i am a neurscience graduate student and I am planning an experiment using mice with in vivo extracellular recordings (and maby also optogenetic stimulations).

  In these kind of experiments, the mouse is getting a reward after executing a (short term) memory involved task.

I noticed that in the papers I read, it is not really possible to know if the observed $\gamma$-oscillations (for instance), derive from memory activation, or arrousal (from thinking of the reward), or from attemtivness (from trying to execute the task correctly).

Are there any ideas or a good reference for this problem of distincting between these related cognitive activities?

Examples of experiments with humens will also help. Maybe not directly but will give some ideas about how these notions can be separated.

Thank you

I am planning an experiment using mice with in vivo extracellular recordings (and maybe also optogenetic stimulation). In these kinds of experiments, the mouse is getting a reward after executing a (short term) memory involved task.

I noticed that in the papers I read, it is not really possible to know if the observed $\gamma$-oscillations (for instance), derive from memory activation, or arousal (from thinking of the reward), or from attentiveness (from trying to execute the task correctly).

Are there any ideas or a good reference for this problem of distinguishing between these related cognitive activities?

Examples of experiments with humans will also help. Maybe not directly but will give some ideas about how these notions can be separated.