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translate information of research proposal paper into a digital poster. check attachmentSource monitoring in confabulation
Irene P. Kan,1,2 Karen F. LaRocque2 & Mieke Verfaellie2
1Department of Psychology, Villanova University; 2Memory Disorders Research Center, Boston VA Healthcare System and Boston University School of Medicine
BACKGROUND
ACKNOWLEDGMENTS & REPRINTS
This research was funded by National Institutes of Health Grant R01-MH 57681, R01-MH 71783, and the Medical
Research Service of the Department of Veterans Affairs (awarded to MV)
The researchers extend our thanks to the patients for their participation, and H. Branch Coslett, MD, Ginette Lafleche,
PhD, and Marianna Stark, PhD for their assistance in patient recruitment
For a reprint, please email Irene Kan at: irene.kan@villanova.edu
PROCEDURES RESULTS
CONCLUSIONS
Characteristics of confabulation
Are confabulators equally impaired at different types of
source monitoring?
• Statements or actions that are based on apparent distortions of memory
› “Honest lying,” with content often rooted in past events
• Commonly observed in patients with:
› Korsakoff’s syndrome
› Alzheimer’s disease
› Schizophrenia
› Ruptured anterior communicating artery (ACoA) aneurysm
• Potential mechanisms that underlie confabulation:
› Most theories point to some type of failure in cognitive control
» Temporal context confusion (e.g., Dalla Barba, 1993; Schnider, 1996)
» Strategic retrieval failure (e.g., Moscovitch & Melo, 1997; Gilboa, et al, 2006)
» Source monitoring deficits (e.g., Johnson, et al, 1991, 2000)
CURRENT STUDY
Methods
• 56 study trials; 112 trials at test. 5-minute study test break
• 2 sessions, spaced at least three days apart
Item recognition performance
Within each subject group, recognition memory for I/P and S/L tasks is similar
(all pairwise comparisons t < 1)
Corrected recognition
(hits – FAs)
Internal source monitoring task: Imagined vs. Perceived
Encoding task: Indoor or outdoor? Test task: Yes/No recognition
If word only, imagine a sketch of the object Word only
Are confabulators equally impaired at internal and external source
monitoring?
• Lesion reconstruction of a sample patient with ruptured ACoA aneurysm
• Compared to non-confabulators, confabulators are differentially impaired at
internal (I/P) source recognition
» This pattern is consistent with the notion that confabulators’ mental experience tends
to be more vivid, and this increased vividness may contribute to the observed internal
source discrimination impairment
ACoA Confabulators
ACoA Non-Confabulators
Matched controls
Source Monitoring
External: discriminating
between two or more
external sources (e.g.,
person A vs. person B)
Internal: discriminating
between internally generated and
externally generated sources
(e.g., imagined vs. perceived)
PROCEDURES
Confabulation assessment & demographics
• Subjects
› 18 patients with ruptured ACoA aneurysm
» Confabulators & Non-Confabulators are classified based on
medical history and responses on Dalla Barba’s (1993)
Confabulation Battery
› 16 healthy controls, matched on age, education, VIQ
Mean (SD) Age Mean (SD) Edu Mean (SD) VIQ
Confabulators (n = 8)
Non-Confabulators (n = 10)
Controls (n = 16)
61 (14.6)
60 (13.3)
61 (13.0)
13 (2.5)
13 (1.8)
15 (2.5)
99 (11.4)
99 (10.5)
107 (14.3)
External source monitoring task: Spatial location
Encoding task: Indoor or outdoor? Test task: Yes/No recognition
Identify corner Word only
couch
imagined or seen?
how confident are you?
couch
apple
doorknob
if “yes”
hammer
top left or botto
