1/3. Classical anomia: a neuropsychological perspective on speech production.We present data collected from two anomic aphasics. Thorough assessment of comprehension, oral reading and repetition revealed no underlying impairments suggesting that both patients were examples of classical anomia--word-finding difficulties without impaired semantics or phonology. We describe a series of experiments in which the degree of anomia was both increased and decreased, by cueing or priming with either a semantically related word or the target item. One of the patients also presented with an 'acquired' tip-of-the-tongue phenomenon. He was able to indicate with a high-degree of accuracy the syllable length of the target, and whether or not it was a compound word. Neither patient could provide the first sound/letter. The data are discussed in terms of discrete two-stage models of speech production, an interactive-activation theory and a distributed model in which the positive and negative computational consequences of the arbitrary relationship between sound and meaning are emphasised.- - - - - - - - - - ranking = 1keywords = reading (Clic here for more details about this article) |
2/3. names and words without meaning: incidental postmorbid semantic learning in a person with extensive bilateral medial temporal damage.The authors describe a densely amnesic man who has acquired explicit semantic knowledge of famous names and vocabulary words that entered popular culture after the onset of his amnesia. This new semantic knowledge was temporally graded and existed over and above the implicit memory he demonstrated in reading speed and accuracy, familiarity ratings, and his ability to make correct guesses on unfamiliar items. However, his postmorbid knowledge was limited to verbal labels denoting famous people and words; he possessed virtually no explicit knowledge of the meaning of these words or the identities of these individuals, although there was some evidence that some of this information had been acquired at an implicit level. Findings are discussed in the context of a neural network model (J. L. McClelland, B. L. McNaughton, & R. C. O'Reilly, 1995) of semantic acquisition.- - - - - - - - - - ranking = 1keywords = reading (Clic here for more details about this article) |
3/3. Investigating the neurobiological basis of cognitive rehabilitation therapy with fMRI.The neurobiological changes occurring during cognitive rehabilitation therapy (CRT) have yet to be systematically studied. In the present study, functional magnetic resonance imaging (fMRI) was used to demonstrate brain plasticity in response to CRT (n = 5) following mild traumatic brain injury. neuropsychological tests and two fMRI activation tasks, a visually guided saccades and a reading comprehension task, were employed pre- and post-CRT. CRT was used to systematically address the identified deficits in visual scanning and language processing. As hypothesized, changes in the pattern and extent of activation within expected neuroanatomical areas occurred post-CRT. Changes in fMRI activation are discussed for each subject and related to changes on neuropsychological measures. This study demonstrates how fMRI can illustrate the neurobiological mechanisms of recovery in individual subjects. The variability in subject responses to CRT supports the notion of tailoring rehabilitation strategies to each subject in order to optimize recovery following brain injury.- - - - - - - - - - ranking = 1keywords = reading (Clic here for more details about this article) |