Swansea University psychologist investigates the 'Tipping Point'

New research conducted with Swansea University, the University of North Texas, Texas Tech University, Florida Institute of Technology, and Reykjavik University has shed light on the brain activity involved in our ‘tipping-point’, a situation where we switch from approach to avoidance in the presence of threat or danger.

Simon DymondDr Simon Dymond (pictured), Reader in Psychology and Director of the Experimental Psychopathology Lab at Swansea University, is co-author of a new article highlighting the research and published in NeuroImage. He explained: “We all have a ‘tipping-point’, a switch that occurs when, instead of instinctively approaching rewarding situations and people, we choose to avoid activities, unfamiliar people and events because of the increased potential threat.

“The point we are talking about is the switch between approach to avoidance – the ‘tipping point’. Or as Popeye famously put it: "That's all I can stands, cuz I can't stands n'more!" Our research has cast light on the brain systems involved in this transition.”

“Psychologists have studied this reaction in approach/avoidance experiments: participants are confronted with situations where they are offered pleasant rewards such as food or money, countered with the occasional presentation of unpleasant events such as losing that food or money or receiving a mild electric shock. As the likelihood of the unpleasant event occurring increases, people tend to switch from approach to threat-avoidance. This is because it’s often better to protect what you have got, rather than risk losing it.”

The researchers devised a unique task to identify the behavioural and neuronal processes underlying peoples’ tipping-points.

Dr Dymond, who holds a visiting position at Reykjavik University, said: “The participants’ task was to decide whether to board spaceships (i.e., approach) or refuse to board spaceships (i.e., avoidance). To help decisions, we presented participants with an ‘alien threat meter’, which highlighted the chances of a spaceship being laden with aliens that would steal all their money and supplies. The aim was to earn as much money as possible and prevent alien attacks. In an earlier phase, levels of the threat meter were made aversive by repeatedly pairing them with a loud scream and angry face.

Dr Mike Schlund, Research Scientist at University of North Texas and lead author of the study said: “It is known that dorsal anterior cingulate (dACC) and dorsomedial prefrontal cortex (dmPFC) are regions implicated in approach-avoidance decisions. Indeed, it is well known that the extent of activation in these regions is related to the complexity of the decisions involved about whether to approach or avoid. However, ventral frontal regions of the brain may also support this decision-making process by increasing activation as the difference between values of choice options increases.

Dr Dymond said: “The alien threat meter task allowed us, for the first time, to track activation along the approach-avoidance continuum. We found that avoidance behaviour, decision times and physiological arousal increased as the likelihood of an alien invasion increased and it produced inverted U-shaped changes in dACC/dmPFC activation. Interestingly, the opposite, U-shaped changes in dorsolateral and ventromedial frontal regions were found at these same points along the approach-avoidance continuum.

“These findings reveal that parallel ventral/dorsal systems modulate human approach-avoidance transitions; as one’s tipping point is reached, and threat becomes ever more likely, avoidance soon becomes the default coping mechanism for dealing with threat. It’s natural that we seek to preserve gains made, but for many people this tendency can lead to a life of excessive, debilitating avoidance, anxiety and depression. Further understanding the brain systems involved in this tipping- point will help to develop effective cognitive-behavioural therapies to overcome excessive avoidance and anxiety.”

The research findings are published in NeuroImage:

Schlund, M. W., Brewer, A. T., Magee, S. K., Richman, D. M., Solomon, S., Ludlum, M., & Dymond, S. (2016). The tipping point: Value differences and parallel dorsal-ventral frontal circuits gating human approach-avoidance behaviour. NeuroImage. doi:10.1016/j.neuroimage.2016.04.070