title: Self-paced vs. externally paced motor tracking by retarded and nonretarded persons.
abstract: An expectancy hypothesis of the psychological refractory period (PRP) was tested as an alternative to an arousal hypothesis to explain retarded persons' longer reaction times. Retarded adolescents, CA-matched nonretarded adolescents, and MA-matched nonretarded children tracked light stimuli presented under self-paced and externally paced conditions. Response latencies under both conditions were longer for the retarded and MA-matched groups, and all groups decreased latencies from the self-paced to externally paced conditions. Neither hypothesis was supported. We suggested that group differences were due to differences in the central delay effect of the PRP.
mesh_terms: D000293:Adolescent; D001143:Arousal; D006801:Humans; D008607:Intellectual Disability / Q000523:psychology*; D011930:Reaction Time; D012033:Refractory Period, Psychological; D013647:Task Performance and Analysis