Novelty processing depends on medial temporal lobe structures

Neurobiology of Learning and Memory, vol. 183, pp. 107464

Abstract

OBJECTIVES: The goal of the present study was to identify the role of the medial temporal lobe (MTL) in the detection and later processing of novelty. METHODS: Twenty-one epilepsy patients with unilateral MTL resection (10 left-sided; 11 right-sided) and 26 matched healthy controls performed an adapted visual novelty oddball task. In this task two streams of stimuli were presented on the left and right of fixation while the patients' electroencephalogram was measured. The participants had to respond to infrequent target stimuli, while ignoring frequent standard, and infrequent novel stimuli that were presented to the left or right, appearing either contra- or ipsilateral to the patients' resections. RESULTS: Novelty detection, as indexed by the N2 ERP component elicited by novels, was reduced by the MTL resections, as evidenced by a smaller N2 for patients than healthy controls. Later processing of novels, as indexed by the novelty P3 ERP component, was reduced for novels presented contra- versus ipsilateral to the resected side. Moreover, at a frontal electrode site, the N2-P3 complex showed reduced novelty processing in patients with MTL resections compared to healthy controls. The ERP differences were specific for the novel stimuli, as target processing, as indexed by the P3b, was unaffected in the patients: No P3b differences were found between targets presented ipsi- or contralaterally to the resected side, nor between patients and healthy controls. CONCLUSIONS: The current results suggest that MTL structures play a role in novelty processing. In contrast, target processing was unaffected by MTL resections.

Authors 7

1. Judith Schomaker corresponding Aachen Faculty of Social Sciences

   Leiden University

   Affiliation as printed

   Faculty of Social Sciences, Leiden University, the Netherlands. Electronic address: judith.schomaker@gmail.com

   Faculty of Social Sciences, Leiden University, the Netherlands

2. M.M.E. Grouls

   Altrecht GGZ

   Affiliation as printed

   GGZ Altrecht, Vesalius Centre for Neuropsychiatry, Woerden, the Netherlands

3. C.G.M. van der Linden Aachen Faculty of Social Sciences

   Leiden University

   Affiliation as printed

   Faculty of Social Sciences, Leiden University, the Netherlands

4. Elias M. B. Rau

   Ruhr University Bochum

   Affiliation as printed

   Department of Psychology, Ruhr University, Bochum, Germany

5. Marc P. H. Hendriks

   Radboud University Nijmegen · Kempenhaeghe · Donders Institute for Brain, Cognition and Behaviour

   Affiliation as printed

   Academic Centre for Epileptology, Kempenhaeghe, Heeze, the Netherlands; Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, the Netherlands

   Academic Centre for Epileptology, Kempenhaeghe, Heeze, the Netherlands

   Donders Institute for Brain, Cognition, and Behaviour, Radboud University, Nijmegen, the Netherlands

6. Albert Colon

   Kempenhaeghe

   Affiliation as printed

   Academic Centre for Epileptology, Kempenhaeghe, Heeze, the Netherlands

7. Martijn Meeter

   Vrije Universiteit Amsterdam

   Affiliation as printed

   Department of Education, VU University, Amsterdam, the Netherlands