Author response image 6. Changes in individual synapses depend on the cross-correlation of the firing rate of pre- and post-synaptic cells.

(a) The STDP window K(T) (red and blue curves) and the cross-correlation CC_θ,θ^′(T) (dashed black line) for two hypothetical place cells. (b) The product K(T) · CC_θ,θ^′(T). (c)-(d) Same as (a)-(b) but for C_θ^′_,θ(T). The rate of change of the synaptic weight is found by integrating the curves in (b) and (d) respectively.