Biomedical subjects

Heather Stewart

Publications and source records attributed to Heather Stewart.

3 recordsLinked to original sources

PubMed2004

Is impaired executive function a single or multidimensional disability?

This study was undertaken to determine if certain logical relations might be found in two pairs of similar executive functioning tasks: (a) Design Fluency and Word Fluency, and (b) the Tinker Toy and Story Telling Tests. Overall, the results were "inconsistent," with there being no meaningful relations found between tests with regard to similarities in task demand, theoretical hierarchical relations, or whether the tasks were verbal or nonverbal (with the exception of a very close relation between Design Fluency and Tinker Toy Test.). Despite the apparent entropy of the findings, they have substantial clinical and theoretical importance given the simultaneously rigid and weak-minded definitions and measures of disexecutive disability in current use.

Adult↗

PubMed2003

Age differences in young children's responses to open-ended invitations in the course of forensic interviews.

To elucidate age differences in responses to free-recall prompts (i.e., invitations and cued invitations) and focused recognition prompts (i.e., option-posing and suggestive utterances), the authors examined 130 forensic interviews of 4- to 8-year-old alleged victims of sexual abuse. There were age differences in the total number of details elicited as well as in the number of details elicited using each of the different types of prompts, especially invitations. More details were elicited from older than from younger children in response to all types of prompts, but there were no age differences in the proportion of details (about 50%) elicited using invitations. Cued invitations elicited 18% of the total details, and the number of details elicited using cued invitations increased with age. Action-based cues consistently elicited more details than other types of cues.

Age Factors↗

PubMed2002

Corticomotoneuronal connections in primary lateral sclerosis (PLS).

BACKGROUND: The relationship between primary lateral sclerosis (PLS) and amyotrophic lateral sclerosis (ALS) is uncertain. The slow progression and dominant upper motor neuron features of PLS are associated with a high threshold to cortical magnetic stimulation and sometimes slow central motor conduction. In ALS the cortical threshold may be reduced early in the disease and central conduction is usually normal. Corticomotoneuronal function appears to be impaired differently in PLS and ALS. SUBJECTS AND METHODS: We assessed corticomotoneuronal function by analyzing the primary peak in the peristimulus time histograms (PSTHs) in 12 PLS and 12 ALS patients. Surface recorded motor evoked potentials (MEPs) and central motor conduction time (CMCT) were determined. PSTHs were constructed from 4-5 different, voluntarily recruited motor units in each patient and the onset latency, number of excess bins, duration and synchrony of the primary peak were measured. RESULTS: The mean cortical threshold of single motor units in PLS was 73.6%, significantly higher than in ALS (60.3%; p < 2.2 x 10(-5)). Profoundly delayed primary peaks occurred in both PLS and ALS. Onset latency and desynchronization of the primary peak were similar in PLS and ALS, but the duration of the primary peak was significantly longer in PLS (p < 0.04). CONCLUSIONS: Desynchronized primary peaks indicate dysfunction or demise of corticomotoneurones. Higher threshold and longer duration of the primary peak in PLS probably reflect different excitability and greater loss of corticomotoneuronal connections than in ALS.

Adult↗