Evoked potential augmenting-reducing: a reply to Connolly and Gruzelier

Connolly and Gruzelier (1982) published a study purporting to evaluate the methods and procedures employed in studies of the Buchsbaum evoked potential (EP) augmenting-reducing effect. Robinson et al. (1984) pointed out that the stimulus intensities employed by Connolly and Gruzelier were much lower than those normally employed by Buchsbaum and his associates. Consequently, the Connolly and Gruzelier data would not really be comparable to the data of Buchsbaum. Connolly and Gruzelier (1986) subsequently criticised the Robinson et al. report. These criticisms are considered in this letter and it is noted that the main points made by Connolly and Gruzelier are based on spurious as well as mathematically incorrect 'conversions' from units of illumination to units of luminance.