Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 86
Filter
2.
Neuropsychol Rehabil ; 20(4): 601-23, 2010 Aug.
Article in English | MEDLINE | ID: mdl-20574915

ABSTRACT

This study examines the reasons for the success of Multiple Oral Re-reading (MOR; Moyer, 1979), a non-invasive, easily administered alexia treatment that has been reported in the literature and is currently in clinical use. The treatment consists of reading text passages aloud multiple times a day. Findings that MOR improves reading speed on practised as well as novel text have been inconsistent, making MOR's role in the rehabilitation of alexia unclear. We hypothesised that MOR's treatment mechanism works through repetition of high frequency words (i.e., bottom-up processing). We designed and controlled our text passages to test the hypothesis that participants would not improve on all novel text but would improve on text that includes a critical mass of the words contained in the passages they were re-reading. We further hypothesised that the improvement would be at the level of their specific alexic deficit. We tested four participants with phonological alexia and two with pure alexia during 8 weeks of MOR treatment. Contrary to the conclusions of previous studies, our results indicate that improvements in top-down processing cannot explain generalisation in MOR and that much of the improvement in reading is through repetition of the practised words. However, most patients also showed improvement when specific phrases were re-used in novel passages, indicating that practice of difficult words in context may be crucial to reading improvement.


Subject(s)
Dyslexia/physiopathology , Dyslexia/rehabilitation , Linguistics , Mental Processes/physiology , Reading , Teaching/methods , Aged , Female , Functional Laterality/physiology , Humans , Language Tests , Male , Middle Aged , Neuropsychological Tests , Treatment Outcome
3.
Phys Rev Lett ; 102(16): 161302, 2009 Apr 24.
Article in English | MEDLINE | ID: mdl-19518694

ABSTRACT

We constrain parity-violating interactions to the surface of last scattering using spectra from the QUaD experiment's second and third seasons of observations by searching for a possible systematic rotation of the polarization directions of cosmic microwave background photons. We measure the rotation angle due to such a possible "cosmological birefringence" to be 0.55 degrees +/-0.82 degrees (random) +/-0.5 degrees (systematic) using QUaD's 100 and 150 GHz temperature-curl and gradient-curl spectra over the spectra over the multipole range 200

4.
Neuropsychologia ; 40(2): 223-34, 2002.
Article in English | MEDLINE | ID: mdl-11640944

ABSTRACT

Patients with phonological alexia (difficulty reading pseudowords) frequently have concomitant difficulty reading functor words and verbs compared with concrete nouns. The current study compares two techniques for helping two patients with phonological alexia regain the ability to read functors and verbs. One technique follows the approach of reorganization of function, while the other relies on the stimulation approach. Study 1, employing a reorganization approach, resulted in both patients increasing their reading accuracy from approximately 10 to 90% or greater. Study 2, using a stimulation approach, resulted in significant improvement, however neither patient was able to achieve accuracy greater than 59%. Study 3 reverted back to the reorganization approach using the same words from Study 2. Both patients demonstrated significant success, achieving 90% or greater accuracy. Whereas the reorganization approach meets with far greater success than the stimulation approach, both approaches can be seen as instances of paired associate learning. An explanation of the advantage of the reorganization approach is developed which focuses on the nature of the pairings in the paired associate learning paradigm: it is proposed that pairings within the same level of representation are easier to learn than pairings that cut across levels of representation.


Subject(s)
Dyslexia/therapy , Reading , Semantics , Aged , Dyslexia/physiopathology , Dyslexia/rehabilitation , Female , Humans , Male , Mental Processes , Middle Aged , Task Performance and Analysis
5.
Neuron ; 30(2): 609-17, 2001 May.
Article in English | MEDLINE | ID: mdl-11395018

ABSTRACT

The hypothesis that ventral/anterior left inferior frontal gyrus (LIFG) subserves semantic processing and dorsal/posterior LIFG subserves phonological processing was tested by determining the pattern of functional connectivity of these regions with regions in left occipital and temporal cortex during the processing of words and word-like stimuli. In accordance with the hypothesis, we found strong functional connectivity between activity in ventral LIFG and activity in occipital and temporal cortex only for words, and strong functional connectivity between activity in dorsal LIFG and activity in occipital and temporal cortex for words, pseudowords, and letter strings, but not for false font strings. These results demonstrate a task-dependent functional fractionation of the LIFG in terms of its functional links with posterior brain areas.


Subject(s)
Brain Mapping , Frontal Lobe/physiology , Language , Occipital Lobe/physiology , Temporal Lobe/physiology , Adult , Brain/physiology , Female , Humans , Magnetic Resonance Imaging , Male , Neurons/physiology , Reading
6.
Brain Lang ; 72(3): 219-37, 2000 May.
Article in English | MEDLINE | ID: mdl-10764518

ABSTRACT

Following the notion that patients with pure alexia have access to two distinct reading strategies-letter-by-letter reading and semantic reading-a training program was devised to facilitate reading via semantics in a patient with pure alexia. Training utilized brief stimulus presentations and required category judgments rather than explicit word identification. The training was successful for trained words, but generalized poorly to untrained words. Additional studies involving oral reading of nouns and of functors also resulted in improved reading of trained words. Pseudowords could not be trained to criterion. The results suggest that improved reading can be achieved in pure alexia by pairing rapidly presented words with feedback. Focusing on semantic processing is not essential to this process. It is proposed that the training strengthens connections between the output of visual processing and preexisting orthographic representations.


Subject(s)
Dyslexia/diagnosis , Dyslexia/therapy , Semantics , Vocabulary , Humans , Male , Middle Aged
7.
J Cogn Neurosci ; 12(2): 281-97, 2000 Mar.
Article in English | MEDLINE | ID: mdl-10771412

ABSTRACT

Brain activation studies of orthographic stimuli typically start with the premise that different types of orthographic strings (e.g., words, pseudowords) differ from each other in discrete ways, which should be reflected in separate and distinct areas of brain activation. The present study starts from a different premise: Words, pseudowords, letterstrings, and false fonts vary systematically across a continuous dimension of familiarity to English readers. Using a one-back matching task to force encoding of the stimuli, the four types of stimuli were visually presented to healthy adult subjects while fMRI activations were obtained. Data analysis focused on parametric comparisons of fMRI activation sites. We did not find any region that was exclusively activated for real words. Rather, differences among these string types were mainly expressed as graded changes in the balance of activations among the regions. Our results suggest that there is a widespread network of brain regions that form a common network for the processing of all orthographic string types.


Subject(s)
Brain Mapping , Brain/physiology , Reading , Visual Pathways/physiology , Writing , Adult , Female , Humans , Language , Magnetic Resonance Imaging/methods , Male , Middle Aged , Models, Statistical , Parietal Lobe/physiology , Temporal Lobe/physiology
9.
Neuropsychology ; 13(3): 350-8, 1999 Jul.
Article in English | MEDLINE | ID: mdl-10447297

ABSTRACT

Patients with probable Alzheimer's disease (AD) are reported to show mild, but reliable, difficulties reading aloud and spelling to dictation exception words, which have unusual or unpredictable correspondence between their spelling and pronunciation (e.g., touch). To understand the cognitive dysfunction responsible for these impairments, 21 patients and 27 age-and education-matched controls completed specially designed tests of single-word oral reading and spelling to dictation. AD patients performed slightly below controls on all tasks and showed mildly exaggerated regularity effects (i.e., the difference in response accuracy between words with regular spellings minus exception words) in reading and spelling. Qualitative analyses, however, did not demonstrate response patterns consistent with impairment in central lexical orthographic processing. The authors conclude that the mild alexia and agraphia in AD reflect semantic deficits and nonlinguistic impairments rather than a specific disturbance in lexical orthographic processing.


Subject(s)
Alzheimer Disease/complications , Alzheimer Disease/diagnosis , Reading , Speech Disorders/etiology , Verbal Behavior , Aged , Cognition Disorders/diagnosis , Cognition Disorders/etiology , Female , Humans , Male , Neuropsychological Tests , Probability , Severity of Illness Index
10.
Neuropsychologia ; 37(7): 807-15, 1999 Jun.
Article in English | MEDLINE | ID: mdl-10408648

ABSTRACT

Different kinds of real words and pronounceable pseudowords (PWs) were presented for writing to dictation to patients with the diagnosis of probable Alzheimer's disease (AD) and to age- and education-matched healthy controls. Though spelling less accurately on all tasks, AD patients responded in a manner generally qualitatively similar to controls. Except for a slightly enhanced effect of spelling regularity in real word writing accuracy, AD patients showed the same sensitivity to various lexical, orthographic and phonological variables as controls. Both groups showed no difference in spelling accuracy for words and PWs with regular vs ambiguous spelling patterns, and groups also showed similar orthographic preferences when spelling PWs having several different acceptable pronunciations. Finally, AD patients and controls produced similar types of errors when spelling real words. Dementia severity was related to the overall accuracy, but not to the pattern, of spelling responses. It is suggested that the decline in response accuracy in cognitively demanding writing tasks in patients with more advanced dementia is most likely due to semantic impairment and impairments of nonlinguistic functions of attention, executive control and praxis, rather than to a disturbance within language specific processes.


Subject(s)
Agraphia/physiopathology , Alzheimer Disease/physiopathology , Alzheimer Disease/psychology , Cognition Disorders/physiopathology , Cognition Disorders/psychology , Aged , Aging , Alzheimer Disease/complications , Attention , Case-Control Studies , Chi-Square Distribution , Cognition Disorders/etiology , Educational Status , Female , Humans , Linguistics , Male , Matched-Pair Analysis , Severity of Illness Index , Word Association Tests
11.
Brain Lang ; 67(3): 188-201, 1999 May.
Article in English | MEDLINE | ID: mdl-10210630

ABSTRACT

An experimental treatment study designed to improve both the accuracy and the speed of reading was administered to a patient with pure alexia and impaired letter naming. The study focused on the use of letter-by-letter reading. A two-stage approach was employed. The first stage implemented a tactile-kinesthetic strategy to improve accuracy. The second stage concentrated on speed. At the end of the treatment, patient DL was reading both trained and untrained words more accurately and with considerably greater speed than prior to treatment. Accuracy and speed of reading at the sentence level improved as well.


Subject(s)
Dyslexia, Acquired/therapy , Linguistics , Reading , Aged , Dyslexia, Acquired/diagnosis , Humans , Kinesthesis , Male , Severity of Illness Index , Touch/physiology , Treatment Outcome
12.
Int J Radiat Oncol Biol Phys ; 44(2): 289-96, 1999 May 01.
Article in English | MEDLINE | ID: mdl-10760421

ABSTRACT

PURPOSE: Chemotherapy and accelerated superfractionated radiotherapy were prospectively applied for inflammatory breast carcinoma with the intent of breast conservation. The efficacy, failure patterns, and patient tolerance utilizing this approach were analyzed. METHODS AND MATERIALS: Between 1983 and 1996, 52 patients with inflammatory breast carcinoma presented to the Medical College of Virginia Hospitals of VCU and the New England Medical Center. Thirty-eight of these patients were jointly evaluated in multidisciplinary breast clinics and managed according to a defined prospectively applied treatment policy. Patients received induction chemotherapy, accelerated superfractionated radiotherapy, selected use of mastectomy, and concluded with additional chemotherapy. The majority were treated with 1.5 Gy twice daily to field arrangements covering the entire breast and regional lymphatics. An additional 18-21 Gy was then delivered to the breast and clinically involved nodal regions. Total dose to clinically involved areas was 63-66 Gy. Following chemoradiotherapy, patients were evaluated with physical examination, mammogram, and fine needle aspiration x 3. Mastectomy was reserved for those patients with evidence of persistent or progressive disease in the involved breast. All patients received additional chemotherapy. RESULTS: Median age was 51 years. Median follow-up was 23.9 months (6-86) months. The breast preservation rate at the time of last follow-up was 74%. The treated breast or chest wall as the first site of failure occurred in only 13%, and the ultimate local control rate with the selected use of mastectomy was 74%. Ten patients underwent mastectomy, 2 of which had pathologically negative specimens despite a clinically palpable residual mass. Response to chemotherapy was predictive of treatment outcome. Of the 15 patients achieving a complete response, 87% remain locoregionally controlled without the use of mastectomy. Five-year overall survival for complete responders was 68%. This is in contrast to the 14% 5-year overall survival observed with incomplete responders. The 5-year actuarial disease-free survival and overall survival for the entire patient cohort was 11% and 33%, respectively. All patients tolerated irradiation with limited acute effects, of which all were managed conservatively. CONCLUSION: Our experience demonstrates that induction chemotherapy, accelerated superfractionated radiotherapy, and the selected use of mastectomy results in excellent locoregional control rates, is well tolerated, and optimizes breast preservation. Based on our present results, we recommend that a patient's response to induction chemotherapy guide the treatment approach used for locoregional disease, such that mastectomy be reserved for incomplete responders and avoided in those achieving a complete response.


Subject(s)
Adenocarcinoma/drug therapy , Adenocarcinoma/radiotherapy , Breast Neoplasms/drug therapy , Breast Neoplasms/radiotherapy , Carcinoma, Ductal, Breast/drug therapy , Carcinoma, Ductal, Breast/radiotherapy , Adenocarcinoma/surgery , Adult , Aged , Breast Neoplasms/surgery , Carcinoma, Ductal, Breast/surgery , Combined Modality Therapy , Cyclophosphamide/administration & dosage , Decision Trees , Disease-Free Survival , Dose Fractionation, Radiation , Doxorubicin/administration & dosage , Female , Fluorouracil/administration & dosage , Follow-Up Studies , Humans , Mastectomy , Methotrexate/administration & dosage , Middle Aged , Prospective Studies , Remission Induction , Treatment Failure
13.
Brain Lang ; 63(1): 32-49, 1998 Jun 01.
Article in English | MEDLINE | ID: mdl-9642019

ABSTRACT

Repetition and reading of various types of pronounceable nonwords (pseudowords) was examined in patients with probable Alzheimer's disease (AD) and healthy elderly controls. Overall accuracy of performance was lower in AD patients compared to controls, but the two groups showed qualitatively similar response patterns when reading different kinds of pseudowords aloud and when repeating pseudowords composed of familiar phonological forms, analogous to those in real English words. AD patients diverged in performance from controls, however, when repeating pseudowords composed of phonologically unusual forms. These results support two conclusions: (1) Aspects of phonological processing may become disrupted in AD patients in association with increasing dementia severity, while orthographic processing remains comparatively less impaired. (2) The results are consistent with the view that the processing of pseudowords is achieved through the same system as real words, and further show that the influence of prior language experience on the processing of novel linguistic forms occurs primarily at the level of phonological, rather than orthographic processing.


Subject(s)
Alzheimer Disease/psychology , Language Disorders/psychology , Aged , Alzheimer Disease/complications , Analysis of Variance , Dyslexia, Acquired/etiology , Dyslexia, Acquired/psychology , Humans , Language Disorders/etiology , Phonetics , Psycholinguistics , United States
14.
Neuropsychology ; 12(2): 218-24, 1998 Apr.
Article in English | MEDLINE | ID: mdl-9556768

ABSTRACT

Semantic memory impairment was investigated in patients with probable Alzheimer's disease (AD) using a threshold oral word reading task to assess priming of different lexical relationships. Healthy elderly controls showed significant priming for associatively related nouns (tempest-teapot) and also for nouns semantically related either because both designate basic-level exemplars of a common superordinate category (cousin-nephew) or because the target names the superordinate category of the prime (daughter-relative). AD patients, in contrast, showed preserved priming of lexical associates but impaired priming of certain semantic relationships. They showed no priming between words designating coordinate exemplars within a category, despite preserved priming of the superordinate category label. Findings are consistent with the view that at least part of the semantic deficit in AD is due to disruption of semantic knowledge that affects relationships among basic-level concepts, more than the relationships between these concepts and their corresponding superordinate category of membership.


Subject(s)
Alzheimer Disease/physiopathology , Association , Cues , Reading , Semantics , Vocabulary , Adult , Aged , Aged, 80 and over , Case-Control Studies , Concept Formation/physiology , Female , Humans , Male , Middle Aged
16.
Brain Lang ; 56(2): 234-47, 1997 Feb 01.
Article in English | MEDLINE | ID: mdl-9027372

ABSTRACT

Recent evidence from patients with progressive language disorders and dementia has been used to suggest that phonological and orthographic processing depend on intact semantic memory. These claims challenge the traditional view that there are functionally separate modules in the language system. The effect of a severe, but nonprogressive, semantic impairment on phonological and orthographic processing was evaluated in LA, a mentally retarded child with hyperlexia. Knowledge of a word's meaning did not affect LA's word repetition, a measure of phonological processing, or his acquisition and retention of orthographic patterns for writing to dictation low-frequency words with exceptional spellings. These findings support the assertion that both orthographic and phonological whole-word representations can be acquired, stored, and retrieved in the absence of a functional link to semantic memory.


Subject(s)
Language Disorders/complications , Memory Disorders/complications , Memory Disorders/diagnosis , Phonetics , Semantics , Child , Humans , Male , Reading , Verbal Learning
17.
Cortex ; 33(4): 653-66, 1997 Dec.
Article in English | MEDLINE | ID: mdl-9444467

ABSTRACT

Repetition of single words and pronounceable nonwords (pseudowords) was assessed in Alzheimer's Disease (AD) patients to evaluate how lexical phonological processing might be accomplished when semantic and conceptual knowledge is impaired. AD patients performed significantly worse than healthy elderly controls on all repetition tasks. However, repetition abilities and dementia severity were not correlated, and AD patients produced the same distribution of error types as controls. Furthermore, despite their semantic problems, AD patients, like controls, showed a significant advantage for repeating real words compared to pseudowords, even when repeating low frequency phonologically complex words whose meaning is not likely to have been retained. The results support the postulated existence of a lexical phonological system that is used to repeat both known and novel words and that processes linguistic information independent of its meaning.


Subject(s)
Alzheimer Disease/psychology , Memory/physiology , Verbal Learning/physiology , Aged , Humans , Mental Processes/physiology , Neuropsychological Tests , Semantics
18.
Acad Med ; 71(9): 979-81, 1996 Sep.
Article in English | MEDLINE | ID: mdl-9125986

ABSTRACT

The Internet's World Wide Web (WWW) offers educators a unique opportunity to introduce computer-assisted instructional (CAI) programs into the medical school curriculum. With the WWW, CAI programs developed at one medical school could be successfully used at other institutions without concern about hardware or software compatibility; further, programs could be maintained and regularly updated at a single central location, could be distributed rapidly, would be technology-independent, and would be presented in the same format on all computers. However, while the WWW holds promise for CAI, the author discusses ten reasons that educators' efforts to fulfill the Web's promise may fail, including the following: CAI is generally not fully integrated into the medical school curriculum; students are not tested on material taught using CAI; and CAI programs tend to be poorly designed. The author argues that medical educators must overcome these obstacles if they are to make truly effective use of the WWW in the classroom.


Subject(s)
Computer Communication Networks , Computer-Assisted Instruction/standards , Education, Medical/methods , Humans , United States
19.
Brain Lang ; 52(1): 114-28, 1996 Jan.
Article in English | MEDLINE | ID: mdl-8741978

ABSTRACT

Reports of five patients whose deep alexic reading all evolved into phonological alexia in a similar fashion point to the hypothesis that deep alexia and phonological alexia represent different points on the same continuum. This hypothesis is explored further through an examination of previously published case reports of eleven patients with phonological alexia. Data from these patients suggest that there is a predictable succession of symptoms which form a continuum of severity of phonological alexia, with deep alexia as its endpoint. An account of the recovery from deep to phonological alexia, based upon a lexical (no-rules) model of reading, is provided (Glosser & Friedman, 1990), and the implications for therapy are considered. The significance of the notion of a continuum of phonological/deep alexia is discussed.


Subject(s)
Brain/physiopathology , Convalescence , Dyslexia, Acquired/physiopathology , Adolescent , Adult , Dyslexia, Acquired/diagnosis , Female , Functional Laterality , Humans , Male , Semantics
20.
Cortex ; 31(2): 397-403, 1995 Jun.
Article in English | MEDLINE | ID: mdl-7555016

ABSTRACT

It is hypothesized, on the basis of a lexical model of reading, that there are two different underlying causes of phonological alexia. It is predicted that these two types of phonological alexia will be accompanied by different sets of symptoms. Published cases of phonological alexia are examined for evidence in support of these predictions. Two distinct groups of phonological alexic patients are observed. These results support the notion of two types of phonological alexia. The failure to find any phonological alexic patients who do not fall into one of these two categories provides evidence against non-lexical reading models.


Subject(s)
Dyslexia, Acquired/diagnosis , Reading , Dyslexia, Acquired/classification , Humans , Language , Models, Psychological , Task Performance and Analysis
SELECTION OF CITATIONS
SEARCH DETAIL
...