The letter A is red, and the musical note middle C is blue, some numbers are a friendly yellow and others more sinister-appearing, the word “love” tastes like chocolate. For people with synesthesia, the world is experienced in ways where the senses cross and blend.

Synesthesia comes from the Greek syn- meaning union and aesthesis meaning sensation. The condition is thought to be a cross-wiring in the brain, that brings two senses into play to create a different perceptual experience. Another theory is cross-activation of brain regions. Normally when one region of the brain is active, neighboring regions are inhibited. A chemical imbalance in the brain, for instance a blocking of an inhibitory neurotransmitter, may allow activity in a region of the brain unrelated to the first, allowing for synesthesia to occur.

According to a study, synesthesia is seven times more common in creative people as in the general population. Synesthetes have a way with metaphor, a natural gift for linking seemingly unrelated concepts and ideas. They have an unusually good memory for things like phone numbers and polysyllabic terminology because numbers and letters are perceived in colors.

Recently, the CBS news show 60 Minutes interviewed Daniel Tammet, a savant who also experiences synesthesia. At Oxford University, Tammet recited the number Pi to 22,514 digits. According to Tammet, the numbers appear to him as a landscape of shapes, colors and textures.

The study of synesthesia first surfaced in 1880, but was dismissed and forgotten until recently as scientists begin to discover brain processes that may explain the phenomenon.

Hearing Colors, Tasting Shapes - Scientific American

Brain Man - 60 Minutes

Synesthesia - Wikipedia

If risk-taking is something you usually avoid, you’re not alone. Most people are twice as sensitive to potential losses than they are to potential gains, which leads to risk aversion. In the Jan. 26 issue of the journal Science, UCLA psychologists present the first neuroscience research comparing how our brains evaluate the possibility of gaining versus losing when making risky decisions.

Researchers using funtional MRI studied brain activity in study participants as they weighed bets, varying the odds and winnings.

“Looking at how your brain responds to potential gains versus potential losses, we can predict how risk-averse you are going to be in your choices,” said study co-author Russell Poldrack, UCLA associate professor of psychology, who holds UCLA’s Wendell Jeffrey and Bernice Wenzel, Term Chair in Behavioral Neuroscience. “Brain activity predicts behavior.”

When we think about possible gain, reward centers in the brain get turned on. However, when weighing potential losses, regions of the brain that process fear and anxiety, such as the amygdala and the insular are not activated.

“What we found instead,” Poldrack said, “is you don’t turn anything up. You turn down the reward areas of the brain, and you turn them down more strongly for losses than you turn them up for gains. Just as people respond more strongly to a $100 potential loss than a $100 potential gain, the brain responds more strongly to a $100 potential loss versus a $100 potential gain.”

Read the full press release:
How Does Your Brain Respond When You Think about Gambling or Taking Risks? UCLA Study Offers New Insights

When you woke up this morning and opened your eyes, the world appeared before you without your having to think about it, call it into being or work out the complex physiology of vision. You didn’t have to consciously interpret the wavelengths of light being reflected off your walls to see the colors and shapes in the wallpaper, your brain busily interprets the signals from your eyes to create the world around you. You take for granted that these perceptions are the real world.

But what happens when we consciously switch visual perception? Ambiguous illusions are pictures or objects that elicit a perceptual “switch” between alternative interpretations. Perhaps the most famous ambiguous illusion is Rubin’s Vase.

When something surrounds another thing, the object surrounded becomes the figure and that surrounding it becomes the ground. The brain shapes the incoming information in one recognizable pattern, but with an ambiguous illusion, there are two possible visual interpretations. Note how your visual perception of the inverted vase differs.

What is your intial interpretation of the image below? Do you see a face? If you study the image, does an alternative interpretation appear? Look again. Do you see an eskimo? Now consciously switch your visual perception by thinking about the alternate interpretations as you look at the image.

Often, the alternate interpretation of an image is only realized after prompting or a period of studying the image. Once realized, it is then difficult for the viewer to see anything but the second interpretation.

For humans, “seeing” the world is not just a function of eyesight, it is influenced by the way the brain interprets the data sent to it by the eyes. Take another look at that wallpaper pattern, you may see something you never noticed before.

Scientists studying fear responses in rats have discovered that although the amygdala plays a central role in emotional learning and processes and expresses fear, a region of the cortex may be involved in learned fear.

By teaching rats to fear a tone by associating it with a shock to the foot at the end of the tone, scientists were able to observe the rats’ response. Ater learning to fear the tone, the rats would spend 70% percent of the time the tone sounded in a frozen state, a typical fear response.

When the researchers chemically blocked activity in the prelimbic cortex, located near the front of the brain, the rats spent only 14% of the time frozen. However, their innate fears were not affected by the blocking of the prelimbic cortex, they still exhibited fear at the sight of a cat or a large open area.

The findings suggest that hyperactivity in that region of the prefrontal cortex might contribute to learned fear disorders in humans, such as post-traumatic stress disorder and anxiety disorders.

The study was authored by Kevin A. Corcoran, PhD, and Gregory Quirk, PhD, of the Ponce School of Medicine in Puerto Rico. Their report appears in the January 24 issue of The Journal of Neuroscience.