This study examined intelligence-related differences in perceptual pro
cessing in a global/local task. Both mentally retarded and nonretarded
persons processed global information faster than local information. F
urthermore, both groups showed a similar global precedence effect. The
effects of extensive practice at naming local features was also exami
ned. Local processing times became faster for both groups as a result
of local naming practice. The implication of the results are discussed
in the context of global/local processing models as well as processin
g in other interference tasks (e.g., the Stroop task; Stroop, 1935). T
hese results point to the need to assess task and processing parameter
s when extending findings of intelligence-related differences across a
pparently similar tasks.