1. A system configured to estimate affective response to a token instance of interest, comprising: a memory configured to store: token instances to which a user was exposed, a total affective response of the user to the token instances, and representations of first and second attention levels of the user in respective first and second token instances from among the token instances; wherein the total affective response is based, at least in part, on values of a user measurement channel that are not utilized to generate the representations of the first and second attention levels; wherein the first and second token instances have overlapping instantiation periods; and wherein the first attention level is greater than the second attention level; a processor configured to select, based on the representations of the first and second attention levels, the first token instance as the token instance of interest; and the processor is further configured to estimate the affective response to the token instance of interest from the total affective response.