What are the most important differences between the consciousness of humans and that of dogs? Can we study the consciousness of dogs scientifically? How?
The development of functional resonance imaging (fMRI) technology has unlocked a whole new world of neuroscience research, and scientists have been able to find ways to apply this new research to the study of animal consciousness. fMRI technology has been proven to be useful in studying the brain's neural activity, which can show scientists what brain behavior, or psychological processes, correlates with what brain tissue. As neural activity in the brain changes, blood flow to the brain changes as well, and fMRI scans are able to detect and capture images of this blood flow.
Scientists have now been able to apply fMRI technology to studying the neural activity of dogs by first training dogs to be able to lie still in an fMRI scanner. One neuroeconomics professor, Dr. Gregory Berns, published in 2013 his own research on dog neural activity. Neuroeconomics is the study of using neural activity to explain the human decision-making process. What Dr. Berns discovered is that the caudate nucleus of the brain is just as active in dogs as it is in humans.
The caudate nucleus is full of dopamine receptors and is located between the brainstem and the cortex, the outermost layer that encases the brain. Dopamine governs the reward and pleasure centers of the brain and controls emotional responses and movement. Hence, dopamine helps us to recognize rewards and to take action to acquire them. As Dr. Berns phrases it, "In humans, the caudate plays a key role in the anticipation of things we enjoy, like food, love and money" (Gregory Berns, "Dogs Are People, Too," The New York Times). More importantly, Dr. Berns has seen that parts of the caudate are so consistently activated that the action in the caudate can allow scientists to predict "preferences for food, music and even beauty."
In dogs, he observed increased caudate activity when shown hand signals to indicate food and when they smelled familiar humans. From this, we know that the same things that trigger positive emotions in the human caudate trigger positive emotions in the dog caudate. This research tells us that dogs are as consciously aware of their emotions as humans, or, as Dr. Berns phrases it, as consciously aware of their emotions as a "human child."
Studies have also been used to determine which animals recognize themselves in a mirror. Scientists consider the ability for humans and animals to recognize themselves in the mirror self-recognition. Though dogs have not passed the mirror test, scientist Marc Bekoff recently developed an experiment to test if dogs will better recognize themselves through scent, seeing as how they rely more on their sense of scent rather than on their sense of sight. His study indicates that dogs recognize what belongs to them through scent, which he concludes shows dogs have a sense of "mine-ness." While we can't yet conclude that having a sense of "mine-ness" equates to having a sense of "I-ness," we do know that dogs, like many other animals are aware of their own existences (Krulwich, "I Sniff, Therefore I Am. Are Dogs Self-Conscious?," National Public Radio).
Hence, these studies show that human consciousness and animal consciousness are similar in that both humans and animals feel genuine emotions they are aware of. Also, many animals, like humans have the ability to recognize themselves, while other animals, possibly because they use their senses differently, can be proven to have a conscious awareness of what belongs to them.
Unlike primates and dolphins, dogs seem to have fairly limited intellectual capabilities, with brains devoted mainly to processing sensory data rather than more abstract cerebral processes. The first major difference between dogs and humans has to do with language. Although dogs can communicate simple desires (e.g. scratching a door when they want to go out), there is little evidence of their being able to communicate abstract, as opposed to simple and concrete, information. Dogs lack any system of writing, and do not use tools. The do have far more acute senses of smell than human beings, and seem to interact with and understand their world more in terms of smell than humans.
Due to our inability to communicate conceptually with dogs, the main way to study their consciousness is through controlled experiments. For example, if we want to understand whether shape or color is more important in dogs' memories, we might construct four doors, a yellow square, red circle, yellow circle, and red square, and hide food behind doors of various types to see how the dogs remember and respond to shape and color.