To determine whether CLN3Δex7/8 miniswine recapitulate the cognitive decline displayed in patients with CLN3 Batten disease (Jalanko and Braulke, 2009; Williams et al., 2006; Lamminranta et al., 2001; Jarvela et al., 1997; Kuper et al., 2018; Adams et al., 2006, 2007), animals were trained in a simple T-maze as previously described (White et al., 2018; Swier et al., 2022). Here, CLN3 is linked to Mental deterioration.