 Jerry Fodor and Ernest LePore (1992) raised an important challenge to Churchland’s psychosemantics. Location in a state space alone seems insufficient to fix a state’s representational content. Churchland never explains why a point in a three-dimensional state space represents a color, as opposed to any other quality, object, or event that varies along three  dimensions.[9].  So Churchland’s account achieves its explanatory power by the interpretation imposed on the dimensions. Fodor and LePore alleged that Churchland never specified how a dimension comes to represent, e.g., degree of saltiness, as opposed to yellow-blue wavelength opposition. One obvious answer appeals to the stimuli that form the “external” inputs to the neural network in question. Then, for example, the individuating conditions on neural representations of colors are that opponent processing neurons receive input from a specific class of photoreceptors. The latter in turn have electromagnetic radiation (of a specific portion of the visible spectrum) as their activating stimuli. However, this appeal to “external” stimuli as the ultimate individuating conditions for representational content makes the resulting approach a version of informational semantics. Is this approach consonant with other neurobiological details?