Network analysis in episodic encoding and retrieval of word-pair associates: a PET study

Citation
Bj. Krause et al., Network analysis in episodic encoding and retrieval of word-pair associates: a PET study, EUR J NEURO, 11(9), 1999, pp. 3293-3301
Citations number
65
Categorie Soggetti
Neurosciences & Behavoir
Journal title
EUROPEAN JOURNAL OF NEUROSCIENCE
ISSN journal
0953816X → ACNP
Volume
11
Issue
9
Year of publication
1999
Pages
3293 - 3301
Database
ISI
SICI code
0953-816X(199909)11:9<3293:NAIEEA>2.0.ZU;2-4
Abstract
The involvement of distributed brain regions in declarative memory has been hypothesized based on studies with verbal memory tasks. To characterize ep isodic declarative memory function further, 14 right-handed volunteers perf ormed a visual verbal learning task using paired word associates. The volun teers underwent positron emission tomography. O-15-butanol was used as a tr acer of regional cerebral blood flow (rCBF). Inter-regional functional inte ractions were assessed based on within-task, across-subject interregional r CBF correlations. Anatomical connections between brain areas were based on known anatomy. Structural equation modelling was used to calculate the path coefficients representing the magnitudes of the functional influences of e ach area on the ones to which it is connected by anatomical pathways. The e ncoding and the retrieval network elicit similarities in a general manner b ut also differences. Strong functional linkages involving visual integratio n areas, parahippocampal regions, left precuneus and cingulate gyrus were f ound in both encoding and retrieval; the functional linkages between poster ior regions and prefrontal regions were more closely linked during encoding , whereas functional linkages between the left parahippocampal region and p osterior cingulate as well as extrastriate areas and posterior cingulate gy rus were stronger during retrieval. In conclusion, these findings support t he idea of a global bihemispheric, asymmetric encoding/retrieval network su bserving episodic declarative memory. Our results further underline the rol e of the precuneus in episodic memory, not only during retrieval but also d uring encoding.