Memory 2 (COG)

Memory 2 (COG)

1. encoding = conversion of info into a mental form. storage = retention of encoded info. retrieval = process by which info is recovered from mem

2. Crowder (1993) suggests STM and LTM are basically the same.

3. STM

   • brief, immediate mem for material that you are currently processing. coordinates the ongoing mental activities ie.. used when having a convo. 1st place we store info originating from the enviro
   • Millers (1956) - MAGIC NO. 7 . limited no. of items retain by humans. 7 +/- 2. limited capacity
     • Chunking - basic unit in stm. consists of several components that are strongly associated with one another. chunk can be single number or letter. can remember random sequence of about 7. stm can hold approx. 7 chunks.
   • Cowan (2000) magical no. is 4+1 if consider "pure capacity" of stm without chunking
   • Peterson x2 (1959) asked ppts - study 3 letters, count back in 3s (cant rehearse) then recall letters. varied length of time betw. test and recall. after 5 secs delay = forgot
   • Brown-Peterson - fragility of mem for items stored for only few secs, if info not rehearsed it is dropped from mem

4. Primacy & Recency Effect (Glanzer & Cunitz, 1966)

   • higher prob of recall on items near start of list = primacy effect. higher prob of recall on items at end of list = recency effect.
   • Occurrence of Primacy
     • transfer of info from STM -> LTM dependant upon amount of attention and rehearsal that info gets. if at start of list - stm gives full attention, more rehearsal
   • Occurrence of Recency
     • as new words come into STM - older words displaced. at end of task, words left in stm are the ones recently heard. better recall of more recent items

5. pronunciation time = longer time word takes to pronounce - longer it takes to be remembered. capacity of WM = determined by limited time for which verbal trace of items endure - approx 1.5 secs

6. WMM (Baddeley & Hitch, 1974) argue MSM too simplistic. Spatial Reasoning Task - ppts rehearse string of no's whilst performing SRT. ppts performed quick and accurate - error rate 5% no matter how many numerals had to be rehearsed. dual task results imply system responsible for digit span cannot be same as learning/reasoning. WM has several components.

   • phonological loop - left hemisphere (language) = Wernicke's & Broca's Area. visual/spatial scratchpad - occipital cortex (visual processing)

7. Sustained Attention to Response Task - presented long sequence of digits. ppts press computer key to all digits except 3. individuals with frontal lobe damage unable to withhold responding. deficit in central executive - involved with response inhibition