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IC‐P‐043: Neural correlates of the serial position effects in dementia: A voxel‐based morphometry study
Author(s) -
Foldi Nancy,
Kivisaari Sasa,
Monsch Andreas,
Taylor Kirsten
Publication year - 2011
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2011.05.112
Subject(s) - psychology , voxel , audiology , recall , dementia , fluency , verbal fluency test , neural correlates of consciousness , voxel based morphometry , serial position effect , cognition , lingual gyrus , free recall , cognitive psychology , developmental psychology , neuropsychology , neuroscience , medicine , magnetic resonance imaging , white matter , disease , pathology , mathematics education , radiology
Background: PatientswithAlzheimer’s disease (AD) exhibit an impaired serial position effect (SPE) during free recall, whereby fewer initial list items (primacy region) are recalled than end-of-list items (recency region), generating a ‘primacy effect’.We performed a voxel-basedmorphometric studywith healthy and dementia patients to determine the behavioral and neural correlates of the SPE.Methods: 62 controls and 69 patients with AD, mild cognitive impairment and other dementias participated. Behavioral measures: All participants received (a) the California Verbal Learning Test, where percent recall scores were calculated for primacy, middle and recency regions (Trials1-5), and (b) Digits Forward, Digits Backward and Animal fluency to estimate, respectively, phonological loop, working memory, and semantic memory. Voxel BasedMorphometry: 3DT1-weighted images were acquired. Preprocessing and volumetric analyses were conducted with modulated gray matter images using the DARTEL procedure in SPM8 in Matlab. Results: Behavior: Groups differed on overall learning performance (F(1,129) 1⁄4 130.4; p < .001). Patients showed the primacy effect (F(1,68) 1⁄4 13.32; p < .001), and primacy performance was associated with fluency (r 1⁄4 + 401, p < .001) but not attentional performance. Controls showed greater primacy recall than patients (Tukey, p< .001)which correlated withmore digits backward (r 1⁄4 +.304, p 1⁄4.02) and a trend for better fluency performance (r 1⁄4 +.217, p 1⁄4.09). Better recency recall correlated with digits forward only for controls (r 1⁄4 +.252, p < .01). VBM: Over both groups, primacy recall significantly correlated with right middle occipital lobe and angular gyrus regions, including Brodmann’s Area 40, and left middle and medial temporal lobes including the hippocampus. Recency recall was associated with grey matter loss in bilateral parahippocampal cortices, hippocampi, superior temporal gyri and temporal poles. Conclusions: Recency recall was associated with low-level attentional processing and bilateral temporal lobe integrity. Primacy recall was associated with working and semantic memory for controls but only with semantic memory performance in patients, and with temporal and parietal lobe integrity over both groups. These results suggest that higher level attentional skills are required to learn and retain primacy items, which patients lack. Since the parieto-temporal network underpinning the primacy effect is affected early in the course of AD, this measure may serve as a powerful cognitive-biomarker of this disease.