in the hippocampus (Csicsvari et al., 2000). The diminishing returns obtained from increasing the assembly size in achieving target control in BMI studies can be interpreted in two different ways. First, that coordinated activity by a few or perhaps dozens of neurons comprises an assembly, which can be regarded by a reader mechanism as ‘good enough’ (Fetz 2007; Serruya et al., 2002). Alternatively, if the goal is to achieve 100% accuracy of performance each time then spiking information from very large numbers of neurons in multiple related brain areas may be needed (Nicolelis and Lebedev, 2009).17
