1Centre for Cognitive Neuroscience, 20014 University of Turku, Finland

2Department of Psychology, 20014 University of Turku, Finland

3Department of Psychology, Åbo Akademi University, 20500 Turku, Finland

4Department of Statistics, 20014 University of Turku, Finland

5Department of Philosophy, 20014 University of Turku, Finland

6Department of Neurology, 20014 University of Turku, Finland.

7Corresponding Author and Address: Christina M. Krause, Centre for Cognitive Neuroscience and Departments of 20014 University of Turku

Acknowledgements: This study was supported financially by the University of Turku and Nokia. A.R. (projects 36106 and 45704) and C.M.K. (projects 7338 and 42536) were supported by the Academy of Finland.

Received 30 November 1999; accepted 7 January 2000