Matters of the mind
Comprehending how the human brain functions — that’s the quest for the Centre for Neuroscience
What makes some people better and faster readers than others? Turns out this relates to a part of our brain called the ‘visual word form area’. When we look at a set of words, this area helps us make sense of them by responding to the words we know, but not to scripts and words of unknown languages.
“The prevalent belief is that when you look at a word there are specific neurons in your brain that respond only to that word, and not to the individual letters that make up the word,” says SP Arun, professor and chair at the Centre for Neuroscience (CNS), which is a part of the Indian Institute of Science, Bengaluru. Neurons are the basic functional units of the nervous system, and the brain has some 86 billion of them.
When Prof Arun and his team decided to test this hypothesis about reading ability with an extensive study, they discovered quite the opposite. “We found that fluent readers — among adults and children — can actually separate letters in a word,” he says. “This is exactly the opposite of what was previously believed.”
Efficient reading is not about detecting the combination of letters but, instead, about separating them, adds Prof Arun, and this has far-reaching implications. Among other things, it can help us understand — and perhaps find a solution for — conditions such as dyslexia. That solution could be a specific sort of training that may help people with the disorder read better.
A fundamental curiosity
“There has always been a fundamental curiosity about how the brain works,” says Prof Arun. “We are often surprised by a lot of our actions, and we cannot always know why we behave in a certain way.” The answer to that — and much more — lies in neuroscience, the study of the brain.
To expand, neuroscience is the study of the intricate web of billions of neurons in the brain and their connections to one another, called synapses, which ‘fire up’ and create ‘impulses’ that cause us to act and think in certain ways. CNS was set up in 2009 to pursue the very basic purpose of finding out how our brains work.
Neuroscience is a relatively young discipline. “The first discoveries in neuroscience came about in the late 1800s,” says Prof Arun. “Compare that with physics, where the first discoveries took place much earlier.”
The advantage here is that neuroscience, as a relatively new field, presents great opportunities for research and pathbreaking findings with practical applications. For example, discoveries in neuroscience thought to be irrelevant 10-15 years ago are being adopted into modern-day medical practice.
CNS has been supported by the Tata Trusts with grants from 2014-15 to 2019-20 that have enabled it to undertake a host of studies — including one on the aging brain — and create state-of-the-art laboratory facilities to further research.
Understanding the brain better will unlock our knowledge about many conundrums. How do our senses (sight, sound and touch) work? What is emotion and cognition, and how does seeing a happy face, as opposed to an angry one, make us react? How does reward or punishment shape our attitude towards certain tasks? How do we act based on certain ‘impulses’? And much more.
Importantly, knowing how the brain functions will also help us diagnose, treat and perhaps even cure brain disorders, which constitute a considerable disease burden in India today (about 30 million Indians suffer from neurological disorders).
Associate professor Sridharan Devarajan and his team at CNS are currently studying an important aspect of the brain related to attention and decision-making. “We investigate the idea of attention by looking at how different regions and networks in the brain allow us to focus on some things and exclude others,” he explains. “Sometimes people feel they have made a ‘wrong’ decision. We want to know why that happens and why the brain makes us commit to certain choices.”
One study in their laboratory brings together 25 carefully selected test subjects and trains them to carry out complex attention tasks. Knowing more about attention provides insights into the classic ‘cocktail party problem’: how we are able to hold a conversation even in the middle of a party. This happens because our brain picks up on, and integrates, auditory and visual clues from those we are speaking to and filters out the background noise. “The brain has a remarkable ability to separate the relevant from the irrelevant,” says Prof Devarajan, “and that is what comprises attention.”
That poses several questions. Why does the brain create these filters and how does it decide what is relevant? How much attention can the brain pay to a certain thing? This ability to filter, adds Prof Devarajan, is both a blessing and a curse. While it enables us to respond efficiently to stimuli in a certain circumstance, it allows us to focus on them only one at a time.
Multitasking make-believe
That means people who claim to be multitaskers are actually just rotating their attention between one task and another, doing them serially rather than simultaneously. “There is little evidence that people can do two completely novel tasks without paying attention to both,” says Prof Devarajan. Only heavily practiced tasks can be carried out on autopilot, so to speak.
Another CNS study looks at whether brain signal-based training can be used to improve attention. Brain signals indicate when somebody is alert and when they are not. So test subjects whose brain signals are being measured in real-time can be informed when their attention is flagging, and this helps them become more attentive.
The brain’s ability to give more attention to one thing over another often creates a ‘bottleneck’. This then becomes a major component of decision-making: we make choices based on what the brain tells us is more important, which implies that attention and decision-making are closely linked.
Associate professor Deepak Nair and his team are trying to understand the brain from the point of view of connectivity: the synapses that exist at the junction of neural cells meeting and the signals or messages that are passed through these synapses.
For a long time scientists thought of synapses as tiny machines, about a millionth of a metre in size, that contain everything needed for neurons to communicate. Inside these synapses there are specialised regions that carefully control the transmission of signals from one neuron to another. If something goes wrong — like changes in these signals or a weakening of their structure — it can lead to diseases like Alzheimer’s.
“We want to understand how a healthy synapse functions and what happens when diseases begin to develop,” says Prof Nair. Over the past decade, researchers at CNS and other institutions have redefined the basic understanding of synapses, revealing that they contain tiny ‘nanomachines’ that are 10–20 times smaller than the synapse itself. These nanomachines are essential for brain health and play a key role in the development of diseases.
Real-world applications
Research at CNS is undertaken not just for scientific discovery but also with an eye towards real-world applications. Prof Devarajan’s team, which has found a link between attention and eye movements, has been approached by automobile companies to design algorithms based on which wearable devices can be created to alert car drivers if their attention is flagging.
Such a device can potentially track brain activity, eye movements or even measure the temperature of the face to warn the driver if he or she is dozing off at the wheel or becoming less mindful of the road.
There are other possibilities for technology of this kind. A similar device can be used to alert students in a classroom when their attention is lagging. “There is a lot of interest among startups that want to create wearables — which can be attached to a cap or behind your ear — to track your attention and send a signal to your phone that lets you know how alert you are,” says Prof Devarajan.
Prof Nair and his team’s study of synapses can help in creating mechanisms that mimic the brain’s neural activities. These ‘neuromorphic devices’, as they are called, can aid people with neurodegenerative diseases — caused by the loss of neurons or a shutting down of synapses — to build and form new circuits and connections.
“Say you have a stroke and want to regain the full extent of your movements,” says Prof Nair. “You may require neuromorphic or advanced electronic devices that will send appropriate signals to the brain to reactivate your motor abilities.”
People with impaired hearing or speech, or even those rendered blind by damage to their optic nerve, could try to restore their senses through neuropathic intervention. “Depending on the kind of damage, if a signal can be ‘collected’ from the optic nerve and sent to a certain part of the brain, it might help,” explains Prof Nair.
Since its establishment at IISc in its centenary year in 2009, CNS has brought together a dedicated group of researchers who have advanced fundamental research toward real-world applications, supported by public funding and charitable grants. Though still in its early stages, CNS serves as a model of how targeted research efforts, unified under one umbrella, can drive meaningful progress in this field.
With a discipline like neuroscience, solving a challenge today may indeed open up possible remedies for future problems. “It may look like there is no point in doing something now, but basic research often leads to profound discoveries that have a huge impact later,” adds Prof Arun.
That’s the very philosophy that, like the synapses, fires up CNS.