOW, SMOKE, RADIO
Short term memory • The typical results • items at the beginning of a list is remembered well (primacy) • items at the end of the list are remembered well (recency)
Short term memory • Typical account: • Recency items recalled from STM • Primacy items recalled from LTM • A variant of the task: • Count backwards by threes before recall • Here is the list: • MOUSE, BARN, SHIP, TRUCK, PHOTOGRAPH, GIRAFFE, SIGN, SLIDE, PIN, DEER, BOTTLE, WINDOW, GARAGE, BUSH, FISH, DOCTOR, AIRPLANE, RAIN, FIRE, TELEVISION
Short term memory • The typical result is that the longer you have to count backwards, the worse your memory for the letters. • The theory is that the counting backwards prevents the rehearsal of information in STM, so it decays away.
Short term memory • Increasing your STM span • Chunking • Grouping information together into larger units • Dog cat mouse shoe sock toe couch pillow blanket • Down flowers the by with chased yellow several girls a river boy. • A boy chased several girls with yellow flowers down by the river. • Notice that the previous two are the same words, but the syntax allows for grouping into meaningful ‘chunks’
Short Term Memory • Properties • rapid access (about 35 milliseconds per item) • limited capacity (7+/- 2 chunks; George Miller, 1956) • fast decay, about 12 seconds (longer if rehearsed or elaborated)
Long term memory • Organization • The Multiple Memory Stores Theory • This theory suggests that there are different memory components, each storing different kinds of information. • Declarative • episodic - memories about events • semantic - knowledge of facts • Procedural - memories about how to do things (e.g., the thing that makes you improve at riding a bike with practice.
Long term memory • How long do our memories last? • Ebbinghaus (1885/1913) • He memorized non-sense syllables. • Memorize them until perfect performance, • Test to relearn the lists perfectly. • This was called the "savings."
Long term memory • Bahrick (1984) • He has done a number of studies asking people about memories for things (e.g., Spanish, faces of classmates, etc.) that they learned over 50 years past. He has found evidence that at least some memories stick around a really long time. • How long do our memories last?
Long term memory • How much can we remember? • Lots. To my knowledge there are no known limits to how much memory storage we have. • Perhaps the more important issue concerns questions about encoding and retrieval • Encoding - getting memories into LTM what gets in? • Retrieval - getting memories out of LTM what gets out? exact memories or reconstructed memories? • Related to these issues are the theoretical construct of Attention.
Long term memory • Properties • Unlimited capacity • Decay/interference, retrieval difficulty • Organized • Associative networks (more on these next week)