Early Simultaneous Brain Indexes of Phonological, Semantic, and Pragmatic Information Access in Language Understanding and Production

It remains debated whether language comprehension and production rely on shared or modality-specific mechanisms, and whether phonological, semantic, and pragmatic information is accessed sequentially (with opposite orders across modalities) or in parallel. EEG was recorded in healthy native German speakers in a fully crossed design, contrasting comprehension (written words) with production (picture naming) and varying pragmatic function (naming vs. requesting), semantic category (tools vs. animals), and word-initial phonology (place of articulation: labial vs. coronal). ERPs showed an ultra-early main effect of modality at ∼100 msec with no interaction with the three linguistic factors, consistent with perceptual differences between written words and pictures. More importantly, between 100 and 200 msec, ERPs showed a three-way interaction of the factors pragmatics, semantics, and phonology without modality involvement, indicating early modality-independent linguistic processing. In 100- to 200-msec source estimates, no significant PoA-specific clusters were observed, likely due to limited spatial resolution for focal articulatory contrasts. By contrast, pragmatics and semantics showed significant effects: Activity was greater in prefrontal-motor regions for requesting versus naming and for tools versus animals, whereas posterior visual regions showed greater activity for naming versus requesting and for animals versus tools, supporting an early neural signature of pragmatic and semantic processing that was statistically indistinguishable between the two modalities. Modality first entered the effects only at ∼400 msec, possibly reflecting earlier decay in comprehension versus sustained activation for utterance generation in production. Overall, results support parallel, modality-general processing underlying both language comprehension and production.