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Biomedical subjects

W G Willis

Publications and source records attributed to W G Willis.

6 recordsLinked to original sources

An alternative to interference indexes in neuropsychological time-sharing research.

Interference indexes are used as criterion measures in a significant proportion of time-sharing paradigms in order to control for the initial discrepancy between left- and right-handed tapping rates. Problems associated with these indexes include low reliability, low statistical power, and especially correlations with baseline tapping rates. An analysis of covariance procedure using raw-score concurrent tapping rates as criterion measures, and baseline tapping rates as covariates, can effectively address these problems as demonstrated through a reanalysis of data.

Functional Laterality

Lateralized interference effects: evidence for a processing style by modality interaction.

A time-sharing paradigm was used to study potential interference effects of concurrent successive-auditory/vocal, successive-visual/motor, simultaneous-auditory/vocal, and simultaneous-visual/motor tasks on right- and left-handed manual-motor behaviors of differential levels of difficulty. Participants were selected from each of three developmental levels from 9 through 20 years of age. Results suggested that processing style (i.e., successive or simultaneous) interacts with modality (i.e., auditory/vocal or visual/motor) in terms of lateralized interference effects; however, potential effects due to age level were obfuscated by differential concurrent-task difficulties.

Adolescent

Visual-spatial orientation, gaze direction and dichotic listening asymmetries.

The effects of visual-spatial orientation on dichotic listening performance were investigated in a sample of right-handed male and female adults. The 30 pairs of dichotic stimuli (/ba/ka/da/ga/ta/pa) were presented under three conditions: eye gaze fixed toward center, eye gaze directed 20 degrees to the right, and eye gaze directed 20 degrees to the left of center. Although no effect for gender or order was evident, a significant right ear advantage was found under all conditions. However, over all dichotic listening accuracy was significantly increased when visual-spatial orientation was directed to the right or left side of space.

Adult

Auditory-successive selective attention for learning disabled and normal boys.

Improvement in auditory-successive selective attention was noted across the age range of 9 through 16 yr. In contrast to comparable paradigms with visual-simultaneous materials, 30 learning disabled and 30 normal boys did not differ. Results of research on selective attention may be affected by task materials and encoding requirements.

Adolescent