The present invention relates to the field of memory and cognitive functions. Here the inventors show that memory stimulations induce autophagy in the mouse hippocampus, while local pharmacological and genetic modulations of hippocampal autophagy strongly influence memory acquisition. More, the inventors observe that hippocampal autophagy declines during aging and they find that restoring autophagy specifically in the hippocampus of aged mice, following autophagy inducers (such as TAT-Beclin-1), can significantly reverse age-related memory decline. Their results reveal a novel physiological role of autophagy in regulating hippocampal-dependent memory functions, and demonstrate the potential therapeutic benefits of modulating autophagy in order to prevent and/or reverse the deleterious effects of aging on cognitive function. The present invention relates to an activator of the autophagy for use in the restoration and/or improvement of cognitive functions in a subject in need thereof.