Novelty-related activation within the medial temporal lobes

TY - JOUR

T1 - Novelty-related activation within the medial temporal lobes

AU - Hunkin, N M

AU - Mayes, A R

AU - Gregory, L J

AU - Nicholas, A K

AU - Nunn, J A

AU - Brammer, M J

AU - Bullmore, E T

AU - Williams, S C R

PY - 2002

Y1 - 2002

N2 - Functional magnetic resonance imaging (fMRI) was used to examine whether (1) verbal associative encoding activates the medial temporal lobes (MTL) and related regions more than non-associative encoding. (2) verbal associative novelty is related to enhanced MTL activation, and (3) verbal item novelty is related to enhanced MTL activation and, if so, whether these activations are in different or overlapping sites. No increase in MTL activation was found during verbal associative encoding relative to non-associative encoding, although associative encoding was related to a relative increase in activation in the posterior cingulate cortex. In contrast, verbal associative novelty was found to activate the MTL and posterior cingulate cortex. Verbal item novelty did not significantly activate any brain region. The verbal associative novelty-related effect occurred despite subjects having little awareness of associative novelty. The verbal associative novelty-related activation in the MTL may be related either to unconscious novelty detection or to a priming effect at encoding. We argue that if the priming explanation is correct then this may account for our failure to observe an associative encoding MTL activation. (C) 2002 Elsevier Science Ltd. All rights reserved.

AB - Functional magnetic resonance imaging (fMRI) was used to examine whether (1) verbal associative encoding activates the medial temporal lobes (MTL) and related regions more than non-associative encoding. (2) verbal associative novelty is related to enhanced MTL activation, and (3) verbal item novelty is related to enhanced MTL activation and, if so, whether these activations are in different or overlapping sites. No increase in MTL activation was found during verbal associative encoding relative to non-associative encoding, although associative encoding was related to a relative increase in activation in the posterior cingulate cortex. In contrast, verbal associative novelty was found to activate the MTL and posterior cingulate cortex. Verbal item novelty did not significantly activate any brain region. The verbal associative novelty-related effect occurred despite subjects having little awareness of associative novelty. The verbal associative novelty-related activation in the MTL may be related either to unconscious novelty detection or to a priming effect at encoding. We argue that if the priming explanation is correct then this may account for our failure to observe an associative encoding MTL activation. (C) 2002 Elsevier Science Ltd. All rights reserved.

UR - http://www.scopus.com/inward/record.url?scp=0036129211&partnerID=8YFLogxK

U2 - 10.1016/S0028-3932(01)00200-7

DO - 10.1016/S0028-3932(01)00200-7

M3 - Article

VL - 40

SP - 1456

EP - 1464

JO - Neuropsychologia

JF - Neuropsychologia

IS - 8

ER -