1. Facilitation in Recognizing Pairs of Words: Evidence of a Dependence between Retrieval Operations By David E. Meyer & Roger W. Schvaneveldt Presented by Zhang Qunxing

2.  Outline:  Research Question and hypotheses  Literature Review  Experiments (2)  Discussion  Serial-decision model  Location-shifting model

3.  Research Question  The present study investigates into the effect of meaning on recognition of pairs of words in lexical decision task.  Hypotheses:  Retrieval operations are separate, successive decisions.  The time taken depends on the associative relation between the two words.

4. Literature Review: semantic factors influencing lexical access  1. Rubenstein et al. (1970)—frequency effect and homograph effect  lexical decision task  Results:  High frequency words < low frequency words  Homographs < nonhomographs  Suggested explanation:  Word frequency affects the order of examining stored words in long-term memory.  More replicas of homographs are stored in long-term memory.  2. Meyer & Ellis (1970) – semantic category effect  semantic decision task  Results:  Smaller category < lexical decision < larger category  Suggested explanation:  Semantic decision involves searching through stored words in the semantic category.

5. Experiments  Task: lexical decision task with two strings of letters on display  yes-no task: yes if both strings are words  same-difference task: same if both strings are either words or nonwords  Procedure: Ready signal (1 sec.) → stimuli display → subject response → interval (2 sec.)  Note: Correct and quick response is encouraged by enforcing penalty on errors and mean RTs longer than 1 sec.

6. Stimuli and Required Response

7. Result Exp. 1: Implication: Degree of association affects lexical decision in the yes-no task.

8. Exp. 2: Exp. 1 VS Exp. 2:

9. Discussion serial-decision model for pair word recognition: separate, successive decisions on the two strings of letters General description:

10.  Explanatory power of the serial-decision model:  1. In yes-no task, Nw-W < W-Nw, Nw-Nw = Nw-W  because only first decision is sufficient when the top string is a nonword.  2. In yes-no task, high error rate for W-Nw pair  because of premature termination of processing after the first decision  3. same-different task RT > yes-no task RT  because same-different task demands comparison of the two decisions.

11.  The time taken to make a lexical decision:  1. to decide that a string is a word: 183 ± 14 msec.  In yes-no task,  T (W-Nw) = T (W) + T (Nw) = 1087 msec.  T (Nw-W) = T (Nw) = 904 msec.  So T (W) = T (W-Nw) – T (Nw-W) = 183 msec.   2. to make a comparison  for “same” decision: 216 ± 68 msec.  for “different” decision: W-Nw RT (same-different task – yes-no task) = 1318–1087 = 231 ± 76 msec.

12.  Operation underlying the decisions: location-shifting model  Words have locations reserved in long-term memory. →  Association effect implies the closer distance between the locations of two associated words. →  Retrieval operation R2 depends on the previous operation R1 – shifting from Location 1 to Location 2.  Explanatory power of location-shifting model:  1. In same-different task, W-Nw < Nw-W.  ∵ Location is preselected to familiar sector (word sector).  ∴ W-Nw involves one major shift:  familiar → unfamiliar  Nw-W involves two major shifts:  familiar → unfamiliar → familiar

13.  2. Schaeffer & Wallace’s studies (1969, 1970) – semantic category decision  Results:  Semantic similarity facilitated “same” response and inhibited “different” response.  Original suggested explanation:  comparing meanings of the words  Revision of the explanation  There are two components in the judgment process: retrieval process (location-shifting) + meaning comparison.

14.  General Conclusion:  No matter what process underlies lexical access, whether it is spread excitation, location shifting, comparison of meanings, or other, there exists association effect in word recognition, which is independent of task type.

15.  Thank you!