Behavioral and brain wave evidence for automatic processing of orthographically regular letter strings

Evidence for the automatic processing of nonword letter strings was sought in subjects who performed two different perceptual tasks. Twelve subjects detected valid words. Twelve other subjects detected Gestalt patterns that contained no letters. The targets and two types of nonword letter strings were interspersed in a stream of nonletter images. Behavioral data showed significant effects of orthographic regularity of letter strings in the group that detected words, but not in the group that detected Gestalt patterns. Brain-wave responses showed the effect of orthographic regularity in both groups. The responses were significantly larger for regular than for irregular strings. This showed that brain waves can be used to study the operation of reading processes in subjects who are performing a task that does not require reading ability.