Visual word recognition: A dissociation of lexical and semantic processing.

These experiments illustrate two new dissociations in word-recognition tasks. In one, relatedness facilitated lexical decision but impaired searching for a common letter in the same pairs of words (a cross-over interaction between relatedness and task). In the other dissociation, lexicality facilitated performance (words processed faster than nonwords) while relatedness impaired performance (related words processed slower than unrelated words) in the letter search task. Two classes of explanation are discussed. In the first, the perception of relatedness serves to focus attention to the word level, thereby making explicit letter level processing more difficult and/or increasing the number of competing lexical entries via priming. In the second, spreading inhibition makes related words more difficult to process than unrelated words. It is often supposed that the mere presentation of a word is a sufficient condition for the lexical representation of that word to be activated. A further received idea is that there is an obligatory spreading of this activation to related lexical entries. These assumptions form the kernel of what can be called an "automaticity hypothesis " and are important components of a number of theories that assume the existence of