Intracerebral stimulation of left and right ventral temporal cortex during object naming

•Naming impairments were evoked by stimulating left and right VTC.•Naming impairments were more frequent in the left VTC.•No semantic impairments were evoked.•Naming is left lateralized in most subjects.•Left VTC is involved in lexical retrieval rather than in semantic processing.

While object naming is traditionally considered as a left hemisphere function, neuroimaging studies have reported activations related to naming in the ventral temporal cortex (VTC) bilaterally. Our aim was to use intracerebral electrical stimulation to specifically compare left and right VTC in naming. In twenty-three epileptic patients tested for visual object naming during stimulation, the proportion of naming impairments was significantly higher in the left than in the right VTC (31.3% vs 13.6%). The highest proportions of positive naming sites were found in the left fusiform gyrus and occipito-temporal sulcus (47.5% and 31.8%). For 17 positive left naming sites, an additional semantic picture matching was carried out, always successfully performed. Our results showed the enhanced role of the left compared to the right VTC in naming and suggest that it may be involved in lexical retrieval rather than in semantic processing.