Cortical dynamics of icon perception: effects of concreteness and attractiveness

Icons, as simplified visual symbols, play a key role in visual communication, yet little neuroimaging research has addressed how icons are represented in the brain. We investigated how concreteness and attractiveness modulate the spatiotemporal dynamics of icon processing in a 2 × 2 factorial design in 35 adults using magnetoencephalography. Source-level event-related field (ERF) analysis and representational similarity analysis (RSA) were used to characterize neural responses, with partial RSA isolating each feature's unique contribution after controlling for low-level visual similarity. ERF results showed that concreteness exerted a robust and sustained influence on neural dynamics, with concrete icons eliciting stronger responses than abstract ones from 90 to 1,000 ms, emerging in bilateral occipital cortices and extending to occipitotemporal, temporal, and parietal regions. RSA confirmed concreteness as a representational dimension across processing stages. Attractiveness showed an early but transient effect in occipital and ventral occipitotemporal regions (80 to 130 ms), though this did not survive RSA after controlling for low-level visual property models. A concreteness × attractiveness interaction modulated early occipital and later parietal processing (100 to 185 ms), indicating these features do not operate independently. Our results reveal that semantic content outweighs esthetic appeal in shaping the neural representation of icons.