Because GBA1 mutations are frequently associated with cognitive impairment [3, 4], and the phenotypes of the GBA1ΔTT homozygotes are similar to those of previously characterized Drosophila models of neurological dysfunction [19, 20], we tested whether GBA1ΔTT homozygotes also exhibited a cognitive defect. This evidence concerns the gene GBA1 and Cognitive impairment.