Social Sciences

Immigration, official language policies, and changing cultural norms mean that many infants are being raised bilingually. Because nearly all experimental work in infant language development has focused on children who are monolingual, relatively little is known about the learning processes involved in acquiring two languages from birth. A new study showed infants who are raised in bilingual homes learned two similar-sounding words in a laboratory task at a later age than babies who are raised in homes where only one language is spoken. This difference, which is thought to be advantageous…

In its ability to learn, the cockroach is a moron in the morning and a genius in the evening. Dramatic daily variations in the cockroach’s learning ability were discovered by a new study performed by Vanderbilt University biologists and published online this week in the Proceedings of the National Academy of Sciences. “This is the first example of an insect whose ability to learn is controlled by its biological clock,” says Terry L. Page, the professor of biological sciences who directed the project. Undergraduate students Susan Decker and Shannon McConnaughey also participated in the study…

Cryptochromes, which fulfill the molecular requirements for sensing the magnetic reference direction, have recently been found in retinal neurons of migratory birds (Mouritsen et al., PNAS, 2004). Furthermore, studies investigating what parts of a migratory bird´s brain are active when the birds use their magnetic compass showed that the cryptochrome-containing neurons in the eye and a forebrain region (“Cluster N”; Mouritsen et al., PNAS, 2005; Liedvogel et al., EJN, 2007) are highly active during processing of magnetic compass information in migratory birds. Sensory systems process their…

Sonia Garel intend to tackle one of the great mysteries of neurobiology - how the brain is built up during embryonic development. There have long been fundamental unanswered questions relating both to the wiring of the brain during growth, and how evolution drove forward the sophisticated neural circuitry associated with mammals. Garel will focus on two key processes involved in development of neural circuitry in the forebrains of young mammals as they grow. One of these processes concerns the formation of connections between neurons, the nerve cells of the brain. These connections are…

Pedophilia, the sexual attraction of adults to children, is a significant public health concern and it does not respond well to treatment. Additionally, the brain mechanisms underlying pedophilia are not well understood. A new study in Biological Psychiatry is the first of its kind to use functional brain imaging to describe neural circuits contributing to pedophilia. Using functional magnetic resonance imaging, or fMRI, Martin Walter and colleagues report that pedophilic patients showed reduced activation of the hypothalamus, a brain region involved in regulating physiologic arousal and…

Whether it’s a mugger or a friend who jumps out of the bushes, you’re still surprised. But your response — to flee or to hug — must be very different. Now, researchers have begun to distinguish the circuitry in the brain’s emotion center that processes surprise from the circuitry that processes the aversive or reward “valence” of a stimulus. C. Daniel Salzman and colleagues published their findings in the September 20, 2007 issue of the journal Neuron. “Animals and humans learn to approach and acquire pleasant stimuli and to avoid or defend against aversive ones,” wrote the researchers. “…

A molecular “recycling plant” permits nerve cells in the brain to carry out two seemingly contradictory functions – changeable enough to record new experiences, yet permanent enough to maintain these memories over time. The discovery of this molecular recycling plant provides new insights into how the basic units of learning and memory function. Individual memories are “burned onto” hundreds of receptors that are constantly in motion around nerve synapses – gaps between individual nerve cells crucial for signals to travel throughout the brain. According to the study’s leader, Duke University…

While the visual regions of the brain have been intensively mapped, many important regions for auditory processing remain terra incognita. Now, researchers have identified the region responsible for a key auditory process—perceiving “sound space,” the location of sounds. The findings settle a controversy in earlier studies that failed to establish the auditory region, called the planum temporale, as responsible for perceiving auditory space. Leon Y. Deouell and colleagues published their findings in the September 20, 2007 issue of the journal Neuron, published by Cell Press. Studies by other…

Research by Portuguese scientists - Ema Alves, Teresa Summavielle, Félix Carvalho and colleagues from the University of Porto and the Porto Polytechnic Institute - reveals how ecstasy can compromise the neurons in the brain by damaging their mitochondria – the structures responsible for energy production in the cell - causing the equivalent to a “power-cut” on the affected neurons. By showing how ecstasy can directly compromise such a crucial cellular process the research might help an eventual resolution of the two decade-long debate over whether or not ecstasy use is dangerous. MDMA (the…

Scientists at the Weizmann Institute of Science and the University of California at Berkeley have now discovered that knowing the molecular structure of a substance can help predict whether we will find its smell pleasant or distasteful. In sight and hearing our perceptions are determined by the physical properties of waves – the length of light waves in sight, and the frequency of sound waves in hearing - yet there was no known physical factor that could explain how our brains sense odors. The new study, conducted by Prof. Noam Sobel and his colleagues, represents a first step in…