The influence of threat

The influence of threat on visuospatial perception, affordances, and protective behaviour: A systematic review and meta-analysis

Erin MacIntyre is a clinician-researcher in the final year of her PhD at the Persistent Pain Research Group. Her research explores links between vision and pain in people with knee osteoarthritis. She is also interested in the development of new technology (eg., virtual reality) that exploits these links between pain and visual perception to reduce pain and improve exercise engagement. 

We are surrounded by threat. And successfully navigating these daily threats is essential for homeostasis (and survival). We seek water when we are thirsty, we seek warmth when we are cold, and we seek protection when we feel pain.

However, over-generalisation of these protective behaviours can be maladaptive. If you are walking in the woods at night and encounter a wolf, running away and seeking safety is a perfectly adaptive response! But the same response is no longer adaptive when you are at your local park and see a puppy. This maladaptive over-generalisation of behavioural responses to threat is a hallmark of many clinical conditions – from phobias to chronic pain.

But what drives this over-generalisation? Lots of research has explored cognitive biases (ways our thinking can be skewed) associated with threat appraisal – you may be familiar with interpretation bias (the tendency to interpret situations in a particular way) or attentional bias (the tendency to pay more attention to certain types of information). However, less is known about how perception can shape threat-evoked responses. That’s because we generally believe that what we see is reality. But is it?

Instead, research suggests that things happening within and around your body can powerfully change the way that you see the world. These changes are adaptive – visual changes are thought to promote advantageous engagement with the world. So, hills are seen as steeper if you are less able to climb them (Bhalla & Proffitt, 1999), and desirable objects (like chocolate bars or $100 bills), are seen as closer than disgusting objects (like dog poo) (Cole et al., 2013). However, less is known about how threat can shape our perception, and in turn our behaviour. Given these gaps, we wanted to explore the influence of threat on visual perception, affordances (i.e., our perceived action capabilities), and behaviour, as well as the inter-relationships between these outcomes.

In our study, just published in Clinical Psychology Review, we found consistent evidence that threat can shape visual perception. For example, threatening objects were seen as closer and larger, and heights were seen as higher when the threat of falling was high. Pain (bodily threat) may have influenced visual perception, although results were conflicting. Affordances were similarly influenced, where high threat reduced people’s perceived ability to act within their environment. Behaviour was rarely assessed, although there was some evidence that visual exaggeration of threat was associated with avoidance behaviour.

But what does this mean clinically?

Visual exaggeration of threat may lead to increased avoidance – a large, looming spider is more likely to be perceived as threatening and therefore avoided. But beyond that, visually inflated threats may also influence other important processes – like attention or working memory.

Visually exaggerated threats grab your attention, which may promote visual vigilance (you can’t let that spider out of your sight!). Disengaging from such threats is cognitively taxing, using up your working memory, which is a limited resource. This extra cognitive load may adversely impact other key processes involved in learning, and therefore reduce the efficacy of common treatments, such as exposure therapy or educational interventions. In the context of chronic pain, if a patient has certain worries or fears, it may be important to consider visual biases first, prior to an educational or behavioural intervention. It’s also important to consider how the environment could impact their ability to take on new information. High environmental threat may make learning more difficult, so consider how you could make your clinic more inviting to power-up learning!

These results also support the potential use of emerging technologies to address perceptual biases directly. For instance, virtual reality-based perceptual re-training programs could be used to reduce visual overestimation. Alternatively, virtual reality could be used to make people feel more robust, thereby reducing the danger of threats (after all, would Superman fear a spider?).

For now, consider the possibility that perception is complex! Many things can influence both the way you see the world, and how you act within it. This is exciting news – as it opens up new treatment targets and opportunities!  There is always hope in finding new ways to promote neuroplasticity, and thus, changes in our experience.

Read the full paper here.

– Erin MacIntyre
SAHMRI Persistent Pain Research Group

References

1. Bhalla, M., & Proffitt, D. (1999). Visual-motor recalibration in geographical slant perception. Journal of Experimental Psychology, 25(4), 1076-1096. Link here
2. Cole, S., Balcetis, E., & Zhang, S. (2013). Visual perception and regulatory conflict: Motivation and physiology influence distance perception. Journal of Experimental Psychology: General, 142(1), 18.

Further reading on perception
Book Review: Pain and Perception, by Dan Harvie and Lorimer Moseley