Monolingualism And Bilingualism
Introduction
It is evident that children who grow up in a bilingual household differ in how they process aspects of linguistics from children who grow up in a monolingual household. Differences include how children can distinguish speech sounds, learn novel words, as well as how they recognize languages (Fecher & Johnson, 2018). These differences between monolingual and bilingual infants have been widely researched and recognized. This study instead, focusses on a new area of research addressing the effects of an infant's perception on the non-linguistic aspects of speech and if bilingualism can lead to enhanced performance.
An immense amount of information can be extracted simply from an acoustic speech signal. When we hear speech, we not only obtain the information being said but we also gain indexical information about the talker such as their gender, age, emotional state, etc. (Fecher & Johnson, 2018). It is evident that all humans extract both linguistic and indexical information from speech in a highly advanced way. However, is an infant's ability to process indexical speech information affected by whether they are engaged in highly diverse linguistic experiences or not? One study addressed in the article concluded that monolingual children were outperformed by their bilingual peers in a talker processing task (Fecher & Johnson, 2018).
However, they never addressed when these differences develop in infancy. This study aims to answer the question, when do these differences emerge? This is done by examining the talker recognition abilities of monolingual and bilingual infants by having them perform a face-voice matching task. To even the playing field an unfamiliar language is tested (Spanish). This is because it is already known that listeners often have a hard time identifying the talker in any non-native language. However, if the exposure to highly diverse linguistic experiences in infancy that bilinguals experience improves the processing of indexical speech cues, then monolingual infants should be outperformed by their bilingual peers in identifying a foreign-language talker.
Methodology
For the study, forty-eight infants from the Greater Toronto Area aged 8. 5-9. 5 months old were tested. 93% of the time the monolingual infants were exposed to English (Fecher & Johnson, 2018). While bilingual infants were frequently exposed to at least one other language in their homes since birth and exposed to English only, on average 53% of the time (Fecher & Johnson, 2018). It is important to note that none of the infants participating in the study had any prior experience with Spanish or any Spanish-accented languages. Infant's gender and age were well balanced across the board, and the socioeconomic status (SES) of the participant's families, based on the family's income and parental education showed no differences between the groups (Fecher & Johnson, 2018). The auditory stimuli were comprised of 40 unrelated sentences spoken in Spanish with a neutral tone of voice in an adult-directed manner (Fecher & Johnson, 2018). The visual stimuli provided, comprised of images of two cartoon characters that differed slightly however, looked relatively the same (Fecher & Johnson, 2018). When exposed to the two stimuli, the mouths of the cartoon characters presented would move at the same time as the speech signal, giving the impression that these characters were talking Infants were placed in a booth facing a computer monitor while on their caregiver's lap. The auditory stimuli were played through speakers while the experimenter was outside the booth monitoring the looking behaviour of the infant (Fecher & Johnson, 2018).
To end each trial a blinking red star was shown to center the infant. The next trial would then only begin once the infant was focussed on the star. In order to make sure the caregivers didn't interfere with the infant's performance they wore noise-canceling headphones and listened to music (Fecher & Johnson, 2018). Infants were tested using a version of the switch habituation paradigm (Fecher & Johnson, 2018). First, the infants were shown two voice-face pairings repeatedly) (Fecher & Johnson, 2018). Infants were repeatedly shown the voice-face pairings over time until they lost interest and stopped looking at the characters (Fecher & Johnson, 2018). Infants were then presented with one same test trial (voice A and face A, or voice B and face B), and one switch test trial (face A and voice B, or face B and voice A) (Fecher & Johnson, 2018). In the switch test infants aren't just tested on whether they could distinguish the voices apart, but they were also required to learn the associate voices while alongside being presented faces. If the infants could detect the mismatch then they would become more interested in the switch test and looking time at the visual display would therefore, increase (Fecher & Johnson, 2018).
Results and Discussion
In order to asses the infant's ability to match voices to faces, the mean-looking time between the same trials and switch trials was compared. If the infant's mean-looking time during the switch test trial was longer than the mean-looking time during the same test trial, then it is assumed that the infant recognized the new combination of faces and voices (Fecher & Johnson, 2018). Figure 1 displays the different scores between the monolingual and bilingual groups. This score is calculated by subtracting the looking time during the same trial from the looking time during the switch trial (Fecher & Johnson, 2018). This suggests that the monolinguals could not detect the mismatch of voice-face pairings. Therefore, it was concluded that these infants had a harder time learning to associate unfamiliar faces and voices in an unfamiliar language (Fecher & Johnson, 2018). On the other hand, the bilinguals looked longer at the switch test trials than the same test trials, making their looking time significant. This suggests that the infants could tell there was a mismatch of voice-face parings. Therefore, it was concluded that the bilinguals could remember and identify the perceptual speech cues that distinguish one talker from another (Fecher & Johnson, 2018). To conclude, this study was the first to provide evidence that bilingual exposure in early infancy affects not only the linguistic aspects of the speech signal but the indexical aspect as well. The findings in this study have improved the understanding of the mechanisms that link bilingualism to an infant's linguistic, cognitive, and social development.
Final Thoughts
As expected, it was found that monolingual infants, when it comes to talker recognition in an unfamiliar language are not successful. This complies with previous findings that monolingual infants 7-8 months old can discriminate between talkers in their native language but not in a foreign language (Fecher & Johnson, 2018). The findings that bilingual infants succeed when it comes to talker recognition in an unfamiliar language, supports the hypothesis that bilingualism has an effect on the processing of non-linguistic aspects of speech. So how can these differences in performance on the talker recognition task between monolingual and bilingual infants be explained? There are many possible explanations for the findings in this study that range from being more general to very specific, however nothing was finalized. It is recognized that bilingual infants display advantages in the processing of visual and auditory stimuli well beyond the language domain (Fecher & Johnson, 2018).
Therefore, one possibility is that overall perceptual and cognitive benefits could arise due to exposure to highly diverse linguistic experiences, which could have increased the infant's ability to distinguish the talkers. Bilingual infants also could have had a more effective way of remembering and determining the talker's identity, due to the fact that these infants have more experience using this information to help with distinguishing their native language on a daily basis. Another idea is that bilingualism early in life advances the infant's perceptual attentiveness and improves acoustic sensitivity. It is known that bilingual infants maintain their sensitivity to speech sounds in non-native languages longer than monolingual infants (Fecher & Johnson, 2018).
Therefore, the finding that bilingual infants had a longer total looking time at the switch test trial could be simply due to delayed perceptual narrowing. The focus and results of this study were particularly interesting but extremely vague in explaining why these differences occur. Nothing in this area of the research was finalized and would require additional work in order to be clarified. Ideas for future research could include examining monolinguals and bilingual's performance in specifically a face recognition task to see if bilinguals excel in particularly the visual stimuli aspect of the study. Another study could be to further investigate the role that visual speech cues have in the talker recognition task. An important area of the research that was not answered clearly was when these differences arise.
In order to clarify this area, future research could be done by performing the same test on both monolingual and bilingual infants but this time with a broader range of ages. This way it can be determined if the monolingual infants ever have success in the talker recognition task and maybe they have simply just lost the ability to distinguish talkers earlier than bilinguals. It would also help determine if there is ever a point when the bilingual infants are unsuccessful at the talker recognition task. These are just a few ideas on how one could improve this study and answer the question why more effectively as well as provide more evidence to support the hypothesis that bilingualism has an effect on the processing of non-linguistic aspects of speech. The studies overall focus was very interesting as this area of psychology is becoming more and more relevant. In today's world, bilingualism and multilingualism is much more common than monolingualism. Bilingualism not only opens up many educational opportunities but social opportunities as well. So, understanding the benefits of growing up in a bilingual or multilingual household could encourage more to educate their children in a second language earlier in life.
