▁and ▁memory ▁processing , ▁among ▁other ▁cogn itive ▁functions . ▁Moreover , ▁the ▁left ▁and ▁right ▁hal ves ▁of ▁the ▁pre front al ▁cor tex , ▁the ▁hi pp oc amp us , ▁and ▁the ▁c ing ulate ▁cor tex ▁appear ▁to ▁become ▁more ▁function ally ▁inter connected ▁in ▁response ▁to ▁consistent ▁aer ob ic ▁exercise . ▁Three ▁reviews ▁indicate ▁that ▁marked ▁improvements ▁in ▁pre front al ▁and ▁hi pp oc amp al ▁gray ▁matter ▁volume ▁occur ▁in ▁health y ▁adult s ▁that ▁regularly ▁eng age ▁in ▁medium ▁intensity ▁exercise ▁for ▁several ▁months . ▁Other ▁regions ▁of ▁the ▁brain ▁that ▁demonstrate ▁moder ate ▁or ▁less ▁significant ▁g ains ▁in ▁gray ▁matter ▁volume ▁during ▁ne uro im aging ▁include ▁the ▁anterior ▁c ing ulate ▁cor tex , ▁par iet al ▁cor tex , ▁c ere bell um , ▁and ▁nucle us ▁acc umb ens . ▁ ▁Reg ular ▁exercise ▁has ▁been ▁shown ▁to ▁counter ▁the ▁shr inking ▁of ▁the ▁hi pp oc amp us ▁and ▁memory ▁imp air ment ▁that ▁naturally ▁occurs ▁in ▁late ▁ad ul th ood . ▁Sed ent ary ▁adult s ▁over ▁age   5 5 ▁show ▁a ▁ 1 – 2 %   decl ine ▁in ▁hi pp oc amp al ▁volume ▁ann ually . ▁A ▁ne uro im aging ▁study ▁with ▁a ▁sample ▁of ▁ 1 2 0   ad ult s ▁revealed ▁that ▁particip ating ▁in ▁regular ▁aer ob ic ▁exercise ▁increased ▁the ▁volume ▁of ▁the ▁left ▁hi pp oc amp us ▁by ▁ 2 . 1 2