Figure 2: Approaches for Neural Activity Perturbations.
(A) Perturbation of neural activity using an external signal (or force) directly applied to the targeted neural population (blue arrow). Such approaches involve the selection of stimulation parameters, such as the amplitude and frequency of the external signal. In some cases, neural activity is also recorded and can be used in a closed loop to guide the selection of stimulation parameters (dashed gray arrow). (B) Perturbation of neural activity via volitional control of the targeted population using BCI. This exerts an internally-generated force to modulate neural activity, which originates in upstream circuits (blue arrows). In the case of BCI, the targeted population comprises the neurons whose activity is read out by the BCI mapping to move the BCI cursor. The animal is provided with moment-by-moment sensory feedback to move the BCI cursor to the target.