highly significantp < 0.0001
A two-way mixed-design ANOVA with the fixed factors of ‘electrode group’ and ‘recalled category’ and the random factors of ‘patient’ and ‘electrode’ (see Methods section for further details), revealed a highly significant interaction (F(1,63) = 17.69, p < 0.0001), indicating that each group of electrodes increased its HFB amplitude when the patients tried to recall images from its preferred category (Fig. 3a ).