Presentation on theme: "Chapter 7 zIn this chapter, we discuss some of the data collected by researchers trying to solve the problems of memory structures and processes. zThe."— Presentation transcript:
Chapter 7 zIn this chapter, we discuss some of the data collected by researchers trying to solve the problems of memory structures and processes. zThe chapter is divided into two sections – short-term memory and long-term memory.
SHORT-TERM MEMORY - Neurocognition and STM - Capacity of STM - The Coding of Information in STM - Retrieval of Information from STM
LONG-TERM MEMORY - Neurocognition and LTM - LTM: Storage and Structure - Very Long-Term Memory (VLTM) - Autobiographical Memories
SHORT-TERM MEMORY zPeterson and Peterson (1959) ysubjects were read a three-letter cluster and asked to recall it after varying periods. During these periods (between hearing the letters andattempting to recall), subjects counted backward by threes from a three- digit number presented immediately after the three-letter cluster, as here: yExperimenter says: CHJ/506 ySubject responds: 506, 503, 500, 497, 494, and so on
STM - Peterson & Peterson zResults: Recall seriously eroded in the absence of rehearsal. yexperiment demonstrated that our capacity to store information in a temporary memory bank is severely limited and susceptible to forgetting if we do not havethe opportunity to rehearse the information. yTheir experiment represented a turning point in our experimental conceptualization of short-term retention (2 memory banks).
2 memory banks? 1. Casual observation suggests some things are remembered for a short time and others for a long time 2. Physiological studies indicate that short term functions can be interrupted, while long term functions seem to remain intact 3. Psych. experiments suggest retrieval of some info is characteristic of a short- term function while other is characteristic of a long term function (primacy and recency)
NEUROCOGNITION AND STM zBrenda Milner (1966) yThe case of H.M. ysevere epilepsy, bilateral surgical excision (of the medial temporal region) was done xprocedure removed parts of the temporal lobe, including the hippocampus. yH.M. became profoundly amnesic and could not seem to store new information in LTM; his STM was unimpaired.
STM Theory zHebb’s Dual Trace Theory If original activity continues for some time, structural changes at the synaptic contacts among cells could carry the memory thereafter. These structural changes would correspond to long-term memory, and the earlier continued identified with short term memory
STM Capacity zMagic Number 7 +/- 2 y(Miller, 1950’s) zChunking (coding single units into larger units) ycan greatly expand STM capacity ydoesn’t work without activating LTM (provides the framework) yFBI, PHD, TWA, IBM easier than FB, IPH, DTW,...
CODING OF INFORMATION IN STM - Auditory Code predominate method in STM, even if info presented visually (research) - Other research suggests visual or semantic codes
LOOK UP! zResearch on the Duration of STM zThe Brown-Peterson Paradigm zResearch on the capacity of STM zResearch on the Acoustic Code in STM zResearch on Verbal Rehearsal and STM zThe Serial Positions Effect zSearching through STM: Serial search zS. Sternberg
LTM zGeneral findings: yRelatively permanent storage yUnknown capacity yOrganized as seen in Free Recall Tasks
LONG-TERM MEMORY zSome experiences are remembered better than others, such as, exciting, ego- involving are, or even traumatic experiences seem to stick in memory better than complicated political theories.
Neurocognition and LTM zWhere do memories reside? (PET) yFrontal area involved in deep processing of info yHippocampus and thalamus involved in formation of memories yCerebral Cortex - permanently stores memories yConclusion - very generalized, all over
Neurocognition and LTM zHow does brain store info? yDonald Hebb - STM info converted to LTM if active for long enough period of time. LTM is chemical and/or structural change
LONG-TERM MEMORY zSUGARCOATED GOLDEN MEMORIES: yFor example: animal studies have indicated that blood stream of epinephrine (adrenaline), which has now been demonstrated to enhance consolidation of a memory (McGaugh, 1990). It is likely that epinephrine does not directly stimulate the brain’s synapses (there is matter of crossing the blood brain barrier), but converts stored glycogen to glucose (a sugar), thereby raising the blood level of glucose, which nourishes the brain.
LTM: Storage and Structure zCODES: In LTM, information is clearly coded acoustically, visually, and semantically. yMultidimensional coding ylittle research on taste, smell, and touch, but probably also coded this way
LTM: Storage and Structure zOrganization: yassumed some order to LTM ynetwork of interrelated and associated info, very complex ynew info is recorded in existing info
LTM: Storage and Structure zCapacity and Duration yHuge, Almost Permanent yLoss of recall can be due to interference or decay
Very Long Term Memory zVLTM - memories more than 3 months old zResearch on yearbook pictures showed: yrecognition about 90% correct over 34 years yName recognition and name matching declined after 15 yrs ysharp decline in recogniton and recall after 35 yrs. May reflect a degenerative process of aging
Very Long Term Memory zResearch on memory for Spanish language ydecline the most over first 3 yrs, then relatively stable over 30 yrs. yMuch of orignially learned info still usable after 50 years - suggested a “permastore”
LTM: Storage and Structure zAutobiographical Memory yMemories of your past history yHard to study objectively - why? yLinton’s “Journal” study - found linear forgetting, and 2 types - interference and decay yFlashbulb memories - special mechanism?
Fallability of Memory zEyewitness Testimony and False Memory ymemory is reconstructive y“recovered Memories” can be false memories yvery susceptible to change