Imagery or meaning? Evidence for a semantic origin of category-specific brain activity in metabolic imaging

from the European Journal of Neuroscience

Category-specific brain activation distinguishing between semantic word types has imposed challenges on theories of semantic representations and processes. However, existing metabolic imaging data are still ambiguous about whether these category-specific activations reflect processes involved in accessing the semantic representation of the stimuli, or secondary processes such as deliberate mental imagery. Further information about the response characteristics of category-specific activation is still required. Our study for the first time investigated the differential impact of word frequency on functional magnetic resonance imaging (fMRI) responses to action-related words and visually related words, respectively. First, we corroborated previous results showing that action-relatedness modulates neural responses in action-related areas, while word imageability modulates activation in object processing areas. Second, we provide novel results showing that activation negatively correlated with word frequency in the left fusiform gyrus was specific for visually related words, while in the left middle temporal gyrus word frequency effects emerged only for action-related words. Following the dominant view in the literature that effects of word frequency mainly reflect access to lexico-semantic information, we suggest that category-specific brain activation reflects distributed neuronal ensembles, which ground language and concepts in perception-action systems of the human brain. Our approach can be applied to any event-related data using single-stimulus presentation, and allows a detailed characterization of the functional role of category-specific activation patterns.

Humans have more distinctive hearing than animals, Hebrew U study shows

from EurekAlert.org

Do humans hear better than animals? It is known that various species of land and water-based living creatures are capable of hearing some lower and higher frequencies than humans are capable of detecting. However, scientists from the Hebrew University of Jerusalem and elsewhere have now for the first time demonstrated how the reactions of single neurons give humans the capability of detecting fine differences in frequencies better than animals.

Amateur singers, singing teachers less likely to identify serious vocal problems

from EurekAlert.org

Even as American Idol reminds us of the best (and worst) that singing has to offer, a new study cautions that amateur singers and singing instructors are less sensitive than their professional peers to the subtle changes to their voices that could have a serious negative impact on their vocal health.

New Therapies Fight Phantom Noises of Tinnitus

from the New York Times

Modern life is loud. The jolting buzz of an alarm clock awakens the ears to a daily din of trucks idling, sirens blaring, televisions droning, computers pinging and phones ringing — not to mention refrigerators humming and air-conditioners thrumming. But for the 12 million Americans who suffer from severe tinnitus, the phantom tones inside their head are louder than anything else.

Left/Right Differences In How Brains Are Wired

from Medical News Today.com

It’s well known that the left and right sides of the brain differ in many animal species and this is thought to influence cognitive performance and social behaviour. For instance, in humans, the left half of the brain is concerned with language processing whereas the right side is better at comprehending musical melody.

Exploring the elements of narrative that emerge in the interactions between an 8-year-old child who uses an AAC device and her teacher

from AAC: Augmentative and Alternative Communication

Narrative abilities have been identified as a link to successful school achievement and, in particular, to the acquisition of literacy. Children who use AAC may be at risk of impaired narrative facility due to the differences in their language learning experiences, limitation of their AAC systems, and limitations from constrained access to physical and social environments. In this study, the elements of narrative that emerged in the interactions between an 8-year-old child who used an AAC device and her teacher are described. This assessment was achieved through use of the Narrative Assessment Profile (Bliss, McCabe, & Miranda, 1998) in the context of five tasks designed to elicit a spectrum of narrative features. Results indicate that the interactions between the child and her teacher made it difficult to assess whether or not the child had control of certain features of narrative. From a purely structural analysis, most narrative discourse dimensions appeared to be severely compromised and therefore in need of immediate intervention. Discussion includes aspects of narrative intervention and suggested topics for further research.

Inner speech: Microgenetic concepts

from Aphasiology

Background: There have been many attempts to characterise and interpret inner speech in normal individuals and in aphasia. In studies of aphasic patients, the role of the anterior and posterior language areas has been noted. The present study takes a new direction in this effort, in exploring the analysis of errors or symptoms from the standpoint of microgenetic theory, in patients with auditory hallucination and disorders of motor speech. The paper describes a model of inner speech that follows on a process theory of aphasia and auditory hallucination, consistent with current imaging research.

Aims: The aim of the study is to provide a new, yet coherent, model of inner speech that departs from traditional ways of thinking yet extends and incorporates prior research studies.

Methods and Procedures: The methodology is descriptive and qualitative, based on an interpretation of the significance of errors in language and auditory perception. It is argued that an understanding of patterns of symptom formation can yield an account of the momentary appearance of pre-processing phases as symptoms or errors, and thus the process underlying normal language production and perception.

Outcomes and Results: The outcome of this study is a model of inner speech that is supported by diverse clinical findings.

Conclusions: Inner speech has a motoric (action) component organised in the (left) anterior language area, and a perceptual component, organised in the left posterior language area. The relative specification, moment to moment, in anterior and posterior processing systems, and thus the degree of derivation of speech and speech perception in each mind/brain state, determines whether the primary phenomenon is speech, speech perception, auditory hallucination, or inner speech. These phenomena lie on a continuum that is revealed by its disruptions in pathology.

Breaking Through Verbal Apraxia

from Topix.net

At age 1, my son Eli was diagnosed with essential tremor. By a year and a half, we became concerned about his lack of speech. via Metro Parent