Category: Perception

Amsterdam coffee-shop study explores the effects of cannabis on eye-witness memory

GettyImages-528895816.jpg
Cannabis intoxication strengthened the correlation between eye-witnesses’ memory confidence and accuracy

By Christian Jarrett

The fallibility of eye-witness memory has been well-documented by psychologists, including how alcohol intoxication undermines witness accuracy still further. In fact, psychological research into the foibles of human memory and the implications this has for legal proceedings is arguably one of the best examples of the discipline making a practical contribution to everyday life.

And yet, as Annelies Vredeveldt at VU University Amsterdam and her team explain in their new paper in Applied Cognitive Psychology, there is a striking gap in the literature: “despite the frequency with which people use cannabis, there is almost no research examining its effects on eye-witness memory.”

Continue reading “Amsterdam coffee-shop study explores the effects of cannabis on eye-witness memory”

Clever study shows how two minds interact to create the spooky sense that an Ouija board is moving by itself

GettyImages-157719078.jpgBy Christian Jarrett

Psychologists have proposed an explanation for why Ouija board users feel as though a spirit is moving the planchette (an ornate pointer) and spelling out messages. It is based on the idea that two (or more) living users unwittingly take turns at controlling the planchette, cooperating implicitly to create a message that starts out random but becomes more predictable as the number of meaningful options decreases.

“It seems that meaningful responses from the Ouija board are an emergent property of interacting predictive minds that increasingly impose structure on initially random events in the sessions,” Marc Andersen at Aarhus University and his colleagues explain in their open-access paper in Phenomenology and the Cognitive Sciences.

Continue reading “Clever study shows how two minds interact to create the spooky sense that an Ouija board is moving by itself”

Researchers have identified a group of patients who are especially prone to out-of-body experiences

GettyImages-519685592.jpgBy Emma Young

People who’ve had an out-of-body experience (OBE) report that their conscious awareness shifted outside their physical body – often upwards, so they felt like they were floating above their own head. It’s thought that OBEs occur when the brain fails to properly integrate data from the different senses, including vision, touch, proprioception (the sense of where the limbs and other body parts are located in space) and from the vestibular system (organs in the inner ear that monitor head orientation, balance and motion). 

Previous research has mostly focused on the role of vision and touch – for example by triggering the illusion of viewing one’s own body – but the vestibular system has largely been neglected. If it does play an important role we should expect that problems with the vestibular system – which often present as feelings of dizziness – lead to OBEs, but do they?  

Historical case studies suggested that they might. And now, published in Cortex, the first systematic study of patients referred to a neurological specialist because of dizziness has found that they can. 

Continue reading “Researchers have identified a group of patients who are especially prone to out-of-body experiences”

People with a keener sense of smell find sex more pleasant and, if they are female, have more orgasms during sex

By Emma Young

Scent plays an often under-appreciated role in sexual attraction, helping to account for why visual attractiveness alone can’t explain just how physically attractive a person is perceived to be. But what role does our ability to smell our partners – or potential partners – play in actual experience? 

We know from past research that men born without the ability to smell tend to have fewer sexual partners. And about half of people who lose their sense of smell, through infection or injury, report negative impacts on their sexual behaviour. However, this could be an indirect effect – an inability to smell is often also associated with depression or social insecurity, which can affect aspects of sexuality – and such studies do not tell us whether sense of smell is related to sexual experience among healthy people. Now, in a new paper in Archives of Sexual Behavior, Johanna Bendas at the Technical University of Dresden, Germany, and her fellow researchers report evidence from healthy, young adults showing precisely that.

Continue reading “People with a keener sense of smell find sex more pleasant and, if they are female, have more orgasms during sex”

Distinct from intelligence or working memory, your “perceptual capacity” predicts how susceptible you are to inattentional blindness (or missing the gorilla in the room)

giphyBy Emma Young

It’s well-known that we can easily miss objects in our environment that are outside the focus of our conscious attention. “Inattentional blindness” is demonstrated by the famous “invisible gorilla” studies, for example. But there’s a darker side to this phenomenon: if it happens while you’re driving – or if you’re a baggage checker at airport security – the consequences could be fatal.

Now a new paper, by Joshua Eayrs and Nilli Lavie at University College London, published in the Journal of Experimental Psychology, shows that some people can handle more visual information than others before developing this and related kinds of attentional blindness, and this is because they have a greater visual perceptual capacity. “We identified a novel trait that is different from working memory, general intelligence or motivational factors,” Lavie said in a press release. 

Continue reading “Distinct from intelligence or working memory, your “perceptual capacity” predicts how susceptible you are to inattentional blindness (or missing the gorilla in the room)”

Three years of research into #thedress, digested – a lesson in humility for perceptual science

The_Dress_(viral_phenomenon).pngBy Christian Jarrett

Three years ago, in a time before Trump and Brexit, someone posted an overexposed photograph of a black and blue striped dress on Tumblr. Soon millions of people had seen it and started arguing about it. The reason? It quickly became apparent that about half of us – more often women and older people – perceive the dress, not as black and blue, but white and gold.

In a neat example of real life echoing a classic psychology experiment (I’m referring to Asch), #thedress was enough to make you think your friends were gas lighting you – how could it be that you and they were looking at the exact same picture and yet seeing entirely different things?

440px-Grey_square_optical_illusion.svg
The squares marked A and B are actually the same shade of grey, via Wikipedia

Of course there are many optical illusions, including others that involve colour (see, for example, the “checker shadow” illusion, pictured right). What was special about #thedress was that it triggered a bimodal split in perceptual experience among the population. Also, many illusions trigger a fluctuating percept, but once someone perceives the dress one way, they usually keep seeing it that way.

Viral hits happen overnight. Science is slow, but it’s catching up. With the passing of the years, numerous studies into #thedress have now been published – 23 according to a new review. Here we present you with a fascinating digest of what’s been discovered so far about the famous frock – researchers have made progress, certainly, yet much remains mysterious, making this a humbling experience for perceptual science.

Continue reading “Three years of research into #thedress, digested – a lesson in humility for perceptual science”

Contrary to popular belief, smiling makes you look older

GettyImages-498317079.jpgBy Christian Jarrett

In the adverts for anti-ageing skin products, everyone is smiling, positively blooming with youthfulness. A canny move by the marketeers you might think – after all, past research has found most of us believe smiling makes people look younger. It’s just that actually, it doesn’t. It makes you look older. That’s according to a new paper in Psychonomic Bulletin and Review that explores an intriguing mismatch between our beliefs and perceptions.

Continue reading “Contrary to popular belief, smiling makes you look older”

People with “misophonia” find background chewing sounds so annoying it affects their ability to learn

Young woman in dress blowing bubbleBy Alex Fradera

Research in clinical settings shows that some people with mental health problems experience extreme distress when hearing non-speech vocal sounds, like coughs and chewing noises, a phenomenon called “misophonia”. Now research from Amanda Seaborne at the University of California, Santa Barbara, and Logan Fiorella at the University of Georgia, published in Applied Cognitive Psychology, suggests that this issue exists in the broader population, and that people sensitive to these sounds perform poorly in their presence.

Seventy-two undergraduates sat in a cubicle and read a technical text about migraines for six minutes, before reporting what they remembered, answering questions on the text, and finally completing a questionnaire about their misophonia sensitivity (they rated how distressing they found sounds like “rustling papers, sneezing, chewing gum, tapping, eating crunchy foods, and heavy breathing”). For half the participants, a nearby cubicle contained a confederate working for the researchers who chewed gum loudly throughout the experiment. Participants in this condition who scored higher on the misophonia questionnaire performed worse at the comprehension measures than lower scorers. 

Interestingly, the reverse pattern was found for the participants in the quiet control condition, with the more sound-sensitive students performing slightly better – perhaps because these conditions were the ones in which they naturally thrive. So misophonia seems to have an impact in non-clinical contexts (none of the rating scores reached clinical levels of sensitivity), although we can’t say whether its origin is in a subtle neurological difference or a psychological preoccupation. But it’s a good reminder that by honouring the expectations in designated quiet spaces, we may be helping others more than we know.

Effects of background chewing sounds on learning: The role of misophonia sensitivity

Alex Fradera (@alexfradera) is Staff Writer at BPS Research Digest

Around 20 to 30 per cent of us hear something when viewing silent videos – do you?

giphy
People who hear silent videos are more likely to report other synaesthesias, including seeing flashes upon hearing sounds in the dark / giphy.com

By Emma Young

If you have a couple of minutes, click through to this survey site of “noisy gifs” – brief silent movies that, for some people at least, evoke illusory sounds. If you hear a thwack when fists collide with a punchbag, or a yell while watching a man silently scream, then you’re experiencing a “visual-evoked auditory response” (vEAR), also called “hearing motion synaesthesia”.

Ten years after the first, preliminary journal paper on the phenomenon, Christopher Fassnidge and Elliot Freeman at City University, London, report – in a new paper  in Cortex – that it’s remarkably common, affecting perhaps 20 – 30 per cent of us. Fassnidge and Freeman also investigated what induces vEAR, providing clues to what’s going on in the brain. 

Continue reading “Around 20 to 30 per cent of us hear something when viewing silent videos – do you?”

Why do we think of the future as being in front? New clues from study of people born blind

GettyImages-811434286.jpgBy Alex Fradera

Where is the future? The tendency in our culture – and most, but not all, others – is to compare the body’s movement through space with its passage through time: ahead are the things we are on our way to encounter. We intuit that the past is linked to the space behind and the future to that in front. But research in the Journal of Experimental Psychology: General has found that some Western people buck this tendency: those born blind.

Continue reading “Why do we think of the future as being in front? New clues from study of people born blind”