ADHD children make poor decisions due to less differentiated learning processes

Attention-Deficit/Hyperactivity Disorder (ADHD) is one of the most common psychiatric disorders among school children. Pupils with ADHD often make poorer decisions than their unaffected classmates.

Researchers from the University of Zurich now discovered that different learning and decision-making mechanisms are responsible for these behaviors, and localized the underlying impairments in the brain.

Which shirt do we put on in the morning? Do we drive to work or take the train? From which takeaway joint do we want to buy lunch?

We make hundreds of different decisions every day. Even if these often only have a minimal impact, it is extremely important for our long-term personal development to make decisions that are as optimal as possible.

People with ADHD often find this difficult, however. They are known to make impulsive decisions, often choosing options which bring a prompt but smaller reward instead of making a choice that yields a greater reward later on down the line.

Researchers from the University Clinics for Child and Adolescent Psychiatry, University of Zurich, now reveal that different decision-making processes are responsible for such suboptimal choices and that these take place in the middle of the frontal lobe.

Mathematical models help to understand the decision-making processes
In the study, the decision-making processes in 40 young people with and without ADHD were examined.

Lying in a functional magnetic resonance imaging (fMRI) scanner to record the brain activity, the participants played a game where they had to learn which of two images carried more frequent rewards.

To understand the impaired mechanisms of participants with ADHD better, learning algorithms which originally stemmed from the field of artificial intelligence were used to evaluate the data.

These mathematical models help to understand the precise learning and decision-making mechanisms better.

"We were able to demonstrate that young people with ADHD do not inherently have difficulties in learning new information; instead, they evidently use less differentiated learning patterns, which is presumably why sub-optimal decisions are often made", says first author Tobias Hauser.

Multimodal imaging affords glimpses inside the brain
To study the brain processes that triggered these impairments, the authors used multimodal imaging methods, where the participants were examined using a combined measurement of functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) to record the electrical activity and the blood flow in the brain.

It became apparent that participants with ADHD exhibit an altered functioning in the medial prefrontal cortex, a region in the middle of the frontal lobe.

This part of the brain is heavily involved in decision-making processes, especially if you have to choose between several options, and in learning from errors.

Although a change in activity in this region was already discovered in other contexts for ADHD, the Zurich researchers were now also able to pinpoint the precise moment of this impairment, which already occurred less than half a second after a feedback, i.e. at a very early stage.

Psychologist Tobias Hauser, who is now researching at the Wellcome Trust Centre for Neuroimaging, University College London, is convinced that the results fundamentally improve our understanding of the mechanisms of impaired decision-making behaviour in people with ADHD.

The next step will be to study the brain messenger substances. "If our findings are confirmed, they will provide key clues as to how we might be able to design therapeutic interventions in future," explains Hauser.

More information: Tobias U. Hauser, Reto Iannaccone, Juliane Ball, Christoph Mathys, Daniel Brandeis, Susanne Walitza & Silvia Brem: Role of Medial Prefrontal "Cortex in Impaired Decision Making in Juvenile Attention-Deficit/Hyperactivity Disorder," in: JAMA Psychiatry, DOI: 10.1001/jamapsychiatry.2014.1093

Autism: Reflecting on the mirror neuron system - A systematic review

There is much interest in the claim that dysfunction of the mirror neuron system in individuals with autism spectrum condition causes difficulties in social interaction and communication.

This paper systematically reviews all published studies using neuroscience methods (EEG/MEG/TMS/eyetracking/EMG/fMRI) to examine the integrity of the mirror system in autism. 25 suitable papers are reviewed.

The review shows that current data are very mixed and that studies using weakly localised measures of the integrity of the mirror system are hard to interpret.

The only well localised measure of mirror system function is fMRI. In fMRI studies, those using emotional stimuli have reported group differences, but studies using non-emotional hand action stimuli do not.

Overall, there is little evidence for a global dysfunction of the mirror system in autism. Current data can be better understood under an alternative model in which social top-down response modulation is abnormal in autism.

The implications of this model and future research directions are discussed.

Read the full article here

Stanford Study: Reading Jane Austen to examine attention and distraction

Researcher Natalie Phillips positions an eye-tracking device on Matt Langione

During a series of ongoing experiments, fMRI images track blood flow in the brains of subjects as they read excerpts of a Jane Austen novel.

Experiment participants are first asked to leisurely skim a passage as they might do in a bookstore, and then to read more closely, as they would while studying for an exam.

The researchers said the global increase in blood flow during close reading suggests that “paying attention to literary texts requires the coordination of multiple complex cognitive functions.”

Blood flow also increased during pleasure reading, but in different areas of the brain suggesting that each style of reading may create distinct patterns in the brain that are “far more complex than just work and play.”

The experiment focuses on literary attention, or more specifically, the cognitive dynamics of the different kinds of focus we bring to reading.

The researchers expected to see pleasure centers activating for the relaxed reading and hypothesized that close reading, as a form of heightened attention, would create more neural activity than pleasure reading.

If the ongoing analysis continues to support the initial theory…teaching close reading (i.e., attention to literary form) “could serve – quite literally – as a kind of cognitive training, teaching us to modulate our concentration and use new brain regions as we move flexibly between modes of focus.”

Pioneering Stanford study uses Jane Austen texts to examine attention and distraction during reading, suggesting different modes of reading may serve as valuable cognitive training for concentration.

Also see graphing Jane Austen.

The Importance of Practice and Sleep for Musicians - Molly Gebrian

Musicians v. Non-Musicians - Molly Gebrian

Most of studies on changes in neuronal activity only last a week or two at the most. 

It’s not logistically feasible to have people coming into the lab for weeks or months on end to have their brains looked at, so, some neuro-scientists think musicians are an ideal population to find out what happens when you practice a motor task repeatedly for years and years.

One of the most obvious changes is that, especially in string players and keyboard players, the portion of the motor cortex devoted to the fingers is much bigger.

At the same time, the neurons in this cortical network are much more efficient.

These two things happen because, presumably, over time, lots and lots of neurons get connected by synapses that wouldn’t normally be connected, and the neuronal ensembles that result from these new connections get much better at what they do because they get to practice everyday.

A musician’s brain is so efficient at things like scales and other simple patterns that are automatic to us that entire brain areas don’t get engaged in a musician’s brain that are very active in a non-musician or amateur’s brain.

Two of these areas are the pre-motor cortex and the supplementary motor area.

These are involved in planning complex movements and coordinating timing, but when musicians play scales or simple rhythm patterns, these areas barely do anything at all.

The only other complex motor tasks that show this lack of activation are overlearned skills such as writing.

What this means is that our basic set of tools and skills as musicians are so automatic that our brain barely has to do anything to execute them.

But what this also means is that when you learn a new skill, especially something like the extended techniques used in contemporary music, there is a necessary period of days or weeks that your brain needs to rewire itself and for new neuronal ensembles and circuits to form.

The other amazing thing that happens in musicians’ brains, as new synapses form, is that our motor cortex gets connected to our auditory cortex.

Think about how strange that is. For most people, what they hear doesn’t cause them to have automatic associations with movement, and moving certainly doesn’t cause them to hear things in their heads.

But if a musician listens to a recording of a piece they know and play well, not only does their auditory cortex light up on a brain scan (fMRI), but the portion of their motor cortex devoted to their fingers does too.

Furthermore, neuroscientists have shown that the motor cortex isn’t just lighting up as a whole unit – the areas that control the individual fingers light up in the order and timing they would to execute the correct fingering (Bangert and Altenmuller, 2003).

NB: When these kinds of studies are done, measures are taken to make sure the musicians aren’t physically moving their fingers.

The opposite happens too: if you tell a pianist to play a piece silently on a tabletop, their auditory cortex lights up as it would if they were actually playing (and hearing) the piece.

These finding just serve to highlight how important it is to always keep singing in your head as you play and to be really clear about what you want to hear.

It affects what comes out of your fingers and arms and mouth, not in some strange metaphysical way, but because your auditory cortex is connected to your motor cortex.

If you aren’t clear on what you want to hear, the auditory cortex has a very limited message to send to your fingers.

The Role of Sleep in Learning

If all of these changes have to take place in your brain before you can play something fluidly and competently, is there anything you can do to speed up the process?

The answer depends on how much you want to speed it up, because it turns out that a very important component of motor (and auditory) learning is sleep.

Matthew Walker and his colleagues here in Boston have done a number of experiments on motor learning during sleep (Walker, et al, 2002, 2003, 2005).

Their basic experimental paradigm involves three groups of people. The first group gets taught a finger tapping task (4-1-2-3-4 where 4 is the pinky finger and 1 is the index finger) at 10am, which they then practice and are tested on multiple times throughout the day.

The second group gets taught and practices the same task at 10am, but they don’t get tested on it again until 10pm.

Then, they are sent home to sleep and tested the next morning at 10am. The final group is trained on the task at 10pm and has their first retest at 10am the next morning. What they found is astonishing.

The first group gets gradually better throughout the day at a rate that you can predict.

The second group shows the same linear increase during the day, but when you test them the next morning, there is a huge jump in their performance (measured by faster sequence execution without loss of accuracy).

The same goes for the group that was trained at 10pm and then retested for the first time the next day – they got much better overnight, even though all they were doing was sleeping!

NB: Everyone was instructed not to practice when they went home.

Even more surprising, there is absolutely no relationship between how much better a person got during daytime practicing and how much better they got after sleeping.

How is this possible and what does it mean? Researchers have concluded that the last result means that practice-dependent learning and sleep-dependent learning are independent processes.

This doesn’t mean, of course, that if you don’t practice, you’ll get better just by sleeping but it does mean that you shouldn’t underestimate the importance of sleep in learning, especially when it’s brand new.

Knowing this can help you use your practice time much more efficiently.

Say, for instance, you have a lot of music to learn for orchestra and not a lot of time to practice it.

You will be much better off practicing your orchestra music for 15 minutes a day until the concert, rather than “wood-shedding” the day before the concert.

Why? Because you’ll have all those nights of sleep for your brain to process the new music. So ultimately, you’ll be able to play the music better with fewer hours of actual practice.

When you’re learning a new piece that you have ample time to practice, keeping the role of sleep in mind can also help you practice more efficiently.

The primary thing that improved with sleep for the people in these studies was speed (at least that’s what the experimenters were measuring).

Since the amount of daytime improvement and learning after sleep aren’t related, spending hours and hours on a really tricky fast passage on the first few days of practicing isn’t as efficient as getting it fluent at a slower tempo and then just leaving it until the next day.

The next day, not only will you be able to play it faster, but you’ll spend much less time getting it to a faster tempo than you would’ve the day before.

No one probably would’ve guessed that just sleeping would make you better at playing your instrument, but researchers have shown that it does, over and over again.

The effects of sleep are really hard to study, but in this case, researchers think they know how it works.

Sleep is divided into two broad types: REM sleep and non-REM sleep (or NREM sleep). REM sleep is when you have dreams.

During what is called Stage 2 NREM sleep, however, electrical brain events occur that are called sleep spindles.

During a sleep spindle, there is a huge burst of electrical activity in a population of neurons that causes massive amounts of calcium to enter those cells.

Calcium is what causes all the changes discussed earlier, from strengthening and weakening synapses, to making new synapses, to synchronizing the firing of neuronal ensembles.

Sleep spindles reach peak intensity late in the night and have been shown to increase following motor learning during the day.

The study by Matthew Walker and his colleagues at Harvard Medical School also found that the percentage of improvement after sleeping strongly correlated with the amount of time the person spent in Stage 2 NREM sleep in the final quarter of the night, precisely when sleep spindle activity is at its peak.

This finding also highlights the importance of getting enough sleep while you’re learning something new.

A full night of sleep was defined as 8 hours in this study, and it was only the last two hours that were really important for learning.

Getting a full night’s sleep may be even more important that we realize.

Read the full article here: http://madisonjazz.files.wordpress.com/

Hearing loss may change brain structure

"In the case of tinnitus, surprisingly, there were few changes to brain structure despite changes to function, suggesting that when sensory deprivation is accompanied by self-generated noise, it may be better at preserving neural tissue," says Fatima Husain.

Researchers used two different imaging modalities in studies of people with hearing loss, normal hearing, and those with hearing loss and tinnitus (ringing in the ears).

People in the hearing loss group showed structural changes in their brains.

“This suggests that functional changes due to sensory deprivation may result in long-term structural changes,” says Fatima Husain, a Beckman Institute faculty member at the University of Illinois.

The goal of the study was to investigate structural gray and white matter changes related to tinnitus and hearing loss and try to dissociate them from changes due only to hearing loss. (Credit: Fatima Husain)

“However, in the case of tinnitus, surprisingly, there were few changes to brain structure despite changes to function, suggesting that when sensory deprivation is accompanied by self-generated noise, it may be better at preserving neural tissue.”

Husain and her collaborators on the study measured neuroanatomical changes in gray and white matter in the brains of participants with only bilateral hearing loss (HL), participants who had HL and tinnitus (TIN), and a control group with normal hearing (NH) without tinnitus.

Their study, reported in the journal Brain Research, looked at neuroanatomical alterations associated with hearing loss and tinnitus.

Read the original study DOI: 10.1016/j.brainres.2010.10.095

The researchers used structural magnetic resonance imaging (MRI) scans and voxel-based morphometry (VBM) to examine changes in gray matter, and diffusion tensor imaging (DTI), to identify changes in white matter tract orientation.

While tinnitus is often accompanied by hearing loss, not everyone with hearing loss experiences tinnitus.

The goal of the study was to investigate structural gray and white matter changes related to tinnitus and hearing loss and try to dissociate them from changes due only to hearing loss.

“We observed that the HL group had the most profound changes in both white and gray matter relative to the other groups,” Husain says. The gray matter decreases seen in the HL group relative to the NH group were in the anterior cingulate, putamen, and middle frontal gyrus.

Two of these regions, the anterior cingulate and frontal cortex, were “also implicated in our companion study that studied functional response of the brain in the same group of subjects and points to involvement of the attention processing network.”

By dissociating the effect of tinnitus from hearing loss, the researchers concluded that “hearing loss rather than tinnitus had the greatest influence on gray and white matter alterations.”

Husain directs the Auditory Cognitive Neuroscience Lab in the Department of Speech and Hearing Science.

More news from the University of Illinois: http://www.beckman.illinois.edu/index.aspx

Autism: refering to themselves as 'you'

One of the first things that autism pioneer Leo Kanner noticed about the children he was seeing was that they had a tendency to refer to themselves as 'you,' echoing his phrasing of questions he asked them.

Nearly 70 years later, we have a technology — functional magnetic resonance imaging, or fMRI — that can peer into the brain to illuminate which regions are involved when people switch personal pronouns in conversation. This task, called deictic shifting, is impaired not just in children with autism, but also in some adults with the disorder.

A new fMRI study published in Brain in July reports that connectivity between two brain regions involved in self-awareness is greatly reduced in people with autism when they engage in deictic shifting.

In the study, researchers presented 15 adults who have high-functioning autism, all but one of them male, and 15 matched controls with images of the front and back covers of a book held by a woman named Sarah. The book covers depict different objects, for example, a carrot on the front and a house on the back. Sometimes Sarah opens up the book to display both covers and sometimes she folds the book so that only one cover is visible.

Over 24 trials, Sarah asked study participants four variations on a single question: "What can ? see now?" Half the time, the "?" was the proper name of the participant or Sarah. The other half of the time, Sarah used a pronoun, either 'you' or 'I.'

In this manner, participants had to execute a series of rapid shifts between "What do you see now?" to "What do I see now?", "What does Sarah see now?" and "What does (participant's first name) see now?"

The researchers found that people with autism respond more slowly and less accurately to questions that require them to shift perspective from 'you' to 'I.' The scans revealed that connectivity between the right anterior insula and the precuneus is significantly lower among individuals with autism when carrying out this task.

Conversely, the precuneus is far more active in the individuals with autism when they're confronted with proper names, suggesting that this brain region is working overtime to properly identify self versus other.

These results suggest that pronoun reversals in autism are not simple semantic glitches. Instead, they appear to provide yet another example of the profound impairment in autism of the ability to understand self and other in reciprocal relationships.

After all, if I can't distinguish between you and me, how can I ever get to the immeasurably more complex category: We.

TOT: Tip-of-the-Tongue and Word Retrieval Deficits in Dyslexia

Tip-of-the-Tongue and Word Retrieval Deficits in Dyslexia -- Hanly and Vandenberg 43 (1): 15 -- Journal of Learning Disabilities

Wikipedia provides a good explanation of TOT It is summarised below;

The tip of the tongue (TOT or Presque vu, from the French for "almost seen") phenomenon is an instance of knowing something that cannot immediately be recalled.

TOT is understood to be an adverse experience or difficulty that we have with our memory recollection. It involves having difficulty retrieving a well-known word or familiar name.

When experiencing TOT, people feel that the blocked word is on the verge of being recovered. So, despite the failure in finding or recalling the word, people have the feeling that the blocked word is figuratively "on the tip of the tongue."

Inaccessibility and the sense of imminence are the two key features of an operational definition of TOTs (A.S. Brown, 1991).

There is a hypothesis that Dyslexia involves phonological processing deficits but not semantic process deficits. To test this hypothesis research scientists brought together a number of children and used tip-of-the-tongue (TOT) responses on a picture-naming task.

Participants in the test included 16 children who were known to be suffering from dyslexia and 31 control children between 8 and 10 years of age who did not differ in receptive vocabulary.

The research seemed to confirm the hypothesis; children with dyslexia demonstrated more TOTs and proportionally more errors in the phonological step of word retrieval but not in the semantic steps. Longer and low-frequency words also prompted more TOTs.

The researchers believe the results provide good evidence of text-independent, on-line phonological processing deficits in readers with dyslexia.

Another Study
A separate study (Maril et al., 2001, p. 657) also found that while attempting to retrieve information, subjects relied heavily on visual spatial clues in correctly retrieving the information.

For example, some subjects in the study that were trying to recall a name described looking at the person's face in attempting to retrieve the name.

Also, when trying to recall the name of an author, the subjects described attempting to read the name of the author from an imagined book.

The authors of the study suggest that the subjects in the fMRI study used a visual imagery strategy when trying to resolve a TOT condition.

This is something that may be familiar when you consider your own memory recollection strategies and that of your children.

Additional Reading
For more information on TOT, including it's use in signing for the deaf and the experiences of multilingual speakers, click on the link to USAToday.