Title: Could mirror neurons be sufficient to explain the origin and functioning of facial mimicry? A literature study based on empirical evidence
Summary
Two main question exist in this thesis. The first is: How do mirror neurons relate to facial mimicry? Can they explain the process of mimicking a facial expression or not? The second question relates to the debate on the origin of facial mimicry. How far can facial mimicry be explained by associative learning? An associative learning process is prevalent in the development of mirror neurons and means that visual neurons correlate with motor neurons in a network. Also known as Hebbian learning. There are presumptions that mirror neurons explain empathy and mimicking of facial. Whether facial mimicry can be regarded as a mirror neuron property has to be answered first in order to understand the origin of facial mimicry. When facial mimicry can be seen as a mirror neuron property, the research on the origin of mirror neurons is evident for facial mimicry as well. The first chapter is an introduction to the topic of facial mimicry, where I provide an overview of the literature of facial mimicry and explain the influences of other cognitive processes on mimicry. For example cognitive load and group dynamics. The goal of the chapter is to show that facial mimicry is more complex than basic muscle imitation, an unconscious muscle response measured early by Dimberg. In chapter 2 I look at mirror neurons, which might be the possible neurobiological bases of mimicry. The function of mirror neurons is discussed here. The first research question: What is the contribution of mirror neurons in facial mimicry? will be answered in chapter 3. Facial mimicry is discussed as a complex process that accompanies basic action imitation and also two pathways for emotional processing. The basic action of mimicry can be explained by mirror neurons but the emotion recognition pathway can only partly be explained by mirror neurons. At the end of the chapter, I introduce a model which contributes to the explanation and which shows the relevant processing stages into one model. There are three separate information streams, one for action-perception and two for emotion recognition. The answer on the research question is in short that facial mimicry can only partly be described as a property of mirror neurons, both for action perception and emotion recognition. The last chapter, chapter 4 focusses on the origin of facial mimicry. I answer the question about the relative contribution of associative learning and genetic explanations for facial mimicry. The answer on the second research question is that humans are born with neurons that code for imitation of facial expressions. One of the reasons is that Infants already copy the gestures of their peers. But associative learning is also present in mirror neurons. It seems that there is a role for both, which is shown in an interesting computer model at the end of this chapter. The theoretic boundaries are mainly formed by an exploration of facial mimicry literature, mirror neuron literature and sensorimotor learning literature. With the literature combined I like to give a well-rounded answer whether facial mimicry can be regarded as the activity of mirror neurons and provide an answer to the question about the origin of facial mimicry.