Without abstract thought, we would be unable to do maths or science, create laws or think about human emotions.
The system could eventually translate thoughts into words automatically.
Both our genetics and the circumstances of our lives influence the exact shape that our brains form.
Male brains (top) show greater connectivity front-to-back, while female brains (bottom) are more connected across the hemispheres.
A fascinating new study on the brains of 949 young people finds striking gender differences in the brain’s connectivity between males and females (Ingalhalikar et al., 2013).
These may help explain some of the classic psychological differences between men and women.
The study uses a type of brain imaging–diffusion tensor imaging–which can reveal the microscopic structures of the living brain.
From the 428 males in the study, the researchers found that the connections in men’s minds ran more between the front and the back, within the same half of the brain.
This may help to explain men’s advantage with motor and spatial skills over women since front-to-back connections help link perception with action.
In the brains of the 521 females in the study, the researchers noted more overall connections between the two hemispheres of the brain.
This may help explain women’s improved memory and social skills, the authors argue, since communication between the halves of the brain helps link intuition with analysis.
Differences emerge at 13
The participants in the study were aged between 8 and 22-years old, as the researchers were looking for clues about how the brain develops.
They found that there were few differences between males and females before the age of 13, but that the different patterns of connectivity kicked in at puberty.
One of the study’s authors, Ruben Gur commented:
“It’s quite striking how complementary the brains of women and men really are. Detailed connectome maps of the brain will not only help us better understand the differences between how men and women think, but it will also give us more insight into the roots of neurological disorders, which are often sex related.”
Image credit: Ragini Verma, Ph.D., Proceedings of National Academy of Sciences
“Hidden caves” that open up in the brain may help explain sleep’s amazing restorative powers.
A new study published in the prestigious journal, Science, has found that the brain may wash away toxins built up over the day during sleep.
The research discovered “hidden caves” inside the brain, which open up during sleep, allowing cerebrospinal fluid (CSF) to flush out potential neurotoxins, like β-amyloid, which has been associated with Alzheimer’s disease.
To reach their discovery, researchers injected mice’s brains with a dye and monitored the flow while they were awake, asleep and anaesthetised (Xie et al., 2013).
One of the study’s authors, Dr Maiken Nedergaard, explained the results:
“We were surprised by how little flow there was into the brain when the mice were awake. It suggested that the space between brain cells changed greatly between conscious and unconscious states.”
For a long time the real physiological purpose of sleep has remained a mystery.
We know that lack of sleep causes all kinds of psychological problems like poor learning, decision-making and so on.
We also know that animals that are chronically deprived of sleep will eventually die: flies or rodents in days to weeks, humans within months or years.
Everyone who has ever enjoyed a blissfully good night’s sleep knows just how restorative it can be, but the actual physiological process wasn’t clear.
This study, though, suggests that the flushing out of toxins by the CSF may be central to sleep’s wondrous powers.
The interstitial spaces in the mouse’s brain took up only 14% of the brain’s volume while it was awake. Yet, while it slept, this increased by almost two-thirds to take up fully 23% of the brain’s total volume.
The difference might seem slight, but the actual physiological effects are profound.
During the day, the CSF mostly covers the surface of the brain. During sleep, though, the CSF is able to move deep inside.
The effect is that potential neurotoxins, like β-amyloid, are cleared twice as fast during sleep as during waking.
The results of this study–if they hold in humans–may help to explain why many neurological diseases, like strokes and dementia, are associated with problems sleeping.
It could be that lack of sleep, and restriction of the brain’s cleaning system, may cause toxic metabolites to building up, leading to long-term damage.
→ Related: 10 Sleep Deprivation Effects.
Image credit: HaoJan Chang
New study demonstrates that the brain treats social pain in a similar way to physical pain.
Being rejected by other people is no fun.
Contrary to the old ‘sticks and stones’ saying, it seems words can and do hurt, and the brain responds accordingly.
A new study from the University of Michigan Medical School has found that the body produces natural painkillers in response to social rejection, just as if it had suffered a physical injury (Hsu et al., 2013).
The lead author, Assistant Professor David T. Hsu, explained:
“This is the first study to peer into the human brain to show that the opioid system is activated during social rejection. In general, opioids [are] released during social distress and isolation in animals, but where this occurs in the human brain has not been shown until now.”
In the study, social rejection was simulated in the lab. Eighteen participants were asked to look at fictional online dating profiles and choose some they were interested in.
Then, while lying in a PET scanner, they were told they’d been rejected by their potential online dates.
The scans showed that in response to the rejection, the brain sent out painkillers in the form of opioids into the spaces between neurons. This dampens down the pain signals.
In fact participants knew in advance that the online dating profiles were not real, and neither was the rejection. Nevertheless, the simulated situation was still enough to set off the release of painkillers.
Participants who were highly resilient were the most likely to produce high levels of the natural painkiller.
At the other end of the scale, those with low painkiller production may be particularly vulnerable to rejection. One of the authors, Professor Jon-Kar Zubieta explained:
“It is possible that those with depression or social anxiety are less capable of releasing opioids during times of social distress, and therefore do not recover as quickly or fully from a negative social experience.”
This is further evidence that social pain is not as different from physical pain as many thought. More and more research is pointing to an overlap in the brain’s response to both.
Image credit: josemanuelerre
Researchers demonstrate the first ever human-to-human brain interface.
Imagine if it were possible for one person to control another person’s movements over the internet, purely using their thoughts.
Well, researchers at the University of Washington have managed to set up the first ever noninvasive human-to-human brain interface.
Rajesh Rao, who has been working on brain-computer interfaces for 10 years, recently managed to use his brain’s electrical activity to send a signal to a colleague, over the internet, and control the other person’s hand movements.
To achieve this they used an EEG machine (electroencephalography) to record the electrical activity in the brain. When the computer detected that the person was trying to move his hand, a signal was sent over the internet to a colleague sitting in a room, on the other side of the university campus.
There, the receiver sat with a special type of magnet attached to his head (TMS, or transcranial magnetic stimulation coil). This coil sat over the part of the brain which is responsible for movement of the hand.
The two researchers were actually using the brain interface to play a simple computer game. It took some practice, but eventually one was able to send the signal and remotely move the other’s hand at a 100% success rate.
Below is a schematic of how the system worked.
Image: University of Washington
Rajesh Rao explained:
“It was both exciting and eerie to watch an imagined action from my brain get translated into actual action by another brain. This was basically a one-way flow of information from my brain to his. The next step is having a more equitable two-way conversation directly between the two brains.”
Image credit: Tim Sheerman-Chase
Pilot study finds mood of chronic pain patients is boosted by left-field use of ultrasound machine. Could it work for all of us?
The unusual idea occurred to Dr. Stuart Hameroff (above) after he heard about ultrasound studies on the brains of mice.
Ultrasound equipment—which uses sound waves to see inside the body—is familiar to anyone with children as it’s used to check the health of an unborn child.
But what would it do, Dr Hameroff wondered, if he used the ultrasound machine on the human brain?
He suggested to his colleagues that they should try it on patients with chronic pain to see if it would help. His colleagues said he should try it on himself first.
So he did.
At first nothing happened, said Hameroff:
“I put it down and said, ‘well, that’s not going to work,’ and then about a minute later I started to feel like I’d had a martini.”
The feeling continued for a couple of hours.
But perhaps this was all placebo: he expected to feel different and so he did.
The only way to get solid evidence was to conduct a study where neither patients nor doctors knew whether the ultrasound machine was switched on or not, then look at the difference between groups.
The pilot study was conducted on 31 chronic pain patients (Hameroff et al., 2012). After having the ultrasound applied to their brains for just 15 seconds, they felt slightly less pain, but the main effect was an improvement in mood:
“Patients reported improvements in mood for up to 40 minutes following treatment with brain ultrasound, compared with no difference in mood when the machine was switched off.”
The exact mechanism for how ultrasound affects mood is still unknown, but:
“What we think is happening is that the ultrasound is making the neurons a little bit more likely to fire in the parts of the brain involved with mood,” thus stimulating the brain’s electrical activity and possibly leading to a change in how participants feel.”
Perhaps the research will lead to a device that can help people with mood disorders:
“The idea is that this device will be a wearable unit that non-invasively and safely interfaces with your brain using ultrasound to regulate neural activity.”
The pilot study is now being followed up in double-blind clinical trials on more patients and using doses of ultrasound up to 30 seconds. The results of this study are currently being analysed.
Watch this space…
Image credit: Stuart Hameroff