On separating processes of event categorization, task preparation, and mental rotation proper in a handedness recognition task
✍ Scribed by Jasmin Bajrič; Frank Rösler; Martin Heil; Erwin Hennighausen
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 748 KB
- Volume
- 36
- Category
- Article
- ISSN
- 0048-5772
No coin nor oath required. For personal study only.
✦ Synopsis
We investigated the nature of event‐related potential (ERP) effects in a handedness recognition task requiring mental rotation. Thirty subjects were tested with rotated and sometimes reflected alphanumeric characters while ERPs were recorded from 18 electrodes. On each trial, a cue provided valid information about the angular displacement of the following probe. This design allowed a distinction between three processing episodes: evaluation of the difficulty of the forthcoming task, preparation for the task, and the mental rotation task itself. The three episodes were accompanied by distinct ERP effects having distinct polarities, a different rank order of amplitudes for different probe orientations, and a different topography. These data confirm previous findings showing that mental rotation is accompanied by a parietal negativity. However, they also suggest that the rotation‐related negativity found after tilted stimuli in standard mental rotation tasks is most likely overlapping with another, simultaneously triggered ERP effect functionally related to an evaluation of task difficulty.