3.1 How brain structures enable mind processes: emotion
Emotion is an aspect of the mind that is relatively well understood in terms of
Based on both clinical observations of patients with damage to their limbic systems, and more modern
It may therefore be reasonable to suggest that other animals who also have a limbic system might also experience emotions. And that species without a limbic system would not experience emotions.
Without looking up any information about different species’ brains first, now have a go at Activity 3.
Activity 3 Which animals might experience emotions?
Which of these animals do you think might experience emotions? For example, do you think any or all of them would be capable of experiencing happiness, sadness, fear or anger?
- chimpanzees
- cats
- crows
- lizards
Discussion
You may be surprised to learn that all of the listed animals display evidence of being able to experience emotions to some degree (based on both behavioural and brain function studies). All of them have a limbic system of some sort – at least the amygdalae.
There is evidence that chimpanzees do experience, communicate and understand emotions (Bard, 2004). which you might have expected as they are very close relatives of humans. And you might not have been very surprised to learn that cats can experience emotions, based on your own experiences of them. There is evidence that cats experience fear in the presence of dogs, with specific responses being found in the amygdalae (Pavlova and Vanetsian, 2006).
Nonetheless, evidence of emotions is not limited to mammals: brain imaging has demonstrated fear responses in crows, again involving the amygdalae (Marzluff et al., 2012).
The lizard (Figure 3) may have been the most surprising animal on the list. Indeed, it was once thought that the ‘lizard brain’, being older in evolutionary terms than the ‘mammal brain’, had not developed the more advanced structures and functions to be able to process emotions. But while the lizard brain lacks the neocortex (the ‘newest’ part of the brain, in evolutionary terms), lizards do have amygdalae (Lanuza et al., 1998), and there is evidence that this enables them to experience some degree of basic emotion. For example, Cabanac and Cabanac (2000) reported what they interpreted as a stress response in the heart rates of iguanas when they were handled by humans.
Taken together, these studies suggest that emotions, and the brain structures that give rise to them, arose quite early on in evolutionary terms, although amphibians in Cabanac and Cabanac’s study did not show the same stress response as the lizards reptiles. These brain structures are found not only in humans, or primates, or even mammals, but also widely throughout
The next section of this course takes a comparative psychology approach, considering how emotions might be experienced and expressed by two different species: humans and domestic dogs.