Posterior compensatory network in cognitively intact elders with hippocampal atrophy.
Hippocampus
; 25(5): 581-93, 2015 May.
Article
in En
| MEDLINE
| ID: mdl-25475988
ABSTRACT
Functional compensation in late life is poorly understood but may be vital to understanding long-term cognitive trajectories. To study this we first established an empirically derived threshold to distinguish hippocampal atrophy in those with Mild Cognitive Impairment (MCI n = 34) from those with proficient cognition (PRO n = 22), using data from a population-based cohort. Next, to identify compensatory networks we compared cortical activity patterns during a graded spatial working memory (SWM) task in only cognitively proficient individuals, either with (PROATR ) or without hippocampal atrophy (PRONIL ). Multivariate Partial Least Squares analyses revealed that these groups engaged spatially distinct SWM-related networks. In those with hippocampal atrophy and under conditions of basic-SWM demand, expression of a posterior compensatory network (PCN) comprised calcarine and posterior parietal cortex strongly correlated with superior SWM performance (r = -0.96). In these individuals, basic level SWM response times were faster and no less accurate than in those with no hippocampal atrophy. Cognitively proficient older individuals with hippocampal atrophy may, therefore, uniquely engage posterior brain areas when performing simple spatial working memory tasks.
Key words
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Main subject:
Cognitive Dysfunction
/
Spatial Memory
/
Hippocampus
/
Memory, Short-Term
Type of study:
Etiology_studies
/
Incidence_studies
/
Observational_studies
/
Prognostic_studies
/
Risk_factors_studies
Limits:
Aged
/
Aged80
/
Female
/
Humans
/
Male
Language:
En
Journal:
Hippocampus
Journal subject:
CEREBRO
Year:
2015
Document type:
Article
Affiliation country:
Australia