Understanding the brain imaging signal

Our perceptions, sensations, emotions and memories rely on the approximately 80 billion neurons we have in our brain. You may wonder, nevertheless, if this number is actually too large, too small or barely enough. Is it the "billions" that makes us special? Or is there more to it than just a number, some neural mechanism that we have not yet envisioned? Cognitive Neuroscience has greatly advanced our understanding of the brain over the past decades. Even so, one may be utterly frustrated by the lack of any unifying theory explaining how we perceive the world around us, let alone understanding complex processes such as consciousness.