Titre
Investigating a network model of word generation with positron emission tomography.
Type
article
Institution
Externe
Auteur(s)
Friston, K.J.
Auteure/Auteur
Frith, C.D.
Auteure/Auteur
Liddle, P.F.
Auteure/Auteur
Frackowiak, R.S.
Auteure/Auteur
Liens vers les personnes
ISSN
0962-8452
Statut éditorial
Publié
Date de publication
1991
Volume
244
Numéro
1310
Première page
101
Dernière page/numéro d’article
106
Langue
anglais
Notes
Publication types: Journal Article ; Research Support, Non-U.S. Gov'tPublication Status: ppublish
Résumé
By using positron emission tomography (PET) we examined the biological validity of a network model describing changes in cerebral activity associated with intrinsic and extrinsic word generation. The production of words not specified by an extrinsic stimulus constitutes willed or intrinsic generation. Perceiving a heard word is an example of extrinsic generation. The model incorporates three neuronal systems: a pool that stores word representations in a distributed fashion, an afferent system conveying sensory input to the pool and a modulating system that alters the responsivity of neurons in the pool. Simulations based on the model suggested that intrinsic generation would be associated with low activity in the pool, consequent on reduced modulation, and extrinsic generation with high activity. We measured cerebral activity with PET during intrinsic (verbal fluency) and extrinsic (responding to heard words) word generation and found this pattern of changes in the left superior temporal region. We were able to designate this region the site of the distributed word store and implicate the left dorsolateral prefrontal cortex (DLPFC) as the source of modulation. The relation between the superior temporal gyrus and DLPFC was shown by examining the correlation between the two regions in terms of cerebral activity. We conclude that the left DLPFC is responsible for modulating the responsivity of a neural system in the superior temporal gyrus and is the probable mediator of changes in attentional and intentional states that underlies the intrinsic generation of words.
PID Serval
serval:BIB_DE962B5A5486
PMID
Date de création
2011-10-06T16:21:29.554Z
Date de création dans IRIS
2025-05-21T05:12:06Z