The Bereitschaftspotential: What Does It Measure and where Does It Come from?

Abstract

The Bereitschaftspotential (BP) is a negative cortical potential which develops beginning 1. 5 to 1 s prior to the onset of a self-paced movement (see Figure 1). The BP was first described by Kornhuber & Deecke in 1964, which makes it about 38 years old. Before the days that citation indices and impact factors came into vogue, one criterion for the significance of a research finding or paper was whether it led to other research studies. By this criterion, the BP has been incredibly influential. The BP has become a well-established tool in the motor physiology laboratory (Marsden et al, 1986), and from recent publications in scientific journals it is evident that the BP is also very much alive and well as a research tool. Its amplitude, slope, and/or latency have been shown to be impaired in neurological disorders such as Parkinson’s disease (Dick et al, 1989; Jahanshahi et al, 1995; Cunnington et al, 1995; Praamstra et al, 1996a), Huntington’s disease (Johnson et al, 2001), dystonia (Van der Kemp et al, 1995; Deuschl et al, 1995), cerebellar disease (Shibasaki et al, 1978; Verleger et al, 1999; Wessel et al, 1994), and psychiatric disorders such as schizophrenia (eg Singh et al, 1992; Fuller et al, 1999; Northoff et al, 2000) and depression (Khanna et al, 1989; Haag et al, 1994) and in patients with focal lesions of the thalamus (Shibasaki, 1975; Green et al, 1999; Feve et al, 1996), basal ganglia (Feve et al, 1994; Kitamura et al, 1996) cerebellum (Shibasaki et al, 1978; Ikeda et al, 1994; Gerloff et al, 1996), prefrontal (Shibasaki, 1975; Singh & Knight, 1990; Honda et al, 1997) or parietal (Knight et al, 1989; Singh & Knight, 1993) cortices. In the last decade, there has been a surge of interest in the BP with the demonstration that besides simple movement Parameters such as force (Kutas & Donchin, 1980) and rate (Mackinnon et al, 1996) higher order motor processes such as movement complexity (Benecke et al, 1985; Simonetta et al, 1991) and mode of movement selection (Jahanshahi et al, 1995; Touge et al, 1995; Praamstra et al, 1996a; Dirnberger et al, 1998) affect its amplitude or slope.