Friday, July 30, 2010

Touch influences social judgements and decisions

Neuro Philosophy, Category: Psychology Posted on: June 25, 2010 10:05 AM, by Mo

Applying for a job? The weight of the clipboard to which your CV is attached may influence your chances of getting it. Negotiating a deal? Sitting in a hard chair may lead you to drive a harder bargain. Those are two of the surprising conclusions of a study published in today's issue of Science, which shows that the physical properties of objects we touch can unconsciously influence our first impressions of other people and the decisions we make about them.

Josh Ackerman of the Sloan School of Management at MIT, and psychologists Chris Nocera and John Bargh of Harvard and Yale Universities, respectively, performed a series of six experiments designed to investigate whether or not the weight, texture and hardness of objects can influence our judgements of, and decisions about, unrelated events and situations. Their findings provide yet more evidence for the embodied cognition hypothesis, which states that bodily perceptions can exert a strong influence on the way we think.

In the first experiment, 54 passersby were asked to evaluate a job candidate on the basis of a CV attached to either a light (0.34 kg) or a heavy (2 kg) clipboard. Those given the CV on the heavier clipboard generally rated the candidate as being better and having a more serious interest in the position than those given the lighter clipboard, even though the CVs used in both cases were identical. Those given the heavy clipboard also rated their accuracy on the task as more important than those given the lighter one, but did not report putting more effort into it. They did not, however, rate the candidate as more likely to get along with co-workers. This suggests that the weight cue affected their impressions of the candidate's performance and seriousness, but not the irrelevant trait of social likeability, and that the observed effects were not due their perception of their own actions.

The effect of an object's weight on decision-making was explored in a second, smiilarly designed experiment. Again, 43 passersby were asked to complete a "social action survey", asking whether various public issues should receive more or less government funding. And again, the weight of the clipboard was found to affect the participants' responses, although an interesting sex difference was observed: men allocated more money when given the survey on the heavier clipboard than when handed the lighter one, whereas women chose to allocate as much funding as possible in both the "heavy" and "light" conditions.

Next, the researchers looked at the effects of an object's texture on participants' perceptions of a social interaction. Participants read a passage describing an ambiguous interaction between two people, and were then asked about their impressions of the situation - whether it was confrontational or friendly, competitve or co-operative, a discussion or an argument. Beforehand, they were asked to complete a five-piece jigsaw puzzle; in one version of the puzzle, the pieces were covered in rough sandpaper, and in the other, they were smooth. Those who completed the rough puzzle perceived the situation as being confrontational and more competitive than those who completed the smooth puzzle.

Texture was also found to affect the decisions made in a social situation. Participants completed either the rough or the smooth puzzle before playing a version of the Ultimatum game. They were given 10 tickets for a $50 lottery, and made to give any number of them to a second anonymous participant. If the second participant rejected the offer, all the tickets are forfeited. Those who had first completed the rough puzzle offered more tickets to the second participant than those who did the smmoth puzzle. The roughness of the puzzle pieces apparently made them perceive the situation as being more difficult and consequently caused them to behave in a compensatory way - they offered more tickets to increase the chances that their offer would be accepted.

The researchers then investigated the effects of an object's hardness. Another group of participants was asked to watch a magic trick, and to try to figure out how it was done. Beforehand, they were asked to examine the object to be used in the trick - either a soft pice of blanket or a hard wooden block. They were then told that the trick was to be postponed, and asked to give their impressions of two individuals (an "employee" and the "boss") involved in an hypothetical interaction. Those previously given the blanket evaluated the employee as being kinder than those given the wooden block.

Finally, texture was also found to affect peoples' behaviour in a bargaining situation. But whereas the other five experiments examined the effects of actively touching an object, this one investigated passive touch. The participants were seated in either a hard wooden chair or a soft cushioned chair, and asked to perform two tasks. In one, they gave their impression of an hypothetical employee. In the second they were required to imagine shopping for a new car priced $16,500 and to negotiate a lower price. In this bargaining task, they were allowed to make two offers on the car, the assumption being that their first offer would be rejected. The participants who sat in the hard chair judged the employee to be more stable and less emotional than those seated in the soft chair. They also deviated less from their first rejected offer.

These experiments show that touch sensations have a strong influence on our impressions of people and the decisions we make about them, even when the people and events are completely unrelated to the objects being touched. Thus, hardness is associated with rigidity, roughness with difficulty, and heavy objects with seriousness. Our metaphors reflect these associations: we sometimes describe people as having a "hard hearted", "rough day", and serious matters are often said to be "weighty". The weight, texture and hardness of touched objects evidently has a strong priming effect on the thought processes that immediately follow, and can trigger the associated concepts. These findings suggest various "tactile tactics" that could be very useful to job seekers, marketers and negotiators.

Ackerman, J., Nocera, C. John A. Bargh, J. (2010). Incidental Haptic Sensations Influence Social Judgments and Decisions. Science 328: 1712-1715. DOI: 10.1126/science.1189993.
Touch is both the first sense to develop and a critical means of information acquisition and environmental manipulation. Physical touch experiences may create an ontological scaffold for the development of intrapersonal and interpersonal conceptual and metaphorical knowledge, as well as a springboard for the application of this knowledge. In six experiments, holding heavy or light clipboards, solving rough or smooth puzzles, and touching hard or soft objects nonconsciously influenced impressions and decisions formed about unrelated people and situations. Among other effects, heavy objects made job candidates appear more important, rough objects made social interactions appear more difficult, and hard objects increased rigidity in negotiations. Basic tactile sensations are thus shown to influence higher social cognitive processing in dimension-specific and metaphor-specific ways.

Making Sense of Sense - The roads less travelled – four paths to get from touch to the body

By Nadia Barnsley, a third year medical students from the University of New South Wales.

Nadia's research interests include bodily awareness, body ownership and immune responses. She is doing an independent learning project on Body in Mind research. Here she reviews Serino and Haggard’s paper “Touch and the Body” which was published in Neuroscience and Biobehavioural Reviews.

Serino and Haggard’s paper gives a four-part model that explains the notion that our sense of touch carries information about both the external object touching our skin and also our own body. Tactile information can influence (or be influenced by) our mental representation of the physical body. Mental body representations (MBR) are simply descriptions in our mind of the parts of the body, their position in space and their organization into a structural whole (us!)

Serino and Haggard firstly examined the idea that the physical body structures tactile sensation – that when we touch or get touched, tactile afferents will map this into a homunculus, “little man”, in the parietal lobe of the brain. This information is conveyed to what’s known as S1 (the primary somatosensory cortex) of the opposite hemisphere.

Serino and Haggard’s second pathway explains that tactile information provides an important afferent input to mental body representations. Importantly they clarified the difference between body schema and body image; where body schema is short-lived and represents the positions of body parts in space, whereas body image remains fixed over time, representing a basic appearance of the body as an object in third person perspective.

Interestingly they reviewed how visual information relates to tactile sensation; the third pathway. They found that tactile acuity improved when subjects viewed the body. Moreover, this is independent from visuo-spatial orienting to the location of the body. The paper explained those with poor tactile ability will have vast improvements in tactile sensation when visual information is added. This has clinical implications for those with reduced sensation following brain lesions.

The last pathway explained how MBRs not only contribute to our body perception, but the perception of external objects. Basically, our touch of external objects is ‘body referenced’. This implies that MBRs are not just a stored body image; they are updated to integrate current sensory information.

So the first pathway tells the brain where we are being touched, the second pathway gives our brain a representation of what we are (our body image), the third is that this representation influences how we understand our sense of touch and the last being that our body image alters how external objects are perceived.

Reference: Serino A, & Haggard P (2010). Touch and the body. Neuroscience and biobehavioral reviews, 34 (2), 224-36 PMID: 19376156 Epub 2009 Apr 17.

Touch and the body
Serino A, Haggard P. Dipartimento di Psicologia and Centro studi e ricerche in Neuroscienze Cognitive, Università degli Studi di Bologna, Italy.

The dual nature of touch has long been understood. The sense of touch seems to carry information at the same time about the external object touching our skin, and also about our body itself. However, how these two interact has remained obscure. We present an analytic model of how tactile information interacts with mental body representations in the brain. Four such interactions are described: the link between the body surface and the maps in primary somatosensory cortex, the contribution of somatosensory cortical information to mental body representations, the feedback pathway from such higher representations back to primary tactile processing in somatosensory cortex, and the modulation of tactile object perception by mental body representations.

Body in Mind Research into the role of the brain and mind in chronic pain disorders

Monday, July 26, 2010

Serotonin cell discoveries mean rethink of depression

If you thought depression was caused by low serotonin levels, think again. It looks as if the brain chemistry of a depressed person is much more complex, with mounting evidence suggesting that too much serotonin in some brain regions is to blame.

Read the full article by Linda Geddes at: NewScientist 22 July 2010 Issue 2770

Source: Neuroscience and Pain Science for Manual Physical Therapists on Face Book

Friday, July 23, 2010

Feeling blue, seeing gray: Reduced contrast sensitivity as a marker for depression

Depression has long been associated with vision - and to colour perception in particular - and the link between them is evident in everyday language. Depression is, of course, often referred to as "feeling blue", and those who suffer from it are sometimes told to "lighten up". The link can be found in art, too - Picasso's so-called "Blue Period", for example, which was brought on by the suicide of his close friend Carlos Casagemas, is characterised by a series of striking paintings in shades of cold blue, which express the deep melancholy he felt at the time.

Although the association between depression and colour is largely metaphorical, there is actually some evidence that they are closely linked. The most recent comes from a new study by German researchers published in the journal Biological Psychiatry. The study shows that depressed people have reduced sensitivity to contrast, and therefore that they may perceive the world differently from others. It also suggests that depression can be diagnosed by objective measurements of electrical activity in the eye.

Earlier work has already shown that there is a physiological link between depression and vision. It has long been known, for example, that reserpine, a drug which is prescribed for psychosis and hypertension and which induces depression in humans, causes excessive sensitivity to light in various animals. Other studies have shown that patients with major depressive disorder (MDD) may also be supersensitive to light and that this can be reversed by anti-depressants; that depression causes changes in the electrical activity of the brain in response to visual stimuli; and that this change in activity can be altered by antidepressants.

Last year, neuropsychiatrist
Ludger Tebartz van Elst of the University of Freiburg and his colleagues reported that patients with MDD exhibited a reduced sensitivity to contrast, while a team of researchers from Yale showed that visual motion perception is enhanced in depression. But these experiments could not establish whether the observed changes were due to alterations in the retina or the various parts of the brain through which visual information travels and is processed. And because they were based on the conscious experiences of the participants, the reported effects could have been modulated by attentional or other mechanisms.

For their latest study, van Elst's group sought to confirm their previous findings using objective methods, and to determine if any observed changes in the contrast sensitivity of depressed patients are due to changes in the eye or brain. They recruited 40 patients diagnosed with MDD and 40 matched, healthy controls. They presented the participants with visual stimuli consisting of black and white checkerboard patterns, and used pattern electroretinography (PERG) to measure the response to the patterns. The PERG is evoked by viewing patterned stimuli and, in this case, its size is indicative of contrast gain. It is recorded at the cornea, and is thought to represent the activity of the retinal ganglion cells, which are involved in the early processing of visual information and whose axons form the optic nerve that carries the information into the brain.

Specifically, the researchers looked for differences between the two groups of participants in activity reflecting contrast gain, the process by which cells in the retina adapt to variance in the light intensity of the visual scene so that the amount of information extracted from it can be maximized. They found a significant difference in the contrast gain-related activity between the depressed patients and controls. The participants diagnosed with depression displayed a marked reduction in contrast gain when compared with the controls. The reduction was observed in both medicated and unmedicated patients. Those taking medication for their depression, however, had slightly lower depressivity scores and correspondingly better contrast gain than unmedicated patients.

Furthermore, the reduction in contrast gain was strongly correlated with the severity of depression - the more severe the depression, the greater was the observed reduction in contrast gain. No difference was observed between patients with recurrent depression and those experiencing their first episode of the condition, or between depressed patients taking selective serotonin uptake inhibitors such as fluoxetine (Prozac) and those taking tricyclic antidepressants such as imipramine. The intensity of the treatment, or dose being taken, did not affect the reduction in contrast gain observed in the depressed patients. Finally, the researchers could predict, with an accuracy of greater than 90%, which of the participants had been diagnosed with depression on the basis of their electroretinographic recordings.

This is a pilot study whose results need to be replicated. Nevertheless, it shows that processing of visual information related to contrast is altered in the retinae of depressed patients. A likely consequence of this is a reduced ability to perceive contrast - depressed people may indeed experience the world as being less colourful. The study further suggests that PERG could be useful in diagnosing and objectively measuring depression. It's still unclear, however, whether reduced contrast processing is a specific marker of depression. The same effect could possibly occur in patients with other neuropsychiatric conditions such as schizophrenia, and this is could be investigated in future work.

Bubl, E., et al. (2010). Seeing Gray When Feeling Blue? Depression Can Be Measured in the Eye of the Diseased. Biol. Psychiatry 68: 205-208. DOI: 10.1016/j.biopsych.2010.02.009.
A related article by Sandy Gantaum on The Mouse Trap also asks the question: Why is the world vivid in mania but bleak in depression?

Move it, baby! Can exercises help to avert dyslexia?

Move it, baby! Can exercises help to avert dyslexia?
by Celia Brayfield

When you gaze at your new baby and wonder what destiny has in store, you hope dyslexia won’t be part of the picture, with its possible consequence of alienation. However, parents can act to minimise the possibility.

According to Sally Goddard Blythe, who runs the Institute for Neuro-Physiological Psychology (INPP), a self-funding research and clinical organisation based in Chester, there are factors of family life that interfere with the development of a child’s mind. Her book The Well Balanced Child describes how the infant mind matures and what action parents can take to help it develop.

She argues that the restrictions of a modern childhood, with small homes, baby-seats and reduced opportunities for movement, produces problems. A couch-potato lifestyle can have mental as well as physical consequences. The INPP has 30 years of experience in working with children whose learning difficulties begin in infancy, when they don’t move enough, and in the right way, for their brains to develop the abilities they need to master reading and writing.

“In the first year of life, important connections are being formed between the brain and the body,” Goddard Blythe says. “Balance, co-ordination and eye movements, which a child needs before it can read, all depend on these connections.”

One thing that interferes is a persistence of the reflex reactions of the newborn. These give the baby survival instincts, prompting it to search for the breast, gain control of its body and react to danger. As the baby grows, the movements of crawling suppress the reflexes, which die as the child develops balance.

Babies who don’t crawl or aren’t active enough in their first year retain their newborn reflexes and have to struggle against them. Not only could they have difficulty in reading and writing, but they may also be clumsy and unco-ordinated, have trouble tying shoelaces, riding a bicycle, catching balls and find it hard to do things that involve two skills together – such as copying from a whiteboard.

Immature reflexes may also show up in a child’s feelings and behaviour, because the balance mechanism in the brain also has emotional connections, so children might be hyper-reactive, have trouble concentrating, be easily upset and be overly anxious, fearful or aggressive.

The INPP has developed a ten-minute remedial exercise programme, being tried out in schools. Studies in Cumbria and Derbyshire have indicated that it is twice as effective as traditional exercise and four times better than none at all, in improving reading and writing and behaviour in primary schoolchildren. A study of 670 children — average age eight — in seven schools in Northern Ireland showed improved concentration and a trend towards higher academic achievements.

Every child with learning difficulties is different and has a unique cluster of physical, mental and emotional challenges to overcome. The analysis isn’t a perfect fit, but in some cases it can turn a child’s life around. Of course, it is better to need no remedial exercises. “The process of maturation is hard-wired into our instincts,” says Goddard Blythe. “All children need to develop normally is the opportunity to do the natural thing.”

This means giving a baby ample space and freedom of movement, particularly in the first year. She suggests that from the age of about six weeks a baby should have “tummy time”, when it can lie on its front and wriggle freely. “And don’t make the mistake I made. I was so delighted to have a girl after two boys that I put her in pretty dresses, which aren’t nearly as easy for a baby to move in as Babygros,” she says.

The baby will naturally start doing “push-ups”, raising its head and upper body, and within a few months will start crawling — this is vital for its neurological development.

Because the sense of balance is so important, she suggests a traditional rocking cradle, and for older children those bouncing and swinging games are developmentally vital. They help children to gain mind-body co-ordination. Old-fashioned swings and roundabouts are probably better than adventure playgrounds.

Goddard Blythe’s recommendations include music and singing, reading, conversation, optimum nutrition and family meals. In fact, she concludes, the classic Enid Blyton childhood, with country picnics, nursery rhymes and cod-liver oil, had an awful lot going for it.

The Institute for Neuro-Physiological Psychology; 01244 311414.

The Well Balanced Child by Sally Goddard Blythe (Hawthorn Press)

Source: Times Online