Lateralization of facial emotion recognition in the human cerebellum

Abstract

The cerebellum, one of the oldest structures in the nervous system, is well-known for the important role it plays in the coordination and timing of movement. However, there has been a paradigm shift with recent clinical, neuroimaging, and experimental research suggesting that the cerebellum also plays a role in higher-order cognitive functions such as attention and emotion. The substantial increase in research regarding the cerebellum's ability for emotional processing has indicated that it may be particularly adept at recognizing and processing negative facial expressions (i.e., fear, anger, sadness). Facial expressions are an important component of non- verbal communication that have specific meanings and are universally recognized. The ability to recognize another person's facial expressions and understand their emotional state and intentions is critical for responding in social situations. It is particularly important for an organism's survival to recognize negative emotions such as fear, anger, and sadness, as it activates defence systems designed to protect against threats. Previous research using functional brain imaging and patients with cerebellar brain injuries provide some evidence of cerebellar lateralization, with the left cerebellum being more specialized for processing emotions than the right. In the proposed study we will further test this hypothesis by applying transcranial direct current stimulation (tDCS) – a non-invasive brain stimulation technique – over the left half of the cerebellum. Specifically, we predict that active tDCS stimulation (i.e., anodal (+) or cathodal (-)) will influence the processing of negative facial emotions compared to a sham (pseudo-stimulation) condition.

Department: Psychology 

Faculty Mentor: Dr. Christopher Striemer