Contrary to popular belief nowadays, science doesn't yet know how consciousness arises in the brain (i.e. see Richard Dawkins and Bill Nye talking about the question they would like to know the answer to the most: youtube).
Neuroscience does show us that our brain plays an important factor in the way we experience this reality, however that does not mean it has to create consciousness, in fact, the data shows something indicating something else.
2. Electrical signals from our brain can cause physical actions of the body, but what gives rise to the signal? We can place electrodes on a person;'s brain and induce an involuntary action, but so far those actions are never went paired with the will of the person of making the involuntary action nor have we ever altered someone's will through an external stimulus.
3. The (Visual) Binding Problem. Different parts of the brains are responsible for receiving different parts of the visual information (like shape, color etc.), the whole visual aspect of the brain is mapped and studies show there is no place in the brain that can potentially unify these different informational aspects into a unified perception. 'The structure of the primate visual system has been mapped in detail (Kaas and Collins 2003) and there is no area that could encode this detailed information.' and 'There is now overwhelming biological and behavioral evidence that there is no high resolution, full field, visual representation in the brain, but that is what we subjectively experience. As is well known, current science has nothing to say about subjective (phenomenal) experience and this discrepancy between science and experience is also called the “explanatory gap” (Martinez-Conde et al. 2008)'
4. Hydrocephalus. This is condition where there is an excessive amount of cerebrospinal fluid in the skull, which hinders normal brain development. Out of the most severe cases (with 95% fluid instead of brain) half of the patients were retarded and the remaining half had IQs greater than 100 and functioned properly. There is a case with a boy who had an IQ over 126 and earned an honors degree in mathematics. "startling as it may seem, this case is nothing new to the medical world. "Scores of similar accounts litter the medical literature, and they go back a long way," observes Patrick Wall, professor of anatomy at University College, London, "but the important thing about Lorber is that he's done a long series of systematic scanning, rather than just dealing with anecdotes. He has gathered a remarkable set of data and he challenges, 'How do we explain it?' link And there is a case with a boy who had no brain at all, just a skull full of fluid and his brain stem, he was blind, could not walk nor speak but still was able to laugh and smile, and went through sleep-wake cycles, showing clear signs of consciousness. link
However brain damage can still alter thoughts, beliefs and personality of beings in a body. This again does not imply the brain must create the consciousness, but it does show they are correlated.