, ▁such ▁as ▁sens ory , ▁cogn itive ▁or ▁motor ▁events . ▁ER P s , ▁when ▁compared ▁to ▁" ment al ▁speed ," ▁have ▁shown ▁a ▁negative ▁correlation ▁with ▁I Q . ▁Research ▁with ▁ER P s ▁suggests ▁that ▁high ▁I Q ▁individuals ▁have ▁a ▁faster ▁response ▁time ▁in ▁some ▁test ▁conditions , ▁have ▁distinguish able ▁ER P ▁wave forms ▁that ▁are ▁different ▁than ▁those ▁of ▁people ▁with ▁lower ▁I Q s , ▁and ▁may ▁have ▁less ▁vari ability ▁in ▁their ▁ER P s . ▁The ▁lack ▁of ▁vari ability ▁suggests ▁that ▁individuals ▁with ▁a ▁high ▁I Q ▁will ▁have ▁good ▁scores ▁in ▁a ▁variety ▁of ▁testing ▁situations . ▁ ▁ER P s ▁can ▁be ▁measured ▁using ▁electro ence phal ography ▁( E EG ), ▁which ▁uses ▁electro des ▁placed ▁on ▁the ▁scal p ▁to ▁measure ▁the ▁elect rical ▁activity ▁of ▁the ▁brain . ▁The ▁ER P ▁wave form ▁itself ▁is ▁constructed ▁from ▁the ▁aver aged ▁results ▁of ▁many ▁tri als ▁( 1 0 0 ▁or ▁more ). ▁The ▁average ▁reduces ▁signal ▁noise ▁from ▁random - bra in ▁activity , ▁leaving ▁just ▁the ▁ER P . ▁An ▁advantage ▁of ▁ER P s ▁are ▁that ▁they ▁measure ▁processing ▁between ▁stim ulus ▁and ▁response ▁continu ously . ▁Having ▁this ▁stream ▁of ▁information ▁makes ▁it ▁possible ▁to ▁see ▁where ▁the ▁brain ' s ▁elect rical ▁activity ▁is ▁being ▁affected ▁by ▁specific ▁stim uli . ▁ ▁Bra in ▁size ▁Using ▁M RI , ▁research ers ▁are ▁able ▁to ▁ac quire ▁vol um et ric ▁measurements ▁of