Growing evidence in biomedical sciences ascertains the need of taking into account the underestimated role of inter- and intra-individual variability. Here, we propose a clinical proof-of concept for testing the potential significance of a functional magnetic resonance imaging (fMRI) variability-based approach in a large sample of children with Developmental Dyslexia (DD) and Typical Readers (TRs), with/without a specific deletion in the DCDC2 gene (READ1). Participants performed a visual-perceptual task (full-field sinusoidal gratings) specifically selected to test the contribution of visual streams (notably, the magno- and parvo-cellular streams).

Brain activations were computed using the Variance Design General Linear Model (VDGLM) (Gaut et al. HBM 2019), testing both mean and variance effects of Blood Oxygenation Level Dependent (BOLD) contrast associated with the experimental conditions.

A 2×2 ANOVA on both mean and variance activation beta maps revealed a significant effect of diagnosis (DD vs. TRs) on variance-related responses in the right medial superior temporal area (V5/MT) during the task condition (p = 0.0094), whereas mean-related analyses showed no significant effects (p = 0.4351).

Although further research is need, this proof-of-concept suggests that variability-based approaches can shed light on orthogonal and putatively complementary features that may work synergistically with “classical” average-based approaches, sparking new intriguing insights into the understanding of single individual’s (a)typical neurocognitive profile.