Timbre in the brain

Timbre, in its very nature, is abstract. The brain, as we all know, is the most complex system that exists. So, one can only imagine the challenges that can be encountered while investigating timbre processing in the brain. The central focus of timbre research from a neuroscientific point of view, until recently, has been typically on brain responses to changes in acoustic structure or related to sound source categorization (ex: violin vs piano)