In humans, visuospatial memory begins to decline as early as the mid-30s, yet the mechanisms involved in this phenomenon are poorly understood. Recent research suggests that growth differentiation factor-11 (GDF-11) can have a beneficial impact on cognitive ability in old age. The mechanisms mediating this effect are unclear and there is currently no information regarding potential impact of GDF-11 on cognitive ability in the middle age years. The goal of this thesis was to explore the effects of GDF-11 treatment on the cognitive ability in middle-aged mice. Young mice and middle aged mice were treated with GDF-11 and the impact on short term memory was evaluated. The data showed significant improvement in the performance of visual memory tasks and increased neurogenesis in middle-aged mice. Taken together, these results suggest that GDF-11 is a promising candidate for combating the age-related cognitive decline associated with middle age.