Neighbourhood frequency effects in visual word recognition and naming

Two experiments are reported that examine the influence of a given word's ortllographic neighbours (orthographically similar words) on the recognition and pronunciation of that word. In Experiment 1 (lexical decision) neighbourhood frequency as opposed to stimulus-word frequency was shown to have a strollg influen ce on recognition Iatencies and errors. Words with at least olle higher.frequency lIeighbour took longer to recognile and resulted in more errors than words with no higher-frequency neighbours. Increasing the number of higher.fre(luency neighbours, however, was shown not to increase interference further. Interference was also shown to be independent of the position of letter change between the stimulus word and its higher-frequency neighbour. In Experiment 2 (word naming), on the other hand, neighbourhood frequency had little effect on pronu llciation latencies to words but these latencies did correlate with total number of orthographic neighbours (independently of their frequency relative to the stimulus word). The results are discussed in terms of processes of activation and competition operating in visual word recognition