The mental action or process of acquiring knowledge and understanding through thought, experience, and the senses

Physical exercise
Aerobic and anaerobic exercise have been studied concerning cognitive improvement.^[38] There appear to be short-term increases in attention span, verbal and visual memory in some studies. However, the effects are transient and diminish over time, after cessation of the physical activity.^[39]
Dietary supplements
Studies evaluating phytoestrogen, blueberry supplementation and antioxidants showed minor increases in cognitive function after supplementation but no significant effects compared to placebo.^[40][41][42]
Pleasurable social stimulation
Exposing individuals with cognitive impairment (i.e., Dementia) to daily activities designed to stimulate thinking and memory in a social setting, seems to improve cognition. Although study materials are small, and larger studies need to confirm the results, the effect of social cognitive stimulation seems to be larger than the effects of some drug treatments.^[43]
Other methods
Transcranial magnetic stimulation (TMS) has been shown to improve cognition in individuals without dementia 1 month after treatment session compared to before treatment. The effect was not significantly larger compared to placebo.^[44] Computerized cognitive training, utilising a computer based training regime for different cognitive functions has been examined in a clinical setting but no lasting effects has been shown.