Ling 580ELexical 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):

bear ramen raminbees valley walleyeagle polar polerturtle

• 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):

whale ramen ramin whelelizard valley walley bizardeagle polar poler eigleturtle turple

• 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