Language attrition

The first linguistic system to be affected by first language attrition is the lexicon.[13] The lexical-semantic relationship usually starts to deteriorate first and most quickly, driven by Cross Linguistic Interference (CLI) from the speaker's L2, and it is believed to be exacerbated by continued exposure to, and frequent use of, the L2.[14] Evidence for such interlanguage effects can be seen in a study by Pavlenko (2003, 2004) which shows that there was some semantic extension from the L2, which was English, into the L1 Russian speakers' lexicons. In order to test for lexical attrition, researchers used tests such as picture naming tasks, where they place a picture of an item in front of the participant and ask them to name it, or by measuring lexical diversity in the speaker's spontaneous speech (speech that is unprompted and improvised). In both cases, attriters performed worse than non-attriters.[7][15][16][17] One hypothesis suggests that when a speaker tries to access a lexical item from their L1 they are also competing with the translation equivalents of their L2 and that there is either a problem with activating the L1 due to infrequent use or with the inhibition of the competing L2.[14]

Grammatical attrition can be defined as "the disintegration of the structure of a first language (L1) in contact situations with a second language (L2)".[18] In a study of bilingual Swedes raised outside of Sweden, who in their late twenties returned to their home country for schooling, there was noted to be attrition of their L1. The participants demonstrated a complete retention of the underlying syntactic structure of their L1. Notably, they exhibited the V2, verb second, word order present in most Germanic languages, except English. This rule requires the tense-marked verb of a main clause to occur in the second position of the sentence, even if that means it comes before the subject (e.g. there is an adverb at the beginning of the sentence). These speakers' ability to form sentences with V2 word order was compared against L2 learners who often overproduce the rigid SVO word order rather than applying the V2 rule. Although the study did not show evidence for attrition of syntax of the person's L1, there was evidence for attrition in the expatriates' morphology, especially in terms of agreement. They found that the bilinguals would choose to use the unmarked morphemes in place of the marked one when having to differentiate between gender and plurality; also they tend to overgeneralize where certain morphemes can be used. For example, they may use the suffix /-a/, which is used to express an indefinite plural, and overextend this morpheme to also represent the indefinite singular.[19] There is little evidence to support the view that there is a complete restructuring of the language systems. That is, even under language attrition the syntax is largely unaffected and any variability observed is thought to be due to interference from another language, rather than attrition.[20][21]

L1 attriters, like L2 learners, may use language differently from native speakers. In particular, they can have variability on certain rules which native speakers apply deterministically.[22][20] In the context of attrition, however, there is strong evidence that this optionality is not indicative of any underlying representational deficits: the same individuals do not appear to encounter recurring problems with the same kinds of grammatical phenomena in different speech situations or on different tasks.[9] This suggests that problems of L1 attriters are due to momentary conflicts between the two linguistic systems and not indicative of a structural change to underlying linguistic knowledge (that is, to an emerging representational deficit of any kind). This assumption is in line with a range of investigations of L1 attrition which argue that this process may affect interface phenomena (e.g. the distribution of overt and null subjects in pro-drop languages) but will not touch the narrow syntax.[20][23][24]

Phonological attrition is a form of language loss that affects the speaker's ability to produce their native language with their native accent. A study of five native speakers of American English who moved to Brazil and learned Portuguese as their L2 demonstrates the possibility that one could lose one's L1 accent in place of an accent that is directly influenced by the L2.[25] It is thought that phonological loss can occur to those who are closer to native-like fluency in the L2, especially in terms of phonological production, and for those who have immersed themselves and built a connection to the culture of the country for the L2. A sociolinguistic approach to this phenomenon is that the acquisition of a native-like L2 accent and the subsequent loss of one's native accent is influenced by the societal norms of the country and the speakers' attempt to adapt in order to feel a part of the culture they are trying to assimilate into.[26] This type of attrition is not to be confused with contact-induced change since that would mean speech production changes due to an increased use of another language and not due to the less frequent use of the L1.[27]

The regression hypothesis, first formulated by Roman Jakobson in 1941 and originally formulated on the phonology of only Slavic languages,[34] goes back to the beginnings of psychology and psychoanalysis. It states that which was learned first will be retained last, both in 'normal' processes of forgetting and in pathological conditions such as aphasia or dementia.[34] As a template for language attrition, the regression hypothesis has long seemed an attractive paradigm. However, regression is not in itself a theoretical or explanatory framework.[34][35] Both order of acquisition and order of attrition need to be put into the larger context of linguistic theory in order to gain explanatory adequacy.[36]

Keijzer (2007) conducted a study on the attrition of Dutch in Anglophone Canada. She finds some evidence that later-learned rules, such as diminutive and plural formation, indeed erode before earlier learned grammatical rules.[35] However, there is also considerable interaction between the first and second language and so a straightforward 'regression pattern' cannot be observed.[35] Also, parallels in noun and verb phrase morphology could be present because of the nature of the tests or because of avoidance by the participants.[35] In a follow-up 2010 article, Keijzer suggests that the regression hypothesis may be more applicable to morphology than to syntax.[36]

Citing the studies on the regression hypothesis that have been done, Yukawa[32] says that the results have been contradictory. It is possible that attrition is a case-by-case situation depending on a number of variables (age, proficiency,& literacy, the similarities between the L1 and L2, and whether the L1 or the L2 is attriting). The threshold hypothesis states that there may be a level of proficiency that once attained, enables the attriting language to remain stable.

Children are more susceptible to (first) language attrition than adults.[4][5][6] Research shows an age effect around the ages of 8 through 13.[6] Before this time period, a first language can attrite under certain circumstances, the most prominent being a sudden decline in exposure to the first language. Various case studies show that children who emigrate before puberty and have little to no exposure to their first language end up losing the first language. In 2009, a study compared two groups of Swedish-speaking groups: native Swedish speakers and Korean international adoptees who were at risk of losing their Korean.[4][37] Of the Korean adoptees, those who were adopted the earliest essentially lost their Korean and those adopted later still retained some of it, although it was primarily their comprehension of Korean that was spared.[37] A 2007 study looked at Korean adoptees in France and found that they performed on par with native French speakers in French proficiency and Korean.[38]

Attrition of a first language does not guarantee an advantage in learning a second language.[37] Attriters are outperformed by native speakers of the second language in proficiency.[37] A 2009 study tested the Swedish proficiency of Swedish speakers who had attrited knowledge of Spanish. These participants did show almost but not quite native-like proficiency when compared to native Swedish speakers, and they did not show an advantage when compared with bilingual Swedish-Spanish speakers.[37]

On the other hand, L1 attrition may also occur if the overall effort to maintain the first language is insufficient while exposed to a dominant L2 environment. Another recent investigation, focusing on the development of language in late bilinguals (i.e. adults past puberty), has claimed that maintenance of the mother tongue in an L1 environment requires little to no maintenance for individuals, whereas those in the L2 environment have an additive requirement for the maintenance of the L1 and the development of the L2 (Opitz, 2013).[39]

There have been cases in which adults have undergone first language attrition. A 2011 study tested adult monolingual English speakers, adult monolingual Russian speakers and adult bilingual English-Russian speakers on naming various liquid containers (cup, glass, mug, etc.) in both English and Russian.[40] The results showed that the bilinguals had attrited Russian vocabulary because they did not label these liquid containers the same way as the monolingual Russian speakers. When grouped according to Age of Acquisition (AoA) of English, the bilinguals showed an effect of AoA (or perhaps the length of exposure to the L2) in that bilinguals with earlier AoA (mean AoA 3.4 years) exhibited much stronger attrition than bilinguals with later AoA (mean AoA 22.8 years). That is, the individuals with earlier AoA were the more different from monolingual Russian speakers in their labeling and categorization of drinking vessels, than the people with later AoA. However, even the late AoA bilinguals exhibited some degree of attrition in that they labeled the drinking vessels differently from native monolingual Russian-speaking adults.

Given that exposure to an L2 at a younger age typically leads to stronger attrition of the L1 than L2 exposure at later ages, there may be a relationship between language attrition and the critical period hypothesis. The critical period for language claims that there is an optimal time period for humans to acquire language, and after this time language acquisition is more difficult (though not impossible). Language attrition also seems to have a time period; before around age 12, a first language is most susceptible to attrition if there is reduced exposure to that language.[4][6][37] Research shows that the complete attrition of a language would occur before the critical period ends.[5]

All available evidence on the age effect for L1 attrition, therefore, indicates that the development of susceptibility displays a curved, not a linear, function. This suggests that in native language learning there is indeed a Critical Period effect, and that full development of native language capacities necessitates exposure to L1 input for the entire duration of this CP.

In Hansen & Reetz-Kurashige (1999), Hansen cites her own research on L2-Hindi and Urdu attrition in young children. As young pre-school children in India and Pakistan, the subjects of her study were often judged to be native speakers of Hindi or Urdu; their mother was far less proficient. On return visits to their home country, the United States, both children appeared to lose all their L2 while the mother noticed no decline in her own L2 abilities. Twenty years later, those same young children as adults comprehend not a word from recordings of their own animated conversations in Hindi-Urdu; the mother still understands much of them.

Yamamoto (2001) found a link between age and bilinguality. In fact, a number of factors are at play in bilingual families. In her study, bicultural families that maintained only one language, the minority language, in the household, were able to raise bilingual, bicultural children without fail. Families that adopted the one parent – one language policy were able to raise bilingual children at first but when the children joined the dominant language school system, there was a 50% chance that children would lose their minority language abilities. In families that had more than one child, the older child was most likely to retain two languages, if it was at all possible. Younger siblings in families with more than two other brothers and sisters had little chance of maintaining or ever becoming bilingual.

There are few principled and systematic investigations of FLA specifically investigating the impact of AoA. However, converging evidence suggests an age effect on FLA which is much stronger and more clearly delineated than the effects that have been found in SLA research. Two studies that consider prepuberty and postpuberty migrants (Ammerlaan, 1996, AoA 0–29 yrs; Pelc, 2001, AoA 8–32 years) find that AoA is one of the most important predictors of ultimate proficiency, and a number of studies that investigate the impact of age among postpuberty migrants fail to find any effect at all (Köpke, 1999, AoA 14–36 yrs; Schmid, 2002, AoA 12–29 yrs; Schmid, 2007, AoA 17–51 yrs). A range of studies conducted by Montrul on Spanish heritage speakers in the US as well as Spanish-English bilinguals with varying levels of AoA also suggests that the L1 system of early bilinguals may be similar to that of L2 speakers, while later learners pattern with monolinguals in their L1 (e.g. Montrul, 2008; Montrul, 2009). These findings therefore indicate strongly that early (prepuberty) and late (postpuberty) exposure to an L2 environment have a different impact on possible fossilization and/or deterioration of the linguistic system.

Frequency of use has been shown to be an important factor in language attrition.[41] Decline in use of a given language leads to gradual loss of that language.[42][43]

In the face of much evidence to the contrary, one study is often cited to suggest that frequency of use does not correlate strongly with language attrition.[44] Their methodology, however, can be called into question, especially concerning the small sample size and the reliance on self reported data.[45] The researchers themselves state that their findings may be inaccurate.[44] The overall evidence suggests that frequency of use is a strong indicator of language attrition.[41][42][43][45]

Motivation could be defined as the willingness and desire to learn a second language, or, in the case of attrition, the incentive to maintain a language.[46] Motivation can be split into four categories,[47] but it is often simply split into two distinct forms: the instrumental and the integrative.[46][47] Instrumental motivation, in the case of attrition, is the desire to maintain a language in order to complete a specific goal, i.e. maintaining a language to maintain a job. Integrative motivation, however, is motivation that comes from a desire to fit in or maintain one's cultural ties.[47] These inferences can be drawn, as strategies for knowledge maintenance will, by definition, precisely oppose actions that lead to forgetting.[48]

There are differences in attrition related to motivation depending on the type at hand. Instrumental motivation is often less potent than integrative motivation, but, given sufficient incentives, it can be equally as powerful.[46] A 1972 study by Gardner and Lambert emphasized the importance of integrative motivation in particular in regards to factors relating to language acquisition, and, by extension, language attrition.[49]