A) Left, the amnesic group (black) was impaired relative to the NC group (gray) overall, responding correctly to a smaller proportion of triads. Middle, a significant interaction in a regression analysis indicated that the amnesic group was relatively more impaired for normatively easy items. Right, the regression analysis revealed no interaction of group with normative solution speed. Whiskers indicate SEM; *, p < 0.05 for relevant contrast or interaction, see main text. B) RT distributions show that the amnesic group responded more slowly than the NC group on average, but both groups responded in <15 sec. (of the 30 sec. response window) during at least 80% of trials. Closed circles show cumulative proportion of response time (RT) and open circles show proportion of response time by bin.