Sensitivity and reliability of language laterality assessment with a free reversed association task--a fMRI study.

Objective: The aim of the study was to evaluate the sensitivity and reliability of assessing hemispheric language dominance with functional magnetic resonance imaging (fMRI) using a 'free reversed association task.'

Methods: Thirty-nine healthy subjects (13 dextrals, 13 sinistrals and 13 bimanuals) underwent two repeated fMRI sessions. In the active phases sets of words were presented via headphones, and an associated target item was named.

Reproducibility of activation in four motor paradigms. An fMRI study.

Most functional imaging data are collected in single session experiments; little is known about the reproducibility or test-retest reliability of the activation patterns found in these experiments. In our study, 15 healthy volunteers performed four simple motor-paradigms ("Hand", "Foot", "Mouth" and "Tongue") for functional magnetic resonance imaging (fMRI) in 3 sessions on different days. Reproducibility of activations in four anatomical regions (pre- and postcentral gyri, paracentral lobule and the supplementary motor area) was measured in terms of voxels active in all sessions (common voxels) relative to voxels active in single sessions, giving reliability coefficients from 0 to 1.

Naming tools and animals: asymmetries observed during direct electrical cortical stimulation.

Semantically bounded disorders of verbal processing that result in selective dysnomias for items belonging to specific semantic categories have been well documented in lesion studies. Most commonly dissociations between the categories of living versus non-living things have been reported. Processing of living things such as animals seems to be impaired after bilateral lesions, whereas lesions resulting in impairment of processing of non-living things such as tools seem to be restricted to the left hemisphere.