‘Smelling’ with our eyes: Descriptions affect odor perception

According to Simona Manescu and Johannes Frasnelli of the University of Montreal’s Department of Psychology, an odour is judged differently depending on whether it is accompanied by a positive or negative description when it is smelled. When associated with a pleasant label, we enjoy the odour more than when it is presented with a negative label. To put it another way, we also smell with our eyes!This was demonstrated by researchers in a study recently published in the journal Chemical Senses.For their study, they recruited 50 participants who were asked to smell the odours of four odorants (essential oil of pine, geraniol, cumin, as well as parmesan cheese). Each odour (administered through a mask) was randomly presented with a positive or negative label displayed on a computer screen. In this way, pine oil was presented either with the label “Pine Needles” or the label “Old Solvent”; geraniol was presented with the label “Fresh Flowers” or “Cheap Perfume”; cumin was presented with the label “Indian Food” or “Dirty Clothes; and finally, parmesan cheese was presented with the label of either the cheese or dried vomit.The result was that all participants rated the four odours more positively when they were presented with positive labels than when presented with negative labels. Specifically, participants described the odours as pleasant and edible (even those associated with non-food items) when associated with positive labels. Conversely, the same odours were considered unpleasant and inedible when associated with negative labels — even the food odours. “It shows that odour perception is not objective: it is affected by the cognitive interpretation that occurs when one looks at a label,” says Manescu. “Moreover, this is the first time we have been able to influence the edibility perception of an odour, even though the positive and negative labels accompanying the odours showed non-food words,” adds Frasnelli.This finding indicates that the perceived edibility of an odour can be manipulated by a description, and that olfactory perception may be driven by a top-down (or directive) cognitive process.Reaction times also affected by odoursVarious studies have shown that odours affect the reaction times of individuals. Thus, unpleasant odours cause rapid reactions (recoil, for example), while pleasant odours cause slower reactions. …

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Positive emotion increases life satisfaction and creates a happy state

Sep. 10, 2013 — By combining the experience of self-reported positive and negative emotions among 1,400 US-residents, researchers created four affective profiles which they then used to discern differences in happiness, depression, life satisfaction and happiness-increasing strategies. The differences between these profiles suggested that promoting positive emotions can positively influence a depressive-to-happy state (defined as increasing levels of happiness and decreasing levels of depression across the affective profile model), as well as increasing life satisfaction.The study, titled “The affective profiles in the USA: happiness, depression, life satisfaction, and happiness-increasing strategies”, was published on September 10th in PeerJ, and targets some of the important aspects of mental health that represent positive measures of well-being. Happiness, for example, can be usefully understood as the opposite of depression. Life satisfaction, another positive measure of well-being, refers instead to a comparison process in which individuals assess the quality of their lives on the basis of their own self-imposed standards. As people adopt strategies to increase their overall well-being, it is important to know which ones are capable of having a positive influence.”We examined 8 ‘happiness-increasing’ strategies which were first identified by Tkach & Lyubomirsky in 2006″, said Danilo Garcia from the University of Gothenburg and the researcher leading the investigation. “These were Social Affiliation (for example, “Support and encourage friends”), Partying and Clubbing (for example, “Drink alcohol”), Mental Control (for example, “Try not to think about being unhappy”), Instrumental Goal Pursuit (for example, “Study”), Passive Leisure (for example, “Surf the internet”), Active Leisure (for example, “Exercise”), Religion (for example, “Seek support from faith”) and Direct Attempts (for example, “Act happy and smile”).”The researchers found that individuals with different affective profiles did indeed differ in the positive measures of well-being and all 8 strategies being studied. For example, individuals classified as self-fulfilling (high positive affect, low negative affect) were the ones who showed lower levels of depression, tended to be happier, and were more satisfied with their lives.With respect to specific happiness-increasing strategies, the researchers found that strategies related to agentic (e.g. autonomy, responsibility, self-acceptance, intern locus of control, self-control), communal (e.g., social affiliation), and spiritual (e.g., religion) values were positively related to a ‘self-fulfilling’ profile. “This was the most surprising finding, because it supports suggestions about how self-awareness based on the self, our relation to others, and our place on earth might lead to greater happiness and mental harmony within the individual” said Garcia.

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Self-fertilizing plants contribute to their own demise

June 10, 2013 — Many plants are self-fertilizing, meaning they act as both mother and father to their own seeds. This strategy — known as selfing — guarantees reproduction but, over time, leads to reduced diversity and the accumulation of harmful mutations. A new study published in the scientific journal Nature Genetics shows that these negative consequences are apparent across a selfing plant’s genome, and can arise more rapidly than previously thought.In the study, an international consortium led by Stephen Wright in the Department of Ecology and Evolutionary Biology at the University of Toronto sequenced the genome of the plant species Capsella rubella, commonly known as Red Shepherd’s Purse. They found clear evidence that harmful mutations were accumulating over the species’ relatively short existence.”The results underscore the long-term advantages of outcrossing, which is the practice of mating between individuals, that gives us the wide array of beautiful flowers,” said Wright. “Selfing is a good short-term strategy but over long timescales may lead to extinction.”Red Shepherd’s Purse is a very young species that has been self-fertilizing for less than 200,000 years. It is therefore especially well-suited for studying the early effects of self-fertilization. By contrasting Red Shepherd’s Purse with the outcrossing species that gave rise to it, the researchers showed that self-fertilization has already left traces across the genome of Red Shepherd’s Purse.”Harmful mutations are always happening,” said Wright. “In crops, they could reduce yield just as harmful mutations in humans can cause disease. The mutations we were looking at are changes in the DNA that change the protein sequence and structure.”The findings represent a major breakthrough in the study of self-fertilization.”It is expected that harmful mutations should accumulate in selfing species, but it has been difficult to support this claim in the absence of large-scale genomic data,” says lead author Tanja Slotte, a past member of Wright’s research team and now a researcher at Uppsala University. “The results help to explain why ancient self-fertilizing lineages are rare, and support the long-standing hypothesis that the process is an evolutionary dead-end and leads to extinction.”The researchers said that with many crops known to be self-fertilizing, the study highlights the importance of preserving crop genetic variation to avoid losses in yield due to mutations accumulating.

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