▁to ▁discover ▁why ▁certain ▁neur ons ▁are ▁connected , ▁if ▁they ▁are ▁indeed ▁aligned ▁in ▁a ▁purpose ful ▁manner ▁and ▁consequ ently , ▁how ▁to ▁repair ▁such ▁path ways ▁when ▁they ▁are ▁dam aged . ▁ ▁In ▁general , ▁there ▁have ▁been ▁two ▁types ▁of ▁intelligence ▁studies : ▁psych ometric ▁and ▁bi ological . ▁Bi ological ▁approaches ▁make ▁use ▁of ▁ne uro im aging ▁techniques ▁and ▁examine ▁brain ▁function . ▁Psych omet rics ▁focus es ▁on ▁mental ▁ab ilities . ▁Ian ▁De ary ▁and ▁associ ates ▁suggest ▁that ▁a ▁greater ▁overlap ▁of ▁these ▁techniques ▁will ▁reve al ▁new ▁find ings . ▁ ▁Psych omet rics ▁Psych omet rics ▁is ▁a ▁field ▁of ▁study ▁specifically ▁dedicated ▁to ▁psych ological ▁measurement ▁and ▁involves ▁two ▁main ▁tasks : ▁( i ) ▁construct ing ▁instruments ▁and ▁procedures ▁for ▁measurement ; ▁and ▁( ii ) ▁the ▁development ▁and ▁ref in ement ▁of ▁theoretical ▁approaches ▁to ▁measurement . ▁Bra in - based ▁intelligence ▁tests ▁are ▁concerned ▁with ▁both ▁of ▁these ▁aspects . ▁Modern ▁techniques ▁have ▁evol ved ▁to ▁focus ▁on ▁a ▁few ▁bi ological ▁characteristics : ▁Bra in ▁ER P s , ▁brain ▁size , ▁and ▁speed ▁of ▁neural ▁condu ction . ▁Vari ous ▁instruments ▁have ▁been ▁employed ▁to ▁measure ▁these ▁things . ▁ ▁Bra in ▁event - related ▁potential s ▁( ER P s ) ▁Bra in ▁ER P s ▁allow ▁for ▁the ▁" sequ encing " ▁of ▁psych olog ically ▁interesting ▁processing . ▁These ▁event - related ▁potential s ▁are ▁measured ▁brain ▁responses ▁to ▁specific ▁stim uli