Plus un vin est cher, plus on prend du plaisir

Par Clare Baldwin

STANFORD, Californie (Reuters) - Plus un vin est cher, plus il est apprécié, sans égard pour son goût, selon les conclusions d'une étude de chercheurs américains.

Des chercheurs de la Graduate School of Business de Stanford et de l'Institut californien de technologie ont constaté que plus un vin est cher plus on s'attend à ce qu'il soit de bonne qualité et qu'on s'autopersuade qu'un vin cher procure plus de plaisir qu'une bouteille bon marché.

Leur étude, publiée lundi dans la revue Proceedings of the National Academy of Sciences, affirme que les attentes qualitatives déclenchent une activité dans le cortex orbito-frontal médial, la partie du cerveau qui exprime le plaisir. Cette réaction se produit même si la partie du cerveau qui interprète le goût n'est pas sollicitée.

Alors que beaucoup d'études se sont jusque-là concentrées sur les effets du marketing sur le comportement, celle-ci est la première qui montre que le marketing a un effet direct sur le cerveau.

Selon les chercheurs, quand vingt adultes testent des échantillons de vin de prix différents, ils disent que plus le vin était cher, plus l'expérience a été agréable. Au même moment, la partie du cerveau qui contrôle leur plaisir montrait une activité significative.

"Nous savons depuis longtemps que la perception est affectée par le marketing, mais maintenant nous savons que le cerveau lui même s'adapte au prix", a déclaré l'une des auteurs de l'étude, Baba Shiv, professeur associée à la Stanford Graduate School of Business.

"Les commerçants vont maintenant y réfléchir à deux fois avant de baisser leur prix", a-t-elle ajouté.

Selon l'étude, si une expérience est agréable, le cerveau va l'utiliser pour guider ses futurs choix. Une conclusion qui a des implications substantielles pour le marketing, dont le but est d'influencer la perception de la qualité.

Version française Mathilde Gardin

Neuroimaging Fails To Demonstrate ESP Is Real

Neuroimaging Fails To Demonstrate ESP Is Real

ScienceDaily (Jan. 4, 2008) — Psychologists at Harvard University have developed a new method to study extrasensory perception that, they argue, can resolve the century-old debate over its existence. According to the authors, their study not only illustrates a new method for studying such phenomena, but also provides the strongest evidence yet obtained against the existence of extrasensory perception, or ESP.

The research was led by Samuel Moulton, a graduate student in the department of psychology in the Faculty of Arts and Sciences at Harvard University with Stephen Kosslyn, John Lindsley Professor of Psychology at Harvard and was published in the Jan. 2008 issue of the Journal of Cognitive Neuroscience. The scientists used brain scanning to test whether individuals have knowledge that cannot be explained through normal perceptual processing.

"If any ESP processes exist, then participants' brains should respond differently to ESP and non-ESP stimuli," explains Moulton. "Instead, results showed that participants' brains responded identically to ESP and non-ESP stimuli, despite reacting strongly to differences in how emotional the stimuli were and showing subtle, stimulus-related effects."

Nearly half of the adults in the United States believe in the existence of ESP, which includes telepathy (direct knowledge of another person's thoughts), clairvoyance (direct knowledge of remote events), and precognition (direct knowledge of the future). People commonly report unexplained knowledge of a loved one's death or a telephone caller's identity, for example, and attribute this knowledge to paranormal mental processing.

The U.S. government lent credence to such claims when it revealed that it had spent millions of dollars recruiting and training psychic spies during the Cold War. Furthermore, research studies have been reported that appear to support the existence of ESP, including an influential series of experiments analyzed by psychologist Daryl Bem of Cornell University. These studies, however, gave little insight into the mechanisms -- normal or paranormal -- that produced the anomalous results. Perhaps more telling, others failed to replicate these results.

To develop a better test of ESP, the authors decided to develop a new method, which directly addressed the presumed source of ESP: namely, the brain. They argue that because the brain enables perception and stores information -- even events people don't consciously perceive or information they can't consciously remember -- it can offer a much more comprehensive test for ESP than self-report or behavior.

"The brain shows a suppressed response to stimuli that a person has seen before, even when those stimuli were presented subliminally, so the person wasn't consciously aware of having seen them; furthermore, it shows an enhanced response to stimuli that a person is expecting," says Moulton. "Because knowledge and expectation bias brain activation, neuroimaging offers us a uniquely powerful test of subtle perceptual or cognitive processes."

To study whether or not ESP exists, Moulton and Kosslyn presented participants with two types of visual stimuli: ESP stimuli and non-ESP stimuli. These two types of stimuli were identical with one exception: ESP stimuli were not only presented visually, but also were presented telepathically, clairvoyantly, and precognitively to participants.

To present stimuli telepathically, the researchers showed the photographs to the participants' identical twin, relative, romantic partner, or friend, who was seated in another room. To present stimuli clairvoyantly, the researchers displayed the photographs on a distant computer screen. And to present stimuli precognitively, the researchers showed participants the photographs again in the future.

Does this conclusively prove that ESP does not exist? "No," says Moulton. "You cannot affirm the null hypothesis. But at the same time, some null results are stronger than others. This is the best evidence to date against the existence of ESP. Perhaps most important, this study offers scientists a new way to study ESP that avoids the pitfalls of past approaches."

This research was supported by the Bial Foundation and the Richard Hodgson Memorial Fund.

Adapted from materials provided by Harvard University.

Belief in Reincarnation Tied to Memory Error

Melinda Wenner - People who believe they have lived past lives as, say, Indian princesses or battlefield commanders are more likely to make certain types of memory errors, according to a new study.

The propensity to make these mistakes could, in part, explain why people cling to implausible reincarnation claims in the first place.

Researchers recruited people who, after undergoing hypnotic therapy, had come to believe that they had past lives.

Subjects were asked to read aloud a list of 40 non-famous names, and then, after a two-hour wait, told that they were going to see a list consisting of three types of names: non-famous names they had already seen (from the earlier list), famous names, and names of non-famous people that they had not previously seen. Their task was to identify which names were famous.

The researchers found that, compared to control subjects who dismissed the idea of reincarnation, past-life believers were almost twice as likely to misidentify names. In particular, their tendency was to wrongly identify as famous the non-famous names they had seen in the first task. This kind of error, called a source-monitoring error, indicates that a person has difficulty recognizing where a memory came from.

Power of suggestion

People who are likely to make these kinds of errors might end up convincing themselves of things that aren’t true, said lead researcher Maarten Peters of Maastricht University in The Netherlands. When people who are prone to making these mistakes undergo hypnosis and are repeatedly asked to talk about a potential idea—like a past life—they might, as they grow more familiar with it, eventually convert the idea into a full-blown false memory.

This is because they can’t distinguish between things that have really happened and things that have been suggested to them, Peters told LiveScience.

Past life memories are not the only type of implausible memories that have been studied in this manner. Richard McNally, a clinical psychologist at Harvard University, has found that self-proclaimed alien abductees are also twice as likely to commit source monitoring errors.

Creative minds

As for what might make people more prone to committing such errors to begin with, McNally says that it could be the byproduct of especially vivid imagery skills. He has found that people who commonly make source-monitoring errors respond to and imagine experiences more strongly than the average person, and they also tend to be more creative.

“It might be harder to discriminate between a vivid image that you’d generated yourself and the memory of a perception of something you actually saw,” he said in a telephone interview.

Peters also found in his study, detailed in the March issue of Consciousness and Cognition, that people with implausible memories are also more likely to be depressed and to experience sleep problems, and this could also make them more prone to memory mistakes.

And once people make this kind of mistake, they might be inclined to stick to their guns for spiritual reasons, McNally said. “It may be a variant expression of certain religious impulses,” he said. “We suspect that this might be kind of a psychological buffering mechanism against the fear of death.”

La dégustation du vin, fruit de notre cerveau ?

PARIS (AP) - Arômes boisés, robe pourpre, tanin, toute la terminologie associée à la dégustation du vin serait-elle inutile car réinterprétée par notre cerveau?
Des chercheurs de l'Institut national de la recherche agronomique (INRA), associés à la faculté d'oenologie de Bordeaux, ont en effet démontré que la dégustation d'un vin et ses prétendues qualités olfactives et gustatives étaient largement influencées par le contexte dans lequel il est bu et la représentation que s'en fait le dégustateur, ainsi que par les propres qualités sensorielles de ce dernier.

L'INRA a soumis à 15 jours d'intervalle le même vin dans deux conditionnements différents (bouteille d'un grand cru classé connu et bouteille étiquetée "vin de table") à 57 étudiants en oenologie: 50 ont noté plus sévèrement le vin de table (8/20 de moyenne) que le grand cru (13/20). Seuls six ont deviné la supercherie.

De plus, lors de la dégustation, le vin de table a été jugé sans retenue alors que le grand vin a bénéficié d'égards et ses défauts ont été plus facilement excusés.

Plus étonnant, la grande majorité des futurs oenologues a perçu une présence boisée dans le grand cru mais pas dans le vin de table... alors que le vin en question n'avait jamais été mis en contact avec le bois.
Selon l'INRA, cette perception résulte "typiquement d'une construction cognitive". "Le dégustateur étant persuadé de la présence du bois dans le vin qu'il goûte, crée une représentation de ce vin contenant le goût boisé", explique l'institut.
Dans ce contexte, tous les dégustateurs s'influencent et sont persuadés d'avoir perçu un goût de boisé.

Autre expérience surprenante révélant le rôle de la couleur dans la perception de l'odeur du vin. Les chercheurs ont constaté que les dégustateurs associaient au vin rouge des odeurs de fruits... rouges (cassis, framboise), et au vin blanc des fruits clairs (abricot, miel). Or lors d'une dégustation à l'aveugle (le vin étant dans des verres noirs), trois fois sur dix le dégustateur se trompe sur le type de vin (rouge ou blanc).

Les chercheurs de l'INRA en ont déduit que les mots étaient employés davantage pour décrire la couleur du vin que son goût. Ils ont donc soumis 54 étudiants en oenologie à un nouveau test consistant à leur faire déguster un vin blanc et un vin rouge, qui était en fait le même vin blanc coloré en rouge grâce à des colorants naturels ne modifiant pas le goût du vin.

Pour le même vin, les étudiants ont effectivement employé les descripteurs olfactifs habituels du vin rouge pour le faux vin rouge et ceux associés au vin blanc pour le vrai vin blanc.

Toutes ces expériences démontrent que la perception du vin n'est qu'une construction de notre cerveau. Le premier message (sensoriel) envoyé à notre cerveau grâce à nos sens est ensuite reconstruit par le cerveau (étape cognitive) avec d'autres perceptions et processus (vue, toucher, puis plaisir, mémoire, etc).

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