CHAPTER 4 RESULTS AND DISCUSSIONS
4.4. The Structure of Speech error and Reaction Time: Task 5
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characteristics, and the strength of lexical network for dual inputs would be stronger.
Therefore, the chance of retrieving the wrong lexicon might get higher.
To sum up, table 4-13 is shown to conclude the above linguistic effects we have discussed so far.
Table 4-13. Summary of Linguistic Effects
Effects Saliency
Initialness Salient in number
Rhyme No
Vowel No
Tone Salient
Phonotactic Regularity Salient Syllable Structure Salient
Stroop Effect Salient
4.4. The Structure of Speech error and Reaction Time: Task 5
In order to testify the possible units in lexical process, we conducted shared unit test and observed their processing speed and error amounts. In this experiment, we recruited six sets of carriers which share different phonological units with the target colors, and we asked subjects to name the visual colors instead of reading the characters. Table 4-14 and figure 4-2 show the results of speech errors and response time in shared unit test.
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Table 4-14. The Structure of RT and Errors N in Test 5 (N=376)
Shared Units Onset Vowel Rhyme Syllable Tone Syl.+tone Average RT 5446.30 5435.59 5264.84 4970.58 5470.20 4571.08 5193.09
Errors N 70 78 69 57 65 37 62.7
Percentage 18.62% 20.74% 18.35% 15.16% 17.29% 9.84% 376
Figure 4-2. Response Time and Speech Error in Experiment 3
From the reaction time among the units, tone-sharing unit took the most time for subjects to name the colors (5470.20ms). Onset-sharing unit was similar with vowel-sharing unit (5446.30 and 5435.59 ms respectively). The response time in rhyme-sharing unit was faster, the average span is 5264.84 ms. When subjects reacted to the syllable-sharing trials, the response span fell to 4970.58 ms. The trials whose color and term was tonal syllable-sharing were processed the fastest among these
5446.30 5435.59
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units, which could fasten to 4571.08 ms. In order to examine the target units induced a facilitation or inhabitation effect in lexical process, we need the statistics to testify these possible units.
Table 4-15. One-way ANOVA for Error Counts Among Target Units
Error N F value Mean Df
According to the computed result, the F-ratio (2.35) exceeds f value (2.26), and we could accept the scientific hypothesis that these phonological units could induce significant difference in error amounts [F (5, 172) = 2.35, p<.05]. The total mean value is 4.35, the mean of these units exceed 4.35 is onset, vowel, and rhyme, which indicates that these units induced rather more speech errors. The other units, such as syllable, bare tone, and tonal syllable, induced less speech errors in this test. We need to refer these results to the post-hoc test in table 4-16.
Table 4-16. Post-hoc Analysis for table 4-15 (Scfeffe)
Post-hoc Pairs 2. Vowel 3. Rhyme 4. Syllable 5. Tone 6. Syl.+tone
Note: *, ** are significant at the .05 and .01 levels respectively.
According to the results of post-hoc in table 4-16, we noticed that only the pair
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of onset and tonal syllable were significant different in their error numbers. The other pairs were of no significant difference. As to the results of table 4-15 and 4-16, the unit of initial caused the most speech errors among subjects, and the unit of whole tonal syllable induced the least. Their amounts of speech error achieve to significantly different level.
Generally speaking, if we compare the amount of speech error among these possible units, it appears that phonological unit really affects the error amount significantly. From the point of error amount, we found that tonal syllable could be a facilitative unit in lexical process, while the unit of initial might be an effect of inhabitation. From the results of 4-15 and 4-16, it seems that phonological units affect the process of lexicon, especially when external competition comes in visual channel.
We need to compare the result of error amount to the one of response time in this test.
Table 4-17. One-way ANOVA for RTs Among Target Units
Error N F value Mean Df
According to 4-17, weighted by the factor of shared phonological units, the data of response time shows the value of F value is 1.43, and it reaches to the significance level. We could reject the null hypothesis and accept the scientific hypothesis that different phonological units caused significant difference of reaction time [F(5, 623165)=1.43, p<.05]. Therefore, the result seems to support the research assumption
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that phonological units might cause facilitation effect or inhibition effect to occur in lexical process. Compared with the result in table 4-14, we could say that the tonal syllable-sharing and bare-syllable sharing units could induce the most facilitation in naming task, while bare tone could not. Table 4-18 shows the post-hoc analysis among these target units.
Table 4-18. Post-hoc Analysis for table 4-17 (Scfeffe)
Post-hoc Pairs 2. Vowel 3. Rhyme 4. Syllable 5. Tone 6. Syl.+tone
1. Onset .85 .000** .000** .001** .000**
2. Vowel .000** .000** .000** .000**
3. Rhyme .000** .000** .000**
4. Syllable .000** .000**
5. Tone .000**
Note: *, ** are significant at the .05 and .01 levels respectively.
With the computed result in table 4-18, the difference seems to be more significant than that in error number. Except for the pair of onset and vowel, all of the other pairs appear significant difference in response time. Therefore, we could provide a hierarchy of response time (from fast to slow) among these phonological units, as shown in (1). In addition, we also provide the hierarchy of error number (from few to many) among these units in (2), based on the result in table 4-14 and 4-15.
(1) RT Cost Hierarchy of Phonological Units:
Tonal syllable < syllable < rhyme < vowel< onset < tone.
(2) Error Number Hierarchy of Phonological Units:
Tonal syllable < syllable < tone < rhyme < vowel < onset.
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Tonal syllable is the unit which subjects processed the fastest and induced the fewest errors than all the other units. We could state that tonal syllable induced the most facilitation effect in lexical process. Syllable could be the secondly fastest unit for subjects to process lexicon as well as the unit to produce penultimatly more speech errors among these units. From the statistics above, we found that the mean values of error number and RT were both below the total mean values, and they passed the significant level of one-way ANOVA in table 4-15 and 4-17. The two units induced rather fewer speech errors and processed faster than the other phonological units. We could say that the units of tonal syllable and syllable sharing could be a facilitative effect in lexical encoding.
Rhyme is the thirdly facilitative unit for subjects to encode a lexicon when dual input came in visual channel, but it induced speech errors the third more from the last, which is more than the unit of tone. It seems to be a watershed among these units. In table 4-15 and 4-17, not only the mean values both exceed individual total mean value, but both of them passed the statistic examination. It indicated that the rhyme sharing unit induced more speech errors and more processing time than the average, which could help to judge that rhyme could be an effect of inhabitation, and rhyme-sharing could not help subjects to reduce speech errors significantly.
The unit of vowel was processed slower than the unit of rhyme and it also induced more speech errors than rhyme-sharing trials. The unit of onset was processed the slowest, and it affected subjects to produce rather more speech errors, which is only fewer than the unit of tone. The mean values of vowel and onset do not exceed their total mean values, and it passed the examination of statistics as well, as shown in table 4-15 and 4-17. The results reveal that onset or vowel sharing units could be an effect of inhabitation in lexical process.
The unit of tone seems to be a special status in lexical process. In these
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hierarchies, tone produced the thirdly fewer speech errors, but it was the most halting in RT among all units. It is hard to judge whether tone is a facilitative unit or not from these hierarchies. However, according to above statistic results in 4-15 and 4-17, we found the mean value in error count went below the total mean value, but it exceeded the total mean value of RT the most. It shows that the unit of tone is effective in reducing the number of speech error, but a kind of inhabitation in processing speed. If we regard the hierarchy in (1) and (2) as a continuum, the left side is lexicon-like, and the right side is segment-like. Tone could be attributed to a segment-like unit in error amount, but it should be regarded as a lexicon-like unit in response time. Tone did not have any significant facilitation in speed when subjects processed tone-sharing in trials, but it could generate more precise and correct lexicon than the units of rhyme, vowel, and onset. Even though tone did not affect as great as the unit of syllable, it still appears a certain of lexical quality. The possible account is that tone might be a lexical organization and encoded in phonological representation, not a pure phonological tone. If it is a phonological tone, the patterns of error number should act as the phonological units of onset, vowel, and rhyme. Therefore, the status of tone seems to support the proposal of Wan & Jaeger (1998) and Wan (2007) that tone is a phonological organization of a lexicon. The following table is the summary among these phonological units.
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Table 4-19. Summary of Phonological Units
Units Criteria Effect
Onset
Bare Tone Error N Facilitation
RT Inhabitation
Syllable Error N Facilitation
RT Facilitation
Tonal Syllable
Error N Facilitation
RT Facilitation