Memory Development. Cognitive Development

Transcription

1 Memory Development Cognitive Development

2 Memory as information storage Memory

3 Why does our memory sometimes fail us?

4 Memory Schachter s Seven Sins of Memory 1. Transience 2. Absent-Mindedness 3. Blocking 4. Misattribution 5. Suggestibility 6. Bias 7. Persistence Tape recorders, filing cabinets, and hard drives don t commit these sins

5 Memory Schachter s Seven Sins of Memory 1. Transience 2. Absent-Mindedness 3. Blocking 4. Misattribution 5. Suggestibility 6. Bias 7. Persistence In kids, these sins are caused by failures in control processes

6 Maintenance Rehearsal Sensory Input Sensory Memory Attention Working Memory Encoding Retrieval Longterm Memory Modal Model of the Mind Memory stores - differ in function, capacity and duration Control processes - control movement of information within and between memory stores

7 Short-term Memory Maintenance Rehearsal Sensory Input Sensory Memory Attention Working Memory

8 Sensory Memory Store Function - holds information long enough to be processed for basic physical characteristics Capacity - large Duration - very brief retention of images.3 sec for visual info 2 sec for auditory info Sensory Input Sensory Memory

9 Sensory Memory Store Sensory Input Sensory Memory Sensory memory forms automatically, without attention or interpretation Attention is needed to transfer information to working memory

10 Working Memory Store Function - conscious processing of information Capacity - limited (holds 7 +/- 2 items*) Attention Maintenance Rehearsal Working Memory Duration - brief storage (about 30 seconds) Code- Often based on sound or speech even with visual inputs.

11 Measures of STM Table I. Tasks commonly used to assess short-term memory (STM) abilities in children Type of STM Method Examples of stimuli a Correct response Ref. Phonological Digit span c Recall of words chin led bag chin led bag e Nonword repetition woogalamic woogalamic a Visuospatial Pattern recall f (3) (3) Corsi blocks (1) (2) (1) (2) c Working memory/ Listening span Oranges live in water no e executive processes Pigs have curly tails yes water, tails Counting span 4,3 e Backward digit span ,2,9 c Day/night Stroop day g a Stimuli printed in italics are either verbally presented or represent experimenter actions (arrows). Actions are pointing actions, with positions of correct pointing responses in sequence shown in parentheses where relevant to the task.

12 Development of STM 1.6 Performance (proportional score) Age trends in Cognitive Sciences Fig. I. Performance on measures of short-term memory as a function of age. Mean performance of each age group is plotted as a proportion of mean performance of nine-year olds. Blue squares, digit span (phonological memory); red triangles, non-word repetition (phonological memory); open circles, forward digit span; green squares, Corsi blocks (visuospatial memory); yellow triangles, listening span (complex working memory); filled circles, backward digit span (complex working memory). All data are redrawn from the following: non-word repetition, Refs a,b; forward digit span, backward digit span, and Corsi blocks, Ref. c; listening span, Ref. d.

13 What changes? One source of changes involves changes in the control process of maintenance rehearsal

14 Maintenance Rehearsal Mental or verbal repetition of information allows information to remain in working memory longer than the usual 30 seconds Maintenance Rehearsal Sensory Input Sensory Memory Attention Working Memory

15 Maintenance Rehearsal Visuospatial sketch pad - holds visual and spatial info Phonological loop - holds verbal information Central executive - coordinates all activities of working memory; brings new information into working memory from sensory and long-term memory Visuospatial Sketch Pad Central Executive Phonological Loop

16 What changes? One source of changes in STM involves changes in the control processes of maintenance rehearsal Maybe due to neuroanatomical changes

17 Neural Changes Table I. Regions of cortical activity associated with short-term memory Type of short- Cortical areas Hemisphere Brodmann term memory areas 20 trends in Cognitive Sciences Fig. I. Sagittal view of the adult brain, with Brodmann areas marked. The four major lobes are demarcated by colour: frontal (yellow), parietal (green), temporal (red), and occipital (blue). Phonological c Storage Posterior paretial Left 40 Rehearsal Broca s area, Left 44, 6 premotor cortex, Left 6 supplementary motor cortex Spatial d Inferior prefrontal Right 47 Storage Anterior occipital, Right 19, 40 Rehearsal posterior parietal Right 6 premotor cortex Working Dorsolateral Left/ 9, 10, 44, memory/ prefrontal cortex bilateral 45, 46 executive processes c,d

18 What changes? One source of changes in STM involves changes in the control processes of maintenance rehearsal Maybe due to changes in memory strategies

19 Organization Unsorted couch banana dog chair apple rat Sorted couch chair banana apple dog rat

20 Effect of Organization The Development of Organizational Strategies in Children: Evidence from a Microgenetic Longitudinal Study Matthias Schlagmüller and Wolfgang Schneider University of Würzburg FIG. 2. Mean level of recall, as a function of session and sorting during learning.

21 Eureka! Moment FIG. 5. Mean ARC clustering scores and recall (both z-transformed) for the last three sessions the children had not sorted the items (SN3 to SN1) and the first four sessions the children had sorted the items (S1 to S4) (data only for transitional group).

22 Utilization Deficiency Seems like kids CAN use strategies even when they don t do so (hence, the abrupt change) More...

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24 Long-Term Memory Store Function - organizes and stores information Capacity - Unlimited Duration - thought by some to be permanent Encoding Retrieval Longterm Memory

25 Long-Term Memory Properties of LTM 1. Hierarchical organization 2. Meaning-based code Encoding Retrieval Longterm Memory

26 Hierarchy WM can store 7+/-2 units Chunking can expand unit-size Hierarchies organize chunks in LTM so long strings (like the alphabet) can be retained for a long period of time

27 Hierarchy Twinkle twinkle little star How I wonder what you are Up above the world so high Like a diamond in the sky AB CDEF G HIJK LMNOP QRS T UV W X Y&Z

28 Time to retrieve next letter in alphabet. Hierarchy

29 Meaning-based Code Much of what we remember is not a literal listing of details (like a phone number or the ABCs) From linguistic and visual input, we often store meaning (or gist ) instead of actual details

30 Meaning-based Code Wanner (1968) demonstrated that after processing a linguistic message, people normally remember just its meaning and not its exact wording

31 Some Ss were given a warning: The materials for this test, including the instructions, have been recorded on tape. Listen very carefully to the instructions because you will be tested on your ability to recall particular sentences in the instructions.

32 One of four instructions were read next: 1. When you score your results, do nothing to correct your answers but mark carefully those answers that are wrong. 2. When you score your results, do nothing to correct your answers but carefully mark those answers that are wrong. 3. When you score your results, do nothing to your correct answers but mark carefully those answers that are wrong. 4. When you score your results, do nothing to your correct answers but carefully mark those answers that are wrong.

33 100% 80% 60% 40% Unwarned Warned Memory for meaning differences was nearly perfect regardless of warning Almost no memory for style differences unless warning Meaning Style

34 Development of Memory Gist vs Verbatim Brainerd & Gordon (1994) One day in class, the teacher asked all the children how they liked to travel best. liked airplanes, liked cars, liked boats, liked trains, and liked buses. Verbatim memory: How many liked airplanes? Gist memory: Did more people like airplanes or cars? Across all ages, Verbatim < Gist; Verbatim: large age differences; Gist: small age differences.

35 Implication IF memory for meaningless details is rapidly forgotten and memory for meaningful details is retained, THEN to encode information in LTM, convert the meaningless into the meaningful.

36 Development of LTM Because LTM is a meaning-based code, age-differences in pre-existing knowledge can have a large effect on LTM Among children, memory for reading passages are strongly correlated with vocabulary and background knowledge Maybe children with lots of knowledge might have better memory than adults?

37 Chi (1978)

38 Chi (1978)

39 Chi (1978)

40 Chi (1978)

41 Is memory development just knowledge based?

42 Memory for Faces of Classmates (Chi, 1977) Ordered scoring: 600 ms Free scoring: 600 ms Ordered scoring: 300 ms Free scoring: 300 ms

43 Development of LTM Encoding Retrieval Longterm Memory While knowledge is important explanation for age differences, speed of encoding time is another important factor

44 Development of LTM Development of Retrieval Forgotten memories can be retrieved through the presentation of a reminder ( cue )

45 Evidence of Cued Recall Campbell & Jaynes (1966) demonstrated that rat pups can retain fear conditioning over 28- days retention intervals, if they are given reminders Rovee-Collier, et al (1980) demonstrated that 3- month-olds can retain mobile training if they are given just one reminder Subsequent research demonstrated that the reminder phenomenon is pervasive in infant memory

46 Three Major Developments in CR 1. Retention intervals increase (e.g., 2-month-olds can be reminded after RI of 18 days, whereas 12- month-olds can have RI of 9 weeks). 2. Time required for reminders decrease (i.e., 3- month-olds require 180 s, whereas 6-montholds require 7.5 s). 3. Generality of reminders increase (for 6-montholds, a reminder must be highly specific, but that 12-month-olds can be successfully reminded in a novel environmental context)

47 Summary Basic memory processes undergo dramatic development MTL and PFC have been implicated in memory and maturation of these areas is likely to be responsible for memory development It is likely that early memory is only semantic in nature and the ability to form verbatim memory comes online later in development