1. A method for simultaneously assessing the functional status of component parts of the nervous system of a subject, said method comprising: (a) presenting to one or more parts of the sensory nervous system of the subject stimulus sequences having different temporal modulation sequences of the appropriate stimulus modality for each stimulated part of the sensory nervous system, the stimuli having different sequences for each stimulated part; (b) temporally modulating the stimuli between a null stimulus condition and at least one non-null stimulus condition selected from the group consisting of an increment stimulus condition and a decrement stimulus condition, relative to the null stimulus condition, wherein the probability of encountering the null stimulus condition in the stimulus sequences is higher compared to the probability of encountering at least one non-null stimulus condition, and wherein the temporally modulated stimuli permit estimation of linear and non-linear weighting functions characterising measured responses to each stimulus presented to each part of the nervous system; (c) estimating some or all of the coefficients of the linear and non-linear weighting functions for each stimulus sequence from the measured responses to said stimuli, to isolate separate responses from the separately and simultaneously stimulated component parts of the nervous system; and (d) estimating separate coefficients for responses to said other stimulus conditions to permit isolation of separate responses from component parts of the nervous system that respond to distinct members of said other stimulus conditions.