1/263. Lexical access via letter naming in a profoundly alexic and anomic patient: a treatment study. We report the results of a letter naming treatment designed to facilitate letter-by-letter reading in an aphasic patient with no reading ability. Patient M.R.'s anomia for written letters reflected two loci of impairment within visual naming: impaired letter activation from print (a deficit commonly seen in pure alexic patients who read letter by letter) and impaired access to phonology via semantics (documented in a severe multimodality anomia). Remarkably, M.R. retained an excellent ability to pronounce orally spelled words, demonstrating that abstract letter identities could be activated normally via spoken letter names, and also that lexical phonological representations were intact when accessed via spoken letter names. M.R.'s training in oral naming of written letters resulted in significant improvement in her oral naming of trained letters. Importantly, as M.R.'s letter naming improved, she became able to employ letter-by-letter reading as a compensatory strategy for oral word reading. M.R.'s success in letter naming and letter-by-letter reading suggests that other patients with a similar pattern of spared and impaired cognitive abilities may benefit from a similar treatment. Moreover, this study highlights the value of testing the pronunciation of orally spelled words in localizing the source of prelexical reading impairment and in predicting the functional outcome of treatment for impaired letter activation in reading. ( info) |
2/263. Treatment of naming disorders: new issues regarding old therapies. I report a series of single case studies involving an aphasic patient, H.G., which illustrates both the usefulness and the limitations of cognitive neuropsychological models and methods in aphasia rehabilitation. The first set of experiments analyze H.G.'s pattern of performance across lexical tasks in order to identify the loci of her damage to the cognitive mechanisms underlying the tasks of naming, comprehension, repetition, reading, and spelling. The second set of studies evaluates her response to two different types of treatment and identifies a few of the variables that influence the effectiveness of treatment. ( info) |
3/263. Phonological naming therapy in jargon aphasia: positive but paradoxical effects. This article is a single-case investigation of phonological naming therapy. The individual involved had fluent jargon speech, with neologisms, verbal paraphasias, and paragrammatisms. The jargon was underpinned by a severe anomia. Content words were rarely accessed either in spontaneous speech or naming. Single word investigations highlighted some preserved skills. Auditory comprehension, at least for concrete words, was relatively intact and although nonwords could not be repeated, words could, and at a level which was far superior to naming. The patient also had some ability to respond to phonological cues. These results suggested that phonological representations were preserved and that there were some intact semantic abilities. It seemed that the naming disorder was primarily due to an inability to access phonology from semantics. Therapy took a phonological approach. The patient was encouraged to reflect upon the syllabic structure and first phoneme of pictured targets. Subsequently, she was required to use this partial phonological knowledge as a self-cue. It was hypothesized that this therapy might equip the subject with a self-cuing naming strategy. Posttherapy investigations of naming demonstrated dramatic improvements, which generalized to untreated items. However, there was little evidence that these were due to a self cuing strategy. Performance on phonological judgment and discrimination assessments, which required conscious phonological reflection, was unchanged, and there were no signs that the patient was self-cuing during naming. Reasons for these paradoxical results are discussed. ( info) |
4/263. Proper name anomia after left temporal lobectomy: a patient study. A patient with a selective deficit in retrieving proper names after left temporal lobectomy is reported. He showed proper name anomia in conversation, in response to photographs, and in verbal descriptions, despite being able to provide semantic information about the people he was unable to name. This report provides evidence that the rostral part of the left temporal lobe plays a crucial role in processing proper names without involvement of other verbal functions. ( info) |
5/263. Pure anomic aphasia caused by a subcortical hemorrhage in the left temporo-parieto-occipital lobe. There have been few case reports of pure anomic aphasia and the underlying mechanism remains to be clarified. We report a patient in whom pure anomic aphasia was caused by subcortical hemorrhage in the left temporo-parieto-occipital lobe. Based on magnetic resonance images and cerebral blood flow imaging, the structural lesion underlying the pure anomic aphasia was thought to be located at the left temporo-occipital junction. ( info) |
6/263. Selective sparing of verb naming in a case of severe Alzheimer's disease. A patient with severe Alzheimer's disease (AD) presented with a severe impairment in naming nouns but selective sparing of the naming of verbs. Her impairment in naming nouns was presented across a wide range of categories investigated. To our knowledge, this is the first case documenting the selective preservation of verb naming in a patient with AD. The implications for the notion of an intrinsic vulnerability of verb naming in AD and for the current knowledge of anatomical correlates of noun/verb processing are discussed. ( info) |
7/263. Functional roles of Broca's area and SMG: evidence from cortical stimulation mapping in a deaf signer. The importance of the left hemisphere in language function has been firmly established and current work strives to understand regional specializations within the perisylvian language areas. This paper reports a case study of a deaf user of American sign language undergoing an awake cortical stimulation mapping procedure. Patterns of sign errors accompanying electrical stimulation of Broca's area and the supramarginal gyrus (SMG) are reported. Our findings show Broca's area to be involved in the motor execution of sign language. These data demonstrate that the linguistic specificity of Broca's area is not limited to speech behavior. In addition, unusual semantic-phonological errors were observed with stimulation to the SMG; these data may implicate the SMG in the binding of linguistic features in the service of language production. Taken together, these findings provide important insight into the linguistic specificity of Broca's area and the functional role of the supramarginal gyrus in language processing. ( info) |
8/263. A progressive category-specific semantic deficit for non-living things. We report a longitudinal study of a patient, ES, with a progressive degenerative disorder resulting from generalised cerebral atrophy. Across a range of tasks, ES showed a greater difficulty in recognising and naming artifacts than living things. This deficit for artifacts emerged over time, as she became more severely impaired. In one task, picture naming, there was a crossover from an initial deficit for living things to the later artifact deficit. All materials were carefully controlled to rule out potential confounding factors such as concept familiarity or age of acquisition. There was no evidence that ES's deficit for artifacts was associated with a greater loss of functional than visual information. The pattern of results are consistent with a recently proposed distributed connectionist model, in which a deficit for artifact concepts can emerge as the result of severe, general damage to semantic memory. ( info) |
9/263. The nature of the disorder underlying the inability to retrieve proper names. Two patients with the syndrome of proper name anomia were investigated. Both patients were only able to produce around 50% of the names of contemporary celebrities, but performed significantly better on a task calling for naming of historical figures. The names of relatives and friends were spared in one patient, while the other retrieved names of people known since childhood much better than those of people familiar to him since the age of 25. Geographical names, names of monuments and masterpieces were preserved. The above dissociations are taken to imply that in moderately impaired patients, a temporal gradient effect concurs to modulate the severity of the naming block. A similar impairment was found in both patients when they attempted to retrieve or relearn familiar telephone numbers. This finding suggests that the core of the disorder resides in the inability to gain access to words used to identify a single entity, regardless of whether they belong to the class of proper or common names. ( info) |
10/263. The role of speech production in auditory-verbal short-term memory: evidence from progressive fluent aphasia. We report investigations of auditory-verbal short-term memory (AVSTM) in a patient with progressive fluent anomic aphasia. Despite having apparently normal AVSTM as measured by digital span, FM was significantly impaired in immediate serial recall of short sequences of familiar words, and even in reproducing a single word after a filled delay of just a few seconds. In both tasks, unlike normal subjects, she produced numerous phonological errors, often consisting of phonological segments from the intended target word concatenated with segments from other words in the stimulus sequence. Her success in these tasks was modulated (i) consistently by word frequency (high > low), (ii) inconsistently by word imageability (high > low), and (iii) most dramatically by 'nameability': that is, FM was much more likely to reproduce a word correctly in AVSTM if it was a word that she could also produce successfully in picture-naming tasks. On the basis of these and additional experiments designed to exclude other interpretations, we conclude that AVSTM may be crucially supported by activation of the lexical phonological representations responsible for production of content words in speech. ( info) |