Ling 580E Lexical Ambiguity Forster & Hector 2002

Salient Nuggets Semantic features active early in the lexical processing cycle Form “features” active early as well Dense orthographic neighborhoods for non-words have an inhibitory effect on lexical decision (less clear for words)? Within orthographic neighborhoods, semantic features of neighbors can affect a modified lexical decision task

Experiments Task: Is the letter string an animal? Question: Do high-N nonwords take longer to classify than others? Question: Do the semantic features of neighbors have an effect?

Experiment 1 Is the letter string an animal? Experiment 1 materials (differing Ns): bearramenramin beesvalleywalley eaglepolarpoler turtle Results: no effect of N Problem: Lit suggests a intrinsic form-first effect for non-words, irrespective of task

Experiment 2 Is the letter string an animal? Experiment 2 materials (differing Ns): whaleramenraminwhele lizardvalleywalleybizard eaglepolarpolereigle turtleturple Results: nonwords with an animal neighbor did have an effect, but nonwords with nonexamplar neighbor (e.g., cishop) had no effect

Experiment 2 Suggests: Semantic properties of individual neighbors are taken into account prior to decision But, semantically irrelevant candidates do not slow the decision process Thus, semantic context – animal or not – affects RT depending on the semantic features of orthographically similar neighbors

Experiment 3 Is the letter string a word? (lex. decision) Experiment 3 materials:

Experiment 3 Experiment 3 results:

Experiment 4 Is the letter string an animal? Experiment 4 materials:

Experiment 4 Results: high non-N nonwords with an animal neighbor did not take longer to reject than low-N nonwords with an animal neighbor In other words, animal neighbor was the most important variable “..what appears to be happening is that the presence of a single animal neighbor does indeed delay any decision...but only one word needs to be checked. The other neighbors are ignored.”

General Info Some models (e.g., links model) predict form processing before semantic processing: therefore, orthographic neighbors should have an effect irrespective of task (e.g., semantic, lexical decision, etc.) Some models (e.g. cascaded semantic- first) predict salient semantic features will affect task, but form will not (e.g., no non- word N effect in semantic task)

General info Experiments 1,2,4 show that semantic effects are important – non-words with animal neighbors faster than others in a semantic categorization task Experiment 3, however, shows the form is also important – non-words with no neighbors much faster in lexical decision What the results don’t tell us: how early are the semantic effects

Relevance Semantic context relevant