“…First, an age-dependent decrease of intracortical inhibition may account for the enhanced long-range connectivity in older age. Animal studies on gamma aminobutyric acid (GABA), which is the most important inhibitory neurotransmitter of the brain, have consistently shown an age-related decrease of GABA effectiveness in the auditory pathways (Caspary et al, 1995(Caspary et al, , 1999Ling et al, 2005;Walton et al, 1998Walton et al, , 2002. Similar findings exist for the visual system which also show a decrease of GABA functioning (Liang et al, 2010;Yang et al, 2008).…”