“Impaired fixation to eyes following amygdala damage arises from abnormal bottom-up attention”

How are fear and the amygdala related?

Patients with abnormalities in their amygdala sometimes lose their sense of fear.

When you see someone who looks angry or in a bad mood, the natural thing would be to keep your distance, but patients with abnormalities in their amygdala sometimes cheerfully approach people like that without any regard to how they look.

Why would this happen?

As is often said, a person will look at the other person’s eyes to tell what emotions they are feeling.

The other person’s eyes contain the most important information for displaying their emotions among the various information that the face in general holds.

Because of this, usually when looking at another’s face, information in the other person’s eyes leaps into your own eyes through the amygdala in an instinctive, bottom-up manner.

The amygdala operates as an “automatic eye information reader”, and without thinking, the person’s line of sight turns to the other person’s eyes and locks onto them.

Based on this information, a person recognizes that the other person is angry or in a bad mood and connects this to some sort of action, but in patients with damage to their amygdala, the “automatic eye information reader” is thought to not to function, preventing information from coming in from the bottom up.

In that case, if you were wondering about such patients they do not look the other person in the eye at all, it is reported that they can look at the other person’s eyes if they turn their awareness to doing so and actively look the other person in the eyes.

The paper I discuss today states that patients with damage to the amygdala are not proficient at directing attention to the other person’s eyes, but this is due to problems with bottom-up attention that involves the amygdala, and it does not apply to the top-down attention used when you actively look for information. People with autism are also supposed to be unable to look the person they are communicating with in the eyes, and the paper suggests that this could also be related to amygdala function.

[Abstract]

SM is a patient with complete bilateral amygdala lesions who fails to fixate the eyes in faces and is consequently impaired in recognizing fear. Here we first replicated earlier findings in SM of reduced gaze to the eyes when seen in whole faces. Examination of the time course of fixations revealed that SM's reduced eye contact is particular pronounced in the first fixation to the face, and less abnormal in subsequent fixations. In a second set of experiments, we used a gaze-contingent presentation of faces with real time eye tracking, wherein only a small region of the face is made visible at the center of gaze. In essence, viewers explore the face by moving a small searchlight over the face with their gaze. Under such viewing conditions, SM's fixations to eye region of faces became entirely normalized. We suggest that this effect arises from the absence of bottom-up effects due to the facial features, allowing gaze location to be driven entirely by top-down control. Together with SM's failure to fixate the eyes in whole faces primarily at the very first saccade, the findings suggest that the saliency of the eyes normally attract our gaze in an amygdala-dependent manner. Impaired eye gaze is also a prominent feature of several psychiatric illnesses in which the amygdala has been hypothesized to be dysfunctional, and our findings and experimental manipulation may hold promise for interventions in such populations, including autism and fragile X syndrome.

Reference URL: Impaired fixation to eyes following amygdala damage arises from abnormal bottom-up attention.

Comments

In the West, looking the person you are speaking to in the eye is considered the right thing to do, while in Japan, looking the other person in the eye too much is frowned upon. Looking someone in the eye is the same as letting them look you in the eye, and this gives rise to powerful communication, if not a joining of hearts.

I thought about how Japanese people consider it admirable to align with the other person, and wondered whether the powerful information exchange that arises from looking someone in the eye might cause too much of a burden, resulting in a culture in which people do not look each other directly in the eye. Perhaps restricting the entry point is the Japanese way and restricting the exit point is the Western way.

A certain degree of not paying attention to the other person’s feelings might sometimes produce a better result.