Divergent neural dynamics of multidimensional semantic access for concrete and abstract words

Semantic comprehension requires accessing multiple dimensions of meaning, yet the temporal dynamics of these dimensions remain unclear. Previous research has predominantly examined the neural dynamics of lexical semantics as a whole, which is equivalent to investigating the average of neural dynamics across various dimensions of semantic processing. Here, we analyzed openly released electrocorticography (ECoG) recordings from 9 participants listening to naturalistic stories and used time-resolved encoding models to decompose neural responses into six semantic dimensions: vision, motor, space, time, socialness, and emotion. When analyzing all words together, nearly all dimensions showed a common response peaking around 350 ms. However, when neural dynamics of multidimensional semantic access were analyzed separately for concrete and abstract words, a dissociation in access latencies emerged: for concrete words, sensorimotor dimensions reached peak activation earlier than non-sensorimotor dimensions; whereas for abstract words, the social dimension peaked at 225 ms, earlier than other dimensions. These findings demonstrate that the brain dynamically prioritizes semantic dimensions depending on concept type.