Article: A Scientific look at visual conflict


Why we won’t look at each other: A scientific look at visual conflicts

Originally published by the York University Excalibur and the Canadian University Press
February 2, 2011

Picture the scene: You are in a pub and you have just met an attractive, interesting new person who you would like to get to know better. The conversation is engaging, but over your partner’s left shoulder a television is showing the hockey game and your favourite song has just come on. Still, you know that if your attention wanders you will appear to be uninterested in the discussion at hand.

Research at York has been investigating what it is about the brain that allows us to be aware of all these different stimuli in our environment but remain able to suppress our automatic impulse to respond to some of them. If we were not able to do so, we would never get anything done!

Ways we suppress automatic behaviour:

  • Responding with “fine” to the question “how are you?”
  • Maintaining eye contact during a conversation
  • Suppressing a sour face at eating something unpleasant to avoid offending the chef
  • Maintaining a poker face when playing games or lying
  • Not turning when someone calls out or a cell phone rings
  • Resisting staring at people when entering an elevator

In a study published recently in Frontiers in Human Neuroscience, graduate student and lead author Shima Ovaysikia used functional Magnetic Resonance Imaging (fMRI) to determine what part of the brain is responsible for processing automatic and controlled processes when these processes conflict or interfere with one another.

Researchers conducted the study in conjunction with the Centre for Vision Research at York, and presented participants with an image of a face with a happy, neutral, or sad expression that was superimposed with text that either matched or contradicted the emotion of the face. They were then asked to either identify the emotion of the word with disregard for the facial expression, or to identify the expression without attending to the word.

This experimental design was modeled after the traditional Stroop test, where individuals are asked to identify coloured words that do not match the colour the text describes – for example, the word “yellow” appearing in blue ink. Identifying emotions added a new dimension to the classic test due to the presumed innate nature of facial recognition, allowing researchers to test much more complex stimuli.

When the word superimposed on the face was incongruous – that is, an image of someone frowning with the word “happy” written across it – reaction time increased.Participants were able to process the written words faster than the facial expressions, which ran counter to what researchers expected. “We thought that facial recognition would be recognized faster because it is a more innate skill than reading, which is learned,” says Ovaysikia, who conducted the experiment under the supervision of Joseph DeSouza, assistant professor of psychology in York’s Faculty of Health.

“The emotion in the word doesn’t match the emotion in the facial expression, which creates a conflict,” says Professor DeSouza. “Our study showed − for the first time − an increase in signal from the left inferior frontal cortex when the study participant was confronted by this conflict between the word and the image and asked to respond to directions that went against their automatic instincts.”

The prefrontal cortex is associated with higher order cognitive functions related to behaviour, like long-term planning, decision-making, emotions, and inhibition. It is the area of the brain that oversees the coordination of thoughts and actions in order to achieve goals.

Pinpointing the region of the brain responsible for regulating such behaviour might have implications for people showing problems with inhibition, such as those with damage to their prefrontal cortex due to a stroke or brain trauma, as well as people with schizophrenia. Another possible area of application is in studying the impulse and suppression involved in a behaviour like gambling, an area where Ovaysikia intends to direct her future research.

“One of the most important things that makes us human is that we don’t just always react to stimuli because we can suppress our urge to act,” says DeSouza. Imagine that a cell phone rings in a classroom, he explains. Most students will turn in the direction of the ring, but some will hold their attention on something else, resisting the distraction. “Our brains have evolved to suppress these natural things that enter our environment,” concludes DeSouza, “or we would spend all of our time reacting.” The results also help to explain what is going on in our brains when two simultaneously competing processes would lead to different behavioural outcomes.