Introduction to Cognitive Psychology - Department of Psychological ...

Prof. Greg Francis 8/16/11Working memoryWorking memoryPSY 200Greg FrancisLecture 17A problem with IQ tests.Purdue University!! Current thought, awareness!!extension of short-term memory!!small capacity!!rapid forgetting!! Processor of information!!not a storage deviceVisuospatialsketchpad!!hypothesizes mechanisms that lead to memorypropertiesPurdue UniversityCentralexecutivePhonologicalloopPhonological loopLoop capacity!! Two components!! Articulatory control process(ACP)»! converts non-speechinformation into speechcode»! rehearsal / refresh!! Phonological store (PS)»! similar to how we firstdescribed STM (itemsdecay from memory)»! Refresh restarts the decayprocessPhonological loopACPPS!! How many items can bekept in the phonologicalloop?!! Depends on two factors!!Duration before decay fromPS!!Speed of rehearsal!! Spinning coins!Phonological loopACPPSPurdue UniversityPurdue UniversityMagic number?!! We earlier noted that memory span was about 7 items (+/- 2)!! The phonological loop suggests that it is not the number ofitems but their rehearsal duration!! To recall a list of items you must rehearse them all before anyof them fade!! The duration of decay in the PS!! Memory span should follow the equation!! Span = (Rehearsal Rate) X (PS decay time)!! Measure memory span (s): around 7 items!! Measure verbal rehearsal rate (r): around 4 items per secondfor English speakers!! Estimate duration of decay in PS (d)!! d=1.75 secondsPurdue University!! Capacity of theEffect of rehearsal ratephonological loop dependson the rate of rehearsal (r)!! A set of items that takeslonger to rehearse shouldbe harder to remember!! more likely that some itemswill drop out before you getback to the first itemPhonological loopACPPSPurdue UniversityPSY 200: Intro. to Cognitive Psychology 1