Learning to control brain activity improves visual sensitivity

Researchers at the Wellcome Trust Centre for Neuroimaging at UCL used non-invasive, real-time brain imaging that enabled participants to watch their own brain activity on a screen, a technique known as neurofeedback. During the training phase, they were asked to try to increase activity in the area of the brain that processes visual information, the visual cortex, by imagining images and observing how their brains responded.

After the training phase, the participants’ visual perception was tested using a new task that required them to detect very subtle changes in the contrast of an image. When they were asked to repeat this task while clamping brain activity in the visual cortex at high levels, those who had successfully learned to control their brain activity could improve their ability to detect even very small changes in contrast.

This improved performance was only observed when participants were exercising control over their brain activity.

Lead author Dr Frank Scharnowski, who is now based at the University of Geneva, explains: “We’ve shown that we can train people to manipulate their own brain activity and improve their visual sensitivity, without surgery and without drugs.”

In the past, researchers have used recordings of electrical activity in the brain to train people on various tasks, including cutting their reaction times, altering their emotional responses and even improving their musical performance. In this study, the researchers used functional magnetic resonance imaging (fMRI) to provide the volunteers with real-time feedback on brain activity. The advantage of this technique is that you can see exactly where in the brain the training is having an effect, so you can target the training to particular brain areas that are responsible for specific tasks.

"The next step is to test this approach in the clinic to see whether we can offer any benefit to patients, for example to stroke patients who may have problems with perception, even though there is no damage to their vision," adds Dr Scharnowski.

Research shows brain hub activity different in coma patients

A team of French and British researchers has found that brain region activity for coma patients is markedly different than for healthy people. In their paper published in the Proceedings of the National Academy of Sciences, the group describes the differences found when comparing fMRI scans of people in a coma with healthy volunteers.

To gain a better understanding of what goes on in the brain when a person is in a coma, and perhaps the nature of consciousness, the researchers performed fMRI brain scans on 17 people who had recently become comatose due to medical conditions that led to blockage of oxygen to the brain. They then compared those scans to those taken of 20 healthy volunteers.

In analyzing the results the team found that global comparisons between the two groups revealed very few if any differences. Blood continued to flow to all of the parts of the brain. When focusing on the brain as a network however, they found very large differences.

To look at the brain as a network requires looking at its different parts as regions that communicate with one another, forming hubs. In healthy people, certain regions or hubs are busier than others as evidenced by more blood flow. But for the people in a coma, the team found, the normally busy hubs grew less busy, while other hubs grew busier, indicating a major change in the flow of information.

The researchers suggest that the brain scans reveal that the normally busy hubs in healthy people are centers of consciousness and their reduced role in communications in comatose patients suggests that they are most likely not conscious of their existence. They point to prior research that has suggested that being in a coma is more likely closer to the experience of being under anesthesia than being asleep. They add that the their research indicates that regions of the brain that are responsible for conscience thought likely require more oxygen rich blood, and are thus likely to be more sensitive to oxygen deprivation than other areas of the brain, which might explain why people go into a coma when those regions are harmed.

Duetting musicians sync brainwaves even when playing different notes

According to a study published by a team of psychologists, musicians playing different parts of a duet aren’t just syncing time — they synchronise brainwaves.

Johanna Sänger of Berlin’s Max Planck Institute for Human Development gathered 32 guitarists and arranged them in pairs to play Sonata in G Major by Christian Gottlieb Scheidler. Each musician was hooked up to electrodes, so Sänger and her team could monitor their brain activity the 60 times they were asked to play the composition. An earlier study from the Institute had already demonstrated that guitarists playing the exact same tune begin to share brainwave patterns. However, in this study Sänger asked the musicians to play different parts from the same piece of music. As well as playing totally different notes, one was asked to take the lead and set the tempo for the other to follow. Her hypothesis was that, if the brainwave patterns again aligned, then it would demonstrate they have an inherently important role in musicians’ “interpersonally coordinated behaviour” — or, their ability to play well as a pair. All pairs did in fact present with synchronised brain oscillations.

"When people coordinate their own actions, small networks between brain regions are formed," said Sänger. "But we also observed similar network properties between the brains of the individual players, especially when mutual coordination is very important; for example at the joint onset of a piece of music."

The synchronisation is known as “phase locking”, and took place largely where the frontal and central electrodes were placed (the frontal lobe is responsible for retaining long term memory, aligning emotion memory with social norms and predicting an action’s consequences).

The results prove, says the paper, that synchronisation of brain patterns plays “a functional role in music performance”, but also “that brain mechanisms indexed by phase locking, phase coherence, and structural properties of within-brain and hyperbrain networks support interpersonal action coordination”.

Sänger also found that the “leader’s” brainwaves were stronger and began before the music did, demonstrating their “decision to begin playing at a certain moment in time” as represented by well-coordinated frontal lobe activity.

Moral evaluations of harm are instant and emotional

People are able to detect, within a split second, if a hurtful action they are witnessing is intentional or accidental, new research on the brain at the University of Chicago shows.

The study is the first to explain how the brain is hard-wired to recognize when another person is being intentionally harmed. It also provides new insights into how such recognition is connected with emotion and morality, said lead author Jean Decety, the Irving B. Harris Professor of Psychology and Psychiatry at UChicago.

“Our data strongly support the notion that determining intentionality is the first step in moral computations,” said Decety, who conducted research on the topic with Stephanie Cacioppo, a research associate (assistant professor) in psychology at UChicago. They published the results in a paper, “The Speed of Morality: A High-Density Electrical Neurological Study,” to be published Dec. 1 and now on early preview in the Journal of Neurophysiology.

The researchers studied adults who watched videos of people who suffered accidental harm (such as being hit with a golf club) and intentional harm (such as being struck with a baseball bat). While watching the videos, brain activity was collected with equipment that accurately maps responses in different regions of the brain and importantly, the timing between these regions. The technique is known as high-density, event-related potentials technology.

The intentional harm sequence produced a response in the brain almost instantly. The study showed that within 60 milliseconds, the right posterior superior temporal sulcus (also known as TPJ area), located in the back of the brain, was first activated, with different activity depending on whether the harm was intentional or accidental. It was followed in quick succession by the amygdala, often linked with emotion, and the ventromedial prefrontal cortex (180 milliseconds), the portion of the brain that plays a critical role in moral decision-making.

There was no such response in the amygdala and ventromedial prefrontal cortex when the harm was accidental.

Researchers find reading uses the same brain regions regardless of language

A team of French and Taiwanese researchers has found evidence to indicate that people use the same regions of the brain when reading, regardless of which language is being read. In their paper published in the Proceedings of the National Academy of Sciences, they describe how fMRI brain scans made while people were reading revealed that there are very few differences in how the brain works as reading occurs.

The researchers note that previous research has suggested that different neural networks might be involved when people read text written in very different types of languages. French, for example, is an alphabetic language, whereas Chinese is logographic. Those of Roman origin are based on abstract concepts while Chinese characters are based on realistic depictions of handwriting strokes.

To learn more, the researchers ran fMRI scans on volunteers reading either Chinese or French material as their native language. The material presented was shown in various forms, e.g. normal, static, backwards or distorted. The researchers also employed priming, which is where words are flashed on a screen for such a short period of time as to be unknown to the reader. Priming has been found to influence the rate at which readers recognize words that are shown thereafter for a normal duration of time. The material written in French was presented as cursive rather than block printed letters.

In analyzing the results, the researchers found the differences in brain activity between the two groups as they read to be minimal. Those differences that were found, centered around a slight increase in the brain regions associated with processing the physical movements that had occurred in creating the characters, which in the brain is recognized as motor skills.

The researchers suggest that their results indicate that because reading is a relatively new process for the human brain, it likely evolved using previously existing neural network circuitry, which would explain why it appears the brain works in roughly the same way when reading, regardless of language.

How we “hear” with our eyes

In everyday life we rarely consciously try to lip-read. However, in a noisy environment it is often very helpful to be able to see the mouth of the person you are speaking to. Researcher Helen Blank at the MPI in Leipzig explains why this is so: “When our brain is able to combine information from different sensory sources, for example during lip-reading, speech comprehension is improved.” In a recent study, the researchers of the Max Planck Research Group “Neural Mechanisms of Human Communication” investigated this phenomenon in more detail to uncover how visual and auditory brain areas work together during lip-reading.

In the experiment, brain activity was measured using functional magnetic resonance imaging (fMRI) while participants heard short sentences. The participants then watched a short silent video of a person speaking. Using a button press, participants indicated whether the sentence they had heard matched the mouth movements in the video. If the sentence did not match the video, a part of the brain network that combines visual and auditory information showed greater activity and there were increased connections between the auditory speech region and the STS.

“It is possible that advanced auditory information generates an expectation about the lip movements that will be seen”, says Blank. “Any contradiction between the prediction of what will be seen and what is actually observed generates an error signal in the STS.”

How strong the activation is depends on the lip-reading skill of participants: The strong-er the activation, the more correct responses were. “People that were the best lip-readers showed an especially strong error signal in the STS”, Blank explains. This effect seems to be specific to the content of speech - it did not occur when the subjects had to decide if the identity of the voice and face matched.

The results of this study are very important to basic research in this area. A better understanding of how the brain combines auditory and visual information during speech processing could also be applied in clinical settings. “People with hearing impairment are often strongly dependent on lip-reading”, says Blank. The researchers suggest that further studies could examine what happens in the brain after lip-reading training or during a combined use of sign language and lip-reading.

Brazilian Mediums Shed Light on Brain Activity During a Trance State

Researchers at Thomas Jefferson University and the University of Sao Paulo in Brazil analyzed the cerebral blood flow (CBF) of Brazilian mediums during the practice of psychography, described as a form of writing whereby a deceased person or spirit is believed to write through the medium’s hand. The new research revealed intriguing findings of decreased brain activity during the mediums’ dissociative state which generated complex written content. Their findings appear in the November 16th edition of the online journal PLOS ONE.

The 10 mediums—five less expert and five experienced—were injected with a radioactive tracer to capture their brain activity during normal writing and during the practice of psychography which involves the subject entering a trance-like state. The subjects were scanned using SPECT (single photon emission computed tomography) to highlight the areas of the brain that are active and inactive during the practice.

The researchers found that the experienced psychographers showed lower levels of activity in the left hippocampus (limbic system), right superior temporal gyrus, and the frontal lobe regions of the left anterior cingulate and right precentral gyrus during psychography compared to their normal (non-trance) writing. The frontal lobe areas are associated with reasoning, planning, generating language, movement, and problem solving, perhaps reflecting an absence of focus, self-awareness and consciousness during psychography, the researchers hypothesize.

Less expert psychographers showed just the opposite—increased levels of CBF in the same frontal areas during psychography compared to normal writing. The difference was significant compared to the experienced mediums. This finding may be related to their more purposeful attempt at performing the psychography. The absence of current mental disorders in the groups is in line with current evidence that dissociative experiences are common in the general population and not necessarily related to mental disorders, especially in religious/spiritual groups. Further research should address criteria for distinguishing between healthy and pathological dissociative expressions in the scope of mediumship.

This is Your Brain on Freestyle Rap: NIDCD Study Reveals Characteristic Brain Patterns of Lyrical Improvisation

Researchers in the voice, speech, and language branch of the National Institute on Deafness and Other Communication Disorders (NIDCD) at the National Institutes of Health (NIH) have used functional magnetic resonance imaging to study the brain activity of rappers when they are “freestyling”—spontaneously improvising lyrics in real time. The findings, published online in the November 15 issue of the journal Scientific Reports, reveal that this form of vocal improvisation is associated with a unique functional reallocation of brain activity in the prefrontal cortex and proposes a novel neural network that appears to be intimately involved in improvisatory and creative endeavors. 

The researchers, led by Siyuan Liu, Ph.D., scanned the brains of 12 freestyle rap artists (who had at least 5 years of rapping experience) while they performed two tasks using an identical 8-bar musical track. For the first task, they improvised rhyming lyrics and rhythmic patterns guided only by the beat. In the second task, they performed a well-rehearsed set of lyrics.

During freestyle rapping, the researchers observed increases in brain activity in the medial prefrontal cortex, a brain region responsible for motivation of thought and action, but decreased activity in dorsolateral prefrontal regions that normally play a supervisory or monitoring role. Like an experienced parent who knows when to lay down the law and when to look the other way, these shifts in brain function may facilitate the free expression of thoughts and words without the usual neural constraints. 

Freestyling also increased brain activity in the perisylvian system (involved in language production), the amygdala (an area of the brain linked to emotion), and cingulate motor areas, suggesting that improvisation engages a brain network that links motivation, language, mood, and action. Further studies of this network in other art forms that involve the innovative use of language, such as poetry and storytelling, could offer more insights into the initial, improvisatory phase of the creative process.