Interpretation
Psychologistsdividethememoryintoinstantaneousmemory(sensorymemory)andshort-termmemoryaccordingtothelengthoftimetheinformationisstoredandthewaytheinformationisencoded,storedandprocessed.Andlong-termmemory.
Short-termmemoryreferstothememoryinwhichpeopleprocess,encode,keepshort-termstimulusinformationandhavelimitedcapacity.Short-termmemoryistheintermediatelinkfrominstantaneousmemorytolong-termmemory.Itsfunctionistotemporarilystoreinformationsothatitcanenterlong-termmemory.
Short-termmemoryincludestwocomponents:directmemoryandworkingmemory.Directmemorymeansthattheinputstimulusinformationisstoredinthebrainforashorttimewithoutfurtherprocessingandcoding,buttheinformationcapacityisverylimited.Workingmemoryreferstothememorythatprocessesandencodestheinputstimulusinformationagaintoexpandtheinformationcapacity.Inshort-termmemory,onlytheprocessed,processedandencodedinformationcanbetransferredtolong-termmemoryforfurtherstorage,otherwiseitwillbeforgotten.
Features
Limitedcapacity
Thecapacityofshort-termmemoryislimited.Thecapacityofshort-termmemoryisalsocalledshort-termmemorybreadth,whichreferstothemaximumnumberofthingsthathavenothingtodowitheachotherafterabriefpresentation.
TheAmericanpsychologistMiller'sresearchonshort-termmemorycapacityshowsthatthereareabout7stimulusitemsmaintainedinshort-termmemory,andthehumanshort-termmemoryspanis7±2Block.
However,someresearchershavefoundthatthememoryspantestoverestimatesthetruecapacityofSTM,becauseparticipantscanuseotherinformationsourcestocompletetasks,suchasechomemory.Therefore,someresearchersestimatethatwhenotherresourcesofmemoryareseparated,thepurecontributionofSTMtothememoryspanofabout7chunksisonly2~4.
Althoughthecapacityofshort-termmemoryislimited,retellingandchunkingcanincreasethepossibilityofcodedinformationbeingretainedinshort-termmemory,sothatwecanremembernormally.
Theretentiontimeisshort
Withoutretelling,theretentiontimeoftheinformationintheshort-termmemoryisonly15-20seconds.
Theroleofblocks
Blockscaneffectivelyexpandthecapacityofshort-termmemory.Whenprocessingandprocessinginformation,peopleusetheknowledgeandexperiencestoredinlong-termmemorytocombineseveralsinglestimuliintolargerinformationunits(ie,chunking),whichcaneffectivelyexpandandincreasethebreadthofshort-termmemoryandimproveMemoryefficiency.
Theroleofretelling
Retellingreferstotheprocessofrepetitionofthematerialthathasjustbeenmemorizedthroughlanguagetoconsolidatethementaloperationofmemory.Inthecaseofretelling,thelearningmaterialskeptinshort-termmemorywilltransfertolong-termmemory.Thecontentofshort-termmemorycanbetransformedintolong-termmemorythroughretelling.
Coding
Codingmethod
Thecodingofshort-termmemoryismainlyauditorycoding,buttherearealsovisualcodingandsemanticcoding.
Auditorycoding
Conrad's1964experimentfoundthatwhensubjectsrecalledvisuallystimulatingletters,whathappenedThevastmajorityoferrorsarehomophonicconfusion.Therefore,itisconcludedthatthereisauditorycodinginshort-termmemory.Thatis,inshort-termmemory,thestimulusinformationismainlyencodedandstoredinauditoryform.Evenifthestimulusinformationispresentedvisually,theindividualwillconvertthemintoauditorycodeswhenprocessingthevisualstimuli.
Visualcoding
PosnerusedtheAaexperimentin1969tofindthatthesubjectsweremorelikelytohavehomomorphicrelationships(AA)thanhomophonicrelationships(Aa)Lettersrespondquickly,buttheadvantagesofthestimulusinformationofthishomomorphicrelationshipcanonlyappearininformationprocessingrelyingonvisualcoding.Therefore,itisconcludedthatintheinitialstageofshort-termmemory,thereisaprocessofvisualcoding,andthenthetransitiontoauditorycoding.
SemanticCoding
Wickensusesproactiveinhibitiondesignexperimentstoshowthatthereisacertainsemanticcodinginshort-termmemory.
Influencingfactors
Wakefulnessstatus.Theawakeningstateistheexcitementlevelofthecerebralcortex,whichdirectlyaffectstheeffectofmemorycoding.Forexample,Ebbinghausfoundthroughexperimentsthatsubjectshadthehighestlearningefficiencybetween11and12inthemorning,andthelowestlearningefficiencybetween6and8intheafternoon.Thismayberelatedtodifferentstatesofawakeningatdifferenttimes.
Processingdepth.Thegreatertheprocessingdepth,thebettertheeffectofshort-termmemorycoding.
Block.Blockingthecontentofthememoryorexpandingtheamountofinformationcontainedineachblockcanimprovethecodingeffectofthememory.
Storage
Aneffectivemethodforshort-termmemoryinformationstorage-retelling.Itcanpreventtheinformationinshort-termmemoryfrombeingdisturbedbyirrelevantstimuliandbeingforgotten.
Retellingisdividedintotwotypes:mechanicalretellingorretentionretelling;fineretelling.Amongthem,fineretellingisanimportantconditionforshort-termmemorystorage.
Extraction
Theextractionofshort-termmemoryreferstorecallingthestimulusinformationintheshort-termmemory,orbeingabletorecognizethestimulusagainwhenthestimulusreappears.Theextractionofshort-termmemoryisextremelyrapid.ExperimentscreatedbySternbergshowthathumanscanextractshort-termmemoryapproximately30timespersecond.
Sternbergconductedanexperimentalstudyofshort-termmemoryretrievalwhenusingadditivereaction.
Assumethatthesubjects’retrievalandretrievalofmemoryitemsinshort-termmemorycanbedividedintothreemethods:(1)Parallelscanning(2)Automaticallystoppingseriesscanning(3)Completeseriesscanning.
Theresultsshowthattheinformationextractionofshort-termmemoryiscarriedoutinacompleteseriesofscans.
Forgetting
Forgettingprocess
Thecapacityofshort-termmemoryislimited,andthestoragetimeisalsoveryshort.Intheabsenceofretelling,short-termmemorycanholdinformationfor15-20s.
Causesofforgetting
Waugh&Normanhasshownthroughexperimentsthattheforgettingofshort-termmemoryismainlycausedbyinterference.Thatis,forgettingisbecausetheinformationinshort-termmemoryisinterferedbyotherirrelevantinformation.