Visual overactivation during metaphor processing: A novel mechanistic account of concretism in schizophrenia

Individuals with schizophrenia show well-documented impairment in metaphor comprehension, often exhibiting a bias toward concrete, literal interpretations. While this tendency has traditionally been linked to psychopathological and cognitive factors, the contribution of perceptual processes remains underexplored. Here, we tested the hypothesis that figurative language impairment reflects altered perceptual processing, whereby the visual representations evoked by metaphors remain abnormally active and hinder abstraction. A sample of 143 individuals with schizophrenia and healthy controls was administered a novel paradigm where metaphors (e.g., Wisdom is a flashlight) served as primes for target words related to the metaphor vehicle based on visual (e.g., microphone), action (e.g., remote), or semantic features (e.g., lamp). While in healthy participants metaphors activated semantically associated words, individuals with schizophrenia showed sustained visual priming, emerging 1000 ms after metaphor presentation and persisting up to 1400 ms, with both groups showing reverse priming for action targets. Critically, greater visual priming predicted lower metaphor comprehension in patients, whereas greater semantic priming was correlated with better metaphor skills in controls. These results suggest that visual-perceptual representations are not only overactivated in patients compared to controls during metaphor processing but may also interfere with figurative comprehension. We argue that concretism arises from an imbalance between bottom-up sensory signals and top-down contextual priors, leading to the persistence of the visual representations and impaired abstraction. More broadly, these results support multimodal and predictive accounts of metaphor processing and point to altered perceptual dynamics as a previously unappreciated mechanism contributing to pragmatic impairment in schizophrenia.