Single-Neuron Responses to Odor-Related Words in the Human Amygdala

Human imaging studies suggest that visually presented words are processed by distributed networks beyond classical language areas, reflecting the properties related to their meanings. Based on human single-neuron recordings, we investigated whether and how the odor aspect of words is processed in mediotemporal lobe regions involved in olfactory perception. We analyzed ensemble activity in response to odor-related versus control words in the piriform cortex, amygdala, hippocampus, entorhinal cortex, and parahippocampal cortex and identified stimulus-responsive and odor-associated neurons. We detected converging evidence for odor-associated responses to words in the amygdala, indicated by increased ensemble activity, and a significant proportion of odor-associated neurons. These findings support and extend the notion that the amygdala integrates information across sensory modalities, allowing for the evaluation of its emotional and social significance.