Control processes The kinds of mental processes carried out on a memory 3 main types –Encoding processes –Retention processes –Retrieval processes

Encoding “encoding” – process by which information is put into the correct form (or code) for the memory More generally, encoding means storing information in a memory E.g., in STM, encoding could be “chunking” (putting information into chunks)

Retention Retention = keeping information in memory E.g., in STM, we do “rehearsal” (repeat information in our minds) to keep info

Retrieval processes Retrieval = bringing information out of a memory so that it can be used in a task E.g., must “search” your memory for information

metamemory Metamemory = your knowledge of your knowledge E.g., most people know that they DO NOT KNOW the names of all presidents in order

Memory Scanning experiment Sternberg, 1966 Aka, memory search RT study of how quickly people can tell whether a single letter was one of a set of letters they just saw In other words, people store a set of letters in STM, then they search STM to see if another letter is in there

Timeline F K L M T Letter set (memory set) Delay (a few secs) L probe Respond “yes” RT

Serial and parallel search Looking through items one-by-one is serial (i.e., in a series) – slow Look through all of the items at the same time (look at all letters simultaneously) – parallel - faster

manipulation Varied the number of items in memory set (small number of items  larger number of items) Number of items in memory  set size If search is serial, then increasing set size will increase RTs If search is parallel, then increasing set size will NOT affect RTs

Prediction for parallel search

Prediction for serial search

Shows serial search “yes” “no” Not self-terminating

More on serial search E.g., looking for “L” and “L” is the middle item in STM Best thing to do when “L” is found (most efficient) is to stop and say “yes” (self- terminating search = stop when you find what you’re looking for) On average, must search ½ of items to find item that is in there  search fewer items on “yes” cases than on “no” cases

Exhaustive serial search Exhaustive = look through all of the items in STM even after you’ve found what you’re looking for Search all items on “yes” cases and all items on “no” cases  “yes” RTs = “no” RTs Not very efficient, but it is how our mind works (could be “ballistic” – can’t stop once it starts)

Long-Term Memory Capacity, duration, code LTM has unlimited capacity, infinite duration, uses all codes E.g., concept of democracy is representing in LTM via semantic code

Conway et al. (1991) P. 115 in Reed text Study of how long people remember information from cognitive psychology class Study of the duration of long-term memory Retention intervals from 3 mos. To 125 mos. Material remembered even after 10 years

Two types of recall tasks Serial recall vs. free recall Serial recall = remember order of items Free recall = don’t remember order, just the items

The Free Recall Experiment Present material to-be-learned (typically, a list of words) –List size within 7+/-2 (testing STM) (subspan) –List size > 7+/-2 (testing LTM) (supraspan) Retention Interval or delay –RI really short (< 30 secs) (testing STM) –RI > 30 secs (testing LTM) Then, the test (retrieval items in any order they want)