Deep language algorithms predict semantic comprehension from brain activity

Charlotte Caucheteux (1, 2, 3) , Alexandre Gramfort (2, 3) , Jean-Rémi King (4)

1 FAIR - Facebook AI Research [Paris]
2 PARIETAL - Modelling brain structure, function and variability based on high-field MRI data
3 MIND - Modèles et inférence pour les données de Neuroimagerie
4 ENS-PSL - École normale supérieure - Paris

Deep language algorithms, like GPT-2, have demonstrated remarkable abilities to process text, and now constitute the backbone of automatic translation, summarization and dialogue. However, whether these models encode information that relates to human comprehension still remains controversial. Here, we show that the representations of GPT-2 not only map onto the brain responses to spoken stories, but they also predict the extent to which subjects understand the corresponding narratives. To this end, we analyze 101 subjects recorded with functional Magnetic Resonance Imaging while listening to 70 min of short stories. We then fit a linear mapping model to predict brain activity from GPT-2’s activations. Finally, we show that this mapping reliably correlates (R=0.50,p<10−15) with subjects’ comprehension scores as assessed for each story. This effect peaks in the angular, medial temporal and supra-marginal gyri, and is best accounted for by the long-distance dependencies generated in the deep layers of GPT-2. Overall, this study shows how deep language models help clarify the brain computations underlying language comprehension.

Mots clés: Neuroscience of language; Deep Neural Networks

Domaines: Intelligence artificielle [cs.AI]; Neurosciences; Informatique et langage [cs.CL]

Charlotte Caucheteux, Alexandre Gramfort, Jean-Rémi King. Deep language algorithms predict semantic comprehension from brain activity. Scientific Reports, 2022, ⟨10.1038/s41598-022-20460-9⟩. ⟨hal-03361426⟩