WHAT WE LOSE IN SPEED ​​READING AND NEW EVIDENCE FOR THE EXISTENCE OF A FAST SEMANTIC CODING SYSTEM

The study aims to examine brain mechanisms of speed reading using a new approach. Five stories (about 2200 words) were presented word-by-word to adult participants (n=31) at two speeds (150 ms/word and 500 ms/word) while 306-channel MEG were recorded. Quick comprehension tests confirm that at least main ideas of stories were catched by the participants. Temporal response function (TRF) (Crosse et al, 2014; Brodbeck et al., 2023), was used to correlate of the MEG response with the parameters of the semantic dissimilarity of a word to its preceding context computed using word2vec. The prediction values of the original model were larger than the random one at the parieto-occipital cluster in both conditions within the first 100-150 milliseconds after word presentation. This result confirms the existence of a rapid semantic system found with traditional event-related potential technique (Sysoeva et al., 2007). At the same time, the slower brain processes (latencies of 150-500 ms) traditionally associated with semantic analysis disappear during fast reading. In particular several significant clusters were revealed that showed higher activity in slow conditions (the left temporal region146–222 ms and 358–482 ms, right temporal region 162–314 ms). This work establishes a new standard in the study of the neurobiology of language, combining ecologically sound natural stimuli with advanced analytical methods. The results pave the way for the development of objective neuromarkers for the diagnosis of reading disorders such as dyslexia.

The work is supported by Russian Science Foundation grant №23-78-00011