Neurological considerations

One of the most promising areas of inquiry in age and acquisition research has been the study of the function of the brain in the process of acquisition. How might neurological development affect second language suc­cess? Does the maturation of the brain at some stage spell the doom of language acquisition ability?

Hemispheric Lateralization

Some scholars have singled out the lateralization of the brain as the key to answering such a question. There is evidence in neurological research that as the human brain matures, certain functions are assigned, or "lateralized," to the left hemisphere of the brain, and certain other functions to the right hemisphere. Intellectual, logical, and analytic functions appear to be largely located in the left hemisphere, while the right hemisphere controls functions related to emotional and social needs. Language functions appear to be controlled mainly in the left hemisphere, although there is a good deal of conflicting evidence. For example, patients who have had left hemi-spherectomies have been capable of comprehending and producing an amazing amount of language. But in general, a stroke or accident victim who suffers a lesion in the left hemisphere will manifest some language impairment, which is less often the case with right hemisphere lesions.

While questions about how language is lateralized in the brain are interesting indeed, a more crucial question for second language researchers has centered on when lateralization takes place, and how that lateralization process affects language acquisition. Eric Lenneberg (1967) and others sug­gested that lateralization is a slow process that begins around the age of two and is completed around puberty. During this time the child is neurologically assigning functions little by little to one side of the brain or the other; included in these functions, of course, is language. And it has been found that children up to the age of puberty who suffer injury to the left hemisphere are able to relocalize linguistic functions to the right hemi­sphere, to "relearn" their first language with relatively little impairment. Thomas Scovel (1969) extended these findings to propose a relationship between lateralization and second language acquisition. He suggested that the plasticity of the brain prior to puberty enables children to acquire not only their first language but also a second language, and that possibly it is the very accomplishment of lateralization that makes it difficult for people to be able ever again to easily acquire fluent control of a second language, or at least to acquire it with what Alexander Guiora et al. (1972a) called "authentic" (nativelike) pronunciation.

While Scovel's (1969) suggestion had only marginal experimental basis, it prompted him (Scovel 1988) and other researchers (e.g., Singleton & Lengyel 1995) to take a careful look at neurological factors in first and second language acquisition. This research considered the possibility that there is a critical period not only for first language acquisition but also, by extension, for second language acquisition. Much of the neurological argu­ment centers on the time of lateralization. While Lenneberg (1967) con­tended that lateralization is complete around puberty, Norman Geschwind (1970), among others, suggested a much earlier age. Stephen Krashen (1973) cited research to support the completion of lateralization around age five. Krashen's suggestion does not grossly conflict with research on first language acquisition if one considers "fluency" in the first language to be achieved by age five. Scovel (1984) cautioned against assuming, with Krashen, that lateralization is complete by age five. "One must be careful to distinguish between 'emergence' of lateralization (at birth, but quite evi­dent at five) and 'completion' (only evident at about puberty)." If lateraliza­tion is not completed until puberty, then one can still construct arguments for a critical period based on lateralization.

Biological Timetables

One of the most compelling arguments for an accent-related critical period came from Thomas Scovel's (1988) fascinating multidisciplinary review of the evidence that has been amassed. Scovel cited evidence for a sociobiological critical period in various species of mammals and birds. Scovel's evidence pointed toward the development of a socially bonding accent at puberty, enabling species (a) to form an identity with their own community as they anticipate roles of parenting and leadership, and (b) to attract mates of "their own kind" in an instinctive drive to maintain their own species.

If the stabilization of an accepted, authentic accent is biologically pre­programmed for baboons and birds, why not for human beings? The socio-biological evidence that Scovel cited persuades us to conclude that native accents, and therefore "foreign" accents after puberty, may be a genetic left­over that, in our widespread human practice of mating across dialectal, lin­guistic, and racial barriers, is no longer necessary for the preservation of the human species. "In other words," explained Scovel (1988: 80), "an accent emerging after puberty is the price we pay for our preordained ability to be articulate apes."

Following another line of research, Walsh and Diller (1981 concluded that different aspects of a second language are learned optimally at different ages:

Lower-order processes such as pronunciation are dependent on early maturing and less adaptive macroneural circuits, which makes foreign accents difficult to overcome after childhood. Higher-order language functions, such as semantic relations, are more dependent on late maturing neural circuits, which may explain why college students can learn many times the amount of grammar and vocabulary that elementary school students can learn in a given period of time.

This conclusion lends support for a neurologically based critical period, but principally for the acquisition of an authentic (nativelike) accent, and not very strongly for the acquisition of communicative fluency and other "higher-order" processes. We return to the latter issue in the next section.

Right-Hemispheric Participation

Yet another branch of neurolinguistic research focused on the role of the right hemisphere in the acquisition of a second language. Obler (1981) noted that in second language learning, there is significant right hemi­sphere participation and that "this participation is particularly active during the early stages of learning the second language." But this "participation" to some extent consists of what we will later define as "strategies" of acquisition. Obler cited the strategy of guessing at meanings, and of using formulaic utterances, as examples of right hemisphere activity. Others also found support for right hemisphere involvement in the form of complex language processing as opposed to early language acquisition.

Genesee (1982) concluded that "there may be greater right hemi­sphere involvement in language processing in bilinguals who acquire their second language late relative to their first language and in bilinguals who learn it in informal contexts." While this conclusion may appear to contra­dict Obler's statement above, it does not. Obler found support for more right hemisphere activity during the early stages of second language acqui­sition, but her conclusions were drawn from a study of seventh-, ninth-, and eleventh-grade subjects—all postpubescent. Such studies seem to suggest that second language learners, particularly adult learners, might benefit from more encouragement of right-brain activity in the classroom context. But, as Scovel (1982) noted, that sort of conclusion needs to be cautious, since the research provides a good deal of conflicting evidence, some of which has been grossly misinterpreted in "an unhappy marriage of single-minded neuropsychologists and double-minded educationalists.... Brain research... will not provide a quick fix to our teaching problems."

Anthropological Evidence

Some adults have been known to acquire an authentic accent in a second language after the age of puberty, but such individuals are few and far between. Anthropologist Jane Hill (1970) provided an intriguing response to Scovel's (1969) study by citing anthropological research on non-Western societies that yielded evidence that adults can, in the normal course of their lives, acquire second languages perfectly. One unique instance of second language acquisition in adulthood was reported by Sorenson (1967), who studied the Tukano culture of South America. At least two dozen languages were spoken among these communities, and each tribal group, identified by the language it speaks, is an exogamous unit; that is, people must marry outside their group, and hence almost always marry someone who speaks another language. Sorenson reported that during adolescence, individuals actively and almost suddenly began to speak two or three other languages to which they had been exposed at some point. Moreover, "in adulthood [a person] may acquire more languages; as he approaches old age, field obser­vation indicates, he will go on to perfect his knowledge of all the languages at his disposal" (Sorenson 1967: 678). In conclusion, Hill suggested that -

the language acquisition situation seen in adult language learners in the largely monolingual American English middle class speech communities... may have been inappropriately taken to be a universal situation in proposing an innatist explanation for adult for­eign accents. Multilingual speech communities of various types deserve careful study....We will have to explore the influence of social and cultural roles which language and phonation play, and the role which attitudes about language play, as an alternative or a supplement to the cerebral dominance theory as an explanation of adult foreign accents.

Hill's challenge was taken up in subsequent decades. Flege (1987) and Morris and Gerstman (1986), for example, cited motivation, affective vari­ables, social factors, and the quality of input as important in explaining the apparent advantage of the child. However, both Long (1990b) and Patkowski (1990) disputed such conclusions and sided with Scovel in their relatively strong interpretation of an age-related critical period for first and second language acquisition.

The significance of accent

Implicit in the comments of the preceding section is the assumption that the emergence of what we commonly call "foreign accent" is of some importance in our arguments about age and acquisition. We can appreciate the fact that given the existence of several hundred muscles (throat, larynx, mouth, lips, tongue, and others) that are used in the articulation of human speech, a tremendous degree of muscular control is required to achieve the fluency of a native speaker of a language. At birth the speech muscles are developed only to the extent that the larynx can control sustained cries. These speech muscles gradually develop, and control of some complex sounds in certain languages (in English the r and / are typical) is sometimes not achieved until after age five, although complete phonemic control is present in virtually all children before puberty.

Research on the acquisition of authentic control of the phonology of a foreign language supports the notion of a critical period. Most of the evi­dence indicates that persons beyond the age of puberty do not acquire what has come to be called authentic (native-speaker) pronunciation of the second language. Possible causes of such an age-based factor have already been discussed: neuromuscular plasticity, cerebral development, sociobiological programs, and the environment of sociocultural influences.

It is tempting immediately to cite exceptions to the rule ("My Aunt Mary learned French at twenty-five, and everyone in France said she sounded just like a native"). These exceptions, however, appear to be (a) isolated instances or (b) only anecdotally supported. True, there are special people who possess somewhere within their competence the ability to override neurobiological critical period effects and to achieve a virtually perfect nativelike pronunciation of a foreign language. But in terms of sta­tistical probability, it is clear that the chances of any one individual commencing a second language after puberty and achieving a scientifically verifiable authentic native accent are infinitesimal.

So, where do we go from here? First, some sample studies, spanning two decades, will serve as examples of the kind of research on adult phono­logical acquisition that appears to contradict Scovel's "strong" CPH.

Gerald Neufeld undertook a set of studies to deter­mine to what extent adults could approximate native-speaker accents in a second language never before encountered. In his earliest experiment, twenty adult native English speakers were taught to imitate ten utterances, each from one to sixteen syllables in length, in Japanese and in Chinese. Native-speaking Japanese and Chinese judges listened to the taped imita­tions. The results indicated that eleven of the Japanese and nine of the Chinese imitations were judged to have been produced by "native speakers." While Neufeld recognized the limitations of his own studies, he suggested that "older students have neither lost their sensitivity to subtle differences in sounds, rhythm, and pitch nor the ability to reproduce these sounds and contours". Nevertheless, Scovel and Long later pointed out glaring experimental flaws in Neufeld's experiments, stemming from the methodology used to judge "native speaker" and from the information initially given to the judges.

In more recent years, Moyer and Bongaerts, Planken, and Schils have also challenged the strong version of the CPH. Moyer's study with native English-speaking graduate students of German upheld the strong CPH: subjects' performance was not judged to be comparable to native speakers of German. The Bongaerts et al. study reported on a group of adult Dutch speakers of English, all late learners, who recorded a mono­logue, a reading of a short text, and readings of isolated sentences and iso­lated words. Some of the non-native performances, for some of the trials, were judged to have come from native speakers. However, in a later review of this study, Scovel carefully noted that it was also the case that many native speakers of English in their study were judged to be nonnative! The earlier Neufeld experiments and these more recent studies have thus essentially left the strong CPH unchallenged.

Upon reviewing the research on age and accent acquisition, as Scovel did, we are left with powerful evidence of a critical period for accent, but for accent only! It is important to remember in all these con­siderations that pronunciation of a language is not by any means the sole criterion for acquisition, nor is it really the most important one.We all know people who have less than perfect pronunciation but who also have mag­nificent and fluent control of a second language, control that can even exceed that of many native speakers. I like to call this the "Henry Kissinger effect" in honor of the former U.S. Secretary of State whose German accent is so noticeable yet who is clearly more eloquent than the large majority of native speakers of American English. The acquisition of the communicative and functional purposes of language is, in most circumstances, far more important than a perfect native accent. Scovel captured the spirit of this way of looking at second language acquisition:

For me, the acquisition of a new language will remain a phenom­enon of natural fascination and mystery, not simply because it is a special skill of such incredible complexity that it remains one of the greatest achievements of the human mind, but because it also is a testimony of how much we can accomplish within the limi­tations that nature has placed upon us.

Perhaps, in our everyday encounters with second language users, we are too quick to criticize the "failure" of adult second language learners by nitpicking at minor pronunciation points or nonintrusive grammatical errors. Cook (1995: 55) warned against "using native accent as the yard­stick" in our penchant for holding up monolingualism as the standard. And so, maybe instead, we can turn those perspectives into a more positive focus on the "multi-competence" of second language learners. Instead of being so perplexed and concerned about how bad people are at learning second languages, we should be fascinated with how much those same learners have accomplished.

Today researchers are continuing the quest for answers to child-adult differences by looking beyond simple phonological factors. Bongaerts et al. (1995) found results that suggested that certain learner characteristics and contexts may work together to override the disadvantages of a late start. Slavoff and Johnson found that younger children (ages seven to nine) did not have a particular advantage in rate of learning over older (ten-to twelve-year-old) children. Longitudinal studies such as Ioup et al.'s (1994) study of a highly nativelike adult learner of Egyptian Arabic are useful in their focus on the factors beyond phonology that might be rele­vant in helping us to be more successful in teaching second languages to adults. Studies on the effect of input, on lexical acquisition, on Universal Grammar, and on discourse acquisition are highly promising domains of research on age and acquisition.

Cognitive considerations

Human cognition develops rapidly throughout the first sixteen years of life and less rapidly thereafter. Some cognitive changes are critical; others are more gradual and difficult to detect. Jean Piaget outlined the course of intellectual development in a child through various stages, which are presented in Illustration – 3.1

A critical stage for a consideration of the effects of age on second lan­guage acquisition appears to occur, in Piaget's outline, at puberty (age eleven in his model). It is here that a person becomes capable of abstrac­tion, of formal thinking which transcends concrete experience and direct perception. Cognitively, then, a strong argument can be made for a critical period of language acquisition by connecting language acquisition and the concrete/formal stage transition.

 

 

Illustration 3.1 - Stages of intellectual development of a child by J. Piaget

 

Ausubel (1964) hinted at the relevance of such a connection when he noted that adults learning a second language could profit from certain grammatical explanations and deductive thinking that obviously would be pointless for a child. Whether adults do in fact profit from such explana­tions depends, of course, on the suitability and efficiency of the explana­tion, the teacher, the context, and other pedagogical variables. We have observed, though, that children do learn second languages well without the benefit—or hindrance—of formal operational thought. Does this capacity of formal, abstract thought have a facilitating or inhibiting effect on lan­guage acquisition in adults? Ellen Rosansky (1975) offered an explana­tion noting that initial language acquisition takes place when the child is highly "centered": "He is not only egocentric at this time, but when faced with a problem he can focus (and then only fleetingly) on one dimension at a time. This lack of flexibility and lack of decentration may well be a necessity for language acquisition."

Young children are generally not "aware" that they are acquiring a lan­guage, nor are they aware of societal values and attitudes placed on one lan­guage or another. It is said that "a watched pot never boils"; is it possible that a language learner who is too consciously aware of what he or she is doing will have difficulty in learning the second language?

You may be tempted to answer that question affirmatively, but there is both logical and anecdotal counterevidence. Logically, a superior intellect should facilitate what is in one sense a highly complex intellectual activity. Anecdotal evidence shows that some adults who have been successful lan­guage learners have been very much aware of the process they were going through, even to the point of utilizing self-made paradigms and other fabri­cated linguistic devices to facilitate the learning process. So, if mature cog­nition is a liability to successful second language acquisition, clearly some intervening variables allow some persons to be very successful second lan­guage learners after puberty. These variables may in most cases lie outside the cognitive domain entirely, perhaps more centrally in the affective—or emotional—domain.

The lateralization hypothesis may provide another key to cognitive dif­ferences between child and adult language acquisition. As the child matures into adulthood, the left hemisphere (which controls the analytical and intellectual functions) becomes more dominant than the right hemi­sphere (which controls the emotional functions). It is possible that the dominance of the left hemisphere contributes to a tendency to overanalyze and to be too intellectually centered on the task of second language learning.

Another construct that should be considered in examining the cogni­tive domain is the Piagetian notion of equilibration. Equilibration is defined as "progressive interior organization of knowledge in a stepwise fashion" (Sullivan 1967), and is related to the concept of equilibrium. That is, cognition develops as a process of moving from states of doubt and uncertainty (disequilibrium) to stages of resolution and certainty (equilib­rium) and then back to further doubt that is, in time, also resolved. And so the cycle continues. Piaget (1970) claimed that conceptual development is a process of progressively moving from states of disequilibrium to equilib­rium and that periods of disequilibrium mark virtually all cognitive devel­opment up through age fourteen or fifteen, when formal operations finally are firmly organized and equilibrium is reached.

It is conceivable that disequilibrium may provide significant motiva­tion for language acquisition: language interacts with cognition to achieve equilibrium. Perhaps until that state of final equilibrium is reached, the child is cognitively ready and eager to acquire the language necessary for achieving the cognitive equilibrium of adulthood. That same child was, until that time, decreasingly tolerant of cognitive ambiguities. Children are amazingly indifferent to contradictions, but intellectual growth produces an awareness of ambiguities about them and heightens the need for reso­lution. Perhaps a general intolerance of contradictions produces an acute awareness of the enormous complexities of acquiring an additional lan­guage, and so perhaps around the age of fourteen or fifteen, the prospect of learning a second language becomes overwhelming, thus discouraging the learner from proceeding a step at a time as a younger child would do.

The final consideration in the cognitive domain is the distinction that Ausubel made between rote and meaningful learning. Ausubel noted that people of all ages have little need for rote, mechanistic learning that is not related to existing knowledge and experience. Rather, most items are acquired by meaningful learning, by anchoring and relating new items and experiences to knowledge that exists in the cognitive framework. It is a myth to contend that children are good rote learners, that they make good use of meaningless repetition and mimicking. We have already mentioned that children's practice and imitation is a very meaningful activity that is contextualized and purposeful. Adults have developed even greater concentration and so have greater ability for rote learning, but they usually use rote learning only for short-term memory or for somewhat arti­ficial purposes. By inference, we may conclude that the foreign language class­room should not become the locus of excessive rote activity: rote drills, pattern practice without context, rule recitation, and other activities that are not in the context of meaningful communication.

It is interesting to note that C2-A2 comparisons almost always refer, in the case of children, to natural untutored learning, and for adults, to the classroom learning of a second language. Even so, many foreign language classrooms around the world still utilize an excessive number of rote-learning procedures. So, if adults learning a foreign language by rote methods are compared with children learning a second language in a nat­ural, meaningful context, the child's learning will seem to be superior. The cause of such superiority may not be in the age of the person, but in the context of learning. The child happens to be learning language meaning­fully, and the adult is not.

The cognitive domain holds yet other areas of interest for comparing first and second language acquisition. Now we are going to analyze what may be the most complex, yet the most illuminating, perspective on age and acquisition: the affective domain.