Autistic Development

Certain regions of the brains of autistic children develop much more slowly than in non-autistic brains, a new study reports. As most of our brains mature throughout our adolescent years, our white matter – the tissue that connects separate brain regions and allows them to communicate with one another – undergoes vast amounts of growth, as areas like the parietal, temporal, and occipital lobes learn to work together more closely. In the brains of autistic adolescents, though, this white matter grows much more slowly. Meanwhile, their gray matter – the tissue composed mostly of neurons’ cell bodies, where most intensive processing takes place – shows overgrowth in…

Hypnotized Eyes

A state of hypnosis creates detectable changes in a person’s eye movement patterns, says a new study. The “glazed” look of a person who’s been hypnotized can be linked to measurable, quantifiable changes in the patterns of that person’s reflexive eye movements – changes that non-hypnotized people aren’t able to replicate. The exact nature – and even the actual existence – of the hypnotic state have been controversial topics since the term was first coined in the 1840s. Some have likened it to a form of sleep (the word itself comes from the ancient Greek hypnos, meaning “sleep”), while others have described it as…

One Eye at a Time

Even as we look at the world through both eyes, our brains can tell which eye is taking in what information – and can direct each eye separately to focus on certain details, says a new study. The more one of our eyes is focused on details in its visual field, the more sensitive it is to changes in the area it sees, and the faster it is to detect changes in that area. These abilities can allow both eyes to work together, or the brain can focus just one eye’s energy on detecting details and changes – even if both eyes…

Digital Friendships

Those of us who have loads of Facebook friends tend to have greater development in several specific brain regions, says a new study. Researchers have found a strong correlation between large numbers of Facebook connections and increased development of gray matter – tissue containing neuron cell bodies, where dense communication occurs – in several regions crucial for social interaction: the amygdala, the right superior temporal sulcus (STS), the left middle temporal gyrus (MTG), and the right entorhinal cortex (EC). Intriguingly, the size of some of these regions seems to correlate only with the size of people’s online social networks – not their real-world ones. It’s not clear yet, though,…

Modified Memories

Each time we retell a story, our actual memories of its events change, says a new study. When we receive hints – true or not-so-true – about a story’s details from our friends, we often revise our version if what they say makes sense to us. But what’s incredible is, it isn’t just our retelling of the story that changes – fMRI scans show that our brains actually rewrite our memories, and we end up remembering the new version as “what really happened.” To understand how this can work at a neurological level, a team led by Micah Edelson at Israel’s Weizmann Institute of Science…

Doubling Up

Our big brains may be the result of a doubled gene that lets brain cells migrate to new areas, says a new study. The gene, known as SRGAP2, has been duplicated in our genomes at least twice in the four million years since our ancestors diverged from those of the other great apes. It codes for a certain protein that interferes with filopodia – tiny molecular structures that shape the growth of neurons in a developing brain. Researchers think that as SRGAP’s protein disrupted the “normal” growth of our ancestors’ filopodia, millions of their neurons migrated outward to thicken the cerebral cortex – the outer…

I Be Strokin’

Watching another person being softly caressed activates very similar brain regions to those that actually allow us to feel a soft touch, says a new study. The sensation of gentle touch is conveyed by a specific type of neuron – tactile C (CT) afferents – found only in hairy skin. These neurons respond most strongly to soft touches and “caress-like” speeds, and send signals to a brain region called the posterior insula, which helps interpret bodily sensations like pain, warmth or cold, heartbeat, a full bladder or stomach, and balance – and also, interestingly enough, the physical feelings associated with music, laughter, and empathy. What this…