Archive for November 2008
Rolf Reber, together with mathematician Morten Brun and psychologist Karoline Mitterndorfer, all from the University of Bergen, Norway, have reported first empirical evidence for the use of beauty as truth and they have provided an explanation for this phenomenon, based on the processing fluency theory of beauty.
Mathematicians and scientists reportedly used beauty as a cue for truth in mathematical judgment. French mathematician Jacques Hadamard, for example, wrote in 1954 in his famous book, “The Psychology of Invention in the Mathematical Field,” that a sense of beauty seems to be almost the only useful “drive” for discovery in mathematics. However, evidence has been anecdotal, and the nature of the beauty-truth relationship remained a mystery.
In 2004, Rolf Reber (University of Bergen), Norbert Schwarz (University of Michigan), and Piotr Winkielman (University of California at San Diego) suggested – based on evidence they reviewed – that the common experience underlying both perceived beauty and judged truth is processing fluency, which is the experienced ease with which mental content is processed. Indeed, stimuli processed with greater ease elicit more positive affect and statements that participants can read more easily are more likely to be judged as being true. Researchers invoked processing fluency to help explain a wide range of phenomena, including variations in stock prices, brand preferences, or the lack of reception of mathematical theories that are difficult to understand.
Applied to mathematical reasoning, processing fluency, stemming either from familiarity with problems or from attributes of a task, is predicted to increase intuitively judged truth. As a first step towards testing this assumption, the authors of the study demonstrated in two experiments that symmetry, a feature known to facilitate mental processing and to underlie perceived beauty, is used as heuristic cue to correctness in arithmetic problems.
The researchers constructed additions, consisting of dots. For example, 12 dots plus 21 dots equaled 33 dots. Half of the additions were correct; the others were wrong, such as 12 dots plus 21 dots equaled 27 dots. Half of the additions had symmetric dot patterns (symmetric additions), the other half asymmetric patterns (asymmetric additions). These additions were presented briefly, e.g., in one experiment 1800 milliseconds, and student participants without training in mathematics had to decide immediately after the addition disappeared whether it was correct or incorrect.
Participants were more likely to judge symmetric additions than asymmetric additions to be correct. As this was also the case when additions in fact were incorrect, the finding cannot be explained by the fact that symmetric additions were easier to count or to estimate: In this case, symmetric additions that were incorrect would have been less likely to be judged correct. The results clearly show that participants used symmetry as an indication to correctness, or beauty as truth.
The authors have shown that people who do not have enough time to analyze the problem use heuristic cues in order to assess the correctness of a proposed solution. This simple setup serves as a model for the more complicated situation where a mathematician has discovered a plausible solution to a problem and now wants a quick assessment of whether this solution “feels” right. These findings suggest a solution to the mystery why beauty serves as a cue for truth in the context of mathematical discovery.
Psychonomic Bulletin & Review, 15, 1174-1178. doi: 10.3758/PBR.15.6.1174
The use of heuristics in intuitive mathematical judgment
Rolf Reber, Morten Brun, and Karoline Mitterndorfer
Anecdotal evidence points to the use of beauty as an indication of truth in mathematical problem solving. In the two experiments of the present study, we examined the use of heuristics and tested the assumption that participants use symmetry as a cue for correctness in an arithmetic verification task. We manipulated the symmetry of sets of dot pattern addition equations. Speeded decisions about the correctness of these equations led to higher endorsements for both correct and incorrect equations when the addend and sum dot patterns were symmetrical. Therefore, this effect is not due to the fact that symmetry facilitates calculation or estimation. We found systematic evidence for the use of heuristics in solving mathematical tasks, and we discuss how these findings relate to a processing-fluency account of intuition in mathematical judgment.
Have you got the new iPhone yet? Do you like changing jobs now and again because you get bored otherwise? Do you go on holiday to different places every year? Then maybe your neural connection between ventral striatum and hippocampus is particularly well developed. Both of them are centres in the brain. The reward system which urges us to take action is located in the striatum, whereas the hippocampus is responsible for specific memory functions.
Connections between the nerves is one factor determining whether a person welcomes a change or tends to avoid anything new.
In innovation-oriented people, both of these centres apparently interact particularly well. At least this is the supposition of the scientists from Bonn, Michael X. Cohen and Dr. Bernd Weber. If the hippocampus identifies an experience as new, it then sends the correspond-ing feedback to the striatum. There certain neurotransmitters are then released which lead to positive feelings. With people who constantly seek new experiences, striatum and hippocampus are evidently wired particularly well. The two researchers were able to show this in the survey now being published.
Method revolutionises the exploration of the brain
Up to now, it has been extremely difficult to make the individual ‘wiring’ of the brain visible. ‘In principle this was only possible using cross sections of the brain of deceased people, which in addition had to be stained in a complex process,’ Dr. Weber explains. Thanks to a new method this is now a lot easier. With modern MRI you can actually determine in which directions the water in the tissue diffuses. Nerve fibres are an impenetrable obstacle for tissue fluid. It can only flow along them. These ‘directional’ streams of water are visible in the tomography image. ‘With this hazard-free method we can work on completely new issues related to the function of the brain,’ Cohen says enthusiastically.
In the current study the Bonn scientists focused on the ‘wiring’ of the striatum. Moreover, the test candidates had to choose descriptions that characterised their personality best from a questionnaire, e.g. ‘I like to try out new things just for fun or because it’s a challenge’ or alternatively ‘I prefer to stay at home rather than travelling or investigating new things.’
By contrast, descriptions such as ‘I want to please other people as much as possible’ or ‘I don’t care whether other people like me or the way I do things’, were about social accept-ance. Here too the researchers noticed a link. ‘The stronger the connection between frontal lobe and ventral striatum, the more distinctive the desire for recognition by that person’s environment,’ Weber says. That is not quite unexpected. For example, it is known that people with defects of the frontal lobe violate social norms more frequently.
The Bonn scientists wish to confirm their results even more. In experiments they would like to investigate whether people actually behave differently depending on the ‘wiring’ of their brain.
Nature Neuroscience Published online: 23 November 2008 | doi:10.1038/nn.2228
Connectivity-based segregation of the human striatum predicts personality characteristics
Michael X Cohen, Jan-Christoph Schoene-Bake, Christian E Elgern & Bernd Weber
We found that personality characteristics are linked to dissociable connectivity streams in the human brain. Whereas fiber tracts between a subcortical network, including the hippocampus and amygdala, and the ventral striatum predicted individual differences in novelty seeking, tracts between prefrontal cortex and the striatum predicted individual differences in reward dependence. These findings suggest that the strength of limbic-striatal connectivity may, in part, underlie human personality traits.
Drug Addiction: Environmental Conditions Play Major Role In Effective Treatment And Preventing Relapses
Environmental conditions play a major role in treating drug addiction and in preventing relapses, according to new research. For the first time, researchers from the Institut de physiologie et biologie cellulaire (CNRS/Université de Poitiers) have shown that positive and stimulating environmental conditions make it easier to treat cocaine addiction.
Even though numerous data exist on the mechanisms of cocaine addiction, there are as yet no effective therapies, making it very urgent that new strategies for treating the disease be developed. According to a study by Marcello Solinas and Mohamed Jaber, carried out by a group of researchers at the Institut de physiologie et biologie cellulaire in Poitiers, exposing mice to an “enriched environment (1)” during cocaine withdrawal removes abnormal behavior related to addiction. An enriched environment, for mice, is an environment which stimulates their curiosity, providing social and physical activity as well as exploration.
After addicting animals to cocaine, the researchers then exposed them to an enriched environment made up of large cages with a small house, a running wheel, tunnels and other appealing toys which were changed weekly.
Three models of animal addiction were used:
* behavioral sensitization, which measures the progressive increase in the stimulating effects of cocaine after chronic administration;
* the location preference, which measures the ability of a context (associated with cocaine consumption) to lead to drug-seeking behavior, and the renewal of this drug-induced location preference;
* measurements of cocaine’s ability to lead to a relapse after a period of withdrawal.
The result was that after thirty days of exposure to an enriched environment, addiction behavior typical of these three models had disappeared.
To identify the brain areas involved in the beneficial effect of an enriched environment, the researchers used an approach from functional neuro-anatomy. They showed that the absence of relapse in “enriched” mice was associated with a decrease in the cocaine-induced activation of a set of brain structures involved in dopaminergic transmission and associated with relapse.
These results, which have both a medical and societal impact, suggest that the living conditions of drug addicts should be taken into account in determining their therapy. A real effort should be made to create enriched environmental conditions, providing patients with different types of social, physical and intellectual stimulation. This also suggests that under deprived environmental conditions, treating addiction can be very challenging.
1) A number of earlier studies had shown that when animals are raised in an enriched environment prior to drug exposure, their vulnerability to addiction was reduced. In such conditions, the enriched environment can be seen as preventive.
Proceedings of the National Academy of Sciences, 2008; 105 (44): 17145
Reversal of cocaine addiction by environmental enrichment
Marcello Solinas, Claudia Chauvet, Nathalie Thiriet, Rana El Rawas, and Mohamed Jaber
Edited by James L. McGaugh, University of California, Irvine, CA, and approved September 17, 2008 (received for review July 17, 2008)
Environmental conditions can dramatically influence the behavioral and neurochemical effects of drugs of abuse. For example, stress increases the reinforcing effects of drugs and plays an important role in determining the vulnerability to develop drug addiction. On the other hand, positive conditions, such as environmental enrichment, can reduce the reinforcing effects of psychostimulants and may provide protection against the development of drug addiction. However, whether environmental enrichment can be used to “treat” drug addiction has not been investigated. In this study, we first exposed mice to drugs and induced addiction-related behaviors and only afterward exposed them to enriched environments. We found that 30 days of environmental enrichment completely eliminates behavioral sensitization and conditioned place preference to cocaine. In addition, housing mice in enriched environments after the development of conditioned place preference prevents cocaine-induced reinstatement of conditioned place preference and reduces activation of the brain circuitry involved in cocaine-induced reinstatement. Altogether, these results demonstrate that environmental enrichment can eliminate already established addiction-related behaviors in mice and suggest that environmental stimulation may be a fundamental factor in facilitating abstinence and preventing relapse to cocaine addiction.
Thanks to our ability to learn and to remember, we can perform tasks that other living things can not even dream of. However, we are only just beginning to get the gist of what really goes on in the brain when it learns or forgets something. What we do know is that changes in the contacts between nerve cells play an important role. But can these structural changes account for that well-known phenomenon that it is much easier to re-learn something that was forgotten than to learn something completely new?
Scientists at the Max Planck Institute of Neurobiology have been able to show that new cell contacts established during a learning process stay put, even when they are no longer required. The reactivation of this temporarily inactivated “stock of contacts” enables a faster learning of things forgotten.
While an insect still flings itself against the window-pane after dozens of unsuccessful attempts to gain its freedom, our brain is able to learn very complex associations and sequences of movement. This not only helps us to avoid accidents like walking into glass doors, but also enables us to acquire such diverse skills as riding a bicycle, skiing, speaking different languages or playing an instrument. Although a young brain learns more easily, we retain our ability to learn up to an advanced age. For a long time, scientists have been trying to ascertain exactly what happens in the brain while we learn or forget.
To learn something, in other words, to successfully process new information, nerve cells make new connections with each other. When faced with an unprecedented piece of information, for which no processing pathway yet exists, filigree appendages begin to grow from the activated nerve cell towards its neighbours. Whenever a special point of contact, called synapse, forms at the end of the appendage, information can be transferred from one cell to the next – and new information is learned. Once the contact breaks down, we forget what we have learned.
The subtle difference between learning and relearning
Although learning and memory were recently shown to be linked to the changes in brain structure mentioned above, many questions still remain unanswered. What happens, for example, when the brain learns something, forgets it after a while and then has to learn it again later? By way of example, we know from experience that, once we have learned to ride a bicycle, we can easily pick it up again, even if we haven’t practiced for years. In other cases too, “relearning” tends to be easier than starting “from scratch”. Does this subtle difference also have its origins in the structure of the nerve cells?
Cell appendages abide the saying “a bird in the hand …”
Scientists at the Max Planck Institute of Neurobiology have now managed to show that there are indeed considerable differences in the number of new cell contacts made – depending on whether a piece of information is new or is being learned second time around. Nerve cells that process visual information, for instance, produced a considerably higher number of new cell contacts if the flow of information from their “own” eye was temporarily blocked. After approximately five days, the nerve cells had rearranged themselves so as to receive and process information from the other eye – the brain had resigned itself to having only one eye at its disposal. Once information flowed freely again from the eye that had been temporarily closed, the nerve cells resumed their original function and now more or less ignored signals from the alternative eye.
“What surprised us most, however, was that the majority of the appendages which developed in response to the information blockade, continued to exist, despite the fact that the blockade was abolished “, project leader Mark Hübener explains. Everything seems to point to the fact that synapses are only disabled, but not physically removed. “Since an experience that has been made may occur again at a later point in time, the brain apparently opts to save a few appendages for a rainy day”, Hübener continues. And true enough, when the same eye was later inactivated again, the nerve cells reorganized themselves much more quickly – because they could make use of the appendages that had stayed in place.
Many of the appendages that develop between nerve cells are thus maintained and facilitate later relearning. This insight is crucial to our understanding of the fundamental processes of learning and memory. And so, even after many years of abstinence, it should be no great problem if we want to have a go at skiing again this winter.
Nature advance online publication 12 November 2008 | doi:10.1038/nature07487; Received 9 July 2008; Accepted 2 October 2008; Published online 12 November 2008
Experience leaves a lasting structural trace in cortical circuits
Sonja B. Hofer, Thomas D. Mrsic-Flogel, Tobias Bonhoeffer & Mark Hübener
Sensory experiences exert a powerful influence on the function and future performance of neuronal circuits in the mammalian neocortex. Restructuring of synaptic connections is believed to be one mechanism by which cortical circuits store information about the sensory world. Excitatory synaptic structures, such as dendritic spines, are dynamic entities that remain sensitive to alteration of sensory input throughout life. It remains unclear, however, whether structural changes at the level of of dendritic spines can outlast the original experience and thereby provide a morphological basis for long-term information storage. Here we follow spine dynamics on apical dendrites of pyramidal neurons in functionally defined regions of adult mouse visual cortex during plasticity of eye-specific responses induced by repeated closure of one eye (monocular deprivation). The first monocular deprivation episode doubled the rate of spine formation, thereby increasing spine density. This effect was specific to layer-5 cells located in binocular cortex, where most neurons increase their responsiveness to the non-deprived eye. Restoring binocular vision returned spine dynamics to baseline levels, but absolute spine density remained elevated and many monocular deprivation-induced spines persisted during this period of functional recovery. However, spine addition did not increase again when the same eye was closed for a second time. This absence of structural plasticity stands out against the robust changes of eye-specific responses that occur even faster after repeated deprivation. Thus, spines added during the first monocular deprivation experience may provide a structural basis for subsequent functional shifts. These results provide a strong link between functional plasticity and specific synaptic rearrangements, revealing a mechanism of how prior experiences could be stored in cortical circuits.
People Short On Self-control Categorize More Items As Necessities
Why do so many of us give up on those New Year’s resolutions to lose weight or curb luxury spending? A new study in the Journal of Consumer Research says it has to do with the way our goals intersect with our natures.
The pathbreaking study by authors Cait Poynor (University of Pittsburgh) and Kelly L. Haws (Texas A&M University) is one of the first to try to understand why some people have more trouble than others regulating behaviors. It uncovers some important differences in the way people categorize “necessities” and “luxuries.”
“The data demonstrates the basic differences among consumers in their tendency to embrace indulgence or restriction goals,” explain the authors. “Even when pursuing the same goal, high and low self-control consumers create dramatically different categories of goal-consistent and goal-inconsistent options.”
In three studies, the researchers examined the process individuals cycle through when trying to make a change. First, they select goals, then they form “implementation intentions,” deciding which options and behaviors are consistent with the goals. “For example, you might make a budget, deciding which items are necessities and which are luxuries, buy a diet book, which tells you which foods you may and may not eat, or organize your weekly schedule to include work sessions and time to participate in leisure activities,” the authors explain.
“Importantly, results suggest that the goal pursuit process can appear to proceed smoothly but in fact be derailed during this second phase.”
Where many people get tripped up is when their goals require them to overcome their default tendencies. For example, people the researchers categorized as having “low self-control” tended to do better with “indulgence goals,” like enjoying purchases more. Individuals with higher self-control preferred “restriction goals,” which led them to categorize fewer items as necessities.
“The most effective self-control interventions may vary depending on one’s selfcontrol level and the nature of one’s chosen goal,” the authors conclude.
JOURNAL OF CONSUMER RESEARCH, Inc. • Vol. 35 • December 2008
Seize the Day! Encouraging Indulgence for the Hyperopic Consumer
Kelly L. Haws, Cait Poynor*
This article explores the phenomenon of “hyperopia,” or an aversion to indulgence, as introduced by Kivetz and Keinan (2006) and Kivetz and Simonson (2002). We first develop a measure to capture hyperopia as an individual difference. Three empirical studies use this measure to demonstrate that hyperopia and high self-control are both conceptually and empirically distinct. Further, we show that altering the level at which an action or item is construed can make an indulgent goal or luxury product more appealing to the high hyperopia consumer by influencing its value in terms of an attractive long-term outcome.
With the days getting shorter (and colder) and the Holidays quickly approaching, many of us start thinking back to days gone by. This sentimentality and desire for the past is known as nostalgia. All of us are struck with nostalgic feelings from time to time but a new study in Psychological Science indicates that nostalgia may serve a greater purpose than just taking us back to the good old days.
Psychologists Xinyue Zhou and Ding-Guo Gao from Sun Yat-Sen University, along with Constantine Sedikides and Tim Wildschut from the University of Southampton explored the connection between loneliness and nostalgia. They ran a series of experiments that had participants answer questions related to feelings of loneliness, social support and nostalgia. The study participants included children, college students and factory workers. In addition, the factory workers were also assessed on their resilience (their ability to recover from traumatic events and adverse life situations).
The results showed that individuals who felt the loneliest reported receiving the least amount of social support. What was interesting, however, was that these participants turned out to be the most nostalgic. In addition, when nostalgia was induced in a number of the study participants, they in turn perceived to have the greatest amount of social support. These findings suggest that nostalgia amplifies perceptions of social support, and in this way, counteracts feelings of loneliness. In addition, the findings revealed that the most resilient individuals are more likely to use nostalgia to overcome feelings of loneliness.
These results have very important implications to clinical psychology and indicate that nostalgia may be used in cognitive therapy, as a coping mechanism that individuals turn to when they are confronted with social exclusion. The authors suggest that “individuals could be trained to benefit from the restorative function of nostalgia when actual social support is lacking or is perceived as lacking”.
Psychological Science Volume 19, Issue 10, Date: October 2008, Pages: 1023-1029 (link)
Counteracting Loneliness: On the Restorative Function of Nostalgia
Xinyue Zhou, Constantine Sedikides, Tim Wildschut, Ding-Guo Gao
ABSTRACT—Four studies tested whether nostalgia can counteract reductions in perceived social support caused by loneliness. Loneliness reduced perceptions of social support but increased nostalgia. Nostalgia, in turn, increased perceptions of social support. Thus, loneliness affected perceived social support in two distinct ways. Whereas the direct effect of loneliness was to reduce perceived social support, the indirect effect of loneliness was to increase perceived social support via nostalgia. This restorative function of nostalgia was particularly apparent among resilient persons. Nostalgia is a psychological resource that protects and fosters mental health.
Are happy or unhappy people more attracted to television? This question is addressed by a new 30-year analysis1 of US national data of nearly 30,000 adults by John Robinson and Steven Martin from the University of Maryland in the US. Examining the activity patterns of happy and less happy people in the General Social Survey (GSS) between 1975 and 2006, the authors found that happy people were more socially active, attended more religious services, voted more and read more newspapers.
In contrast, unhappy people watched significantly more television in their spare time. These results also raise questions about recent and previous time-diary data, in which television rated quite highly when people were asked to rate how they felt when they engaged in various activities in “real time” in these daily diaries.
“These conflicting data suggest that TV may provide viewers with short-run pleasure, but at the expense of long-term malaise,” said Professor Robinson. He also noted that earlier general satisfaction surveys also showed people rating TV below average as a significantly less satisfying free-time activity on the whole. “What viewers seem to be saying is that while TV in general is a waste of time and not particularly enjoyable, the shows I saw tonight were pretty good.”
The authors also noted the many other attractions associated with TV viewing in relation to other free-time activities. Viewers don’t have to go anywhere, dress up (or at all), find company, plan ahead, expend energy, do any work-or even pay anything – in order to view. This becomes an unbeatable combination when added to its being quite enjoyable in the short run. This probably accounts for TV taking up more than half of Americans’ free time.
The relationship between happiness and television viewing becomes particularly noteworthy, since in theory, engaging in a highly enjoyable activity time like watching television should improve the quality of people’s lives.
However, Robinson and Martin’s data point in the opposite direction, with unhappy people watching an estimated 20 percent more television than very happy people, after controlling for their education, income, age and marital status – as well as other demographic predictors of both viewing and happiness.
What remains unclear is whether happiness leads to lower viewing or more viewing leads to unhappiness. Robinson and Martin recommend that given the time Americans spend watching television, the question of whether it is responsible for unhappiness needs much closer study and clarification.
Unhappy people were also more likely to have unwanted extra time on their hands (51 percent) compared to very happy people (19 percent) and to feel rushed for time (35 percent vs. 23 percent). Of the two, having extra time on their hands was the bigger burden.
Professor Martin concluded by making a comparison with addiction: “Addictive activities produce momentary pleasure but long-term misery and regret. People most vulnerable to addiction tend to be socially or personally disadvantaged, with TV becoming an opiate.”
Social Indicators Research, December 2008
What Do Happy People Do?
John P. Robinson1 Contact Information and Steven Martin1
(1) Department of Sociology, University of Maryland, College Park, MD, USA
Received: 26 June 2008 Accepted: 7 July 2008 Published online: 31 July 2008
Abstract Little attention in the quality-of-life literature has been paid to data on the daily activity patterns of happy and less happy people. Using ratings-scale information from time-diary studies, this article examines the hypothesis that people who describe themselves as happier engage in certain activities more than those who describe themselves as less happy. Based on 34 years of data collected by the General Social Survey (GSS) on social activities and media usage, it is found that people who are happy report being more active in most social activities, in religion and in newspaper reading. On the other hand, happier people report less time watching television, a relation that holds after control for education, marital status and other predictors of happiness. The need to replicate these findings using panel data is highlighted.