Arrouf, S. , Wens, V. , Goldman, S. , De Tiège, X. & Bertels, J.
ULB Neurosciences Institute, Laboratory of Functional Cerebral Cartography, Université Libre de Bruxelles
Visual statistical learning (VSL) refers to the ability to extract and learn visual patterns in the environment. It is usually measured with post-exposure behavioural tasks, precluding the exploration of ongoing learning processes and limited by a lack of sensitivity. To overcome these biases, the frequency-tagging method has been recently used to study the neural responses mirroring the detection of regularities embedded in auditory (but not visual) streams. Here, we used that technique to evaluate whether frequency-tagged responses can mirror VSL.
Participants (n=10) were first presented with a random stream of twelve shapes (6/s), and then with a statistical stream of the same shapes grouped as triplets (2/s). Their brain activity was recorded with magnetoencephalography. Behavioural tasks were then used to evaluate the implicit vs. explicit nature of their triplet knowledge.
Single shape frequency-related responses were observed during exposure to both streams. Crucially, after exposure to the statistical (vs. random) stream, triplet frequency-related oscillations emerged in occipital areas. Behavioural results suggest that these brain responses occurred in the absence of explicit triplet knowledge.
These findings demonstrate that frequency-tagging is a promising tool for studying VSL, notably in populations in which behavioural tasks cannot provide reliable measures of learning.