International Journal of Applied Psychology

p-ISSN: 2168-5010    e-ISSN: 2168-5029

2013;  3(5): 139-147

doi:10.5923/j.ijap.20130305.03

Cognitive Psychology and Bilingualism

Rupashree Brahma Kumari, Anamitra Basu

School of Humanities Social Sciences and Management, IIT Bhubaneswar, Bhubaneswar, 751007, India

Correspondence to: Rupashree Brahma Kumari, School of Humanities Social Sciences and Management, IIT Bhubaneswar, Bhubaneswar, 751007, India.

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Copyright © 2012 Scientific & Academic Publishing. All Rights Reserved.

Abstract

Cognitive psychology explores the internal mental process of human beings. The present paper is aimed at identifying the association between language and cognitive process of the human brain. It is found that using two languages in regular life is not only beneficial to various cognitive developments but also helps in communicating with the contemporary world. This paper also deals with the processing of language in bilinguals and monolinguals. Several experimental or behavioural paradigms have been used and discussed in measuring language process of bilinguals like Dichotic Listening Test, Tachistoscopic Test and Stroop Test. The behavioural paradigms reveal not only the language process of bilinguals and monolinguals but also identify who performs better in cognitive skills. The current paper particularly focuses on examining the benefits of bilingualism, discuss the behavioural paradigms and its applications.

Keywords: Cognitive Psychology, Bilingualism, Behavioural Paradigm, Benefits of Bilingualism

Cite this paper: Rupashree Brahma Kumari, Anamitra Basu, Cognitive Psychology and Bilingualism, International Journal of Applied Psychology, Vol. 3 No. 5, 2013, pp. 139-147. doi: 10.5923/j.ijap.20130305.03.

Article Outline

1. Introduction
2. Language
    2.1. Bilingualism
    2.2. Multilingualism
3. Language and Human Brain
    3.1. Language Centre in Human Brain
    3.2. Hemispheric Involvements in Language
4. Classification of Monolingualism and Bilingualism
    4.1. Benefits of Bilingualism
    4.2. Difficulties of Bilingualism
5. Behavioural Paradigms of Study
6. Studies
7. Discussion
8. Conclusions
ACKNOWLEDGEMENTS

1. Introduction

Cognitive psychology is a dynamic field which scientifically investigates the internal mental process of the human brain such as memory, perception of language, communication, emotion, and attention. Cognitive psychology was first introduced by an American psychologist named Ulric Neisser in his book “Cognitive Psychology”. Neisser has defined, “Cognitive psychology refers to all processes by which the sensory input is transformed, reduced, elaborated, stored, recovered, and used”[80]. Language is an essential function of human cognition. It is associated with mental activities such as thinking about ideas and dealing with emotions and feelings. Various languages are found around the world and the users are categorised according to their uses of languages. Bilingualism has been used by psychologists, neurolinguists, and modern linguists and used in educational programs as it is the best way to educate all types of children in the contemporary world[45] This paper also examines how bilingualism influences cognitive as well as linguistic performances of bilinguals and monolinguals.

2. Language

Language is regarded as “The jewel in the crown of cognition’’[86]. According to Riegler & Riegler, language is defined “as a set of symbols and principles for the combination of those symbols that allows for communication and comprehension”[92]. It shapes our thought and the thought process is connected with language. Total number of languages are spoken around the world is 6000-7000[103],and most of the people can speak two or more languages.

2.1. Bilingualism

Bilinguals refer to individuals who use two languages in their everyday life[52]. Second language users come under this category. Many studies have proved that bilinguals are smarter than monolinguals in relation to insight problem solving task,[77, 29, 85]. Monolingualism has been introduced by Romaine in his book Bilingualism[93]. People who have knowledge of, and use only one language are known as monolinguals or unilinguals. The native language users come under this category[39].

2.2. Multilingualism

Multilingualism is a global phenomenon in the current world. It relates to different fields of studies, namely anthropology, linguistics, psychology and neuroscience[31]. Multilingualism operates in different ways of perceiving the surrounding world, enhancing thought process and ideas[42]. A study on multilingualism not only contributes to social factors but also to learning pattern of adults and children[82]. People who have knowledge of and use more than two languages come under this category. Being multilingual is beneficial in personal and social life, and helpful in higher order problem solving capacity[82].

3. Language and Human Brain

3.1. Language Centre in Human Brain

Human brain is divided into four major areas. The Frontal Lobe is associated with the motor function, memory, planning, reasoning, impulse control, judgment and the area of speech known as Broca’s area for language production. Parietal Lobe is responsible for somatosensory processing of human brain. The Occipital Lobe is related with the visual processing. Lastly, the Temporal Lobe is responsible for auditory processing and Wernicke’s area where the sound images are stored.
Broca’s area and Wernicke’s area: Paul Broca (1864) found that left frontal lobe of the brain is responsible for speech and it was named as Broca’s area. Carl Wernicke (1875) had found that left temporal lobe, located at posterior part of the auditory cortex is responsible for language understanding and is known as Wernicke’s area[72, 97].

3.2. Hemispheric Involvements in Language

Structurally human brain is divided into two hemispheres namely the right hemisphere (RH) and the left hemisphere (LH) and they are structurally and functionally different[72]. Hemispheric lesion deficit researches have been proved that LH is concerned with language, mainly grammar and phonology i.e., speech sound where as RH is associated with the emotional properties of non-verbal stimuli[79].

4. Classification of Monolingualism and Bilingualism

The following criteria have been used to access the behavioural paradigms. Researchers have classified them as- monolingualism, bilingualism and subtypes ofbilingualism[61].
Monolinguals - a person having knowledge and understanding of one language through reading, writing and speaking.
Bilinguals - a person having knowledge and understand ding of at least two languages with the capability of reading, writing and speaking.
Early Bilinguals- Two languages when acquired by the bilinguals earlier than the age of 6 years and hence, both languages of bilinguals are considered L1.
Late Bilinguals- Two languages when acquired by the bilinguals later than the age of 6 years is considered as late bilinguals.
Proficient Bilingual- When bilinguals’ language performances on standard language proficiency exam exceeds 85% accuracy; they are rated as high proficiency.
Non-proficient Bilingual - When the bilinguals do not have the above criteria for proficiency of language, they are categorised under non- proficient.

4.1. Benefits of Bilingualism

Bilingualism is an integral part of our society and knowledge of two languages helps an individual’s overall achievement in the modern world. It turns the human being smarter, intelligent, and has a powerful effect that helps to improve cognitive skills[29]. Ample numbers of studies have concluded that bilinguals are proficient in diverse problem solving activities, and are intelligent, possess creativity, and are cognitively flexible than monolinguals. In early 1962, it is marked that the performances of bilinguals are superior to monolinguals on both verbal and nonverbal intelligence tasks[84]. Furthermore studies have concluded that bilinguals have more metalinguistic understanding[9, 10, 13, 34, 35, 43, 50, 54, 64, 90,102] along with greater conceptual analysis and figurative presentation of skills[3, 5, 7, 24, 34, 51, 68 78]. A study was conducted on hemispheric specialisation among monolinguals and fluent French - English bilingual adults for speeded rhyme and syntactic category matching. The study concluded that, late bilinguals performed better than early bilinguals andmonolinguals[106]. Besides bilinguals also have superior capacity in analysing problems and solving skills because they have greater ability to perceive significant information by ignoring non significant information[ 4, 11, 12, 15, 38, 99]. In addition, bilinguals have greater creativity, innovative thinking ability, and cognitive pliability[19, 58, 73, 90, 98, 54, 63, 75, 76]. In a recent research it was found that bilingual adults have more fluency and flexibility than monolinguals[69].
Bilinguals have more divergent thinking in solving insight problems than monolinguals. In this study the numbers of subjects who participated were classified as, monolinguals - 102, bilinguals- 64 and the following tasks were used - three insights and three non-insights problems. The result found that monolinguals were good at solving the non-insight problems than their own task of insight problems and late bilinguals identified similar performance in these two problems whereas early bilinguals show opposite result that gives advantage in solving insight problems than non-insight problems. The study illustrated that early bilinguals performed better in insight problem solving task than monolinguals. Apart from cognitive advantage of bilingual children, academic and social benefits were also observed, which is the effect of functioning and using of two languages in their everyday life. One can communicate with the persons who would not able to communicate with other society due to the barrier of language. Bilingualism also acts as a mediator when interpretation of other language is done[66].

4.2. Difficulties of Bilingualism

Previously it is believed that bilingualism had negative impact on developing minds, as a consequence the learning of two languages may creating confusion[53]. Research on adult bilinguals and children have manifest that bilingual children are weaker in verbal skills than monolingual groups. For example, in a picture naming task bilinguals are slower than monolingual groups[17, 27, 46, 57, 47, 91]. The bilinguals’ also have slower in comprehending and articulating words, though the words are presented in L1 [89, 65]. Another study pointed out that bilinguals were not strong in their L2 than L1 when using arithmetic digit in word format both (L1 and L2)[44].
Recent study have analysed the effect of bilingualism on letter and category fluency tasks were measured in primary school children. The participants were selected from three cities of Iran, such as Persian monolinguals of Tehran, Turkish–Persian bilinguals of Tabriz, and Kurdish–Persian bilinguals of Sanandaj. The study concluded that bilinguals have both advantage, disadvantage and dissociative effect. Thus the degree of language proficiency of bilinguals is a necessary factor during the measurement of language[71].

5. Behavioural Paradigms of Study

Laterality studies can be done using different paradigms namely dichotic listening technique, dichaptic technique and split visual field technique.
In dichaptic test: Tactual sensations are measured by selectively presenting the subjects with stimuli contralaterally[69].
Split visual field technique: The visual field is divided into left and right so as to measure the hemispheric bias. In split visual field technique, the visual objects are projected laterally. When the objects are presented to the left visual field (LVF), the visual data is transmitted to the RH and when the stimuli are presented to the right visual field (RVF), the visual data is transmitted to the LH. In this technique, the visual field is virtually divided into left and right as if the brain is also divided[72].
Dichotic Listening Technique: In dichotic listening technique when the auditory stimuli are played simultaneously in both ears it reaches both hemispheres through ipsilateral and contralateral pathways[72]. This technique is used to evaluate the accuracy of word recognition through right and left ears. Whereas in visual test the pictures are projected for a short time then the accuracy of correct responses and interval duration are measured.

6. Studies

The study of bilingualism was conducted in the early 1970s, both experimentally and clinically[2, 104, 106]. Basically, earlier studies through the use of dichotic listening paradigm have concluded that the LH is dominant for speech and language[20, 21, 70, 101]. In addition, further studies have been conducted on language laterality in Native American children. Both studies have been administered with dichotic consonant-vowel task. Results concluded that Navajo children are more accurate in identifying left ear stimuli, which refers to the fact the Navajo has greater RH mediation of language, while the Anglo children were more accurate in identifying right ear stimuli, that refers to the greater LH mediation of language[63]. In a visual test, laterality dissimilarity for word identification in bilinguals was examined. The study concluded that LH advantage was observed for processing of both Spanish and English, irrespective of which language was learnt first[110].
Behavioural, neurological and imaging studies have significant role in language process[6]. Researches from variety of areas also proposed that RH is dominant for language processing. Similarly, other studies have documented that RH is relatively more involved in language processing[67]. Current studies have proved that RH is involved in language comprehension[28]. Another study on bilinguals has marked a slower language processing than monolinguals not only in second language L2 but also in first language L1[32, 48]. In clinical evidences researchers have mentioned that both languages of bilinguals are served by the LH in the same area of the monolinguals whereas experimental studies have reported no significant difference in lateralisation between bilinguals and monolinguals[83]. A further study revealed that LH is superior for verbal functions whereas RH is superior for visuospatial abilities configuration based face processing[ 56].
A study was conducted to assess the differential processing efficiency of the cerebral hemispheres in right and left-handed adults by using behavioural laterality tasks with linguistic stimuli. They concluded that, the LH is superior in the task, whereas RH was more involved in reading process[109]. Further study examined the role of RH in the comprehension of speech. The numbers of participants were 78. The result of this experiment showed that, RH supports in comprehension of speech and deals with the intention of the speaker[59]. To investigate the differences between RH and LH a cross modality study (auditory and visual) was conducted, using message-level sentences. 32 right- handed participants used computer based lexical decision task to record reaction time and errors. The result revealed that RH is dominant for message level information in sentences[49]. Recent study showed that emotional words (positive and negative) are processed faster than neutral words[74].
In a study sixty five behavioural studies were compared, with 24 monolingual groups and 51 bilingual groups. The variables of the experimental paradigms are coded as; dichotic listening (DL), visual preferences (V), age of L2 acquisition (early and late) and level of L2 proficiency (proficient and non-proficient). The study concluded that late bilinguals and monolinguals are LH dominant in language tasks regardless of the proficiency[61].
A recent meta-analysis has examined the behavioural laterality studies of the bilinguals and monolinguals. They concluded that early bilinguals have bilateral involvement for both languages, where as monolinguals and late bilinguals have LH dominance for both languages[62]. By using concurrent activities paradigm, a study was conducted on language lateralisation task and the study concluded that, LH superiority is observed in both groups. The total numbers of participants were- 32. Sixteen male bilinguals (Portuguese - English) between ages 20-35 years with a mean of 24.2 years participated; their first language was Portuguese and they first came in contact with English after the age of 12. Similarly other sixteen male monolinguals (English) who participated in this study were between 20-24 years with a mean age of 21.3 years[95]. All participants were strong right handers, as determined by a short questionnaire[22, 81]. The bilingual subjects, who had taken part in the study, were selected for equal and high fluency in Portuguese and English. Their fluency was examined by a questionnaire in which the subjects rated their fluency in reading, writing, speaking and understanding of Portuguese and English. The participants in this study were adult-right handed males (Portuguese- English bilinguals and English speaking monolinguals). The task includes two experiments. In experiment-1, the words of bilinguals of both languages were presented in a mixed blocks. In experiment-2, the words were presented in a separate block. The result also showed that LH is dominance for both groups’ bilingual and monolinguals[95]. Furthermore, a study on Portuguese - English bilinguals and a group of English monolinguals with concurrent activity and time task paradigm was conducted and the result revealed that there were no lateralisation differences among bilinguals and monolinguals[96].
In further study researchers have examined the preferences for English words among native Hebrew speakers by using visual studies. They concluded that LVF superiority was observed in the early bilingual group and the RVF superiority was present in the late bilingual group. The study showed that there is a RH relevant for the early stage of language acquisition[94]. Whereas late bilinguals marked no visual field differences and early bilinguals marked LVF superiority, in semantic task[105]. In addition research on normal adults reported that the RVF advantage is less for concrete words. The findings suggested that concrete words are more prevalent to the RH[23].
A study was conducted on Kannada-English bilingual adults with concrete nouns by using tachistoscopic study. The stimuli were presented bilaterally and the result concluded that subjects responded more words correctly in LVF[8]. A similar study was conducted on abstract and concrete nouns in Kannada with monolingual Kannada adults, with the help of tachistoscopic test. The result revealed that no visual field differences were found in concrete and abstract nouns[88]. Further study on monolingual Kannada children and bilingual Kannada - English children were conducted with a tachistoscopic technique to investigate the hemispheric superiority of either Kannada or English by using concrete nouns from both the languages. Ten monolinguals and bilinguals each were selected who were studying Kannada and English. The subject’s mother tongue was Kannada. Bilingual groups were examined for their fluency, comprehension and expression in the second language English. All participants were right handed. After comparing the monolinguals’ and bilinguals’ performances in the study, the result revealed better performance by monolinguals than bilinguals in first language Kannada. The researcher also found the superiority of LVF compared to the RVF in both monolinguals and bilinguals[25].
Another study concluded that language differences and script differences may depend on the two hemispheric differences[55]. A laterality study on the orthographic (writing and spelling system of language) cue with French-English bilinguals was conducted. For this study sixteen French-English late bilinguals performed a speeded language recognition task on lateralised words that were either marked or unmarked. When the words were presented in the LVF, the response latency was faster to orthographically marked than unmarked words, particularly in second language English. In addition, L2 marked words were responded to, faster than L1 marked words. The study suggested that RH is associated with orthographic cues in recognition of language[108]. A recent study was conducted by using fMRI (Functional Magnetic Resonance Imaging) to identify primary factors that deal with semantic and orthographic processing of bilinguals in Chinese-English bilinguals. The researchers used both tasks, such as Chinese characters (L1) and English words (L2). They concluded that L2 (English) is more responsible for activation for RH than native language (Chinese)[36].
Bilinguals are capable of managing and controlling attention than monolinguals. Research on bilingualism [12, 14, 16, 41] have concluded that, bilingual peers are more prone to attentional control than monolinguals, while performing non verbal and linguistic tasks. The stroop paradigm has been used by many researchers[87]. The paradigm mainly deals with measuring the cognitive control mechanism of bilinguals and monolinguals. It is mainly concerned with attention[100]. Another study insight that bilinguals’ language acquisition status was also responsible for the language lateralisation. The study divides bilinguals as, early bilingual, late bilingual, and monolingual but the researcher tested only late Chinese-English bilinguals with stroop paradigm. The study concluded that LH is dominant for Chinese character processing[85].
Recent research show dissimilar result in semantic processing mechanism due to different language processing of L1 and L2, for e.g. non-literal language or figurative language[37]. Another also study supported that LH produced the activation of both L1 and L2 where as RH is related with the non-literal or figurative language processing of L1 and literal accessible of L2[26. In a hemispheric lateralisation study of Mandarin tone, four groups were tested (Native Mandarin listeners, English–Mandarin bilinguals, Norwegian listeners having experience with Norwegian tone and American listeners having no tone experience) by using dichotic technique to examine or identify which tone they have heard in both ears. They noticed that there is no ear advantage observed in Norwegian or American listeners. They also concluded that LH is dominant for native and proficient bilingual listeners (Mandarin tone) and no lateralisation was found for the non-native listeners, in spite of acquaintance with lexical tone[111].
Another study also mentioned that RH is more dominant for language processing of L2 than L1[1]. Similarly other studies also cited the greater involvement of RH than LH during the processing of language[40]. Furthermore, recent advanced studies such as neuroimaging, Positron-emission Tomography (PET) and functional MRI have reported the dominant of RH in processing of language[33, 18]. Generally it is found that LH is more relevant in understanding and creating verbal language of human brain. Recent study has examined the effect of similarity between languages on hemispheric differences in bilinguals’ brains. This study tested two groups such as, German native speaker (L1) with English as L2 and Italian native speaker (L1) with English as L2. The level of association of LH and RH was measured during language processing both groups with L2. The study examined by dichotic paradigm with words of L1 and L2. The result concluded that LH is dominant in number of responses for both languages and both groups. Moreover the LH was more relevant for processing of English language in German group[30].

7. Discussion

Both the languages (L1 and L2) of bilinguals are not separate, but they co-exist and rely on a common underlying proficiency (CUP). This characteristic will be beneficial for the proficiency in the first language (L1) as well as second language (L2) for bilinguals[45]. Numbers of studies have concluded that cognitive psychology not only reveals the cognitive flexibility of bilinguals in comparison to monolinguals but also language processing of bilinguals and monolinguals[16, 57, 73, 90, 98, 53, 63, 75, 76]. Thus this may be responsible for variation of results among bilinguals and monolinguals.
Other studies have mentioned that during processing of language bilinguals are slower than monolinguals in L1 and L2[32, 48]. Another study mentioned that monolinguals are better performed than bilinguals in L1[22]. These above studies reveal that the age of language acquisition (L1 and L2) may lead to different results among bilinguals and monolinguals. In a study it is found that RH is associated with orthographic cues in recognition of language[108, 36].This may occur due to the particular writing system or style (script) of the language, leads to the different hemispheric involvement of both groups.
Furthermore studies have discussed on the superiority of LVF and RVF regarding the language processing among bilinguals and monolinguals[94, 96, 25]. In addition many evidences on hemispheric involvement on processing of language have showed that some have greater level of language dominance which is observed in LH where as others mentioned dominance of RH among both groups (bilinguals and monolinguals)[66,28,60 ,49,61,96].
On the other hand, studies have also mentioned that there are no lateralisation differences found among bilinguals and monolinguals[83]. Similarly, another study cited that there is no visual field differences were observed among bilinguals and monolinguals[88], which may be attributed to the extraneous variables, such as age, gender, language proficiency, and handedness. Hence these studies have committed inaccuracy in statistical analysis. In a stroop paradigm, it is proved that the characteristics of bilinguals such as early bilinguals or late bilinguals are also related to language processing of bilinguals[85].

8. Conclusions

However by reviewing many evidences in bilingualism and monolingualism, it can be concluded that there are no clear concepts or evidences on hemispheric dominance for language in bilinguals and monolinguals. It is suggested that more researches could be conducted to clarify the hemispheric superiority in LH and RH among bilinguals and monolinguals in language processing.
The current paper also concludes that bilingualism has a significant benefit in cognitive, social and academic areas in comparison to monolinguals. This suggests that future studies should identify the usefulness of these advantages in different fields. Besides, future studies should clarify the characteristics of the participants such as age, gender and language proficiency. Lastly, behavioural paradigms have manifested mixed results on bilingualism and monolingualism.

ACKNOWLEDGEMENTS

I express my special gratitude to Indian Institute of Technology Bhubaneswar for providing support for research. I would like to thank my family and friends for their best support and understanding in publishing this paper in International Journal of Applied Psychology.

References

[1]  Ahlsen, E. (2006). Introduction to Neurolinguistics. Amesterdam: John Benjamins.
[2]  Albert, M., & Obler, L. K. (1978). The bilingualism brain: psychological and neurolinguistic aspects of bilingualism. New York: Academic Press, 157-201.
[3]  Bamford, K. W., & Mizokawa, D. T. (1990). Cognitive development of children in an additive-bilingual program: The third report. Paper presented at the meeting of the American Educational Research Association, Boston, MA.
[4]  Bamford, K. W., & Mizokawa, D. T. (1991). Cognitive and language development in an additive-bilingual program: Report after four observations. Paper presented at the meeting of the American Educational Research Association, Chicago, IL.
[5]  Bamford, K. W., & Mizokawa, D. T. (1992). Spanish - immersion children in Washington State: Fourth year of a longitudinal study. Paper presented at the meetin of the American Educational Research Association, Seattle, WA.
[6]  Banich, M. T. (2002). The divided visual field technique in laterality and interhemispheric integration. In K. Hugdahl Ed. Experimental methods Neuropsychology, Boston: Kluwer.
[7]  Berguno, G., & Bowler, D. M. (2004). Communicative interactions, knowledge of a second language, and theory of mind in young children. Journal of Genetic Psychology, 165, 293-309.
[8]  Bharathi, N. S. (1987). A tachistoscopic on bilingual adults. Unpublished masteral dissertation. University of Mysore, Mysore.
[9]  Bialystok, E. (1987). Words as things: Development of Word Concept by Bilingual Children. Studies in Second Language Acquisition, 9, 133-140.
[10]  Bialystok, E. (1988). Levels of Bilingualism and Levels of Linguistic Awareness. Developmental Psychology, 24, 560-567.
[11]  Bialystok, E. (1999). Cognitive Complexity and Attentional Control in the Bilingual Mind. Child Development, 70, 636-644.
[12]  Bialystok, E. (2001a). Against Isolationism: Cognitive Perspectives on Second Language Research. Selected Proceedings of the Second Language a Research Forum, 97-103.
[13]  Bialystok, E. (2001b). Bilingualism in Development: Language, Literacy, and Cognition. Cambridge, UK: Cambridge University Press.
[14]  Bialystok, E. Craik, F. I. M., Klein, R., & Viswanathan, M. (2004). Bilingualism, Aging, and Cognitive Control: Evidence From the Simon Task. Psychology and Aging, 19, 290-303.
[15]  Bialystok, E. (2005). Consequences of Bilingualism for Cognitive Development. In Kroll, J. F. & De Groot , A. M. B. Eds., Handbook of bilingualism: Psycholinguistic Approaches, 417-432. New York, NY: Oxford University Press.
[16]  Bialystok, E. Craik, F. I. M., & Ryan, J. (2006). Executive Control in a Modified Anti-Saccade Task: Effects of Aging and Bilingualism. Journal of Experimental Psychology: Learning, Memory, and Cognition, 32, 1341-1354.
[17]  Bialystok, E. et al. (2008) Lexical access in bilinguals: effects of vocabulary size and executive control. Journal of Neurolinguisticst, 21, 522–538.
[18]  Birdsong, D. (2006). Age and second language acquisition and processing. In M. Gullberg & P. Indefrey (Eds.), The cognitive neuroscience of second language acquisition (pp. 9-49). USA: Blackwell Publishing
[19]  Braccini, F., & Cianchi, R. (1993). The influence on some linguistic and cognitive skills of the early learning of a foreign language. Rassegna Italiana Di Linguistica Applicata, 25, 53-66.
[20]  Broadbent, D. E. (1954). The Role of Auditory Localization in Attention and Memory Span. Journal of Experimental Psychology, 47, 191-196.
[21]  Bryden, M. P. (1963). Ear preference in auditory perception. Journal of Experimental Psychology, 65, 103-105.
[22]  Bryden, M. P. (1977). Measuring handedness with questionnaires. Neuropyschologia, 15, 617-624.
[23]  Bub, D. N., & Lewine, J. (1988). Different modes of word recognition in the left and right visual fields. Brain and Language, 33, 161-188.
[24]  Chan, K. T. (2005). Chinese-English bilinguals’ theory - of-mind development. Dissertation Abstracts International, Section A: The Humanities and Social Sciences, 65, 10-A.
[25]  Chengappa, S., & Ray, J. (2007). A Tachistoscopic Study of Monolingual and Bilingual Children, Journal of All India Institute of Speech & Hearing, 26, 1-8.
[26]  Cieslicka, A. B., & Heredia, R. (2011). Hemispheric asymmetries in processing L1 and L2 idioms: Effects of salience and context. Brain and Language, 116, 136–150.
[27]  Costa, A. and Santesteban, M. (2004) Lexical access in bilingual speech production: evidence from language switching in highly proficient bilinguals and L2 learners. Journal of Memory and Language. 50, 491–511.
[28]  Coulson, S., Federmeier, K. D., Van Petten, C., & Kutas, M. (2005). Right hemisphere sensitivity to word-and sentence- level context: Evidence from event-related brain potentials, Journal of Experimental Psychology: Learning, Memory and Cognition, 31,129-147.
[29]  Cushen, P. J., & Wiley, J. (2011). Aha! Voila! Eureka Bilingualism and insightful learning. Journal of Learning and Individual differences, 21, 458-462.
[30]  D'Anselmo, A., Reiterer, S., Zuccarini, F., Tommasi, L., & Brancucci, A. (2013). Hemispheric asymmetries in bilinguals: Tongue similarity affects lateralization of second language. Neuropsychologia, 51, 1187-1194.
[31]  Dash, T. Bi/Multilinguallism: Issues and Concerns. Available: http://linguaakshara.org/yahoo_site_admin/assets/docs/Bilingualism_T_Dash.8095523.pdf
[32]  De Groot, A. M. B., Borgwaldt, S. R., Bos, M., & Van den Eijnden, E. (2002). Lexical decision and word naming in bilinguals: Language effects and task effects. Journal of Memory and Language, 471, 91-124.
[33]  Dehaene, D., Dupoux, E., Mehler, J., Cohen, L., Paulesu, E., Perani, D., et al. (1997). Anatomical variability in the cortical representation of first and second languages. Neuro Report, 8, 3809–3815.
[34]  Diaz, R. M. (1985). The intellectual power of bilingualism. Quarterly Newsletter of the Laboratory of Comparative Human Cognition, 7, 16-22.
[35]  Diaz, R. M., & Klinger, C. (1991). Towards an explanatory model of the interaction between bilingualism and cognitive development. In E. Bialystok Ed., Language processing in bilingual children, 167-192. Cambridge, UK: Cambridge University Press.
[36]  Ding, G. Perry, C. Peng, D. Ma, L. Li, D. Xu, S. Luo, Q. Xu, D. & Yang, J. (2003). Neural mechanisms underlying semantic and orthographic processing in Chinese-English bilinguals. Neuroreport,14 (12), 1557-62.
[37]  Dijkstra, T., & van Heuven, W. J. B. (2012). Word recognition in the bilingual brain. The handbook of the neuropsychology of language. Blackwell Publishing Ltd.
[38]  Duncan, S. E. (2005). Child bilingualism and cognitive functioning: A study of four Hispanic groups. Dissertation Abstracts International, A: The Humanities and Social Sciences, 658, 2895–A..
[39]  Ellis, E. (2006). Monolingualism The unmarked case. Estudios de Socialinguistica, 7, 2,173-196Available:www.socialinguitica.uvigo.es/descarge-gratis, asp? Id=201.
[40]  Ellis, R. (2008). The study of second language acquisition (2nd ed). Oxford: Oxford University Press.
[41]  Emmorey, K., Luk, G., Pyers, J. E., & Bialystok, E. (2008). The source of enhanced cognitive control in bilinguals. Psychological Science, 19, 1201-1206.
[42]  European Communities: (2009). Available:http://eacea.ec.europa.eu_llp_studies_documents_study_on_the_contribution_of_multilingualism_to_creativity_compendium_part_1_en.pdf
[43]  Ferdman, B. M., & Hakuta, K. (1985). A population perspective on bilingualism in Puerto Rican children. Paper presented at the meeting of the Society for Research in Child Development, Toronto, Canada.
[44]  Frenck-Mestre, C., & Vaid, J. (1993). Activation of number facts in bilinguals. Memory and Cognition, 21, 809-818.
[45]  Garcia, O. (2009). Bilingual Education in 21st Century: A Global Perspective. Malden, MA and Oxford: Basil/ Blackwell.
[46]  Gollan, T.H. et al. (2005) Bilingualism affects picture naming but not picture classification. Memory and Cognition 33, 1220–1234.
[47]  Gollan, T.H. et al. (2007) The bilingual effect on Boston Naming Test performance. Journal of the International Neuropsychological Society. 13, 197–208.
[48]  Gollan, T. H., Slattery, T. J., Goldenberg, D., Van Assche, E., Duyck, W., & Rayner, K. (2011). Frequency drives lexical access in reading but not in speaking: The frequency-lag hypothesis. Journal of Experimental Psychology: General, 140, 186-209.
[49]  Gouldthorp, B., & Coney, J. (2009). The sensitivity to right hemisphere to contextual information in sentences. Brain and Language, 110, 95-100.
[50]  Goetz, P. J. (2000). A comparison of 3 and 4-year-old English monolinguals, Mandarin monolinguals, andMandarin-English bilinguals on a series of theory of mind-related tasks. Dissertation Abstracts International, B: Sciences and Engineering, 61, 1110–B.
[51]  Goncz, L. (1988). A research study on the relation between early bilingualism and cognitive development.Psychologische Beitrage, 30, 75–91.
[52]  Grosjean, F. (2010). Bilingual: Life and Reality. Cambridge, MA: Harvard University Press.
[53]  Hakuta, K. (1986) Mirror of Language: The Debate on Bilingualism,. New York:Basic Books.
[54]  Hakuta, K. (1990). Bilingualism and bilingual education: A research perspective. Occasional Papers in Bilingual Education, No. 1. Washington, DC: National Clearinghouse for Bilingual Education.
[55]  Hamers, J., and Blanc, M. (2000). Bilinguality andBilingualism. 2nd edition. Cambridge University. Press, Cambridge, UK.
[56]  Hausmann, M., Durmusoglu, G., Yazgan, Y., & Gunturkun, O. (2004). Evidence for reduced hemispheric asymmetries in non-verbal functions in bilinguals. Journal ofNeurolinguistics, 17, 285-299.
[57]  Herna´ndez et al. (2000) In search of the language switch: an fMRIstudy of picture naming in Spanish-English bilinguals. Brain and Language, 73, 421–431
[58]  Ho, D.Y.(1987). Bilingual effects on language and cognitive development: With special reference to Chinese-English bilinguals. Bulletin of the Hong Kong Psychological Society, 18, 61–69.
[59]  Holtgraves, T. (2012). The role of the right hemisphere in speech act comprehension. Brain and Language, 121, 58-64.
[60]  Huber, E., & Lasagabaster, D. (2000). The cognitive effects of bilingualism. ITL, Review of Applied Linguistics 129-130 Aug: 191-224.
[61]  Hull, R., & Vaid, J. (2006). Laterality and Language experience. Laterality, 11, 436-464.
[62]  Hull, R., & Vaid, J. (2007). Bilingual language lateralisation: A meta-analytic tale of two hemispheres. Neuropsychologia, 45, 1987-2008.
[63]  Hynd, G., & Scott, S. (1980). Propositional and appositional modes of thought and differential speech lateralisation in Navajo Indian and Anglo Children. Child Development, 51, 909-911.
[64]  Iannaccone, A., Fraternali, O. T., & Vaccia, R. (1992). Cognitive flexibility and early bilingual education. Rassegna Italiana Di Linguistica Applicata, 24, 149–165.
[65]  Ivanova, I. and Costa, A. (2008) Does bilingualism hamper lexical access in speech production? Acta Psychologica.,127, 277–288.
[66]  Jirage. R. (2012). Benefits of Being Bilingual.Available:http:// www.buzzel.com.
[67]  Joanette, Y., Goulet, P., & Hannequin, D. (1990). Right hemisphere and verbal Communication. New York: Springer-Verlag.
[68]  Johnson, J. (1991). Constructive processes in bilingualism and their cognitive growth effects. In E. Bialystok Ed., Language processing in bilingual children. 193-221. Cambridge, UK: Cambridge University Press.
[69]  Kharkhurin, A. V. (2007). The role of cross-linguistic and cross-cultural experiences in bilinguals’ divergent thinking. In I. Kecskes & L. Albertazzi Eds., Cognitive aspects of bilingualism, 175-210.
[70]  Kimura, D. (1967).Functional asymmetry of the brain in dichotic listening. Cortex 3, 163-178.
[71]  Kormi-Nouri, R., Moradi, A., Moradi, S., Akbari - Zardkhaneh, S., & Zahedian, H. (2012). The effect of bilingualism on letter and category fluency tasks in primary school children: Advantage or disadvantage? Bilingualism: Language and Cognition, 15 (2), 351-364.
[72]  Kolb, B., & Whishaw, I., Q. (2009). Fundamentals of Human Neuropsychology. 6th edition. Worth Publishers; New York.
[73]  Konaka, K. (1997). The relationship between degree of bilingualism and gender to divergent thinking ability among native Japanese-speaking children in the New York Area. Unpublished doctoral Dissertation, New York University.
[74]  Kousta, S., Vinson, D.P., & Vigliocco, G. (2009). Emotional words, regardless of polarity have a processing advantage over neutral words. Cognition, 112 (3), 473-481.
[75]  Kovacs, A. M., & Teglas, E. (2002). Integrating two languages, theories of minds, and executive functions. Odense Working Papers in Language and Communication, 3, 1.
[76]  Kozulin, A. (1999). Reality monitoring, psychological tools and cognitive flexibility in bilinguals: Theoretical synthesis and pilot experimental investigation. Lloyd, Peter (Ed), Fernyhough, Charles (Ed), et al. (1999). Lev Vygotsky: Critical assessment: Future direction, Vol. IV. (187-198). New York, NY, USA: Routlrdge xxviii, 454.
[77]  Martin, D. C., Costa, A., Dering, B., Hoshino N., Thierry, Wu J.Y. (2012). Effects of speed of word processing on semantic access: The case of bilingualism. Journal of Brain and Language, 121, 61-65.
[78]  McLeay, H. (2003). The relationship between bilingualism and the performance of spatial tasks. International Journal of Bilingual Education and Bilingualism, 6, 423–438.
[79]  Nagae, S., & Moscovitch, M. (2002). Cerebral hemispheric differences in memory of emotional and nonemotional words in normal individuals. Neuropsychologia, 40, 1601- 1607.
[80]  Neisser, U. (1967). Cognitive Psychology. New York: Appleton-Century Crofts.
[81]  Oldfield, R. C. (1971). The assessment and analysis of handedness: The Edinburg inventory. Neuropsychologia, 9 (1), 97-113.
[82]  Otwinowska., A., & De Angelis, G. (2012). Introduction: Social and affective factors in multicultural research. International Journal of Multilingualism, 9 (4), 347-351.
[83]  Paradis, M. (1990). Language lateralization in bilinguals: enough already! Brain and Language, 39, 576-86.
[84]  Peal, E., & Lambert, W. E. (1962). The relation of bilingualism to intelligence. Psychological Monographs, 76, 1-23.
[85]  Peng, G., & Wang, W. S. -Y. (2011). Hemispheric lateralisation is influenced by bilingual status and composition of words. Neuropsychologia, 49, 1981-1986.
[86]  Pinker, S. (1994c). The Language Instinct. New York: William Marrow & Co.
[87]  Qiu, J., Luo, Y., Wang, Q., Zhang, F., & Jhang, Q. (2006). Brain mechanism of interference effect in Chinese characters. Brain Research, 1072, 186-193.
[88]  Radhika, P.G. (1987). A tachistoscopic study in Kannada monolingual adults. Unpublished masteral dissertation Speech & Hearing, University of Mysore, Mysore.
[89]  Ransdell,S.E. andFischler, I.(1987) Memory in a monolingual mode: when are bilinguals at a disadvantage? Journal of Memory and Language, 26, 392–405.
[90]  Ricciardelli, L. A. (1993). An investigation of the cognitive development of Italian- English bilinguals and Italian monolinguals from Rome. Journal of Multilingual and Multicultural Development, 14, 345–346.
[91]  Roberts,P.M. et al. (2002) English performance of proficient bilingual adults on the Boston Naming Test. Aphasiology 16, 635–645.
[92]  Robinson- Riegler, G., & Robinson- Riegler, B. (2008). Cognitive Psychology: Applying the Science of the Mind. 2nd edition. New Delhi: Pearson Education.
[93]  Romaine, S. (1995). Bilingualism. 2nd edition. Oxford: Blackwell.
[94]  Silverberg, R., Bentin, S., Gaziel, T., Obler, L., & Albert, M. (1979). Shift to visual field preference for English words in native Hebrew speakers. Brain and Language, 8, 184-190.
[95]  Soares, C., & Grosjean, F. (1981). Left hemisphere language lateralisation in bilinguals and monolinguals. Perception and Psychophysics, 29, 599-604.
[96]  Soares, C. (1984). Left-Hemisphere Language Lateralisation in Bilinguals: Use of the Concurrent Activities Paradigms, Brain and Language, 23, 86-96.
[97]  Solso, R., L. (2001). Cognitive Psychology. 6th edition. New Delhi: Pearson Education
[98]  Srivastava, B. (1991). Creativity and linguistic proficiency. Psycho-Lingua, 21, 105-109.
[99]  Stephens, M. A. (1997). Bilingualism, creativity, and social problem-solving. Dissertation Abstracts International, AAT 9729615.
[100]  Stroop. J. (1935). Studies of interference in serial verbal reactions. Journal of Experimental Psychology. 18, 643-662.
[101]  Studder-Kennedy, M., & Shankweiler, D. (1970). Hemisphere specialisation for speech perception. Journal of the Acoustical Society of America, 48, 579- 594.
[102]  Titone, R. (1997). Early second-language learning: Bilingualism and metalinguistic development. Europe Plurilingue, 12-13, 138-149.
[103]  UNESCO. (2005). First Language First- Based Literacy Programs for Minority Language Context in Asia. Bangkok 10110.
[104]  Vaid, J., & Genesee, F. (1980). Neuropsychological approaches to bilingualism: a critical review. Canadian Journal of Psychology, 34, 417-445.
[105]  Vaid, J. (1984). On Reading on Aphasia in Bilinguals and Polygots. Journals of the History of the Behavioural Sciences, 20, 372-374.
[106]  Vaid, J., & Green, A. (1986). Methodological issues In the Use of the Concurrent Activities Paradigm. Brain and Cognition, 5, 465-467.
[107]  Vaid, J. (1987). Visual Field Asymmetries for Rhymes and Syntactic Category Judgement in Monolinguals and Fluent Early and Late Bilinguals. Brain and Language, 30, 263-277.
[108]  Vaid, J., & Frenck-Mestre, C. (2002). Do orthographic cues aid language recognition? A laterality study with French-English bilinguals. Brain & Language, 82, 47-53.
[109]  Waldie, K. E., & Mosley, J., L. (2000). Hemispheric Specialisation for Reading. Brain and Language, 75, 108-122.
[110]  Walters, J., & Zatorre, R. (1978). Laterality differences for word identification in bilinguals. Brain and Language, 6, 158-167.
[111]  Wang, Y., Behne, M. D., Jongman, A., & Sereno, J. A. (2004). The role of linguistic experience in the hemispheric processing of lexical tone. Applied Psycholinguistics , 25, 449–466.