There are different levels of explanation, and one level (e.g. chemistry) may not map in a one-to-one fashion to the next level (e.g. behaviour). In particular, when trying to explain some examples of behaviour such as memory, learning, or attention, it does no good to know which chemicals or brain regions were involved. Instead, what is needed is needed is a model in psychological terms (e.g. Rescorla-Wagner model). Psychological models can be instantiated in different ways, in different brain regions, with different chemical events. But they predict and explain behaviour because they are the appropriate level of explanation. Until neuroscientists (and chemists?) appreciate they are dealing with psychological terms, their “explanations” of behaviour will be neuvo-phrenology.

“In order to understand the mind—especially the emotional mind, there’s no alternative but to take an evolutionary perspective. The only organ we have in the body that is clearly evolutionarily layered is the brain.”

“My feeling is that the social brain has many levels. If you don’t understand the foundational level, then you can do brain imaging until you’re blue in the face, but you still will not understand the process at a deep causal level.”
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For me, it is not so much the need to understand cause and effect as it is to stop psychologists from proposing that their work establishes it. Visual appeal is a function of chemically activated ligand-receptor binding, for example. Each time I read that brain imagery has established a link between facial or other appealing physical characteristics and behavior, I want to ask the authors: Is there am animal model for that? But I know what the answer must be. Olfactory/pheromonal input establishes visual appeal in every other species, so pictures of brain activity are like pictures of other people or pictures of food, and pictures do not directly link cause and effect to brain-based behavior. Pictures link associations and conditioned responses to the chemistry of behavior.