Biomedical subjects

Janet L Ingles

Publications and source records attributed to Janet L Ingles.

4 recordsLinked to original sources

PubMed2007

Temporal processing deficits in letter-by-letter reading.

Theories of the cognitive impairment underlying letter-by-letter reading vary widely, including prelexical and lexical level deficits. One prominent prelexical account proposes that the disorder results from difficulty in processing multiple letters simultaneously. We investigated whether this deficit extends to letters presented in rapid temporal succession. A letter-by-letter reader, G.M., was administered a rapid serial visual presentation task that has been used widely to study the temporal processing characteristics of the normal visual system. Comparisons were made to a control group of 6 brain-damaged individuals without reading deficits. Two target letters were embedded at varying temporal positions in a stream of rapidly presented single digits. After each stream, the identities of the two letters were reported. G.M. required an extended period of time after he had processed one letter before he was able to reliably identify a second letter, relative to the controls. In addition, G.M.'s report of the second letter was most impaired when it immediately followed the first letter, a pattern not seen in the controls, indicating that G.M. had difficulty processing the two items together. These data suggest that a letter-by-letter reading strategy may be adopted to help compensate for a deficit in the temporal processing of letters.

Adult↗

PubMed2005

Disconnection of language and memory in semantic dementia: a comparative and theoretical analysis.

In this paper, we present an illustrative case of Semantic Dementia (SD) and we review the literature on this relatively rare progressive neurodegenerative disorder. After reviewing the clinical, neuroimaging, neuropathological, and genetic features of SD, we propose a theoretical framework that addresses features of SD and relates them to features of other well known neuropsychiatric syndromes. Our 'on-line / off-line disconnection' model seeks to conceptualize SD as a syndrome of disconnection between two large distributed cortical networks, namely, between those networks that subserve language function and those that subserve memory function.

Brain↗

PubMed2002

Neuropsychological predictors of incident dementia in patients with vascular cognitive impairment, without dementia.

BACKGROUND: Vascular cognitive impairment that does not fulfill dementia criteria (ie, vascular cognitive impairment, no dementia [CIND]) is common. Although progression to dementia is frequent, little is known about factors that predict progression. We examined whether performance on neuropsychological tests administered at baseline could predict incident cases of dementia in patients with vascular CIND after 5 years. Summary of Report- The Canadian Study of Health and Aging is a prospective, cohort study of 10 263 randomly selected persons aged > or =65 years. Of 149 people diagnosed with vascular CIND, 125 completed a battery of neuropsychological tests at baseline. Follow-up cognitive diagnoses were available for 102 individuals. After 5 years, 45 patients (44%) developed dementia. Low baseline scores on tests of memory and category fluency were associated with incident dementia. CONCLUSIONS: Neuropsychological measures can indicate risk of dementia in patients with vascular CIND. This study did not suggest a prediction-to-progression profile distinct from that seen in Alzheimer disease.

Aged↗

PubMedDate not supplied

Five-year outcomes for dementia defined solely by neuropsychological test performance.

Cognitive impairment that does not meet criteria for dementia is common and progresses to dementia at a high rate. It is not clear how best to define this type of cognitive impairment. We assessed the predictive validity of different case definitions for cognitive impairment and dementia by comparing rates of adverse outcomes for individuals who did not meet dementia criteria but had neuropsychological test results indicating dementia (NPDementia), those who had traditional dementia diagnoses (mild and moderate-severe severity), those who had other cognitive impairment but no dementia (CIND), and those with no cognitive impairment (NCI). Our sample comprised 1,659 participants who had completed a neuropsychological assessment in the Canadian Study of Health and Aging, a prospective, cohort study of 10,263 randomly selected persons aged 65 years or older. Outcomes were determined after 5 years. Institutionalization and death rates for the NPDementia and CIND groups were higher than for the NCI group. Both groups had lower institutionalization rates than the two Dementia groups and lower death rates than the Moderate-Severe Dementia group. Rates of progression to dementia were increased in NPDementia and CIND groups, relative to the NCI group, and the NPDementia group was less likely than the CIND group to revert to a diagnosis of NCI at the 5-year follow-up. Thus, individuals with NPDementia and CIND have substantially worse outcomes over 5 years than those with NCI. The case definition of NPDementia identified individuals with cognitive impairment that is unlikely to resolve and likely to progress to dementia.

Aged↗