The Brain
What is Reality?
What Makes Me?
Who is in Control?
How Do I Decide?
Why Do I Need You?
Who Will We Be?
The Brain

    The Brain

    The Brain with David Eagleman investigates the scientific story of why we feel and what we think. By asking questions like "Who am I?" and "Who's in control?" The Brain allows viewers to explore how our brains control our behavior, and what that means for humanity.

    In this interactive, viewers can explore clips from each of the six episodes of the show. Whether hoping to understand how the brain develops or how it perceives the world around us, viewers can gain a deeper understanding of one of the body's most complicated and essential organs.

    Visual illusion & The brain cave

    The chequer shadow illusion is a way to show that our perception of reality has more to do with what our brain is constructing than what's going on in the outside world. To fully appreciate why reality is a construction of the brain, imagine you could climb inside the skull where the brain is locked in silence and darkness.


    Syncing the senses & The brain is like a city

    The brain processes sensory information at different speeds; athletes at the starting line respond to the sound of a gun differently versus a red light. The brain edits it all together so that our perception of reality feels multi-sensory at any one time. The brain is like a city in that it is interconnected, and no one region exists in isolation.


    The internal model: How the brain builds on expectations

    The world we see is a beautifully rendered internally generated simulation of what's out there in the physical world. This simulation is called the Internal Model and moment to moment, it is being updated based on what we see or experience. An illusion (the hollow face illusion) and some shaky camera footage allow us to witness the Internal Model in action.


    Humans are born dependent but with adaptable brains

    Human babies are born much more dependent than other mammals who are often born able to walk, swim, or stand. This is because the human brain is born relatively unfinished, which allows it to develop and make connections based on a child's environment. This strategy has made human beings one of the most adaptable species on the planet.


    The flexibility of the young brain

    A child's brain has almost the same number of neurons as an adult's but what's going on inside is much different. In the first two years of life a toddler's brain can form up to 2 million new connections every minute. This process of over-connection is then followed by a period of pruning back the connections so that there are fewer but stronger ones, according to the child's environment.


    The aging brain & the concept of "cognitive reserve"

    As the brain ages, it can begin to deteriorate, and this can effect who we are. At Rush University Medical Center, research into the aging brain is focused on studying a relatively stable population of nuns and priests whose brains are dissected after their death. The results of each post-mortem is cross referenced with detailed data about each individual when they were alive. The results of the study reveal that being physically and cognitively active can make a difference to whether or not we will exhibit the signs of age-related brain pathologies. The theory of 'cognitive reserve' posits that in an active brain, as areas of the aging brain deteriorate or fail, other areas can compensate.


    Why so much of what we do is unconscious

    Cup-stacking junior world champion Austin Naber competes with David Eagleman in order to show the way in which skills get automatised in the brain. When we learn a new skill, it moves from the level of conscious awareness to unconscious networks that we no longer have control over. Why? The answer is revealed as Austin's and David's brains are read using EEG data. Austin, who is doing highly intricate moves compared to David is showing a readout that is near serene, while David's brain is screaming along with activity. Moving skills to the level of unconscious awareness allows for speed and efficiency.


    The role of consciousness

    Consciousness is like the CEO of a vast corporation, able to take the long view, rise above the daily detail, and make important decisions. When there is conflict between unconscious subsystems — say you're on a diet but you're hungry — consciousness then gets involved and becomes the arbiter. It is also a way for trillions of cells to see themselves as one entity, a mirror on the system.


    Free will

    Professor Alvaro Pascual-Leone uses transcranial magnetic stimulation (TMS) to demonstrate that the feeling we have of our own free will may not be so straightforward. The conscious mind is capable of claiming ownership for decisions it almost certainly did not make. What if we have no free will? What if our decisions are being made and guided by forces that are as predictable as any that operate in the physical world? Dr. Eagleman uses a tank of ping pong balls on mouse traps to demonstrate that in a system as complex as the human brain, embedded in the complex system of other brains, our actions and thoughts are unpredictable in practice.

    The Trolley Dilemma

    The trolley dilemma is a thought experiment that showcases the struggle between two systems in the brain: logic and emotion. In scenario one of the trolley dilemma you must make a logic only decision but in scenario two, a new brain system is recruited into the decision: emotion. This tips the balance and changes the outcome.

    The Iowa Gambling Task

    The Iowa gambling task explores the role of the unconscious in decision making, revealing that there are times when our unconscious registers the correct choice before we consciously do.

    The brain is primed for social interaction

    The human brain is so primed for interaction with other people that we see social meaning even when there isn't any. People shown animated shapes on a video screen interpret what's going on in terms of human relationships. One of the important ways we navigate the social world is by working out the intentions of others. To find out if this is something we are born with or something we learn, David Eagleman invites a group of babies to a puppet show. Will they be able to tell the kind puppet from the unkind one?

    Decoding others

    Placing electrodes on our facial muscles allows activity in those muscles to be mapped. This technique, called EMG (electromyography), reveals that people mirror each others facial expressions. Why? To answer this question EMG was used on Botox users who mirrored others faces less, and on non-Botox users. Both groups were then given a test called 'reading the mind in the eyes test' or RMET, which requires subjects to describe the expressions on people's faces where only the eyes are visible. The Botox users consistently scored less on the test. We mirror others so that the brain can get a sense of what others are feeling.

    Expanding the senses

    The human brain's flexibility or plasticity means that in the future we may be able to plug new sensory inputs into the cortex, which the brain will learn to interpret. In David Eagleman's lab he is experimenting with a new vibratory sense, which allows words to be encoded as vibrations on the skin. In the future we may be able to plug new data streams into our brain, like real time weather data or stock market data. We are not limited to the senses we have evolved with.

    Enhancing and extending our bodies

    In the future we will be able to enhance and extend our bodies using brain-computer interfaces (BCI) such as the one that allows Jan Scheuermann to control a bionic arm despite her paralysis from the neck down.

    Artificial intelligence & the mystery of consciousness

    iCub is a robot the size of a 2 year old, and is a modern day attempt to produce artificial intelligence that learns from experience in the same way children do. But iCub isn't having an internalised conscious experience of the world. The philosopher John Searle's Chinese Room analogy explores the difficulty of producing truly intelligent AI, and exposes the mystery at the heart of neuroscience: how do physical pieces and parts, like neurons, produce consciousness?

    What ants can tell us about human consciousness

    An enduring mystery at the heart of neuroscience is how the interaction of simple parts — brain cells — can give rise to something as complex as human consciousness. One theory is that neurons behave in a similar way as ants living in a complex society. Although each ant follows simple local signals, the colony as a whole amounts to something more complex, which each ant has no awareness of. It may be the same with the brain. Simple local signals between cells may produce something much bigger, something as complex as consciousness.