How the Brain Works: It’s all about layers part 1

The brain has a layered structure. You can think of it a bit like the layers of the Earth, from the crust, to the mantle, down to the burning, ancient core.

The outer layers of the brain process information without caring too much about goals or emotions. Some call it ‘cold cognition’. The inner layers increasingly process information in terms of goals and emotions, so-called ‘hot cognition’.

spider-1403889352yvkThe innermost layers coordinate with the functioning of the rest of the body. When I see a1280px-man_running_scared_cartoon_vector-svg spider, cold cognition recognises the visual pattern, hot cognition gets worried, the body is informed that its heart should race in preparation for fight-or-flight action, and cold cognition prepares the instructions to jump. The layers work together as an integrated whole.

This week’s blog explores how the outer layer, the cortex, works.

The Outer Layer (aka The Cortex)

As we’ve seen, the cortex is big in humans compared to other animals. The back and the front do different things.

The cortex, is a sheet of neurons for processing information. The sheet of neurons, 2 millimetres thick, is just a bit smaller than a sheet of A3 paper, and it needs to be crumpled up to fit it in the skull.  The sheet processes information without caring too much about the results. Where you are on the sheet doesn’t radically change how the information is processed, it just changes what is processed.

The back part of the cortex houses regions involved in sight (vision), hearing (audition), and the processing of space. Senses are processed along two routes. One route, called the ‘what’ pathway, tries to identify what things are. The other route, the ‘where’ pathway, processes where things are in space. You might want to combine this information: catch a cricket ball (howzat!) but don’t catch a snowball (duck!).

The motor areas are towards the front. At the boundary is an area for sensing the body, and the motor circuits for controlling parts of the body. Further towards the front are areas involved in planning, decision-making, and control. As we’ll see, these are still sort of motor circuits.

Between the back and the front, the sensory and motor systems are organised in hierarchies, moving from simple to complex. You can think of these hierarchies as being like a tower with many floors, with a separate tower for each sense. Each floor combines the work done below, and each floor has a farther view than the floor below. The lowest floor spots patterns in sensory information. The next floor up spots patterns within patterns. The next floor, patterns within patterns within patterns. Sensory and motor systems are trying to see patterns within patterns within patterns – and then make connections between the screenshot-2019-03-13-at-18-30-44patterns.

After a while, the upper floors of the towers might know a thing or two about what patterns are likely. Based on their knowledge, the upper floors like to make suggestions to the lower floors on what they may be perceiving (just to help out, mind). The upper floors of the towers for the different senses talk to each other, across cables strung between the upper floors, to see if they can agree what’s out there in the world. The upper layers are connected to the frontal parts of the brain, to pass on conclusions and see if their view fits with expectations.

The motor system has a hierarchy too, but its higher levels are different. They’re about patterns more distant in time. The lowest levels are about immediate actions. The higher levels are about more complex sequences of actions, further forward in time. The lowest level says ‘Do it!’ (primary motor cortex). The next layer says, ‘Prepare to do it’ (supplementary cortex). The next layer up says, ‘You may want to do it sometime in the future’ (prefrontal cortex). A complex sequence of motor actions to be carried out at some future point in time can be described as a plan. Pre-frontal cortex, the planning and decision-making part of the brain, can also be seen as the top of the motor system hierarchy, looking the furthest forward in time.

We saw in the section on evolution that humans have more cortex. This means that humans can build their towers higher than other animals. In their senses, humans can discern more patterns within patterns, more complicated concepts; and in their motor systems, they can build further forward, creating plans into the more distant future.

Read more at howthebrainworks.science!

Using research in the classroom: Teaching in a multi-linguistic classroom

roberto-filippiWelcome to our series in which we ask researchers to tell us how their research is of use and relevance for the classroom. Today, we are delighted to welcome Roberto Filippi, Associate Professor at UCL Institute of Education.

What is the focus of your research?

My area of research is second language acquisition with specific focus on the effects of bilingualism (or multilingualism) on cognitive development across the lifespan. This has become a very hot topic in recent years, mostly due to the increased multiculturalism in our societies. According to some reliable estimates, more than half of the world’s population is fluent in two or more languages – more than three billion people!  We can safely say that bilingualism is not an exception and studying multilingual speakers offers a unique opportunity to understand how language develops and what its interactions are with the rest of the cognitive system.

What led you to this area of research? 

Being the father of two bilingual children, I can’t deny that I have a strong personal interest. I began studying bilingual children more than 10 years ago in a London primary school in which the large majority of children were bilinguals. I directly experienced the challenges that teachers face everyday, but also the advantages that a multicultural / multilinguistic community can offer. Building a bridge between science and education was a very rewarding experience, an experience that I wish to continue even more here at the UCL Institute of Education.

Could you summarise your findings?

A decade of research in this area has shown many positive effects of second language development. I should say that studying bilingual / multilingual speakers is not an easy task. Second language learning occurs everyday and defining someone as “bilingual” does not explain the complexities of this phenomenon. Nonetheless, our studies try to take into account the many variables that might affect our findings like, for example, our participants’ linguistic experience, age of second language acquisition/exposure, levels of proficiency in both languages and socio-economic status.

Our studies have shown that bilingual children who learnt two languages from birth and bilingual adults who started to learn a second language much later in life, enjoy the remarkable ability to filter out sound interference when attending to a task – in our case the comprehension of speech. A possible interpretation of these finding is that bilinguals have to deal with two languages in a single mind. They need to filter out interference from the non-target language (i.e., the language that is not in use) and activate that target one (i.e., the language that one wants to speak or listen to). As a result of this intense and daily “brain training”, bilinguals may develop a stronger resilience than monolingual speakers to environmental distractions. Remarkably, in another study in which we used modern neuroimaging techniques, we found that the ability to control verbal interference in bilinguals is associated with a specific area of the cerebellum. This may indicate that the bilingual brain has a different functional and structural development compared to the monolingual brain, even in areas that were largely unexplored, such as the cerebellum.

What do you think this means for teachers in the classroom?

We are continuously bombarded by visual and auditory stimuli that affect our concentration. Our attention skills are very limited and prone to distractions that may impair our performance in everything we do. Classrooms are very noisy environments in which children need to learn in the presence of many environmental distractors. If our studies confirm that acquiring two (or more) languages early in life may enrich a capacity for filtering out distractors and learning more efficiently, I think we will offer educators and policy makers additional scientific evidence that multilanguage acquisition is beneficial for cognitive development.

If you could give one tip to teachers based on your work, what would it be?

Never discourage parents from raising their children in multilingual environments. Unfortunately, there are still cases in which educators advise multilingual families to raise their children as monolingual, to avoid “mental confusion”. This advice comes from early research showing that bilingualism was detrimental for a child’s cognitive development. However, this research has proven to be flawed. Decades of more rigorous and controlled scientific studies have not supported this view at all: there is no evidence that second language acquisition can impair development.

Therefore, I think it is the responsibility of the scientific community to provide research-based evidence and actively engage with education professionals. We need to work together to give our children everything they need.

You can read more about Roberto’s research in these papers; on bilingual advantage of language interference in adults, in children and on control of language interference.
Teachers and parents might also be interested in the many resources available on the Bilingualism matters website and the book Raising multilingual children.

Increased perceptual capacity in autism – a double-edged sword

In this week’s seminar, Dr Anna Remington talked about her research showing that autistic children and adults can take in more information than their non-autistic counterparts. This can confer distinct advantages in certain processing tasks, but there is also the risk of overload.

You can read more about Anna’s work – and test your own perceptual abilities – in a piece she wrote in The Conversation and in a paper about Deutsche Bank’s internship programme for autistic graduates. If you’re a Twitter user, you can follow Anna @annaremington and CRAE (the Centre for Research into Autism and Education) @CRAE_IoE