I've been trying to work on the question about how we should individuate, or count, perceptual experiences at a time, and whether or not there is any substantive issue here.
   I am currently looking at my computer, and my desk, and a cup. Is this one visual experience, or three, and what decides this? Individuating experiences across sensory modalities seems an easier task, and we may just say that are as many experiences as there are senses, or something to that effect, but within a modality, things seem much harder to judge.
   The following may be various potential methods for individuating experiences at a time, that may be put to use: experiences might be individuated according to content&character, by the instantiation of phenomenal properties, by appeal to 'phenomenal articulation' to use a phrase of Tim Bayne's (this could also be spelled out by appeal to counterfactuals, i.e., 'if I could have had the same experience of the computer without the bottle, then they are separate experiences), by appeal to neural events, or by appeal to some facts about visual experiences, such as the fact that we cannot experience colour without shape, and so these properties must be within the same experience (it seems possible to do this with the other senses: we cannot perceive pitch without volume and timbre in audition, for example).
   My question is whether any of these methods of individuating experiences (at a time) reflect any substantive issue, or is there simply no carving nature at the joints here, and so we can safely individuate experiences only according to theoretical need.

The more general thinking behind this worry is that there seem to be consequences for the issue of the unity of consciousness, specifically the question of how we should think of phenomenal unity, or 'experienced togetherness'. Tye claims that the 'received view' of phenomenal unity, on which the issue is one of how individual experiences are unified, what relation holds between them,  and what the relation of the unified experiences to the maximal unifying experience is, is mistaken. Tye puts forward several criticisms of this received view, two of which come in the form of supposed infinite regresses that start once we posit a third experience that is responsible for unifying two experiences. Tye, on the other hand, claims that at a time a subject has simply one experience, which can be described in more or less fine-grained ways, and that the issue of how different experiences are phenomenally unified dissolves.
   if there is no substantive difference between methods of individuating experiences, my worry is that Tye's criticisms of the received view cannot be met with 'yes, but there has to be some relation that holds between experiences, as a subject does not have (in most cases) simply one experience at a time'.

Any thoughts on this greatly appreciated.