Novelty Processing Depends on Medial Temporal Lobe Structures

Abstract

ObjectivesThe goal of the present study was to identify the role of the medial temporal lobe (MTL) in the detection and later processing of novelty stimuli.MethodsTwenty-one epilepsy patients with unilateral MTL resection (10 left-sided; 11 right-sided) 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. Patients responded to infrequent target stimuli, while ignoring frequent standard, and infrequent novel stimuli that could appear either contra- or ipsilateral to the resected side.ResultsNovelty detection, as indexed by the N2 ERP component elicited by novels, was not affected by the MTL resections. Later processing of novels, however, as indexed by the novelty P3 ERP component, was reduced for novels presented contra-versus ipsilateral to the resected side. Target processing, as indexed by the P3b, was unaffected.ConclusionsThe current results suggest that MTL structures play a role in novelty processing, but that the novelty signal may originate from a distinct neural source.

Modulation of Spectral Representation and Connectivity Patterns in Response to Visual Narrative in the Human Brain

“…The temporal lobe sites, however, responded with broadband power increase to expected chronological flow of Seq images and decrease in power to the unexpected sequence of Scr scenes. These contrasting frontal and temporal responses reinforce our current understanding of their distinct roles in detecting novel events vs encoding episodic memory, respectively ( Ranganath and Rainer, 2003 ; Petrides, 2007 ; Schomaker et al, 2020 ).…”

“…Together, our findings suggest that the cognition of visual narrative may involve both novelty and temporal processing via an intricate network of frontal-temporal signaling ( Tiitinen et al, 1994 ; Petrides, 2007 ; Cohn, 2014 ; Miller et al, 2015 ; Schomaker et al, 2020 ).…”

“…The parietal lobe has higher connectivity to the temporal lobe during Scr vs. Seq (pink arrow). (Tiitinen et al, 1994;Petrides, 2007;Cohn, 2014;Miller et al, 2015;Schomaker et al, 2020).…”