In a recent rodent study, top neuroscientists from universities in Beijing, Texas, and Toronto found that “elevation of brain magnesium, by a novel magnesium compound [magnesium-l-threonate (MgT)], enhances synaptic plasticity in the hippocampus and learning and memory” 
Twelve scientists at MIT conducted a study on magnesium-L-threonate and concluded that “an increase in brain magnesium enhances both short-term synaptic facilitation and long-term potentiation and improves learning and memory functions.” 
A study using magnesium-L-threonate to treat Alzheimer’s Disease discovered that “Elevation of Brain Magnesium Prevents and Reverses Cognitive Deficits and Synaptic Loss” 
In Early 2014, two human studies on magnesium-L-threonate will be released to the public.
Science Based Discussion on the Role of MagTein: FREE PDF
Taurine (found in Magnesium Taurate):
Researchers at Tufts University found that "Taurine increased choice reaction time" and "Taurine reversed the effects of caffeine-withdrawal symptoms" 
A recent study on taurine's neuroprotective properties concluded that taurine supplementation "significantly ameliorated the age-dependent decline in spatial memory acquisition and retention" and can "forestall the age-related decline in cognitive functions". 
In Japan, a study of 25 male college students found that "taurine supplementation alleviates visual fatigue induced by visual display terminal (VDT) work" 
Glycine (found in Magnesium Glycinate):
A 2012 study on healthy male volunteers found that "glycine improves daytime sleepiness and fatigue induced by acute sleep restriction" 
A study on individuals with continuous complaints about the quality of their sleep concluded that "glycine ingestion significantly improved the following elements: 'fatigue', 'liveliness and preppiness', and 'clear-headedness'." 
When studying the effects of glycine ingestion before bedtime on volunteers who have been experiencing unsatisfactory sleep, scientists in Japan found that it "improved the volunteers' satisfaction with their sleep, the difficulty of sleep onset, and sleep efficiency"