Abstract
An experimental design based on the combination of dichaptic presentation associated to the Posner's paradigm was adopted to investigate laterality effects for verbal and spatial non-linguistic stimuli in male and female adult normal subjects. In a grapheme similarity judgment task based on "Name Identity" a right hand/left hemisphere advantage was found. Conversely, laterality effects were neither observed when the task involved "Perceptually Identical" or "Different" letter pairs. In a further experiment, the same methodology was adopted to verify hemispheric effects with spatial non-linguistic material, and a significant advantage for the left hand/right hemisphere was observed. Contrary to many previous studies, no gender or gender × task effects have been detected in both experiments. The present results suggest the existence, also in the tactile domain, of a direct link between input type and the linguistic or non-linguistic processing to which the two hemispheres are devoted. The overall pattern of data seriously hampers Witelson's [Cortex 10 (1974) 3] original hypothesis that letter stimuli presented in the tactile modality are primarily processed as spatial stimuli, and are therefore dependent on the right hemisphere functioning.
Original language | English |
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Pages (from-to) | 1896-1901 |
Number of pages | 6 |
Journal | Neuropsychologia |
Volume | 42 |
Issue number | 14 |
DOIs | |
Publication status | Published - 2004 |
Keywords
- Laterality effects
- Posner's paradigm
- Tactile stimuli
ASJC Scopus subject areas
- Arts and Humanities(all)
- Neuroscience(all)
- Behavioral Neuroscience
- Psychology(all)
- Neuropsychology and Physiological Psychology