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Late Episodic Memory (EM) effects (and their possible association with weak memory traces). and Age-related effects. Doreen Nessler. David Friedman Ray Johnson, Jr. Michael Bersick Letecia Latif. right frontal EM effect. AF8. 500. 1000. 1500. FPz. FP. FP. 2. 1. AF. AF. 7. 3.
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Late Episodic Memory (EM) effects(and their possible associationwith weak memory traces) and Age-related effects Doreen Nessler David Friedman Ray Johnson, Jr. Michael Bersick Letecia Latif
right frontal EM effect AF8 500 1000 1500 FPz FP FP 2 1 AF AF 7 3 4 8 AF AFz AF F F 7 8 F F F F F F F Hits 5 3 1 Z 2 4 6 Correct Rejections FT FT 7 8 FC FC3 FC FC FC FC FC 5 1 Z 4 2 6 C C C C C C C 5 3 1 Z 2 4 6 LM RM CP2 CP5 CP3 CP1 CP CP4 CP6 Z TP7 TP8 P P P P P P P 5 3 1 Z 2 4 6 P P 7 8 PO PO PO 3 4 PO Z 8 PO7 O O O 1 Z 2 Late Episodic memory (EM) effects Retrieval success (Wilding & Rugg, 1996, 1997; Mecklinger & Meinshausen, 1998) Post-retrieval processes (Allan et al., 1998; Mecklinger, 2000) Monitoring and verification processes (Rugg et al., 2000) Retrieval effort/ Retrieval attempt (Trott, Friedman et al. 1999; Rugg, Otten, & Henson 2002)
Late Parietal Negativity FPz FP FP 2 1 AF Pz AF 7 3 4 8 AF AFz AF 500 1000 1500 F F 7 8 F F F F F F F Hits 5 3 1 Z 2 4 6 Correct Rejections FT FT 7 8 FC FC3 FC FC FC FC FC 5 1 Z 4 2 6 C C C C C C C 5 3 1 Z 2 4 6 LM RM CP2 CP5 CP3 CP1 CP CP4 CP6 Z TP7 TP8 P P P P P P P 5 3 1 Z 2 4 6 P P 7 8 PO PO PO 3 4 PO Z 8 PO7 O O O 1 Z 2 Late Episodic memory (EM) effects (2) Response-related (Wilding & Rugg, 1997) Sensory-specific source search and/or retrieval (Cycowicz, Friedman et al., 2001; Wegesin et al, 2002; Johansson et al., 2002) Late parietal negativity can also reflect action monitoring (Johansson & Mecklinger, 2003)
Late Episodic memory (EM) effects (3) Late right frontal effect: post-retrieval processes Late parietal negativity: retrieval of attribute conjunction, action monitoring Late EM effects signs of Re-encoding?
Left frontal electrode Old High + Old Low 10 μV Frontal negativity Young - 800 1600 2400 Adapted from Friedman, 2003 Aging andLate Episodic memory (EM) effects Elderly no right frontal effect (Senkfor and VanPetten, 1996; Trott, Friedman et al., 1996, 1997; Wegesin et al. 2002) Age-related frontal lobe deficit Young and Elderly similar right frontal effects (Mark and Rugg, 1998; Li, Morcom and Rugg, 2004) Late parietal negativitystronger for the elderly than for the young (Trott, Friedman et al., 1997; Wegesin et al. 2002; Li, Morcom and Rugg, 2004) The eldery rely more on perceptual information Elderly with good memory performance show left frontal negativity (Fabiani, Friedman et. al. 1999, see Friedman, 2003) Successful compensation
Questions and Hypotheses 1.) Late parietal negativity: more prevalent in the data of the elderly? 2.) Late left frontal negativity for the elderly: reflection of compensation? A late frontal negativity is expected for conditions that elicited similar recognition performance in the young and the elderly. 3.) Late EM effects: Re-encoding of items that were difficult to recognize? If late EM effects reflect post-retrieval processes that strengthen the memory trace they are expected to be smaller in a repetition of the recognition test.
ACORN heavy S1 500ms ISI 500ms ACORN CAT FEATHER S2 300ms match? ACORN 300ms OLD:Low Selection NEW FEATHER OLD:High Selection Paradigm Encoding Low Selection High Selection LS no match LS match Repetition of concept old/new Recognition
Repetition Encoding 2 Second encoding for the 120 words from Study 1 Recognition 2 120 OLD words 120 NEW words Design Encoding 1 120 words 60 words High Selection 60 words Low Selection Recognition 1 120 OLD words 120 NEW words
FPz FP FP 2 1 AF AF 7 8 AF AFz AF 3 4 F F 7 8 F F F F F F F 5 3 1 Z 2 4 6 FT FT 7 8 FC FC FC FC FC FC FC 5 3 1 Z 2 4 6 C C C C C C C 5 3 1 Z 2 4 6 LM RM CP CP CP CP CP CP CP 5 3 1 Z 2 4 6 TP TP 7 8 P P P P P P P 5 3 1 Z 2 4 6 P P 7 8 PO PO PO 3 4 PO Z 8 PO 7 O O O 1 Z 2 EEG Methods 62 sintered Ag/AgCl Electrodes Offline re-referred to linked mastoids Recording: DC - 100 Hz 500 Hz sampling rate
n.s. * * Behavioral Results: RecognitionTest 1
Elderly Young Late right frontal EM effect trend Late parietal negativity Hits, HS condition Correct rejection Recognition Test 1 High Selection
Young Elderly Late right frontal EM effect Left frontal negativity Correct rejection Parietal negativity Hits, LS match condition Recognition Test 1 Low Selection match
Elderly Young Late right frontal EM effect Parietal negativity Left frontal negativity Parietal negativity Correct rejection Hits, LS no-match condition Recognition Test 1 Low Selection no-match
n.s. * * Behavioral Results: Recognition Test 1 Test 2
Young Elderly Left frontal negativity Hits, HS condition Correct rejection Recognition Test 2 High Selection
Elderly Young Left frontal negativity Hits, LS condition test 2 Correct rejection Recognition Test 2 Low Selection
Discussion The elderly seem to post-process physical features, while the young seem to work more with abstract information. 1.) Late parietal negativity: more prevalent in the data of the elderly? Late parietal negativity: Reflection of action monitoring? Late frontal negativity does not always seem to reflect successful compensation. 2.) Late left frontal negativity for the elderly: reflection of compensation? Late EM effects seem to reflect re-encoding processes. 3.) Late EM effects: Re-encoding of items that were difficult to recognize?
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