Abstract: To explore the unique and unitary of CEF, three CEFs(random generation, selective attention, and memory updating) wereconsidered. Subjects were 31 young adults and 31 old adults. Each subject attended 6 tasks of 2 difficult levels of 3 CEFsand RAVENS test. The results showed that 1) age effect was significant on random generation and memory updating(MU). However, there was no age effect on selectiveattention. 2) The age effect was significant on MUeven if age deficits in FI were controlled. 3) Although different levels had similar ageeffect(a strong all-or-none effect) within each CEF, different CEFsdid not. 4) After FI was statisticallycontrolled,the correlation between different CEF tasks was not significant, but thecorrelation between different levels within each CEF was still significant.These results suggested that the deficit in CEFshould be unique, and at least partially independent of age differences in general FI(referring to result 2, 4); moreover, CEF shouldnotbea unitary system but include separable functions(referring to result 1, 3).

Key words: working memory, central executivefunction, fluid intelligence, age difference