The puppeteers under our noses

Brexit. Trump. Hothouse earth. Recent years have seen one global upheaval after another, and psychology has responded with an increasingly outward-focused, social and political stance. Our own magazine groans under a burden of expectation, over managing modern interpersonal relations and working in unstable and austere times. It can feel we have the weight of the world on our shoulders. So what could be better than a retreat to the Lake District for an annual dose of microbes, glucose, polyphenols and more? It's a reminder that there's a whole lot going on under the bonnet, and we are perhaps surprisingly unaware of it. What's really driving brain and behaviour?

Many of the talks covered what we put into our bodies. Kicking off the conference, Daniel Lamport (University of Reading, presenting Matthew Grout's PhD study) found that a low glycaemic-index diet which sustains glucose across the day led to higher feelings of fullness and lower anxiety, yet no clear benefits were seen for cognition. Angela Bonner (Staffordshire University) showed how poor regulation of glucose can impair recognition memory, and can be detected in subtle neurophysiological signals. Libby Orne (Northumbria University) used similar measures to demonstrate that performance on an attentionally demanding task was faster and less effortful following the consumption of commercially available purple grape juice (containing polyphenols). Philipa Jackson (Northumbria University) found that a Vitamin B complex helped people get to sleep quicker, but reduced total sleep time by around 40 minutes – despite this, people reported better sleep. And Jess Eastwood (University of Reading) revealed that a dose of B6 (in Marmite) was associated with increased neural inhibition in the visual cortex, and a reduction in anxiety levels. 

Some researchers move beyond sustenance to recreation, with several presentations on smoking and drinking. Anna-Marie Marshall (Northumbria University) looked into how e-cigarettes alleviate the symptoms of withdrawal from smoking, while Lucy Walker (Manchester Metropolitan University) advocated the use of facial morphing technology to encourage smokers to stop – 'here's what you'll look like in 20 years if you keep smoking'. Physiological activity during this intervention was related to smoking outcome, with Walker suggesting that the ideal is for the person to be stressed by it, but not too stressed. Turning to the drink, Francesca Zaninotto (Kingston Uni) took one for Team Science by braving the disapproving looks of Waitrose checkout staff in order to ply her participants with vodka. She found that people with high social anxiety might be more sensitive to alcohol's effects on eye movements, spending more time looking at the angry face stimuli. And Chris Alford (University of the West of England) gave students six vodkas at 9 in the morning, finding greater impacts on subjective state and attention measures than with 5pm adminstration. 'If you want a greater hit, drink in the morning, but you're more likely to crash'.

Several speakers went with a gut instinct, on the importance of the multitudes of microbes who are good enough to let us live in their world. Andy Smith (University of Cardiff) administers inulin, a natural food component found in many plants, often with explosive results for his participants. 'This was often referred to as the farting study', he said. There was some evidence for inulin-enriched breakfast cereal being associated with improved wellbeing, mood and cognition. Leigh Gibson (University of Roehampton) found that a combination of prebiotic treatment and a gluten/casein-free diet led to encouraging improvements in social behaviour in children with Autism Spectrum Disorders. Both researchers called for further study of the mechanisms behind these gut-brain interactions. 

The man for that particular job is likely to be John Cryan (University College Cork), whose keynote tour de force through dozens of published papers painted microbes as 'the brain's Geppetto… puppeteers of neural function and behaviour'. Stress is a whole body syndrome, and Cryan moved from animal models to humans to show how signatures of early trauma can persist in an altered microbiome. We also get a 'handover' of microbes from our mother during the birthing process – if you bypass this due to a c-section delivery, your microbiome is different and it appears you have an increased response to acute psychosocial stress. It's a complex area with confounding factors, and Cryan emphasised that a lot of this research is in its early days, with questions remaining over how these effects happen. His own gut feeling over this involves short chain fatty acids, the way microbes enable us to extract crucial things for brain development (such as sciatic acid), and the importance of a diverse diet. Cryan has emulated many of the core symptoms of depression in the rat by taking microbiota from depressed human, and found negative outcomes for germ free animals in terms of social behaviour. 'We have extinguished microbes that our ancestors had', he warned. Will the coming years see a 'psychobiotic revolution', with people increasingly focused on altering their own gut environment via diet and more palatable methods of feacal transplants ('crapsules')?   

Others also addressed this lack of insight into what's going on under our bonnets. Michael Smith (Northumbria University) found that people who say that they respond more drastically to stress in the real world actually show less cardiovascular reactivity to a multitasking stress task. And keynote speaker Sarah Garfinkel (University of Sussex) wowed with a series of eye-catching findings around how good or poor people are at monitoring their own internal signals, and how good or poor they think they are. You may think your heart is just beating away blandly in the background, but cardiac signals actually appear to guide emotion and memory. People with autism spectrum condition turn out to be significantly impaired in their accuracy in knowing when their heart is beating, even though they think they are really good at it. That mismatch in 'interoceptive metacognition' is also implicated in the alienation from surroundings, and feeling 'divorced' from memories, that is seen in dissociation. And this is not a general metacognitive deficit, it's specific to interoceptive measures. So who's got decent interoceptive accuracy? London traders (well, better than groups of medics and students), and that ability predicts their money made during the year. 

There's more. 'What I think is so beautiful about the heart is that it doesn't beat regularly,' Garfinkel enthused. Research can take advantage of cardiac signals of different states, and even 'time lock' stimuli to specific parts of the cardiac cycle. Cardiac timing influences our memory (for example for presented words), and that's modulated by both interoceptive sensitivity and our metacognition around it. There's also a small yet systematic propensity for fear faces to be judged as more intense on as opposed to off the heartbeat, and Garfinkel is looking into whether this opens up a target for therapy.  

As I left the conference, I saw on Twitter that a key message from the Division of Health Psychology event, going on at the same time, was that we mustn't ignore the 'bio' in the 'biopsychosocial' model. The Lakes is a yearly reminder of that, and a much-needed dose of quality, multi-method, interdisciplinary science (see Mark Wetherell on what it's like developing a study protocol with computer scientists, to assess the effects of psychosocial stress on how we type). The researchers are usually refreshing in their willingness to admit that it's early days, that mechanisms can be complex and uncertain, and that replications are important. There are many more mysteries to unravel in the search for exactly what is pulling our strings.