Interaction between a verbal working memory network and the medial temporal lobe

Abstract

The irrelevant speech effect illustrates that sounds that are irrelevant to a visually presented short-term memory task still interfere with neuronal function. In the present study we explore the functional and effective connectivity of such interference. The functional connectivity analysis suggested an interaction between the level of irrelevant speech and the correlation between in particular the left superior temporal region, associated with verbal working memory, and the left medial temporal lobe. Based on this psycho-physiological interaction, and to broaden the understanding of this result, we performed a network analysis, using a simple network model for verbal working memory, to analyze its interaction with the medial temporal lobe memory system. The results showed dissociations in terms of network interactions between frontal as well as parietal and temporal areas in relation to the medial temporal lobe. The results of the present study suggest that a transition from phonological loop processing towards an engagement of episodic processing might take place during the processing of interfering irrelevant sounds. We speculate that, in response to the irrelevant sounds, this reflects a dynamic shift in processing as suggested by a closer interaction between a verbal working memory system and the medial temporal lobe memory system.

Regional activation of the human medial temporal lobe during intentional encoding of objects and positions

“…However, no significant effect of content was found during preparation or rehearsal stages. These results are inconsistent with previous studies that have implicated distinct roles for MTL regions object and spatial working memory (Stern et al, 2001;Petersson et al, 2006;Olson et al, 2006a,b;Nichols et al, 2006;Axmacher et al, 2007Axmacher et al, , 2008. Such studies have demonstrated a role of the MTL and inferior temporal cortex in active maintenance of novel information.…”

On sense and reference: Examining the functional neuroanatomy of referential processing

“…On the other hand, our results may also partly reflect reciprocal attenuation between lateral prefrontal and parietal regions (e.g., Greicius et al, 2003). Future research will need to address the functional connectivity patterns to uncover interactions between the neural networks involved in different aspects of language comprehension (e.g., Petersson et al, 2006).…”

Bridging Integrator 1 (BIN1) Genotype Effects on Working Memory, Hippocampal Volume, and Functional Connectivity in Young Healthy Individuals

“…Using seeds in the bilateral hippocampus, patients with AD demonstrated markedly reduced functional connectivity with the prefrontal cortex (Allen et al, 2007;Wang et al, 2006). Hippocampal-prefrontal connectivity has been shown to contribute to WM in several functional connectivity studies of fMRI data (Axmacher et al, 2008;Petersson et al, 2006;Rissman et al, 2008). More specifically, evidence suggests that these two regions serve complementary roles during WM processes (Hasselmo and Stern, 2006;Stern et al, 2001).…”