W ORD R ECOGNITION
4.3 Visual Lexical Decision
4.3.4 Phonological Priming
4.3.4.2 Unmasked Phonological Priming from L1−L2 (Experiment 4A)
Using an unmasked paradigm, Experiment 4A investigated whether there is cross- language phonological priming in Bodo−Assamese bilinguals. The participants made lexical decisions on Assamese words which were preceded either by a phonologically related or an unrelated control Bodo prime.
4.3.4.2.1 Method
Participants.
Fifty-two Bodo−Assamese bilinguals with an average age of 31.3 years (SD = 8.4) from Ganeshpara and IIT Guwahati participated in this and the following phonological priming experiments. However, there was at least a fifteen- day gap between all the experimental sessions. The order of the sessions was also counterbalanced across participants. All of the participants were native speakers of Bodo (L1) who learned Assamese (L2) as a second language at different ages. All of them were right-handed and had normal or corrected-to-normal vision. They completed a Bodo version of the Language Background Questionnaire (see Appendix C (ii)). A summary of participants’ mean proficiencies in Bodo and Assamese are displayed in Table 4.35.Self-reported measures on a 7-point Likert scale showed that speaking, reading, writing, and comprehension skills were rated as being significantly better in Bodo than in Assamese. Moreover, the ratings for Assamese on all four proficiency measures were higher for the high proficient groups than for the low proficient group.
Table 4.35 Self-Report Ratings in Bodo and Assamese for All Three Bilingual Groups in Experiment 4A
Bodo (L1) Assamese (L2)
Early (n =
20)
Late High (n = 17)
Late low (n = 15)
Early (n =
20)
Late High (n = 17)
Late Low (n = 15)
Age of acquisition (years) 2 2 3 3.8 10.7 12
Mean daily usage (%) 52.4 % 50.6 % 49.6 % 37.3 % 37.8 % 19.6 % Self-ratings (7 point
scale)
Speaking 6.5
(0.6)
7 7 6.4
(0.9)
6 (0.9)
5.2
Reading 6.5
(0.6)
7 7 5.8
(0.9)
5.8 (1.0)
3.5 (0.7)
Writing 6.5
(0.6)
6.8 (0.4)
7 5.5
(2.0)
4.2 (1.9)
3
Comprehension 6.2 (0.5)
7 7 4.8
(1.3)
4.5 (2.6)
3 (0.7)
In order to further assess the proficiency levels of the bilinguals, all participants took part in an objective naming test. Table 4.36 provides the mean scores on the objective naming test in both Bodo and Assamese.
Table 4.36 Mean Scores on the Objective Naming Test in Bodo and Assamese for All Three Bilingual Groups in Experiment 4A
Bilingual Group Bodo Assamese
Early High Proficient 53.3 47.4
Late High Proficient 54.1 46.5
Late Low Proficient 53.3 34.3
The results of the Objective Naming Test show that the average L1 score for all three bilingual groups is similar. In case of L2, the average score for the Late High Proficient group matches the average score for the Early High Proficient group (46.5 vs. 47.4 respectively) and the scores do not yield a significant difference [t(49) = 1..01, p = .781]. This indicates that the proficiency level of the two groups is similar.
However, the average score of the Late High Proficient group is noticeably higher
than the average score of the Late Low Proficient group (46.5 vs. 34.3) and the scores yielded a significant difference [t(48) = 8.04, p = .000].
Stimuli.
Twenty Bodo and Assamese word pairs were selected as primes and targets (see Appendix J). Half of the targets were cognate words and the other half were non-cognate words. The cognate and non-cognate words were similar with respect to mean word length and mean frequency. Each Assamese target word (e.g., i [sorai] ‘bird’) was paired with two types of Bodo word primes: (1) a phonologically related prime (e.g., गराय [gorai] ‘horse’), and (2) an unrelated control prime (e.g.,बेसर [besor]‘mustard’) (see Appendix J for complete stimuli list). The phonological relatedness between Assamese targets and Bodo primes was assessed in a norming study (see Appendix E (iv)). In addition to the word targets, twenty nonword targets in Assamese were created which were preceded phonologically related and unrelated Bodo primes. Table 4.37 presents an example of a stimulus set.Table 4.37 Examples of a Stimulus Set Used in Experiment 4A
Cognate Non-cognate
Prime Type Word Nonword Word Nonword
Phonological फोथा−,
“bindi−forehead”
फोथा−, उथुमाय−0,'
“navel−stomach”
उथुमाय−0'
Control जोगोनार−,
“pumpkin−forehead”
जोगोनार−, राव−0,'
“language−stomach”
राव−0'
Note. *फोथा [phwtha]; *, [kopal]; *जोगोनार [zwgwnar], *, [mopal]; *उथुमाय [uthumai];
*0,' [pet]; *राव [rau]; *0' [ghet]
Procedure.
Each participant was tested individually in a quiet room. Instructions were provided in Assamese. The task was to make a lexical decision to the target in Assamese. Participants were instructed to make their decisions as quickly and accurately as possible by pressing the ‘m’ (Yes) or ‘z’ (No) keys in the keyboard. At the beginning of each trial, a fixation sign (+) was presented for 500ms.Subsequently, a prime in Bodo was presented for 100 ms. Finally, an Assamese target was presented. The target remained on the display until the participant made a response or for a maximum of 2,000 ms. Reaction times were measured from target onset until participant’s response. Participants completed fifteen practice trials to familiarize themselves with the task prior to the main experimental trials. The session was divided into two blocks: (1) phonologically related and (2) phonologically unrelated. The order of stimuli within a block was randomized for each participant.
4.3.4.2.2 Results
Outliers were removed and the mean reaction times for correct responses on the Assamese targets and the mean error rates were analyzed using mixed-effects analysis. Table 4.38 presents the mean reaction times and percentage of errors as a function of Prime Type and Cognate Status.
Table 4.38 Mean RTs (ms) and Percentage of Errors for Cognate and Non-Cognate Targets Primed by Phonologically Related and by Unrelated Control Primes in Experiment 4A
Cognate Status
Overall Cognate Non-cognate
Prime Type RT (Error %) RT (Error %) RT (Error %) Cognate effect Phonological 924 (15.4) 949 (20.4) 899 (11.5) −50
Control 876 (12.9) 894 (14.1) 859 (11.5) −35
Priming −48 −55 −40
In the reaction time data, the main effect of Prime Type was marginally significant [F(1,36) = 2.446, p = .18]. However, the priming effect was inhibitive as lexical decisions to the targets primed by phonologically related primes were slower (924 ms) compared to the targets primed by unrelated primes (876 ms). Although,
responses to cognate words (921 ms) were slower than to non-cognate words (879 ms), the main effect of Cognate Status did not approach significance [F(1,36) = 1.926, p = .174]. However, the main effect of Bilingual Group was significant [F(2,49) = 6.165, p = .004]. There was a significant interaction between Cognate Status and Bilingual Group [F(2,1847) = 14.561, p = .000]. The interaction between Prime Type and Bilingual Group was also significant [F(2,1847) = 5.633, p = .004].
The three-way interaction also approached significance [F(2,1847) = 10.427, p = .000].
To evaluate the significant interaction between Bilingual Group and other variables, separate planned interaction contrasts were carried out to assess the phonological priming effects for each of the three Bilingual Groups. In general, the Early High Proficient bilinguals responded to targets significantly faster (812 ms) than the Late High Proficient (920 ms) and Late Low Proficient (968 ms) bilinguals. However, no phonological priming effect was observed for Early High Proficient and Late High Proficient bilinguals. For these bilinguals, phonologically related primes produced inhibition rather than facilitation as compared to unrelated primes. A significant phonological priming effect of 18 ms was evident only for the Late Low Proficient bilinguals, in which participants responded faster to targets that were primed by phonologically related primes (900 ms) compared to unrelated primes (918 ms).
Table 4.39 presents the mean reaction times and percentage of errors as a function of Prime Type, Cognate Status, and Bilingual Group.
Results of the error data did not reveal a main effect of Prime Type [F < 1]. The main effect of Cognate Status approached significance [F(1,36) = 5.734, p = .001].
Non-cognate targets were responded to more accurately as compared to cognate targets. The main effect of Bilingual Group approached significance in the error analysis [F(2,49) = 8.390, p = .000]. Moreover, there was a significant interaction between Cognate Status and Bilingual Group [F(2,1847) = 5.413, p = .000]. For the cognate targets, fewer errors were observed for the Late High Proficient bilinguals than the Late Low Proficient and Early High Proficient bilinguals; on the other hand, for the non-cognate targets, fewer errors were numerous for the early bilinguals as compared to the late bilinguals.