Do studies exist that can map specimens of neocortex to the functions they perform(ed) in vivo? Much brain research has proposed that the brain (the neocortex, esp.) is set up in areas - an area for faces, an area for language, etc..

The experiments typically go 1) damage an area 2) observe what function is lost. And this has produced a good deal of evidence that behavior ends up being localized. But for me, this information is incomplete, especially in the light of studies that show that every part of the cortex does essentially the same thing! 

Has anybody ever done a study where, looking at tiny areas of neocortex, scientists can identify a) what information it contains b) what it does, or c) from what part it came?
...studies that show that every part of the cortex does essentially the same thing!


I would be much interested in seeing these studies - Although the brain is plastic and inter-individual differences can be substantial, it is generally accepted that functional regions are well defined in terms of their anatomical locations and brain mapping was, and still is, a field of research in its own right.

Studies where 


  tiny areas of neocortex [were studied]


have been done, and showing 


  what it does


Notable examples include singe-unit recordings (cellular level - as tiny as you can get) that mapped the primary visual cortex (V1) and auditory cortex (AI). Such studies have shown that V1 contains retinotopic maps, and AI contains tonotopic maps, i.e., these studies showed that each region in the retina projects to a well-defined and neatly organized region in V1 (e.g., Cowey, 1979), and well-defined anatomical locations in the cochlea project to well-defined and well organized regions in AI (e.g., Ozaki &amp; Hashimoto, 2007). 


  what information it contains


is hard to answer, as the brain is not a hard disk that can be read back. However, studies on Alzheimer patients do reveal that old memories are often relatively spared, while new ones fail to be stored properly, indicating indirectly what information the affected cortex contains. 

References
- Cowey, Quarterly J Exp Psychol; 31(1): 1-17
- Ozaki &amp; Hashimoto, Can J Neurol Sci (2007); 34(2): 146-53