Current and past research is clearly showing us just how smart and emotional nonhuman animals (animals) really are, and that they are conscious, sentient, beings (see also "Scientists Finally Conclude Nonhuman Animals Are Conscious Beings" and "A Universal Declaration on Animal Sentience: No Pretending").
While we can no longer pretend we don't know this, there are some, a very few, who remain skeptical about what's happening in the minds of other animals and they want to wait to see what neuroimaging can tell us about beings who can't verbally report what they're thinking or feeling. Of course, when these sorts of studies are performed on humans they need to be non-invasive and there are now similar studies being done on other animals. Here are some examples that can be used as a foundation for future comparative work.
In a recent essay in Scientific American Mind called "Crows Show Off Their Social Skills" (the title in the print edition is "Social Skills to Crow About"), Harvey Black summarizes some of the fascinating data that have been collected on these most amazing birds (see also Psychology Today essays under the heading "Avian Einsteins"). What caught my eye in this short essay is the following statement: "A crow recognizes human faces using the same visual pathways in the brain as humans do. A 2012 study using PET scans found that when crows viewed human faces that they associated with threat or care, the birds had increased activity in the amygdala, thalamus and brain stem—areas related to emotional processing and fear learning. In response to threatening faces, areas that regulate perception, attention and fleeing also lit up. The similarity to human brain activity and the parallels in social intelligence in general are significant because they may have evolved after our last common ancestor existed 300 million years ago. That would make our species' similarities a case of convergent evolution, when two vastly different organisms develop the same traits independently. 'Evolution has arrived at the same solution again and again,' says Alex Taylor, a crow expert at the University of Auckland in New Zealand." (my emphasis)
Similar work is being done on dogs (see, for example, Emory University's Gregory Berns's research and a review of neuroimaging on non-human primates and a review of research on rats), and the widespread application of non-invasive neuroimaging on diverse animals will surely provide ample data that they (other animals) and we share many of the same neurobiological systems for information and emotional processing. Indeed, one would expect such similarities using Charles Darwin's ideas about evolutionary continuity (for details please see "Animal Minds and the Foible of Human Exceptionalism").
Are human infants conscious? "A new study finds a possible brain signature of consciousness in infants as young as five months"
Another essay in the same issue of Scientific American Mind called "What do Babies Really Know?" (the title in the print edition is "The Conscious Infant") also caught my eye. In this essay, renowned neuroscientist Christof Koch reviews what we know about a human infant's subjective experiences. And, once again, neuroimaging comes to the rescue, in this case recording brain waves, or EEGs. Based on this research we now know that "one-year-old children, at least, do have a brain signature similar to that associated with conscious perception in adults. The electrical signal is perhaps a third of the speed it is in an adult, reflecting the delayed myelination (myelin is the covering of the axon that speeds up transmission of long-distance electrical communication) and immaturity of the young brain."
The concluding paragraph of Dr. Koch's essay contains much food for thought. He writes, "Indeed, it may well be that the fetus feels as much as we do when we are in a deep, dreamless sleep. It may be that the dramatic events attending birth, including drawing its first breath, are the triggers for its first conscious experience of life. This, too, we shall know one day." And, this too -- we shall know one day for nonhuman animals.
Surprised? Some people are and others are not. However, what is important for future research is that techniques are available and are being developed that can tell us about what is happening in the brains of young human children and other animals who cannot verbally tell us what they are experiencing. And, of course, careful observations in the case of nonhumans, who never will be able to tell us verbally what they're thinking and feeling, show clearly that they are smart and sentient and care very much what happens to them, their families, and their friends. Absent verbal language, other animals plainly tell us what they need and want and what they are thinking and feeling, and we need to listen carefully to them.