Emotion and the brain: Mapping the missing link

By Ramtin Hakimjavadi, BMSc Candidate

Sometime in the 17th century, René Descartes, the great French philosopher, famously posited his ideas about mind-body dualism – that the mind and the physical body are separate and fundamentally distinct in nature. Today, the fascination with bridging the gap between our understanding of the mind and its relationship to the physical brain underlies many scientific endeavours in cognitive neuroscience research.

Derek Mitchell, PhD, associate professor in the Departments of Psychiatry and Anatomy and Cell Biology at Schulich Medicine & Dentistry, leads the Emotional Cognition Lab based at Western's Brain and Mind Institute (BMI). His work focuses on the functional neuroanatomy underlying the experience and control of emotions. The research also explores new approaches to the diagnosis and treatment of psychiatric disorders.

Early in his career, Mitchell was involved in risk assessment, examining high-risk individuals in the prison system. One particular encounter with an inmate profoundly shaped the direction he would end up pursuing in his future as a scientist. The inmate was a violent offender who went on a crime spree one evening, severely harming several people. In discussing his crimes, Mitchell was struck by the inmate’s emotional response to hearing about the traumatized victims. "He said that he really didn’t understand what the victims were, as he put it, 'whining about'."

For Mitchell, it was clear that there was something fundamentally different about the way this person responded emotionally, with deficits on a biological level. This early encounter with the psychopathic inmate sparked Mitchell's initial interest in studying emotion at a neurobiological level.

Emotion is governed by a complex neurocognitive system that is deeply integrated with many other aspects of cognition, like attention, memory and decision-making. The pervasiveness of emotion drives Mitchell’s inspiration and fuels his curiosity on a daily basis. "Because emotion plays a role in so many things, nothing gets stagnant. Emotion, by its nature, interacts with all cognitive systems," he said.

Mitchell emphasizes this interactive component of emotion. To say one is thinking emotionally in one instance and rationally or practically in another is inaccurate. It is the intimate interaction between our emotional and cognitive processes which gives rise to human behaviour. “It really is about the blurring of the boundaries between the two,” he explained.

Two research projects in particular – focused on disruptive behavioural disorders (DBD) in children and frontotemporal dementia (FTD) in mid-life adults – showcase how a deeper understanding of emotional and empathic processes can facilitate the discovery of compounds or techniques as effective therapies.

Children given the same diagnosis of DBD may clinically present in very different ways. One important way they may differ is in their capacity for empathy. Mitchell is exploring the extent to which these differences in empathic styles can be targeted and changed by directing the attention of children to various social cues. Ideally, through an 'empathy amplification' intervention, children who attend to certain distress cues would experience increases in their empathic responses to social situations.

In a study funded by the Canadian Institutes for Health Research, Mitchell is collaborating with Dr. Elizabeth Finger, associate professor with the School's Department of Clinical Neurological Sciences, to evaluate novel treatments for the behavioural variant of frontotemporal dementia (FTD). This form of dementia is characterized by a progressive loss of the capacity for empathy, often resulting in deficits in social functioning and emotional responses to others. Using sensitive measures developed in cognitive neuroscience, Mitchell and Dr. Finger are looking at the potential effectiveness of oxytocin – a maternal hormone – in improving empathy-related deficits associated with FTD.

Recently, Mitchell was awarded an NSERC Discovery Grant for his research examining the impact of stress and negative emotion on cognition and human performance. In the past, the Yerkes-Dodson curve has represented the impact of stress on performance. Although this model is accurate in some instances, the reality is that a little bit of stress doesn’t impact all aspects of cognition the same way.

Mitchell and his team are working to determine the parameters that influence how stress impacts performance and which aspects of cognition are the most susceptible to these effects.

Another line of research at the Emotional Cognition Lab examines the effects of violent media exposure. There is a long-standing debate over whether there is a significant association between violent media exposure and aggressive behaviours. The problem is that current findings on the issue are equivocal – both sides are interpreting the same epidemiological data in very different ways.

Mitchell and his team are taking a novel approach by applying cognitive neuroscience tools to the problem. Previous studies on psychopathy have produced tools capable of identifying neurocognitive abnormalities associated with aggression, poor decision-making, impulsivity and other socially disruptive outcomes. Using brain imaging techniques and computerized tests, the goal is to determine whether violent media exposure is a risk factor for negative outcomes like aggression and antisocial behaviour.

Mitchell envisions his research significantly contributing to clinical practices and the cognitive neuroscience field as a whole. A major part of his work involves assessing existing diagnostic categories and identifying potential cross-diagnostic relationships for certain disorders.

More broadly, Mitchell hopes that his efforts will change the way people think about emotion and empathy – to begin recognizing that these processes are grounded in the brain. Emotional processes are the building blocks of what we recognize as the self and give rise to individuals with unique personalities. However, the fact that these mental processes reside in the brain is not necessarily widely accepted in fields outside of cognitive neuroscience.

Importantly, shifting the way these neurocognitive processes are understood could influence our understanding of social cognitive disorders. There are neurocognitive risk factors for disorders associated with empathy similar to how there are biological risk factors for other diseases like cancer or hypertension, “The playing field for emotions, just like the playing field for a lot of things, isn’t equal,” said Mitchell.

The early encounter with the psychopathic inmate is what prompted Mitchell to begin thinking about emotion and empathy at a neurobiological level. Today, his research at the Emotional Cognition Lab is fundamentally changing the way these neurocognitive systems are understood in the scientific community at large.