intelligent birds use a structure called the 'visual wulst' for reasoning tasks, a highly-evolved brain 'bulge' used for making decisions about visual stimuli.

intelligent birds use a structure called the 'visual wulst' for reasoning tasks, a highly-evolved brain 'bulge' used for making decisions about visual stimuli. It's in some ways different from our cortex but similar in that it's a recent structural addition, under selection pressure and impairs learning when damaged. There may be some truth to the author's claim that 'absolute brain size is less important than relative'. Spider brains are so important that some small jumping spiders have neural tissue spreading into their legs for lack of space. (Not the same phenomenon as octopi with distributed brains in their arms; spiders have one large central brain). And jumping spiders have a reputation for learning / reasoning smarts.