Schedule of Events | Symposia

Distinct temporal lobe areas modulate language representations in the left inferior frontal gyrus.

Poster Session E - Monday, March 31, 2025, 2:30 – 4:30 pm EDT, Back Bay Ballroom/Republic Ballroom

Benedikt Winzer¹ (benedikt_winzer@urmc.rochester.edu), Rishika Chikoti¹, Madalina Tivarus^2,3, Emma Strawderman¹, Steven Meyers^1,2, Kevin Walter¹, Webster Pilcher^1,4, Bradford Mahon¹, Frank Garcea^1,3,4; ¹Department of Neurosurgery, University of Rochester Medical Center, ²Department of Imaging Sciences, University of Rochester Medical Center, ³Department of Neuroscience, University of Rochester Medical Center, ⁴Del Monte Institute for Neuroscience, University of Rochester Medical Center

The left inferior frontal gyrus (LIFG) is a key area supporting verbal fluency, but its specific functional roles in word production are topics of continued research. Here we test whether the LIFG integrates the outputs of lexical semantic processing and phonological encoding supported by the left anterior temporal lobe (LATL) and left posterior temporal gyrus (LPSTG), respectively. This framework predicts that participants with lesions to the LATL will exhibit weaker functional MRI (fMRI) responses in the LIFG when engaging in a category fluency task, whereas participants with lesions to the LPSTG will exhibit relatively weaker fMRI responses in the LIFG when engaging in a letter fluency task. The prediction was tested via a retrospective analysis of 52 participants with brain tumors who took part in a category fluency and a letter fluency task while undergoing fMRI. We used an atlas-defined LIFG to extract fMRI responses during each task, and lesion-symptom mapping to test which lesion sites were associated with reduced fMRI responses in the LIFG. In support of our hypothesis, we found that participants with lesions involving the LATL exhibited weaker fMRI responses in the LIFG during the semantic fluency task. In contrast, participants with lesions involving the LPSTG exhibited weaker fMRI responses in the LIFG during the letter fluency task. Our finding suggests that left inferior frontal gyrus underlies single word production by integrating semantic and phonological representations prior to word articulation.

Topic Area: LANGUAGE: Semantic