Speech recognition is an active process that involves some form of predictive coding. This statement is relatively uncontroversial. What is less clear is the source of the prediction. The dual-stream model of speech processing suggests that there are two possible sources of predictive coding in speech perception: the motor speech system and the…

Recent studies have implicated anatomical differences in speech-relevant brain regions of adults who stutter (AWS) compared to normally fluent adults (NFA). The present study focused on the region of the corpus callosum (CC) which is involved in interhemispheric processing between the left and right cerebral hemispheres. Two-dimensional…

Behavioral experience is at work modifying the structure and function of the brain throughout the lifespan, but it has a particularly dramatic influence after brain injury. This review summarizes recent findings on the role of experience in reorganizing the adult damaged brain, with a focus on findings from rodent stroke models of chronic upper…

Schwann cells normally form myelin sheaths around axons in the peripheral nervous system (PNS) and support nerve regeneration after nerve injury. In contrast, nerve regeneration in the central nervous system (CNS) is not supported by the myelinating cells known as oligodendrocytes. We have found that: 1) low frequency electrical stimulation can be…

A basic tenet of developmental neurobiology is that certain areas of the cortex will re-organize, if appropriate stimulation is withheld for long periods. Stimulation must be delivered to a sensory system within a narrow window of time (a sensitive period) if that system is to develop normally. In this article, we will describe age cut-offs for a…

Tinnitus is a vexing disorder of hearing characterized by sound sensations originating in the head without any external stimulation. The specific etiology of these sensations is uncertain but frequently associated with hearing loss. The "neurophysiogical" model of tinnitus has enhanced appreciation of central nervous system (CNS) contributions.…

Premature infants have a disproportionately increased risk for brain injury based on several mechanisms including intraventricular hemorrhage, ischemia and the vulnerability of developing neuronal progenitor cells. Injury to the developing brain often results in neurologic abnormalities that can be correlated with a structural lesion; however more…

In normal-hearing children the latency of the P1 component of the cortical evoked response to sound varies as a function of age and, thus, can be used as a biomarker for maturation of central auditory pathways. We assessed P1 latency in 245 congenitally deaf children fit with cochlear implants following various periods of auditory deprivation. If…

Speech production involves the integration of auditory, somatosensory, and motor information in the brain. This article describes a model of speech motor control in which a feedforward control system, involving premotor and primary motor cortex and the cerebellum, works in concert with auditory and somatosensory feedback control systems that…

The concept of pathologic left-handedness is reviewed, from historical and empirical perspectives. It is suggested that there is no adequate evidence to justify its continued use, and the fact that the concept is still much used may be the result of a desire to restore lost symmetry to the brain. (Author/CL)

Fifteen aphasic and 15 normal adults demonstrated use of a right hemisphere visuospatial strategy to analyze printed whole words and word parts such as prefixes and suffixes. The performances of the two groups were similar, suggesting that the hypothesized strategy could be useful as a reading approach for aphasics. (Author/CL)

Reviews research indicating linguistic knowledge is not innate, that the infant brain is highly differentiated at birth, that processing biases that lead to the "standard brain plan" are innate and localized but not specific to language, and that the infant brain is highly plastic, permitting alternative "brain plans." (Author/CR)

This review discusses how general principles of brain development have contributed to both human brain plasticity and the acquisition of the human capacity for speech. Specifically, the role played by plastic developmental processes in the evolution and development of articulate control over vocalization in speech is examined. (Contains…

Three studies investigated whether anatomical measures could separate phonologically based reading disability (PD) from non-phonologically based learning disabilities such as specific language impairments (SLI) in children. Results indicate that PD and SLI are qualitatively different disorders associated with anatomical deviations in opposite…

This article discusses findings concerning the plasticity of auditory cortical processing mechanisms in adults, including the effects of restricted cochlear damage or behavioral training with acoustic stimuli on the frequency selectivity of auditory cortical neurons and evidence for analogous injury- and use-related plasticity in the adult human…