Posts tagged theory of mind
Articles and news from the latest research reports.
Key Brain ‘Networks’ May Differ in Autism
Differences in brain connectivity may help explain the social impairments common in those who have autism spectrum disorders, new research suggests.
The small study compared the brains of 25 teens with an autism spectrum disorder to those of 25 typically developing teens, all aged 11 to 18. The researchers found key differences between the two groups in brain “networks” that help people to figure out what others are thinking, and to understand others’ actions and emotions.
"It is generally agreed that the way the networks are organized is not typical [in those with autism]," explained study lead researcher Inna Fishman, assistant research professor of psychology at San Diego State University.
The prevailing idea until now, she said, has been that these neurological networks are under-connected in people with autism. However, “we found they were over-connected — they talk to each other way more than expected at that age.”
The study is published in the April 16 online edition of JAMA Psychiatry.
New study settles how social understanding is performed by the brain
A new study settles an important question about how social understanding is performed in the brain. The findings may help us to attain a better understanding of why people with autism and schizophrenia have difficulties with social interaction.
In a study to be published in Psychological Science, researchers from Aarhus University and the University of Copenhagen demonstrate that brain cells in what is called the mirror system help people make sense of the actions they see other people perform in everyday life.
Using magnetic stimulation to temporarily disrupt normal processing of the areas of the human brain involved in the production of actions of human participants, it is demonstrated that these areas are also involved in the understanding of actions. The study is the first to demonstrate a clear causal effect, whereas earlier studies primarily have looked at correlations, which are difficult to interpret.
One of the researchers, John Michael, explains the process:
“There has been a great deal of hype about the mirror system, and now we have performed an experiment that finally provides clear and straightforward evidence that the mirror system serves to help people make sense of others’ actions,” says John Michael.
Understanding autism and schizophrenia
The study shows that there are areas of the brain that are involved in the production of actions. And the researchers found evidence that these areas contribute to understanding others’ actions. This means that the same areas are involved in producing actions and understanding others’ actions. This helps us in everyday life, but it also holds great potential when trying to understand why people with autism and schizophrenia have difficulties with social interaction.
“Attaining knowledge of the processes underlying social understanding in people in general is an important part of the process of attaining knowledge of the underlying causes of the difficulties that some people diagnosed with autism and schizophrenia experience in sustaining social understanding. But it is important to emphasise that this is just one piece of the puzzle.”
“The findings may be interesting to therapists and psychiatrists who work with patients with schizophrenia or autism, or even to educational researchers,” adds John Michael.
Facts about the empirical basis
The participants (20 adults) came to the lab three times. They were given brain scans on the first visit. On the second and third, they received stimulation to their motor system and then performed a typical psychological task in which they watched brief videos of actors pantomiming actions (about 250 videos each time). After each video they had to choose a picture of an object that matched the pantomimed video. For example, a hammer was the correct answer for the video of an actor pretending to hammer. This task was intended to gauge their understanding of the observed actions. The researchers found that the stimulation interfered with their performance of this task.
Innovative method
The researchers used an innovative technique for magnetically stimulating highly specific brain areas in order to temporarily disrupt normal processing in those areas. The reason for using this technique (called continuous theta-burst stimulation) in general is that it makes it possible to determine which brain areas perform which functions. For example, if you stimulate (and thus temporarily impair) area A, and the participants subsequently have difficulty with some specific task (task T), then you can infer that area A usually performs task T. The effect goes away after 20 minutes, so this is a harmless and widely applicable way to identify which tasks are performed by which areas.
With continuous theta-burst stimulation, you can actually determine that the activation of A contributes as a cause to people performing T. This method thus promises to be of great use to neuroscientists in the coming years.
Brain interactions differ between religious and non-religious subjects
An Auburn University researcher teamed up with the National Institutes of Health to study how brain networks shape an individual’s religious belief, finding that brain interactions were different between religious and non-religious subjects.
Gopikrishna Deshpande, an assistant professor in the Department of Electrical and Computer Engineering in Auburn’s Samuel Ginn College of Engineering, and the NIH researchers recently published their results in the journal, “Brain Connectivity.”
The group found differences in brain interactions that involved the theory of mind, or ToM, brain network, which underlies the ability to relate between one’s personal beliefs, intents and desires with those of others. Individuals with stronger ToM activity were found to be more religious. Deshpande says this supports the hypothesis that development of ToM abilities in humans during evolution may have given rise to religion in human societies.
“Religious belief is a unique human attribute observed across different cultures in the world, even in those cultures which evolved independently, such as Mayans in Central America and aboriginals in Australia,” said Deshpande, who is also a researcher at Auburn’s Magnetic Resonance Imaging Research Center. “This has led scientists to speculate that there must be a biological basis for the evolution of religion in human societies.”
Deshpande and the NIH scientists were following up a study reported in the Proceedings of the National Academy of Sciences, which used functional magnetic resonance imaging, or fMRI, to scan the brains of both self-declared religious and non-religious individuals as they contemplated three psychological dimensions of religious beliefs.
The fMRI – which allows researchers to infer specific brain regions and networks that become active when a person performs a certain mental or physical task – showed that different brain networks were activated by the three psychological dimensions; however, the amount of activation was not different in religious as compared to non-religious subjects.
(Source: wireeagle.auburn.edu)
Similar connectivity profiles in humans and monkeys used to generate a Theory of Mind
The ability to infer emotion or intention in others from their outward appearance and behavior, has been called a “Theory of Mind” (TOM). While cognitive scientists have debated whether animals other than humans possess a TOM, many animals (like monkeys) clearly react to facial expression or body movements. One area of the human brain that has received considerable attention in discussions of TOM, is the temporo-parietal junction (TPJ). If each half of the brain is viewed as a boxing glove, the TPA corresponds to the junction between the “thumb” and body of the glove. To explore whether the TPJ regions of humans and monkeys have similar “functional connectivity” profiles, a group of Oxford researchers turned to high resolution at-rest fMRI. The researchers generated correlation maps between each time series obtained for specific voxel regions of interest. Their results, just published in PNAS, show that the most similar TPJ connectivity profiles correspond to areas that process, among other things, faces and social stimuli within the temporal cortex.
When the brain first begins to develop in the womb, the cortex is basically a smooth sheet. The most noticeable topological feature in the cortex of all higher vertebrates, the lateral or Sylvian fissure, begins to take shape as an invagination in the side that proceeds from front to back. This fold, with the TPA at its apex, remains as the primary feature of the cortex even as it grows increasingly convoluted. It is little wonder that many of the most interesting mental phenomena, and malady, are often attributed to this region. Stimulation of this area has produced effects as widespread as out of body experiences, impostor syndromes, and even phantom body doubles with precise geometrically offsets to the primary body position.
It is a bit of a paradox perhaps, that many studies which look for uniform or predictable features in the brain have instead hit upon the very region where any such pigeonholing is most labile. In other words, when the brain folds, the TPA is precisely the region where the most scrunching happens, with the result the mature structure typically shows the most variance. In animals like cats and many monkeys, the cortical gyri and sulci, have virtually the same pattern in each individual. In humans however, attempts to assign names to specific folds of the TPA region is like playing a game of pin the tail on the donkey. For example, the Angular gyrus, Wernicke’s area, Supramarginal gyrus, and Inferior parietal area, can all be variously designated as part of the TPA.
Recent attempts to define a default mode network (DMN) using fMRI have included this same region. In theory, the DMN can be used to distinguish sleep from arousal. It was noted that neurons which project out of the cortex in this region have, in effect, more options open to them than those virtually anywhere else in the brain. For example, directly under the angular gyrus is the area known as the temporo-parietal fiber association area. It includes at least seven long range white matter superhighways. That is not to say TPA neurons have free reign to board any tract they choose, (especially those like the optic radiations whose foundations are strongly and quickly set by myelin), but certainly the wide variance in behavioral correlates of these cells has an anatomical basis.
The Oxford study used Macaques, a monkey which has been on a separate evolutionary path from humans for around 30 million years. They note that the superior temporal (STS) region of the Macaque contains face cells that have been found to be more responsive to social cues rather than to identity. The researchers included the STS in their MRI meta-analysis, and also incorporated information from the BrainMap database, a large repository of neuroimaging data. While it is encouraging to see big data being put to use, it is often difficult to follow exactly how the data is processed to yield the so-called “activation likelihood estimation maps for activity elicited by theory of mind paradigms and by face discrimination or processing.”
As various federal projects begin to assemble connectomes for the human brain, functional connectivity studies that use highly processed MRI data, will need to be made as simple and straightforward as possible if they are to be put to widespread use. MRI tractography is a related technology that can assign physical connectivity by performing a meta-analysis on diffusion tensor data. Using scans and connectomes to generate theories to explain some of the strange mental phenomena generated secondary to stroke or by various kinds of electromagnetic stimulation are the best approaches we have at the moment. New technologies generated by the BRAIN Initiative will hopefully allow a finer-grained exploration of theory of mind.
Thinking about others is not child’s play
August 9, 2012
MIT study reveals changes in brain activity as children learn to read other people’s behavior.
When you try to read other people’s thoughts, or guess why they are behaving a certain way, you employ a skill known as theory of mind. This skill, as measured by false-belief tests, takes time to develop: In children, it doesn’t start appearing until the age of 4 or 5.
Several years ago, MIT neuroscientist Rebecca Saxe showed that in adults, theory of mind is seated in a specific brain region known as the right temporo-parietal junction (TPJ). Saxe and colleagues at MIT have now shown how brain activity in the TPJ changes as children learn to reason about others’ thoughts and feelings.
The findings suggest that the right TPJ becomes more specific to theory of mind as children age, taking on adult patterns of activity over time. The researchers also showed that the more selectively the right TPJ is activated when children listen to stories about other people’s thoughts, the better those children perform in tasks that require theory of mind.
The paper, published in the July 31 online edition of the journal Child Development, lays the groundwork for exploring theory-of-mind impairments in autistic children, says Hyowon Gweon, a graduate student in Saxe’s lab and lead author of the paper.
“Given that we know this is what typically developing kids show, the next question to ask is how it compares to autistic children who exhibit marked impairments in their ability to think about other people’s minds,” Gweon says. “Do they show differences from typically developing kids in their neural activity?”
Saxe, an associate professor of brain and cognitive sciences and associate member of MIT’s McGovern Institute for Brain Research, is senior author of the Child Development paper. Other authors are Marina Bedny, a postdoc in Saxe’s lab, and David Dodell-Feder, a graduate student at Harvard University.
Irony seen through the eye of MRI
A French team has shown that the activation of the ToM neural network increases when an individual is reacting to ironic statements. Published in Neuroimage, these findings represent an important breakthrough in the study of Theory of Mind and linguistics, shedding light on the mechanisms involved in interpersonal communication.
In our communications with others, we are constantly thinking beyond the basic meaning of words. For example, if asked, “Do you have the time?” one would not simply reply, “Yes.” The gap between what is said and what it means is the focus of a branch of linguistics called pragmatics. In this science, “Theory of Mind” (ToM) gives listeners the capacity to fill this gap. In order to decipher the meaning and intentions hidden behind what is said, even in the most casual conversation, ToM relies on a variety of verbal and non-verbal elements: the words used, their context, intonation, “body language,” etc.