Author Interviews, Psychological Science, Technology / 09.03.2017 Interview with: Indrajeet Patil PhD former PhD student at SISSA, Trieste and currently a postdoctoral researcher at Harvard University What is the background for this study? Response: Human societies are built on mutually beneficial cooperation, which relies on our prosocial and altruistic impulses to help each other out. Psychologists have been trying to understand the psychological basis of altruistic behavior for a while now, but studying costly altruism - a kind of helping behavior in which the altruist pays a heavy price to help others - has been difficult to study in lab settings given the ethical problems associated with creating any paradigm where participants stand to get hurt. Thus, the question is how do you study the motivation behind acts that involve a very high risk of physical injury to the self while helping others? Such situations are common in emergency contexts where people can be faced with the choice of either saving their own life or risking it to save someone else's life. (more…)
Author Interviews / 27.01.2017 Interview with: DR. Y. (YAÏR) PINTO Faculty of Social and Behavioural Sciences Programme group Brain and Cognition UvA What is the background for this study? Response: I've done research into patients in whom the corpus callosum was entirely removed surgically, at an adult age, to relieve epileptic seizures. The removal of the corpus callosum all but eliminates communication between both cerebral hemispheres. Therefore these patients are referred to as split-brain patients. The canonical view of these patients is that their consciousness is split as well. That is, the notion, which is found in many textbooks and reviews, is that in a split-brain patient each hemisphere is an conscious agent, independent of the other hemisphere. This notion is mainly based on the following key observation. When an image is presented to the left visual field, the patient indicates verbally, and with his right hand, that he saw nothing. Yet, with his left hand he indicates that he did see the object! Conversely, if a stimulus appears in his right visual field, he will indicate awareness of this stimulus when he responds verbally or with his right, yet with his left hand he will report that he saw nothing. This exactly fits the notion that in a split-brain patient the two separated hemispheres each become an independent conscious agent. The left hemisphere perceives the right visual field, controls language and the right side of the body. The right hemisphere experiences the left visual field and controls the left hand. This, and other discoveries on split-brain patients, earned Roger Sperry the nobel-prize in Medicine in 1981. (more…)
Aging, Author Interviews, Neurological Disorders, Yale / 22.12.2016 Interview with: Ifat Levy, PhD Associate Professor Comparative Med and Neuroscience Yale School of Medicine What is the background for this study? What are the main findings? Response: The proportion of older adults in the population is rapidly rising. These older adults need to make many important decisions, including medical and financial ones, and therefore understanding age-related changes in decision making is of high importance. Prior research has shown that older adults tend to be more risk averse than their younger counterparts when making choices between sure gains and lotteries. For example, asked to choose between receiving $5 for sure and playing a lottery with 50% of gaining $12 (but also 50% of gaining nothing), older adults are more likely than young adults to prefer the safe $5. We were interested in understanding the neurobiological mechanisms that are involved in these age-related shifts in preferences. An earlier study that we have conducted in young adults provided a clue. In that study, we measured the risk preference of each participant (based on a series of choices they made between safe and risky options), and also used MRI to obtain a 3D image of their brain. Comparing the behavioral and anatomical measures, we found an association between individual risk preferences and the gray-matter volume of a particular brain area, known as “right posterior parietal cortex” (rPPC), which is located at the back of the right side of the brain. Participants with more gray matter in that brain area were, on average, more tolerant of risk (or less risk averse). This suggested a very interesting possibility – that perhaps the increase in risk aversion observed in older adults is linked to the thinning of gray matter which is also observed in elders. In the current study we set out to test this hypothesis, by measuring risk preference and gray matter density in a group of 52 participants between the ages of 18 and 88. We found that, as expected, older participants were more risk averse than younger ones, and also had less gray matter in their rPPC. We also replicated our previous finding - that less gray matter was associated with higher risk aversion. The critical finding, however, was that the gray matter volume was a better predictor of increased risk aversion than age itself.  Essentially, if both age and the gray matter volume of rPPC were used in the same statistical model, rPPC volume predicted risk preferences, while age did not. Moreover, the predictive power was specific to the rPPC – when we added the total gray matter volume to the model, it did not show such predictive power. (more…)