Memory 3265 Course website address http www yorku

Memory 3265 • Course website address • http: //www. yorku. ca/npark/memory_f_14

Introduction and History of Memory Research • History – Ebbinghaus (1885) is credited with being the first person to scientifically study memory – prior to Ebbinghaus relatively little was written about memory

Introduction and History of Memory Research • History – however, people did write about factors affecting memory performance äattentiveness and rehearsal aid memory – Aristotle (4 th Century BC) äproposed laws of associationism. Most important is the law of contiguity-- two events or experiences occurring closely in time will come to be associated with each other

Introduction and History of Memory Research • History – Romans (e. g. , Cicero) and others were concerned with using mnemonics to assist memory – mnemonics generally remember something new by pairing it with already known information ädeveloped the method of loci. In this method a person places items to be memorized in particular locations well known to the memorizer

Introduction and History of Memory Research • History – Ebbinghaus (1885) published Memory: A contribution to Experimental Psychology – first experimental study of memory; inspired by Fechner’s work on the psychophysical study of sensation

Introduction and History of Memory Research • History – experimental procedure of Ebbinghaus äMaterials. Used nonsense syllables (CVC) to try and study acquisition and memory for brand-new stimuli äParticipant. Ebbinghaus äProcedure. Presented nonsense syllables one at a time at a fixed rate of presentation. Studied list until he could recall entire list in serial order without error (method of complete mastery)

Introduction and History of Memory Research • History – experimental procedure of Ebbinghaus äProcedure (cont’d). Ebbinghaus was concerned with the rate of forgetting as a function of the time interval between initial learning and his attempt to recall the list. If he made one or more errors, Ebbinghaus restudied list until he could recite the list perfectly. The dependent variable was the savings score, ie, the time or trials saved in learning list again. Example, initially took 1500 seconds to learn list; took 600 seconds to relearn list; savings = 900/1500 = 60%

Introduction and History of Memory Research • History – experimental procedure of Ebbinghaus äResults. Ebbinghaus produced his famous forgetting curve. There is a precipitous drop in retention shortly after a list was acquired

Ebbinghaus’ forgetting curve

Introduction • History – the tradition of Ebbinghaus ähighly controlled experiments äsimple stimuli äquantifiable dependent measures – reaction to its restrictiveness äGestalt psychologists, Bartlett, and cognitivists

Introduction • History – Cognitive tradition (William James) ä In his classic text, principles of psychology, James distinguished between different types of memory ä Habits were 1 type of memory that mediated skills such as walking, writing, and singing ä James believed these resulted from a concatenation of reflex mechanisms and pathways, which could combine to produce complex behaviors ä Two other forms of memory according to James were: ä Primary memory – now called short-term working memory ä Secondary memory – now called long-term memory

Introduction • History – Cognitive tradition (William James) äJames did not explicitly distinguish between habit and memory äBergson (1911) proposed that representation of the past has two distinct types of memories – habits and memories äAs we shall see, the distinctions proposed by James and Bergson continue to be made

Introduction • Other traditions – ecological validity – neuropsychology • Ecological validity – argues that the Ebbinghaus tradition is concerned with unimportant problems with little applicability to real world problems

Introduction • Ecological validity (cont’d) – this approach, spearheaded by Neisser (1978, 1982) is controversial – and there are strong critics of this approach (e. g. , Crowder)

Introduction • Other traditions (cont’d) Neuropsychology – Neuropsychology: study of disorders of perception, memory, language, thought, emotion, and action in neurological patients – Gall proposed theory of cortical localization in which individual cognitive functions are mediated by specific brain regions – No real evidence for this idea because he examined bumps on skull, which he related to cognitive functions (e. g. , pride, vanity, language, and speech)– now called phrenology

Introduction • Other traditions (cont’d) Neuropsychology – Broca 1861 ä 51 year old man; lost power to speak (“Tan” was one of the only speech sounds he could make) ä Paralyzed on right side with a loss of sensitivity ä Mouth not paralyzed; he could understand speech ä Autopsy revealed damage to left inferior part of frontal lobe ä on the basis of a brain-behaviour case study he claimed that language is localized to the inferior part of the left frontal lobe

Introduction • Broca (cont’d) – two important parts of claim ä 1. Language can be dissociated from other cognitive functions ä 2. Language function can be localized to a particular brain region

Introduction • Carl Wernicke (1894) – Reported case of a patient who could produce speech, but could not understand speech – Damage to left temporal cortex suggested that this was site for speech comprehension – this approach to understanding cognitive function led to the rise of the diagram makers (1860 1905)

Introduction • Logic of diagram makers – identify distinct syndromes, then attempt to theoretically link the different syndromes – for example, they identified what they believed were several distinct types of aphasia äBroca’s aphasia--speech is nonfluent; ie, short phrases, poor melodic content, limited grammatical form äWernicke’s aphasia-- speech is fluent, but comprehension is impaired

Lichtheim’s Neuropsychological model of language Function Word concept elaboration 3 Motor word representations (Broca) Speech motor output Auditory word centre (Wernicke) Auditory input

Criticisms of diagram makers • Work of diagram makers has a contemporary flavour and is now appealing to 20 th century eyes – Work was attacked for following reasons ä 1. Postulated that the functions they hypothesized could be precisely localized; evidence do not support this claim ä 2. Psychological concepts were inadequate; e. g. , aphasia was a word-based deficit; evidence suggests that syntax is an important component of the deficit

Criticisms of diagram makers – Work was attacked for following reasons ä 1. Postulated that the functions they hypothesized could be precisely localized; evidence do not support this claim ä 2. Psychological concepts were inadequate; e. g. , aphasia was a word-based deficit; evidence suggests that syntax is an important component of the deficit ä 3. Did not carefully and systematically observe the patients on which theoretical ideas were based

Group study approach (1940 -1970) • Rejected the single-case approach to neuropsychology in favour of the group study approach • clinical observations became an insufficient basis for theoretical speculation

Cognitive Neuropsychology • Use information processing models to describe cognitive function; these models are very similar to Lichtheim – note: you can conceptually ‘lesion’ information processing models • returned to the use of the case study – however, an experimental approach was used – attempt to use case studies to discriminate between different models of normal function

Cognitive Neuropsychology • Memory findings by early neuropsychologists – early investigators studied anterograde amnesia – impaired ability to recall newly learned information – Retrograde amnesia – loss of memories acquired prior to onset of brain trauma

Cognitive Neuropsychology • Ribot (1882) – Reviewed a large number of cases of retrograde amnesia following brain damage and head trauma – Memories acquired remotely prior to insult were better retained compared to memories acquired more recently before insult – This result is called Ribot’s law or the law of regression – Concluded that memories require time to be organized and consolidated

Cognitive Neuropsychology • Alzheimer (1906) – Reported the case of a patient with dementia now known as Alzheimer’s disease (AD) – Showed that 2 important symptoms of AD were: anterograde amnesia and retrograde amnesia (graded; i. e. , remote memory better retained than more recent memory)

Introduction: Memory • What sorts of functions are subserved by memory? – Who am I? äIf you have no memory of the events that you have experienced (autobiographical memory), then it would be difficult to answer this question – What do I know? äSemantic knowledge about the world

Introduction: Memory • What sorts of functions are subserved by memory? – Memory for actions äprocedural memory; memory is expressed by performance rather than by recollection or verbal description ähow do you tie your shoelace? äHow do you play a musical piece ähow do you use a hammer

Introduction: Memory • What sorts of functions are subserved by memory? – How do I learn? – Why do I forget? Is it functional?

Introduction: Memory Methodology • Distinctions – Learning refers to the acquisition of new skills and information – Memory refers to the retention of what has been learned over time

Introduction: Memory Methodology • The memory process is composed of three main phases: – encoding or registration: transformation of information presented to a person into a form that can be retained – retention: storage of information – retrieval: recollection or remembering of stored information

Introduction: Memory Methodology • Incidental versus intentional memory • Explicit memory – conscious recollection of previous experience äe. g. , tell me your telephone number äe. g. , try to recall when you first decided to take this course – explicit memory can be intentional or unintentional äe. g. , remembering an argument you had with your friend is explicit, but may be unintentional

Introduction: Memory Methodology • Measuring explicit memory – recall (free or cued) – recognition • Implicit memory – indirect memory test; conscious recollection not involved – e. g. , mere exposure effect; word stem completion

Introduction: Memory Methodology • Episodic versus semantic memory – episodic memory is memory for events or episodes; it is stored in terms of its autobiographical reference to already stored information – semantic memory is the memory necessary for language; it is a mental thesaurus, organized knowledge a person possesses about words, and other verbal symbols and their meaning

Introduction: Memory Methodology • Independent variables – factor that influence performance of some dependent measure – in memory research it is a factor that affects memory performance

Introduction: Memory Methodology • Types of independent variables – organismic: relatively permanent characteristics of an individual that affect memory performance äe. g. , age, intelligence, health – antecedent variables: sleep, drugs, time of day

Introduction: Memory Methodology • Types of independent variables (cont’d) – task variables: äinstructions (e. g. , intentional vs incidental) äpresentation conditions (e. g. , rate of presentation) ästimulus variables (e. g. , picture, word, type of word) äcontext in which task occurs

Introduction: Memory Methodology • Types of dependent variables – accuracy änumber of items recalled, recognized ätypes of errors made äscoring criterion: strict…(need to operationalize) äWhat do you do about guessing? – speed – order in which items were recalled

Introduction: Memory Methodology • Some standard memory tasks – serial learning: recall items from a list in the exact order in which they were presented – free recall: recall as many items from a list in any order – cued recall: present cue-target pairs at study; at test present cue and have participant recall target

Introduction: Memory Methodology • Some standard memory tasks (cont’d) – Recognition test ämultiple-choice test. Participant selects which of 2 or more alternative choices is correct ätrue-false test (yes/no test)

Non-traditional memory tasks • Autobiographical memory – memory of old TV shows – famous faces

Non-traditional memory tasks • Implicit memory has become increasingly popular – amnesics remember information when tested using implicit memory procedures; however, amnesics are unable to remember this information when they are tested using explicit memory procedures

Non-traditional memory tasks • Warrington and Weiskrantz (1970) – tested amnesics and controls on explicit and implicit memory tasks äsubjects were presented a list of words to study; amnesics were much inferior to controls in their explicit recall and recogniton of the studied words äalso tested memory on two implicit memory tasks (word fragment identification and word stem completion e. g. , cha----); on these two implicit memory tasks amnesics performed as well as controls

Non-traditional memory tasks • Conclusion – amnesics may have selective damage to that part of the memory system that mediates explicit recollection of stored information