Microstructure of white matter association tracts in the temporal lobe predicts the timing of electrophysiological activity and behaviour in picture naming

Higher fractional anisotropy in the right inferior fronto-occipital fasciculus is linked to shorter electrophysiological P2 latency, which predicts faster picture-naming response times.

• Why it matters: White-matter microstructure is known to relate to picture-naming accuracy, but its relationship to naming timing and underlying electrophysiological activity is unclear.
• What they did: In individuals of varying age, with or without stroke, diffusion-weighted imaging FA of bilateral temporal-lobe tracts was correlated with mean response times and response-time variability, and with P2 onset latency time-locked to picture onset.
• The result: Path modelling showed FA predicted P2 latency, and P2 latency predicted response times, with P2 sources reconstructed near posterior segments of the right IFOF.