Independency of coding for affective similarities and for word co-occurrences in temporal perisylvian neocortex
This repository accompagnies our paper Independency of coding for affective similarities and for word co-occurrences in temporal perisylvian neocortex. It containes fMRI data and anatomical scans of twenty-two healthy invidividuals. All participants provided informed consent prior to data collection in accordance with experimental procedures approved by Ethics Committee of the University Hospital of Leuven.
Word valence is one of the principal dimensions in the organization of word meaning. Co-occurrence based similarities calculated by predictive Natural Language Processing models are relatively poor at representing affective content, but very powerful in their own way. Here, we determined how these two canonical but distinct ways of representing word meaning relate to each other in the human brain both functionally and neuroanatomically. We re-analysed an fMRI study of word valence. A co-occurrence-based model was used and the correlation with the similarity of brain activity patterns was compared to that of affective similarities. The correlation between affective and co-occurrence-based similarities was low (r = 0.065), confirming that affect was captured poorly by co-occurrence modeling. In a whole-brain representational similarity analysis, word embedding similarities correlated significantly with the similarity between activity patterns in a region confined to the superior temporal sulcus to the left, and to a lesser degree to the right. Affective word similarities correlated with the similarity in activity patterns in this same region, confirming previous findings. The affective similarity effect extended more widely beyond the superior temporal cortex than the effect of co-occurrence based similarities did. The effect of co-occurrence-based similarities remained unaltered after partialing out the effect of affective similarities (and vice versa). To conclude, different aspects of word meaning, derived from affective judgements or from word co-occurrences, are represented in superior temporal language cortex in a neuroanatomically overlapping but functionally independent manner.
Liuzzi, A.G.,* Meersmans, K.,* Storms, G., De Deyne, S., Dupont, P., Vandenberghe, R., (2022). Independency of coding for affective similarities and for word co-occurrences in temporal perisylvian neocortex. Neurobiology of Language (In press)