Hallucinations are a common symptom of schizophrenia and related disorders, but mentally well people experience them, too. In fact, work suggests that 6-7% of the general population hear voices that don’t exist. However, exactly what predisposes well people to experience them has not been clear. Now a major new study of 1,394 people native to 46 different countries, led by Peter Moseley at Northumbria University, provides support for two hypotheses from earlier, smaller studies — namely, that a history of childhood trauma and a propensity to hear non-existent speech among background noise are both associated with experiencing hallucinations — but does not support three others.
“In terms of reproducibility, these results may be a cause for concern in hallucinations research (and cognitive and clinical psychology more broadly),” writes the team in their paper in Psychological Science. In firming up a few ideas, the work does, though, help to clarify what aspects of cognition as well as past experience are — and are not — linked to being more prone to hallucinations.
Facial expressions can be hard to read — and not just when someone is experiencing a mild emotion or feels ambivalent. Research has suggested that when we witness someone in the throes of a particularly acute emotional state, like intense joy or pain, we find it hard to pinpoint exactly what they’re feeling.
A new study looks at a similar phenomenon, this time focusing on vocalisations such as laughter, cries, screams and moans. Writing in Scientific Reports, Natalie Holz and colleagues from the Max Planck Institute for Empirical Aesthetics find that our ability to identify emotions increases as vocalisations become more intense — but only to a point. When these sounds reach peak intensity, we find it surprisingly hard to classify them.
Take a look at this 1930 painting, “Rhythm, Joy of Life”, by French artist Robert Delaunay. Do you find it colourful? And do you like it?
Now what if every pixel in a digital version was rotated an equal distance on a “colour wheel” that represents every colour that people can see? Technically, the number of different colours in the image would be the same — but you’d probably perceive it to be less colourful. And, even if you’d never seen the original before, you’d probably like it less. That, at least, is the conclusion of a fascinating new paper in the Journal of Experimental Psychology: Human Perception and Performance. The work contributes to our understanding not only of why certain colours are more common in art, but also of how we perceive colour.
We’re all familiar with the phrase “healthy body, healthy mind”. But this doesn’t just refer to physical fitness and muscle strength: for a healthy mind, we need healthy senses, too. Fortunately, there’s now a wealth of evidence that we can train our many senses, to improve not only how we use our bodies, but how we think and behave, as well as how we feel. Trapped as we are in our own “perceptual bubbles”, it can be hard to appreciate not only that other people sense things differently — but that so can we, if we only put in a little effort.
But if we’re going to make the most of using and improving our senses to enhance our wellbeing, we have to consider more than sight, hearing, taste, touch and smell. Aristotle’s desperately outdated five sense model may still be popular, but it vastly under-estimates our extraordinary human capacity for sensing.
How do you know whether to trust what someone is telling you? There’s ongoing debate about which cues are reliable, and how good we are at recognising deception. But now a new paper in Nature Communications reveals that we reliably take a particular pattern of speech pitch, loudness and duration as indicating either that the person lying or that they’re unsure of what they’re saying — and that we do it without even being aware of what we’re tuning into.
Back in the 1970s, the developmental psychologist Jean Piaget discovered that, if you ask young children to explain the mechanics of vision as they understand them, their answers tend to reveal the exact same misconception: that the eyes emit some sort of immaterial substance into the environment and capture the sights of objects much like a projector.
Although this belief declines with age, it is still surprisingly prevalent in adults. What’s more, so-called extramission theories of vision have a long-running history dating all the way back to antiquity. The Greek philosopher Empedocles was amongst the first to suggest in the 5th century BC that our ability to see must stem from an invisible fire beaming out of our eyes to interact with our surroundings. This view was subsequently endorsed by intellectual authorities like Ptolemy and Galen.
Now, a duo of researchers behind a recent publication in PNAS think they might have found an explanation for the intuitive appeal of extramission theories. According to their paper, this worldview might just be a reflection of the mechanisms that play out within our brains when we follow other people’s gazes and track where they pay attention. This is because, to carry out this process, our brains actually conjure illusory beams of motion emanating from other’s faces — a quirk of evolution with interesting consequences.
As an English-speaker, I might “see red” with anger, go “green” with envy or, on a bad day, “feel blue”. To me, it seems natural to associate certain colours with particular emotions — but is the same true for people around the world? And if so, do we all make the same emotion/colour matchings? These questions have been investigated in a new study, published in Psychological Science, which has produced some fascinating results.
If you were to play your favourite song right now, I imagine you’d have little difficulty clapping along with the beat. Our appreciation of beat allows us to clap, dance, march and sway in time with a piece of music — or just with each other. As the authors of a new paper published in the Journal of Experimental Psychology: General point out, these behaviours occur spontaneously across human cultures. But while moving to a beat seems effortless, it involves all kinds of perceptual processes.
The team, led by Jessica E. Nave-Blodgett at the University of Nevada, Las Vegas, now report that our ability to perceive beat becomes ever more refined and also nuanced through childhood and adolescence. It may seem like an instinctive ability, but it is learned — and training does make it better.
It’s one of the best-known and also controversial experiments in psychology: in 1963, Stanley Milgram reported that, when instructed, many people are surprisingly willing to deliver apparently dangerous electrical shocks to others. For some researchers, this — along with follow-up studies by the team — reveals how acting “under orders” can undermine our moral compass.
Milgram’s interpretation of his findings, and the methods, too, have been criticised. However, the results have largely been replicated in experiments run in the US, Poland, and elsewhere. And in 2016, a brain-scanning study revealed that when we perform an act under coercion vs freely, our brain processes it more like a passive action rather than a voluntary one.
Now a new study, from a group that specialises in the neuroscience of empathy, takes this further: Emilie Caspar at the Social Brain Lab at the Netherlands Institute for Neuroscience and colleagues report in NeuroImage that when we follow orders to hurt someone, there is reduced activity in brain networks involved in our ability to feel another’s pain. What’s more, this leads us to perceive pain that we inflict as being less severe. This process could, then, help to explain the dark side of obedience.
Of all “cross-modal” findings, the most famous is surely the bouba-kiki effect — that we tend to pair round, blobby shapes with the sound bouba and spiky shapes with kiki. However, research has not yet revealed why this effect is common among adults who speak very different languages — and even in infants as young as four.
Various theories have been put forward. One holds that levels of emotional arousal may be key — that both kiki and a spiky shape trigger relatively high levels of arousal, compared with bouba and a blob. Now a new study, reported in Psychological Science, provides compelling evidence for this idea. The researchers also take their findings further, arguing that they could have important implications for understanding the early evolution of languages.