Introduction. Chapter 5: Working Memory Forming and Using New Memory Traces. Serial Position Effect 1/20/2015

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1 Chapter 5: Working Forming and Using New Traces 1 Introduction Episodic Semantic Sensory Iconic Echoic Issues Format STM LTM Storage Capacity STM Retention Working Retrieval Sternberg Task Working Executive Functioning Neuroscience Phonological Loop 2 Applications & Ind Diff Visuospatial Sketchpad Central Executive Buffer Age Culture Educ Introduction Episodic vs. Semantic for episodic events vs. general knowledge Episodic: Storage, Retention, Retrieval Traditional View of Episodic Two distinct memory systems Short-Term : primary memory, short-term storage, Long-Term : secondary memory, long-term storage, Evidence: e.g. Serial Position Effect (+1 +2) Iconic or Sensory advocated by some Very transient storage of external stimuli Usually discussed in context of Perception 3 Serial Position Effect Primacy Effect Better memory for early items in list Rehearsal (+1) Long-Term Recency Effect Better memory for later items in list Delay (+1) Short-Term Primacy Recency 4 Delay (filled to prevent rehearsal) results in loss of Recency items, not Primacy items () Number of rehearsals correlated with recall for Primacy, not Recency () Delay 5 Sensory Very transient memory for sensory events Veridical: i.e., exact replication of external stimulus Lost very quickly, or over-written May allow time for perceptual processes Specific to different sensory systems: Iconic, Echoic, Iconic Brief store of visual information in raw, uncoded form Move finger rapidly, sparkler (slide 1 +1), Large capacity Fades in less than 1 second Varies with properties of stimulus (brightness) and background (light vs. dark) 6 1

2 Iconic Duration Segner (1740), Swedish scientist Glowing ember on spinning wheel Increase speed until complete circle seen Calculated time for full revolution to estimate duration of visual sensory register Estimate = 100ms, shorter than some other procedures 7 7 Visual Persistence & Iconic Erikson & Collins (1967) Successive partial displays 8 Items in top two panels shown sequentially Meaningless alone but superimposed images reveal letters VOH Maximum interval at which letters identified Inter-stimulus interval (ISI) of ms Top Display Short Interval Middle Display Image Seen at Short Intervals Estimated Duration of Brief Visual Stimulus Haber & Standing (1970) Estimate duration for flash to fade completely; adjust click to coincide with stimulus on and off Subjects 1 & 2: Diagonal if Perceived = Actual 250 ms estimate for Sensory Register 10 9 Primary Iconic task Early History Multiple letters shown briefly by Cattell (1885) and others to measure Span of Apprehension: How much information can people extract from single glance? Baxt (1871): Subjects reported 4-5 letters from single glance Similar claims about number of objects people can perceive out of brief views of complex displays Cattell had concerns about such estimates Subjects said they saw more items than could report Items faded quickly Sperling Task 10 Sperling Task Display shown briefly () 3, 4, 5, 6, 8, 9, 12, 16 letters Whole Report Participants report 4-5 items, about 38% correct Subjectively, briefly saw more but lost before reported Partial Report AFTER display off, Tone or other signal randomly cues row to report 3 out of 4 or 75% correct for row, therefore.75 X 12 = 9 items in Iconic (+1) Lost after short delay (+2) Partial and Whole Report With immediate cue (No Delay), subjects recalled almost perfectly Partial Report Score = Proportion Correct for Row X Number of Items in Display (e.g., ¾ from cued row X 12 items in display = 9) 2

3 When cue for row delayed even 300 ms (.30 sec), recall lower and closer to whole report value Sperling concluded that complete information in Sensory Register but lost very rapidly Forgetting also due to Masking effect (+1) Partial Report and Decay 13 Masking Effect of Circle Using circle to indicate location masks (i.e., erases) letter at that location Subjects not even aware anything presented in cued position 14 Echoic Errors Echoic (Auditory) Four-eared partial report technique, cued by light Echo lasts longer than icon, perhaps 20 seconds Suffix effect: another sound presented after target masks echoic memory May be cued by category Tactual Issues Sensory may allow time for perception Attention: hearing name Some question usefulness 15 Short-Term Temporary memory 16 Longer than Sensory STM Tasks Free Recall: Recency Span Probe-Digit Task (later) Brown-Peterson Task Present 3-Consonant Trigram B K G Participant counts backward by 3 s Results () Phonological Code Modality effect: auditory > visual Similar sounding letters: confuse G & P more than R & P () Also words: map, man, mad vs cow, day, few Same confusions in STM and listening tasks: BCPTV vs. FMNSX, r =.64 between errors Word length ( +1) STM Storage Format Word Length Effect: Span 18 3

4 Reading Speed span greater for material read more quickly (-1) Articulatory Suppression () Repeat sound Disrupts STM Eliminates word length effect (Baddeley et al, 1975) Storage: Capacity of STM Capacity Amount of information that can be stored in STM Depends on qualities of stimuli: e.g., word length Reading Speed Capacity larger for items that can be read faster Word length, # Syllables, slide 18 Later slides on Culture (Language) & STM Chunking Units can be integrated into Chunks: e.g., letters vs words Miller: hypothesized Chunks, BUT Training & Chunking ( ) 20 Chunking: Binary Digits Can encode binary digits (0, 1) into higher-order units: Octal coding (or higher below) (results +1) =0 001=1 010=2 011=3 100=4 101=5 110=6 111=7 E.g., 18 binary digits: = 6 digits: Span and Chunking Ericsson (1980) 23 4 Subjects practiced digit span task Chunking 1 hr day, 3-5 days a week for 20 months (230 hrs) Digit span increased from 7 to 80, especially for SF & Practice NB: did not generalize to other stimuli SF: cross-country runner grouped numbers into sets of 3-4 digits stored as running times, track races, ages, or significant dates (Yount, p. 76) e.g., 3492 = 3 min 49.2 sec mile, near record STM: Retention & Forgetting Retention duration: about 20 seconds What is forgetting due to? Decay Passage of time Interference By subsequent events Waugh & Norman Probe-Digit task (right) # interfering items critical, rather than time Subtle effect of time? END OF LIST 24 4

5 STM: Retrieval How do we find items in STM? Appears automatic, but Sternberg Scanning Task View memory set: 1-6 letters Probe letter: In memory set? RT for yes or no responses Possible results (F5.4 ) Parallel (A) Serial Self- Terminating (B) Serial Exhaustive (C) Results () 25 Working Baddeley 26 Found that holding items in STM interfered with various cognitive tasks A is before B B A Reading Recall Proposed WM model limited capacity temporary storage that underpins complex thought 4 Components (F5.5 ) WM Span Tasks Visuospatial: e.g., memory for locations of dots on screen WM & SITS Stimulus Independent Thoughts (SITS) Thoughts or images unrelated to task: e.g., daydreaming, rumination, SITS & interfering tasks (Teasdale et al, 1995) Verbal: silly sentences task, Bishops can be bought in shops Visual/Spatial: find hidden figures (above) Stopped at times to ask their thoughts Fewer SITS in both cases Also fewer with less practiced tasks Concluded that Executive implicated in SITS 27 Executive Functioning People with higher WM 28 capacity better able to control cognitive focus! Less susceptible to inattentional blindness Less attention drawn to misleading cues Anti-saccade task () Dichotic listening: hear own name in unattended ear 20% vs 65% Better at reasoning and decision making Less misled by leading questions in eyewitness task WM = STM + Attentional Control Neuroscience of implicates numerous regions of brain Information not stored in specific location Diverse processes involved in memory & forgetting Case Study of H.M. Surgery removed most of hippocampus, amygdala, other temporal lobe areas Could not transfer new memories to LTM (but see later material on Implicit ) Could remember information from years before operation Supports distinction between STM and LTM Frontal Lobes Executive Functioning impaired: distractible, inhibition 29 PET Scan Studies Baddeley WM model Verbal WM: left frontal and parietal lobes Spatial WM: right parietal, temporal, and frontal lobes Supports Baddeley s view of separate components of WM (below, +1) Hebbian Learning, Long-Term Potentiation 30 5

6 31 WM & Frontal Lobes Patients with early Schizophrenia (Sumiyoshi et al, 2013) Report #s in order Individual Differences & Applications Childhood Development STM & WM develop slowly during childhood (F12.4 ) & Metacognitive Ability (Yussen & Levy, 1975) Young children poor judges of how much they will remember on STM tasks () Speech rate (+1) 32 Childhood Development, Speech Rate, and STM - Slow, Medium, and Fast Speakers at each Age (Hulme et al, 1984) STM Retrieval (Sternberg task) Age & Ability (Keating & Bobbitt, 1978) Effects of various individual differences on STM Retrieval (Hunt, 1978) Age: HS vs. Adult Aging: Adult vs Elderly (+1) Ability: Adult/HS vs. Low Ability Adult vs. Mnemonist (parallel?) Culture (Language) & STM 36 Aging, STM, and Chunking (Taub, 1974) 35 Word Length Effect Within & Between languages Languages differ in # syllables in words, numbers, (below) STM and Reading Rate Across Languages (+1) Language Articulation Rate Digit Span Chinese 265 ms/digit 9.9 English 321 ms/digit 6.6 Welsh 385 ms/digit 5.8 (Hoosain & Salili, 1988; Ellis & Hennelly, 1980) 36 # English Arabic Hebrew Chinese 0 Zero Sifer Ef-es Ling 1 One Wahid AH-aht Yee 2 Two Ithinin Shtah-yeem Uhr 3 Three Thalatha Shah-losh Sahn 4 Four Arba a Ar-bah Suh 5 Five Khamsa Hah-mesh Woo 6 Six Sita Sesh Lyo 7 Seven Saba a Sheh-vah Chee 8 Eight Thamania Shmoh-neh Bah 9 Nine Tisa a Tay-shah Jo 6

7 STM and Reading Rate across Languages 37 STM & Education Various ways in which STM relevant to Education 38 Learning to read Poor readers: reduced memory spans, difficulty manipulating phonological information (e.g., given Stop, reply Top) Language comprehension: STM patients, such as TB, have some difficulty comprehending complex sentences e.g. The boys pick the apples OK, but The two boys pick the green apples from the tree impaired 37 General Cognitive Ability STM/WM tasks appear on Ability tests STM/WM correlates with IQ, which correlates with academic success, employment success, and other factors Ackerman et al (2005): meta-analysis, 86 studies, average r =.48 between WM and IQ; higher for aggregate measures (+1) 38 STM and creativity : generation of animal names (+2) Reanalysis of Ackerman et al by Oberauer et al. (r =.85) General Intelligence Articulatory Suppression reduced difference STM / WM & Success Education () 41 Job Performance High STM / WM demand jobs: e.g., Air- Traffic Controller Correlation with job performance (Verive & McDaniel, 1996) Meta-analysis of 11 studies, 34,262 subjects STM predicted performance in job (r =.41) and training (r =.49) STM tests showed smaller racial mean differences than test of general cognitive ability 42 STM / WM & Clinical Psychology STM/WM deficits have 42 been observed in diverse disorders: PTSD Schizophrenia (Kopelowicz et al, 2005) ADHD (Martinussen, 2005) Anxiety (Neubauer, 1999): fail to exclude irrelevant information Deficits in Schizophrenia improve on remission (Kopelowicz et al, 2005) Good STM capacity may provide buffer against other risk factors for alcohol abuse (Finn & Hall, 2004) () 7

8 active process involving encoding, storage, and retrieval Modal approach divides memory into Sensory, Short-Term, and Long-Term STM holds about 7 pieces of information for about 20 seconds without rehearsal Code in STM appears to be acoustic Review 43 Searching STM is serial, exhaustive process New conception of STM is Working, emphasizing its active nature Visuospatial sketchpad Phonological loop Episodic buffer Central executive Brain structures such as hippocampus play role in memory formation Many applications of WM 8