FUnctional neuroimging indices of normal and atypical spoken language

by weber and gaillard
in brain, behavior, and learning

in general, studies of infant and older children's left hemispheres support the critical period hypothesis.

"Overall, evidence supports the theory that areas of language processing may be less consolidated and more bilateral in younger children"

94% of healthy right-handed adults have language in left hemisphere.

Cerebral organization of component processes in reading

by pugh et al.

AN fMRI study found that "Orthographic processing made maximum demands on extrastriate sites, phonological processing on a number of frontal and temporal sites, and lexical-semantic processing was most strongly associated with middle and superior temporal sites." Men and women processed reading differently: "females did not show an increase in the numbers of activated pixels from the rhyme to semantic category subtractions while males did."

p9 typo? "males displayed greater activation in the LH" shouldn't it be RH?

"in extrastriate regions (as in the total area analysis) females fail to show patterns of increased activation for real words (semantic category-line) relative to nonwords (rhyme-line) while males do show them.

lateral extrastriate region - orthographic processing
medial extrastriate region - real words than to nonword strings of letters
frontal regions - phonological processing
temporal regions - phonological and semantic processing

phonological and semantic networks overlap spatially in women more than man

Rethinking the neurological basis of language

stowe, haverkort, zwarts

The clasical view of neurolinguistics assumed that language was localized in the left hemisphere, Broca's and Wernicke's area were the main areas involved in language, and they were only involved in language. These are incorrect.

Peterson et al. performed the first neuroimaging study of normal individuals in 1989.

In the classical view, Broca's was involved in production and Wernicke's in comprehension. Neuroimaging studies have shown that linguistic centers cannot be split up this way.

They are both necessary for normal language functioning. Both light up for semantic and syntactic tasks. Broca's area might be responsible for general working memory and storage of information. This is why Broca's aphasics have trouble with syntax and leave out function words.

It is possible that there are two functionally seperate systems in one anatomical area. Broca's area can be divided into 3 sections. It sometimes lights up when a person hears music.

The anterior temporal lobe on both the right and left sides are somehow involved in the comprehension of syntactically, lexically, or semantically ambiguous sentences.

articulatory rehearsal and error detection are utilized when the sentence is difficult or ambiguous. This lights up motor areas and the right cerebellum, which may be involved in error detection.

The superior frontal gyrus is involved in semantic evaluation.

The anterior insula is used in articulation. The "left anterior insula is important for fine motor coordination in speech."

"The posterior inferior temporal and fusiform gyrus are important for various aspects of langauge processing.

These areas are not dedicated to language, but are part of the language system.

The right frontal lobe is important for understanding metaphors, for humor comprehension, and inferring topic shifts.

The right hemisphere figures out nonliteral meanings of sentences.

"when processing demands increase, activation in the right hemisphere increases."

"Language as a complete anatomical network is not modular, relative to other cognitive functions. Component functions within the language network may be specific to language."

"interpreting Words"

Chapter 5 of Images of Mind by Michael Posner, 1994

The researchers first asked subjects to perform a very simple task: looking at a cross on a computer monitor. The tasks became increasingly complex until the authors finally asked the subjects to produce words in response to a prompt. PET scans were taken during every task. The researchers identified the areas of the brain involved in looking at the simplest task; when these areas of the brain were activated during the next task, the researchers subtracted these areas from the second scans to identify the areas of the brain needed for the second task. Eventually, the researchers were able to isolate the areas of the brain used for accessing lexical meaning.

There are 2 models of how humans read; neurological and cognitive. They disagree as to whether or not our visual interpretation of the word goes through the phonetic representation before we comprehend it. The cognitive model says no, that top-down processing will recognize the word. The neurological model (Wernicke first said it) says yes.

Language processing can proceed thru many dif. areas of the brain.

A verb generation task made many different areas of the brain light up, including Broca's area.

Practicing the verb generation task changes the neural pathways required for the exercise.

Prediction of children's reading skills using behavioral, functional, and structural neuroimaging measures

by Hoeft et al. 2007 in Behavioral Neuroscience


Neuroimaging methods combined with behavioral tests predicts children's future reading skills better than either method in isolation.

The bilingual brain: Cerebral representation of languages

Franco Fabbro 2001

"When a second language is learned formally and mainly used
at school, it apparently tends to be more widely represented in the cerebral cortex
than the first language, whereas if it is acquired informally, as usually happens with
the first language, it is more likely to involve subcortical structures (basal ganglia
and cerebellum) (cf. Paradis, 1994; Fabbro & Paradis, 1995; Fabbro et al., 1997;
Fabbro, 2000)."

Right hemisphere is associated with pragmatics (Chantraine et al 1998)

L2 language processes (phonology, morphology, syntax) are not in the right hemisphere (Paradis 1994, 1998)

Klein et al. 1995 performed the first neuroimaging study on bilinguals

Translation and comprehension are subserved by different processes.

Neural Substrates of Language Acquisition

Patricia Kuhl and Maritza Rivera-Gaxiola

Neuroimaging is being used with infants. "The goal on experiments on infants has been to determine whether the initial state and the learning mechanisms are speech specific and species specific."

"The combination of computational and social abilities may be exclusive to humans (Kuhl 2007)."

"The studies suggest that exposure to language in the first year of life begins to set the neural architecture in a way that vaults the infant forward in the acquisition of language."

EEG/ERP is inexpensive, noiseless, "excellent temporal resolution"

At birth infants are capable of distinguishing between all phonemes that are possible in human languages, but with exposure to the native language, infants learn to "tune out" the phonemes that are not distinguished in their native language.

"By the end of the first year, the infant brain is no longer universally prepared for all languages, but instead primed to acquire the language(s) to which the infant brain has been exposed."

So adults truly cannot learn a second language the same way infants learn their first.

In a study (Kuhl et al 2003), a group of infants exposed to a live person speaking Mandarin were able to distinguish Mandarin sounds, while groups exposed to television and audio Mandarin tested the same as groups that were never exposed to Mandarin at all. So social interaction is very important to infant language acquisition. This could be due to the ways humans learned language for centuries--we could be evolutionary accustomed NOT to learn language from computers.

"A sudden increase in vocabulary typically occurs between 18 and 24 months of age--a "vocabulary explosion" (Granger & Brent 2004, Fernald et al. 2006)--but word learning begins much earlier. Infants show recognition of their own name at four and a half months (Mandel et al. 1995)." p. 520

"new words may be encoded in the same neural regions as previously learned words."

""Newborns tested by Imada et ak showed no activation in motor speech areas for any signals, whereas auditory areas responded robustly to all signals, suggesting that perception-action linkages for speech develop by three months of age as infants produce vowel-like sounds."

"Studies across languages showed that by one year of age infants do not accept mispronunciations of common words, words in stressed syllables, or monosyllabic words, indicating that their representations of these words are well-specified by that age." references omitted

Researchers are "strongly interested" in which comes first: phonemes or words, or if learning is bidirectional.

Data on bilingual infants has conflicting results.

Some believe that it may take bilingual infants longer to accumulate a normal vocabulary in their native languages because of decreased input. There have not been many studies on bilingual infants.

Second language research using magnetoencephalography: a review

schmidt and roberts

This article first touts MEG as a very useful tool in studying SLA and neurolinguistics, then summarizes previous SLA MEG studies.

MEG is the magnetic version of EEg. Subjects are more comfortable doing an MEG than other neuroimaging devices. But it is expensive and subjects must stay very still.


Phiko and others (2001;2002) found that the L2 is processed more like the L3 than the L1 in early bilinguals.

Zhang and others (2001; 2005) found that Japanese can detect the difference in /r/ and /l/ when there is no vowel afterwards. This suggests "backward masking."


The MEG was used with Japanese and German speakers to determine that both groups recognized kanji "holistically, rather than piecemeal."


Ihara and Kakigi found that Koreans process Hangul and Kana in different parts of their brains.

Phonology can also be studied with the MEG. Differences in pitch changes resulting in changed meaning of words can be taught to SLL. French and Spanish speakers show different areas of the brain allotted to vowels because French has 7 more vowels than Spanish.

Bialystok et al 2005 examined whether bilinguals perform better than monolinguals at the Simon task. The two groups had speedy responses when different areas of the brain were activated. Bilinguals were fast when the "cingulate and superior and inferior frontal regions" and slower with the "right visual cortex." Monolinguals were fast with the "left middle frontal activation" and slow with the "right motor cortex."

Valaki et al (2004) found that Mandarin speakers' brains were less strongly lateralized.

Bilingual and Monolingual Brains Compared:

Bilingual and Monolingual Brains Compared: A
Functional Magnetic Resonance Imaging Investigation
of Syntactic Processing and a Possible ‘‘ Neural
Signature’’ of Bilingualism

Ioulia Kovelman1,2, Stephanie A. Baker1, and Laura-Ann Petitto

Journal of Cognitive Neuroscience 2008

"Eleven Spanish-English right-handed bilinguals...and 10 English right-handed monolinguals" were asked to judge the plausibility of sentences containing relative clauses while in the fmri. OS and SO sentences were both used. Bilinguals judged twice as many sentences as monolinguals. Results indicate that bilinguals have differentiated language systems and use more left brain gray matter than monolinguals.

Because English is an analytic language and Spanish is syntactic, there was no difference in brain functioning when bilinguals were judging OS and SO in Spanish; English monolinguals showed more activity when processing SO ("difficult") than OS ("easy").

A Neurolinguistic Theory of Bilingualism: Neuroimaging studies of the Bilingual Brain

Michael Paradis

Chapter 6

Neuroimaging studies have neglected to replicate other studies; therefore, all findings from this field are not proved.

Surely the left-brain is associated with most aspects of language and the right brain kicks in when pragmatics is needed to understand--usually, when the L2 left-brain knowledge is insufficient.

Also, declarative and procedural memory is surely processed in different areas. If the left brain is damaged in early life, the right brain will take on language-learning tasks.

"...a natural (ecological) task such as the comprehension of a short story..."

Don't use single-word recognition, because this is not "language."

"The majority of studies to date (28) have used single words as stimuli (173)."

Paradis looks for converging evidence in the truly linguistic (e.g. ecological) tasks from published studies: procedural memory for language = perisylvian area

"declarative memory and hence metalinguistic knowledge"= parahippocampal gyri, mesial temporal lobes, anterior cingulate

pragmatics=areas of the right hemisphere

Paradis 2000a: "Comprehension is easier than production"

It is almost impossible to fully control for all areas of processing the task. :-(

I think my dissertation should test and retest and retest subjects to ensure validity.