"Memory and the Computational Brain" by Gallistel & King
If you are interested in information theory and neuronal physiology, you shouldn't be looking for an intro to cognitive neuroscience, but rather cellular neuroscience.  Most applications of information theory in modern neuroscience are related to neural coding.  The classic (and recently updated) text is Kandel's "Principles of Neural Science".  Byrne and Roberts' "From Molecules to Networks" has a more quantitative approach, but is not as comprehensive.