A Comparison of White Matter Brain Differences in Monolingual and Highly Proficient Multilingual Speakers.

Language processing relies on the communication between brain regions that is achieved through several white matter tracts, part of the dorsal, ventral, and medial pathways involved in language processing and control (Coggins et al., 2004; Friederici & Gierhan, 2013; Hickok & Poeppel, 2007; Luk et al., 2011).

Electrophysiological study of visual processing in children with cochlear implants.

Electrophysiological studies of congenitally deaf children and adults have reported atypical visual evoked potentials (VEPs) which have been associated with both behavioral enhancements of visual attention as well as poorer performance and outcomes in tests of spoken language speech processing. This pattern has often been interpreted as a maladaptive consequence of early auditory deprivation, whereby a remapping of auditory cortex by the visual system ultimately reduces resources necessary for optimal rehabilitative outcomes of spoken language acquisition and use. Making use of a novel electrophysiological paradigm, we compare VEPs in children with severe to profound congenital deafness who received a cochlear implant(s) prior to 31 months (n = 28) and typically developing age matched controls (n = 28).

Visual attention for linguistic and non-linguistic body actions in non-signing and native signing children.

Evidence from adult studies of deaf signers supports the dissociation between neural systems involved in processing visual linguistic and non-linguistic body actions. The question of how and when this specialization arises is poorly understood. Visual attention to these forms is likely to change with age and be affected by prior language experience.

Electrophysiological Examination of Ambient Speech Processing in Children With Cochlear Implants.

Purpose: This research examined the expression of cortical auditory evoked potentials in a cohort of children who received cochlear implants (CIs) for treatment of congenital deafness ( = 28) and typically hearing controls ( = 28).

Method: We make use of a novel electroencephalography paradigm that permits the assessment of auditory responses to ambiently presented speech and evaluates the contributions of concurrent visual stimulation on this activity.

Results: Our findings show group differences in the expression of auditory sensory and perceptual event-related potential components occurring in 80- to 200-ms and 200- to 300-ms time windows, with reductions in amplitude and a greater latency difference for CI-using children.

Semantic word integration in children with cochlear implants: Electrophysiological evidence.

Differential auditory experiences of children with hearing-loss who receive cochlear implants (CIs) may influence the integration of lexical and conceptual information. Here we measured event-related potentials during a word-picture priming task in CI-using children (n = 29, mean age = 81 months) and typically-hearing children (n = 19, mean age = 75 months) while they viewed audiovisual-word primes and picture targets that were semantically congruent or incongruent. In both groups, semantic relatedness modulated ERP amplitude 300-500ms after picture onset, signifying an N400 semantic effect.

Cortical Encoding of Manual Articulatory and Linguistic Features in American Sign Language.

The fluent production of a signed language requires exquisite coordination of sensory, motor, and cognitive processes. Similar to speech production, language produced with the hands by fluent signers appears effortless but reflects the precise coordination of both large-scale and local cortical networks. The organization and representational structure of sensorimotor features underlying sign language phonology in these networks remains unknown.

Effects of age on American Sign Language sentence repetition.

The study of deaf users of signed languages, who often experience delays in primary language (L1) acquisition, permits a unique opportunity to examine the effects of aging on the processing of an L1 acquired under delayed or protracted development. A cohort of 107 congenitally deaf adult signers ages 45-85 years who were exposed to American Sign Language (ASL) either in infancy, early childhood, or late childhood were tested using an ASL sentence repetition test. Participants repeated 20 sentences that gradually increased in length and complexity.

A novel EEG paradigm to simultaneously and rapidly assess the functioning of auditory and visual pathways.

Objective assessment of the sensory pathways is crucial for understanding their development across the life span and how they may be affected by neurodevelopmental disorders (e.g., autism spectrum) and neurological pathologies (e.

Putting underspecification in context: ERP evidence for sparse representations in morphophonological alternations.

Numerous studies have shown evidence for a sparse lexicon in speech perception, often in the guise of underspecification, where certain information is omitted in the specification of phonological forms. While previous work has made a good case for underspecifying certain features of single speech sounds, the role of phonological context in underspecification has been overlooked. Contextually-mediated underspecification is particularly relevant to conceptualizations of the lexicon, as it is couched in item-specific (as opposed to phoneme-specific) patterning.

Auditory and Visual Electrophysiology of Deaf Children with Cochlear Implants: Implications for Cross-modal Plasticity.

Deaf children who receive a cochlear implant early in life and engage in intensive oral/aural therapy often make great strides in spoken language acquisition. However, despite clinicians' best efforts, there is a great deal of variability in language outcomes. One concern is that cortical regions which normally support auditory processing may become reorganized for visual function, leaving fewer available resources for auditory language acquisition.

Distinguishing underlying and surface variation patterns in speech perception.

This study examines the relationship between patterns of variation and speech perception using two English prefixes: 'in-'/'im-' and 'un-'. In natural speech, 'in-' varies due to an underlying process of phonological assimilation, while 'un-' shows a pattern of surface variation, assimilating before labial stems. In a go/no-go lexical decision experiment, subjects were presented a set of 'mispronounced' stimuli in which the prefix nasal was altered (replacing [n] with [m], or vice versa), in addition to real words with unaltered prefixes.

Phonological awareness for american sign language.

This paper examines the concept of phonological awareness (PA) as it relates to the processing of American Sign Language (ASL). We present data from a recently developed test of PA for ASL and examine whether sign language experience impacts the use of metalinguistic routines necessary for completion of our task. Our data show that deaf signers exposed to ASL from infancy perform better than deaf signers exposed to ASL later in life and that this relationship remains even after controlling for the number of years of experience with a signed language.

Deaf readers' response to syntactic complexity: evidence from self-paced reading.

This study was designed to determine the feasibility of using self-paced reading methods to study deaf readers and to assess how deaf readers respond to two syntactic manipulations. Three groups of participants read the test sentences: deaf readers, hearing monolingual English readers, and hearing bilingual readers whose second language was English. In Experiment 1, the participants read sentences containing subject-relative or object-relative clauses.

Lexical processing in deaf readers: an FMRI investigation of reading proficiency.

Individuals with significant hearing loss often fail to attain competency in reading orthographic scripts which encode the sound properties of spoken language. Nevertheless, some profoundly deaf individuals do learn to read at age-appropriate levels. The question of what differentiates proficient deaf readers from less-proficient readers is poorly understood but topical, as efforts to develop appropriate and effective interventions are needed.

Cross-linguistic differences in the neural representation of human language: evidence from users of signed languages.

Studies of deaf individuals who are users of signed languages have provided profound insight into the neural representation of human language. Case studies of deaf signers who have incurred left- and right-hemisphere damage have shown that left-hemisphere resources are a necessary component of sign language processing. These data suggest that, despite frank differences in the input and output modality of language, core left perisylvian regions universally serve linguistic function.

Exploring perceptual processing of ASL and human actions: effects of inversion and repetition priming.

In this paper, we compare responses of deaf signers and hearing non-signers engaged in a categorization task of signs and non-linguistic human actions. We examine the time it takes to make such categorizations under conditions of 180° stimulus inversion and as a function of repetition priming, in an effort to understand whether the processing of sign language forms draws upon special processing mechanisms or makes use of mechanisms used in recognition of non-linguistic human actions. Our data show that deaf signers were much faster in the categorization of both linguistic and non-linguistic actions, and relative to hearing non-signers, show evidence that they were more sensitive to the configural properties of signs.

Analysis of naming errors during cortical stimulation mapping: implications for models of language representation.

This study reports on the characteristics and distribution of naming errors of patients undergoing cortical stimulation mapping (CSM). During the procedure, electrical stimulation is used to induce temporary functional lesions and locate 'essential' language areas for preservation. Under stimulation, patients are shown slides of common objects and asked to name them.

Neuronal correlates of functional magnetic resonance imaging in human temporal cortex.

The relationship between changes in functional magnetic resonance imaging and neuronal activity remains controversial. Data collected during awake neurosurgical procedures for the treatment of epilepsy provided a rare opportunity to examine this relationship in human temporal association cortex. We obtained functional magnetic resonance imaging blood oxygen dependent signals, single neuronal activity and local field potentials from 8 to 300 Hz at 13 temporal cortical sites, from nine subjects, during paired associate learning and control measures.

A human mirror neuron system for language: Perspectives from signed languages of the deaf.

Language is proposed to have developed atop the human analog of the macaque mirror neuron system for action perception and production [Arbib M.A. 2005.

Distributed XQuery-Based Integration and Visualization of Multimodality Brain Mapping Data.

This paper addresses the need for relatively small groups of collaborating investigators to integrate distributed and heterogeneous data about the brain. Although various national efforts facilitate large-scale data sharing, these approaches are generally too "heavyweight" for individual or small groups of investigators, with the result that most data sharing among collaborators continues to be ad hoc. Our approach to this problem is to create a "lightweight" distributed query architecture, in which data sources are accessible via web services that accept arbitrary query languages but return XML results.

Signed language and human action processing: evidence for functional constraints on the human mirror-neuron system.

In the quest to further understand the neural underpinning of human communication, researchers have turned to studies of naturally occurring signed languages used in Deaf communities. The comparison of the commonalities and differences between spoken and signed languages provides an opportunity to determine core neural systems responsible for linguistic communication independent of the modality in which a language is expressed. The present article examines such studies, and in addition asks what we can learn about human languages by contrasting formal visual-gestural linguistic systems (signed languages) with more general human action perception.

Preference for language in early infancy: the human language bias is not speech specific.

Fundamental to infants' acquisition of their native language is an inherent interest in the language spoken around them over non-linguistic environmental sounds. The following studies explored whether the bias for linguistic signals in hearing infants is specific to speech, or reflects a general bias for all human language, spoken and signed. Results indicate that 6-month-old infants prefer an unfamiliar, visual-gestural language (American Sign Language) over non-linguistic pantomime, but 10-month-olds do not.

Unobtrusive integration of data management with fMRI analysis.

This note describes a software utility, called X-batch which addresses two pressing issues typically faced by functional magnetic resonance imaging (fMRI) neuroimaging laboratories (1) analysis automation and (2) data management. The first issue is addressed by providing a simple batch mode processing tool for the popular SPM software package (http://www.fil.

Sign language processing and the mirror neuron system.

In this paper we review evidence for frontal and parietal lobe involvement in sign language comprehension and production, and evaluate the extent to which these data can be interpreted within the context of a mirror neuron system for human action observation and execution. We present data from three literatures--aphasia, cortical stimulation, and functional neuroimaging. Generally, we find support for the idea that sign language comprehension and production can be viewed in the context of a broadly-construed frontal-parietal human action observation/execution system.