Alzheimer’s disease (AD) is a neurodegenerative disease and the world leading cause of dementia, yet still no effective treatments are available. Recently, a non-invasive therapy based on 40 Hz gamma stimulation using sensory stimuli (GENUS) showed beneficial effects on memory performances in several AD mouse models and mild probable AD patients. However, mechanisms underlying these positive effects, such as amyloid plaque clearance, microglial activation or gamma rhythm restauration, are still matter of intense debate. Here, we test the alternative hypothesis that GENUS might rescue memory deficits by acting on global brain dynamics, which is known to be early altered in the time course of the disease. We therefore performed high-density EEG recordings on the APPNL-F/MAPT double Knock in (dKI) mouse model, which mimics early preclinical AD, during performance of an associative memory task. Subsequently, we evaluated the impact of chronic visual GENUS (vGENUS) treatment on memory function and global brain dynamics. At 4 months old, dKI mice exhibited first recognition deficits in an object in place memory task. Using EEG microstates and manifold flow analyses, we identified alterations in global brain dynamics associated with these memory impairments, characterized by increased rigidity and reduced complexity. Strikingly, 2 weeks of vGENUS protocol restored memory performances in dKI mice and EEG dynamics. Our results therefore provide new insight into early network dynamic alterations in AD and mechanisms underlying beneficial effect of a non-invasive gamma visual stimulation.