PET Imaging: The Real Positronic Brain?

In Isaac Asimov’s 1950 short story collection I, Robot, intelligent robots with positronic brains exist alongside humans. Unlike conventional computer hardware, the word positronic implies that electrical current is carried in the wires of these robots’ brains by  positrons, the antimatter counterpart of the familiar electron. Though the advantage of antimatter here is anyone’s guess, the stories of I, Robot may have introduced the positron to the public.  And as bizarre as Asimov’s fantasy sounds, neuroimaging has given the term “positronic brain” yet another meaning.

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The Ultimate Thought Experiment Part III: Flowers for Algernon

In Part II of this series, we considered artificial intelligent in the context of Arthur C. Clarke’s novel and Stanley Kubrik’s film 2001: A Space Odyssey. In Space Odyssey, intelligence is arguably seen as an end in-and-of itself, rather than a means to an end. Flowers for Algernon, a short story later turned into a novel by author Daniel Keyes, questions that assumption while considering the ethical implications of artificially manipulating a person’s intelligence.

The protagonist of Flowers for Algernon is Charlie Gordon, a janitor who begins the story with intellectual disability, or mental retardation as it was referred to at the time when Keyes wrote the story. Gordon’s intellectual disability is a result of phenylketonuria, a real life metabolic disorder resulting from mutations of the gene encoding phenylalanine hydroxylase, an enzyme that breaks down the amino acid phenylalanine. An inability to metabolize this amino acid causes its toxic build up in the brain, often resulting in a low IQ and other problems, such as mental disorders.

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The Ultimate Thought Experiment Part II: 2001: A Space Odyssey

In our previous post, we considered the Philip K. Dick novel Do Androids Dream of Electric Sheep? in the context of a thought experiment: a thinking tool used by scientists and philosophers to reframe an unintuitive problem in a new, more familiar context.

Another great thought experiment of the 1960s is 2001: A Space Odyssey. Developed in parallel as both a novel by Arthur C. Clarke and a film by Stanley Kubrick, Space Odyssey is a story about the evolution of humanity and intelligence. Beginning with the invention of tool use in Africa, the story asks how intelligence might continue to evolve after humans develop sophisticated technology. Both the novel and the film follow astronaut Dave Bowman on his journey to the Outer Solar System guided by HAL 9000, an artificial intelligence (AI) that controls the spaceship and is responsible for the well being of the crew.

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The Ultimate Thought Experiment Part I: Do Androids Dream of Electric Sheep?

Let’s imagine something crazy.

What if each person in China was ordered to simulate a neuron in a brain, making an enormous “China brain?” Every participant in this grand experiment would be given a two-way radio to communicate with other people, similar to how neurons talk to each other. Some people play the role of “effector neurons,” which control parts of a giant robot, just as motor neurons in our nervous system control bodily movements.

Basically, imagine that the entire nation of China became a giant robot’s brain. What might happen?

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What the Heck is a Claustrum?

Given its subjective nature, consciousness is already a controversial topic in the world of brain science. While some neuroscientists doubt that consciousness can even be studied, others still endeavor towards identifying parts of the brain that support subjective awareness. At a gathering of neuroscientists February 15 in Bethesda, Maryland, an announcement has thrust the quest to understand consciousness into the spotlight once again. A team of neuroscientists lead by Christof Koch has identified neurons in a relatively obscure brain region known as the claustrum that send fibers far throughout the entire cerebral cortex, well beyond where they are expected to project. One neuron shown in the presentation engulfed the brain like a “crown of thorns” with its colossal fibers. According to Nature News, “Koch sees this as evidence that the claustrum could be coordinating inputs and outputs across the brain to create consciousness.”

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What Happens If You Stick Your Head in a Particle Accelerator?

What would happen if you stuck your body inside a particle accelerator? The scenario seems like the start of a bad Marvel comic, but it happens to shed light on our intuitions about radiation, the vulnerability of the human body, and the very nature of matter. Particle accelerators allow physicists to study subatomic particles by speeding them up in powerful magnetic fields and then tracing the interactions that result from collisions. By delving into the mysteries of the Universe, colliders have entered the Zeitgeist and tapped the wonders and fears of our age.Continue reading

What is Obsessive Compulsive Disorder?

Our thoughts are often mysterious to us. You probably don’t know why you suddenly think about a Komodo dragon while sitting in traffic or Citizen Kane while shopping for groceries. Such moments remind us that we are each the emergent property of an amazingly complex organ that never stops surprising us. Nonetheless, we usually feel in control of our thoughts. Even with the occasional unexpected thought, life continues as normal.Continue reading

Stimulating Neural Circuits with Magnetism

Brain stimulation might sound like some Frankensteinian demonstration from a Victorian science fair. But in reality, it is a contemporary technique making a huge impact in neuroscience by addressing a longstanding limitation of traditional methods for investigating human brain function. Such techniques, like EEG and fMRI, can only be used to infer the effects of a stimulus or task on brain activity, and not vice versa. For example, a scientist might use EEG to study the effect of a task like arm movement on brain activity, but how can one study the effect of brain activity on arm movement?Continue reading

This is Your Brain on Starbucks

My father often jokes that hundreds of years from now, future anthropologists will speak of the cult of the Seattle goddess, her shrine adorning every airport, shopping mall, and train station in America.  The worshippers partake in a holy communion of coffee, tea, and espresso.  In fact, anthropologists today tell us that in some indigenous American cultures, drinking psychoactive peyote tea is an important part of religious ceremony.  And yet, the very phrase psychoactive tea is somewhat redundant.  All tea and coffee, unless decaffeinated, is psychoactive, albeit usually not to the same extent as peyote, a cactus native to the American Southwest that contains a hallucinogenic alkaloid called mescaline.Continue reading