RT Journal Article SR Electronic T1 Anterobasal Temporal Lobe Lesions Alter Recurrent Functional Connectivity within the Ventral Pathway during Naming JF The Journal of Neuroscience JO J. Neurosci. FD Society for Neuroscience SP 12679 OP 12688 DO 10.1523/JNEUROSCI.0645-13.2013 VO 33 IS 31 A1 Pablo Campo A1 Claudia Poch A1 Rafael Toledano A1 José Manuel Igoa A1 Mercedes Belinchón A1 Irene García-Morales A1 Antonio Gil-Nagel YR 2013 UL http://www.jneurosci.org/content/33/31/12679.abstract AB An increasing amount of evidence supports a crucial role for the anterior temporal lobe (ATL) in semantic processing. Critically, a selective disruption of the functional connectivity between left and right ATLs in patients with chronic aphasic stroke has been illustrated. The aim of the current study was to evaluate the consequences that lesions on the ATL have on the neurocognitive network supporting semantic cognition. Unlike previous work, in this magnetoencephalography study we selected a group of patients with small lesions centered on the left anteroventral temporal lobe before surgery. We then used an effective connectivity method (i.e., dynamic causal modeling) to investigate the consequences that these lesions have on the functional interactions within the network. This approach allowed us to evaluate the directionality of the causal interactions among brain regions and their associated connectivity strengths. Behaviorally, we found that semantic processing was altered when patients were compared with a strictly matched group of controls. Dynamic causal modeling for event related responses revealed that picture naming was associated with a bilateral frontotemporal network, encompassing feedforward and feedback connections. Comparison of specific network parameters between groups revealed that patients displayed selective network adjustments. Specifically, backward connectivity from anterior to posterior temporal lobe was decreased in the ipsilesional hemisphere, whereas it was enhanced in the contralesional hemisphere. These results reinforce the relevance of ATL in semantic memory, as well as its amodal organization, and highlight the role of feedback connections in enabling the integration of the semantic information.