Discussion

6.4.1 Interim discussion for the gating session

In the gating session, the temporal aspect of word processing was investigated. Word processing consists of interactions between top-down processing, such as information about word categories and world knowledge as well as bottom-up processing, such as analyzing the input phonemes and other phonological features. The focus of this session is whether one can recognize word category information of a proper name or a common noun with the provided auditory gates. As the results showed, the percentage of correct answers was not independent of word category. For both 100 ms and 160 ms gates, the percentage of correct answers for the proper name items was not higher than a random distribution; on the contrary it was lower. For both gate lengths, the percentage of correct answers for the common noun items was higher than a random distribution.

Both percentage of correct answers for proper names and common nouns did not follow a random distribution. This implies that the participants did not ‘guess’ the word category by chance but applied some strategies, which could lead to success or failure of the word category judgment task. One can observe that relative to the random value, there were more wrong answers for proper names while there were more correct answers for common nouns. The advantage for common nouns and the disadvantage for proper names were independent from the length of gates. Obviously, the participants were not able to identify word category information within the provided gates, at least for proper names.

As to the accuracy for common noun items, it is somehow difficult to interpret without a control condition. It remains unclear, whether the participants really recognized the presented words as common nouns or whether they just preferred to select the answer common nouns. In the post-experimental interview, some participants indicated that they always guessed common nouns if they did not know how to decide.

On the other hand, one may predict that participants better recognized the words as common nouns than they did as proper names for two reasons, namely, frequency effect and ‘morphological dependence’. Firstly, high frequency of use which

characterizes common nouns may probably explain the observed result. When one is confronted with a phoneme, which is a word initial of several word candidates, the dominant word-cohort with higher frequency of exposure, may lead the ongoing phonological processing. However, the posteriori analysis did not support this point of view. The results showed that there was no correlation between the frequency of the first character of target words and the accuracy of answers. One still must treat this issue with caution since the frequency used for the analysis was related to the written language.

Furthermore, morphological dependence of Chinese proper names on Mandarin Chinese may explain why participants could not recognize proper names at an early point in time. As mentioned in 2.2, Chinese proper names are not morphologically independent, since morphemes from all word categories can be used as proper names.

This dependency may make the word category judgment task for proper names difficult, if there are not enough distinctive phonological or morphological features available in the 160 ms gates. Prosodic features are very important to activate the meaning of the words because Mandarin Chinese is a tonal language. It has been suggested that tonal information can be used to identify word meaning within 200 ms of word onset (Brown-Schmidt & Canseco-Gonzalez, 2004). It has also been revealed that Mandarin Chinese speech and tonal information can be correctly identified with 200 ms gates (Wu & Shu, 2003). However, it is critical if 160 ms from word onset can provide efficient tonal information. The cognitive system is occupied with primary phonological processing and the capacity for interaction between other information, such as meaning, word category, etc. is limited. This approach may explain why English and German speakers are able to recognize word category with 120 ms or 100 ms gates in word category judgment task with the same gating paradigm (Müller & Kutas, 1997; Werner & Müller, 2001) and why Mandarin speakers failed in the same task. 160 ms gates may contain efficient phonological information which is helpful for the judgement of word category for German speakers and English speakers, whereas the same gate length don’t provide enough tonal information for Chinese speakers.

6.4.2 Interim discussion for the visual choice reaction time session

In this session, the reaction time of visual category decision task was measured. As the results show, the reaction time of category decision task differed with word categories.

This holds for both the subject level and item level. However, results of post hoc comparisons of item effect and subject effect were not quite consistent. The test of item effect showed a very clear dissociation between proper names (personal names and geographical names) and common nouns whereas the test of subject effect only

revealed a significant difference in reaction time between personal names and brand names as well as geographical names and brand names.

According to the results, one can clearly observe that brand names function similar to common nouns in the sense of the choice reaction time. In the sense of reaction time, visual brand names may not be categorized as a class of proper names. This holds for the test by subject and the test by item.

Regarding the first hypothesis, which postulates that personal names and common nouns are two distinctive categories, then the item effect (but not the subject effect) supports the dissociation between personal names and common nouns. One may say that the dissociation between personal names and common nouns, in the sense of reaction time, generally exists at the language level and the information of word category can be differentiated by speakers of the language (LSD post hoc comparison supports this view). But the information of word category is probably not the most important element contributing visual word recognition, since the Bonferroni post hoc comparison can not provide convincing evidence.

Regarding the second hypothesis, which postulates that geographical names and common nouns are two distinctive categories, then the item effect (but again not the subject effect) supports the dissociation between personal names and common nouns.

One may say that there is a great difference of the reaction time between geographical names and common nouns at language level since the item effect is significant.

Furthermore, participants may respond faster to geographical names than common nouns, at least for most speakers of Mandarin Chinese.

Regarding the third hypothesis, which postulates that brand names and common nouns are two distinctive categories, then both the test by subject and the test by items failed to provide any indices. The behavior in sense of evoked reaction time in category decision task is similar between brand names and common nouns. Moreover, as predicted, there is no distinctive choice reaction time between personal names and geographical names since they both belong to the class of proper names. This is supported by the test by subject and the test by item.

6.4.3 Interim discussion for the auditory choice reaction time session

In this session, the reaction time of the auditory category decision task was measured.

The main result is that different word categories had a significant effect on the reaction time. This holds for both subject level and item level.

Both the test of subject effect and the test of item effect support the dissociation between personal names and common nouns. Mandarin Chinese speakers can recognize personal names faster than common nouns. Personal names and common

nouns can be classified into two different word categories in the sense of the auditory choice reaction time. The first hypothesis is supported at the language level and at the level of language users.

Also, the dissociation between geographical names and common nouns is supported according to the test of subject effect and the test of item effect. The choice reaction time for spoken Chinese geographical names was faster than the choice reaction time for Chinese common nouns. Both post hoc comparison of subject effect and item effect can not support the view that brand names and common nouns are two distinctive categories. No reaction time difference between was observed between common nouns and brand names. Common nouns and brand names can be classified in the same word category in auditory modality whereas spoken personal names and geographical names can be considered as equivalent due to statistical evidence.

The data of brand names is somehow complicated since there were some inconsistent results between subject effect and item effect. One may still say that grouping brand names and common nouns in the same word category is more plausible, although the more strict statistical analysis does not allow one to make a generalization of this statement.