The post below is something I posted on VB a little over 2 years ago. Granted, the article I was referring to was about
self-awareness, but I think it illustrates how we can't always be sure about what capacity might or might not be there when a brain is concerned. And I would say this holds true for animal brains as well.... :
This topic comes up every now and then, both here and elsewhere, when people try to decide which animals are sentient and which aren't- and it sometimes turns into a debate about which animals humans could eat without feeling guilty about it. The link below doesn't address this directly, but it describes a case of a man with severe brain damage having more brain function- specifically, self-awareness- than scientists and doctors would have thought possible:
Brain Damaged 'Patient R' Challenges Theories of Self Awareness - Yahoo News
I say, when it's not certain whether or not an animal can feel or be aware of anything, it's best to give an animal the benefit of the doubt.
EDITED TO ADD: I quote some of the article below:
Feinstein and colleagues set out to test Patient R's level of self-awareness using a battery of tools that included a mirror, photos, tickling, a lemon, an onion, a personality assessment and an interview that asked profound questions like "What do you think happens after you die?" Their conclusion — that Patient R's self-awareness is largely intact in spite of his brain injury — indicates certain regions of the brain thought crucial for self-awareness are not.
Brain anatomy
Self-awareness is a complex concept, and neuroscientists are debating from where it arises in the brain. Some have argued that certain regions in the brain play critical roles in generating self-awareness.
The regions neuroscientists have advocated include the insular cortex, thought to play a fundamental role in all aspects of self-awareness; the
anterior cingulate cortex, implicated in body and emotional awareness, as well as the ability to recognize one's own face and process one's conscious experience; and the medial prefrontal cortex, linked with processing information about oneself.
Patient R's illness destroyed nearly all of these regions of his brain. Using brain-imaging techniques, Feinstein and colleagues determined that the small patches of tissue remaining appeared defective and disconnected from the rest of the brain.
........
An exception
R's brain injury took away his sense of
smell and taste, as well as much of his memory. R partially acknowledges his memory loss, even describing himself as a "normal person with a bad memory," However, he does not admit that he cannot smell or taste.
The researchers put this to the test by blindfolding him and then offering him an onion or lemon or odorless items and asking what he smelled. With the blindfold on, he could not smell the lemon or onion. With it off, he claimed to smell them, explaining, "I guess sight makes things easier."`
Knowing one's limitations is an aspect of self-awareness, Feinstein said.
Patient R & the origin of self-awareness
Finally, in an interview the researchers assessed his capacity for introspection, asking him questions about free will, the self, emotion and other abstract concepts.
"I think what the interview reveals is clearly somebody who is not impaired in most aspects of self-awareness," Feinstein said. "If you were asking someone who was
a zombie, you wouldn't get any of these sorts of answers."
The results of the assessment are clear, he and colleagues contend: Neither the insula cortex, the anterior cingulate cortex nor the medial prefrontal cortex play crucial roles in self-awareness.
Patient R's self-awareness does, however, support the theory that sets of neurons in the brain stem may provide the foundation for consciousness and the sense of self. This part of R's brain is undamaged. The team also suggests other parts of the brain,
the thalamus and the posteromedial cortex, play a role in self-awareness.
