Conscious Emotions

Emotions are often beautiful, sometimes agonizing, occasionally annoying – but from an evolutionary biology perspective, they are nothing more than the body's way of assessing external stimuli and responding accordingly: fear of wild bears and disgust at spoiled meat warn us of dangers to life and limb. Conversely, we can trust someone we love without worry and have children with them.

Being able to say “I'm afraid” or “I love you” requires that these feelings enter our consciousness. However rich a person's emotional life may be, this is the exception rather than the rule. This is because although the limbic system in the brain constantly generates emotions, we usually don't notice them. Only when the signals from this system, which consists of several structures and developed early in the evolution of mammals, reach the evolutionarily younger cerebral cortex are fear, love, hate, joy, anger, or sadness consciously perceived. This, if at all, only happens at the end of a complex process.

Anyone who is wandering through the forest and suddenly comes face to face with a bear actually experiences fear twice – via two different mechanisms. The first analyzes the situation imprecisely, but at lightning speed: information from the sensory systems is transmitted directly to the amygdala via the thalamus. This part of the limbic system, also known as the amygdala because of its almond-like shape, assesses in a few milliseconds whether the stimulus is harmful or beneficial to us. When encountering the bear, the amygdala complex concludes that it is a potential danger. So, it triggers the appropriate physical defensive response via the hypothalamus and brain stem: the heart begins to beat faster, blood pressure rises, sweat breaks out. The purpose of all this is to prepare for a fight or to initiate flight. All this happens before we even realize that we are afraid.

The second pathway runs from the thalamus to the cerebral cortex and is significantly slower. However, this system processes the situation in greater detail. It involves the visual cortex, whose activation allows us to consciously perceive the bear, and the hippocampus, from which memory content is retrieved – the brain compares the current situation with previous experiences. The prefrontal cortex (PFC) also plays an important role. It processes emotions by integrating them into the overall picture and draws conclusions about the best course of action. It is also the region of the brain where emotional stimuli from the limbic system are converted into conscious feelings.

The importance of the PFC for a person's personality and emotional life is demonstrated by the case of Phineas Gage, a worker who lost this part of his cerebral cortex in an accident (see info box). Once the dangerous situation has been thoroughly analyzed, the frontal cortex sends its information back to the limbic system for reassessment. And, if necessary, modification.

This has been demonstrated in studies of people with arachnophobia. In their brains, the visual cortex and prefrontal cortex are highly active when the eight-legged creature comes into view. The amygdala also fires excessively. If such patients manage to get their phobia under control through behavioral therapy, researchers measure, contrary to what might be expected, not less activity in the amygdala after treatment – instead, the prefrontal cortex works harder: the phobic patients have learned to reevaluate the fear-inducing stimulus “spider” and to assess its danger differently.

Neuroscientist António Damásio distinguishes between emotions and feelings: emotions, he says, are physical reactions that follow a stimulus and are visible to the outside world; feelings, on the other hand, arise when the brain analyzes and consciously perceives the body's reactions. Cats without a cerebral cortex can still show anger as an expression of emotion by hissing and trying to scratch. This was demonstrated by physiologist Walter Cannon (1871–1945) as early as the 1920s.

However, such animals are no longer able to feel the actual emotion of anger: their rage is directed at nothing in particular and is not aimed at the source of the stimulus that makes them angry. Furthermore, as Cannon called it, the sham rage immediately dissipates when the stimulus is removed. This suggests that the cerebral cortex is responsible for controlling the emotional response to a stimulus. In other words, it directs the response toward the cause or inhibits it if the cause is not relevant enough.

At least in humans, control goes a step further. By activating the cerebral cortex, emotions can be consciously perceived, with the result that we better understand what is happening to us. On the other hand, emotional experience can also be influenced by thoughts. António Damásio at the University of Southern California investigated where exactly which conscious emotions are processed in the brain: The emotion researcher asked test subjects to imagine situations in which they had felt happiness, sadness, anger, or fear, and looked under their skulls using functional magnetic resonance imaging, an imaging technique that makes brain activity visible.

The result: different areas of the cerebral cortex were activated depending on the type of emotion. When feeling happy, the right cingulate gyrus, the left insula, and the right somatosensory cortex were particularly active, while the left cingulate gyrus fired less than normal. When the test subjects were sad, the insular cortex on both sides was more active than usual, as was the anterior cingulate gyrus; the posterior cingulate gyrus, on the other hand, remained silent. Anger and fear also resulted in very specific activation patterns. However, there is no single area for anger and no specific region for happiness. Rather, the neural networks that are activated by certain emotions overlap to a large extent and are also active, at least in part, when other emotions are experienced. Colleagues criticize Damásio's conclusions from this study as rather speculative.

Surprisingly, there is little difference between men and women when it comes to where they process emotions in the brain: several studies have confirmed that the neural activation patterns are comparable in both sexes, regardless of whether the emotions are positive or negative.

Everyone knows from their own experience that emerging emotions can influence how attentive we are and thus how well we perform a task. Various experiments confirm this: for example, when test subjects are asked to name the font color of a word, phobic individuals have more difficulty when the term of the object they fear appears. Surprisingly, feelings can be changed simply by the direction of gaze: In 1987, US researcher Roger Drake reported for the first time that men who had to turn their gaze to the right to look at a photo generally liked the image better than men who had to look to the left. Two years later, Dutch scientists discovered the same phenomenon in women. The explanation for this is the theory that when a test subject looks to the right, the left hemisphere of the brain is activated, which is more involved in positive feelings, while the right hemisphere tends to generate negative feelings.

Even stimuli that are so brief that we are not consciously aware of them influence our feelings and moods. Researchers at Tilburg University in the Netherlands showed a group of test subjects frightening images, such as rabid dogs. They presented a second group with disgusting scenes, such as a dirty toilet. The control group was only shown neutral images, such as chairs. The images were only shown for a short time, so that their content escaped the conscious perception of the test subjects. And yet they still had an effect. Those who viewed the disgusting images subsequently refused to take part in a food test, while those who had seen the frightening scenes, even if not consciously, did not feel like watching a horror movie. However, the test subjects were unable to explain why they had made these decisions. Feelings are often beautiful, sometimes painful, and occasionally annoying. And they have a great power over our behavior. Whether they enter our consciousness or not.

Further reading

• Damasio, A., et al.: Subcortical and cortical brain activity during the feeling of self-​generated emotions. Nature Neuroscience. 2000; 3(10):1049 – 1056 (zum Abstract).

First published on August 23, 2011
Last updated on September 11, 2025