With Halloween fast approaching, people are going to get scared. Zombies, ghosts, and werewolves will soon be stalking the streets of Boston, frightening innocent college students. Yet, when we are jumping back in fright from costumed pranksters, what is really happening inside of our brains? For years, it was considered fact that the amygdala, a part of the limbic system in our brain that processes components of emotion, was solely responsible for this reaction. Yet, this simplistic explanation doesn’t truly explain was happens inside our brains every time we feel fear. To investigate what really happens, we need to first talk about anxiety.
One thing I have always struggled with in reading philosophy is the doctrine of Innatism, which holds that the human mind is born with ideas or knowledge. This belief, put forth most notably by Plato as his Theory of Forms and later by Descartes in his Meditations, is currently gaining neuroscientific evidence that could validate the belief that we are born with innate knowledge of our world.
Have you ever seen a goat (or any animal, for that matter) do this?
Neither had I. But these are the sorts of things that come up at family parties and pique my curiosity. Perhaps the nickname and title of the YouTube video “fainting goats” is a misnomer (as National Geographic pointed out) as the goats are not actually losing consciousness when they go rigid and topple over. So why the wipe-outs? More
The year is 1966. After months of extensive preparation and creative troubleshooting, three scientists studying the brain’s unique split personality eagerly awaited the results of their carefully designed experiment. By placing an electrode into a cat’s corpus callosum, they were hoping to decode the brain’s elusive internal code. What they ended up finding was something much more profound, and much more revealing… More
Zombies are terrifying creatures. The most panic-inducing aspect of their completely factual existence among us is that they have a taste for human blood and they will do anything to get to it. Recently, the Zombie Research Society (ZRS) has been attempting to scan (with some difficulty due to the fact that zombies aren’t huge fans of staying still in MRIs) and create a map of the zombie brain. A leading researcher in ZRS, Dr. Bradley Voytek, lectured about these terrors at Nerd Night SF. In his presentation he gives a medical term to describe the zombie condition: “consciousness deficit hypoactivity disorder (CDHD)- the loss of rational voluntary and conscious behavior replaced by delusional/impulsive aggression, stimulus-driven attention, and the inability to coordinate motor or linguistic behaviors.” So with those messy scans and some preliminary facts we know about the living dead, researchers such as Dr. Voytek have been able to come up with multiple images of what a real zombie brain must look like. More
Lobsters, Axons, Telephones, and Extracellular Recordings – A look at how neuronal signals can be transmitted differently under certain pharmacological conditions.
Neuronal signals are normally transmitted from cell bodies, or somas, to terminals via extensions called axons. At these terminals, connections called synapses are made with other neurons whereby the signals are released via the aide of chemical messengers called neurotransmitters. Many still believe that axons are reliable conductors of these signals.
However, with several years’ worth of experiments, scientists have questioned the fidelity of axonal conduction. They’ve realized that axons do not work like telephones. While telephones and axons may both have buttons – at the terminals in axons – only telephones faithfully conduct signals. And only telephones ring aloud and send messages to voicemail…
In any case, neuronal signals, unlike telephone signals, can change along their paths. Moreover, the pre-synaptic neuron may communicate a different message from the one originally sent from the soma to the synapse with the post-synaptic cell. Researchers at the lab I’ve been working at this summer, the Whitney Laboratory for Marine Bioscience, have focused on the role of neuromodulation in signal transmission along axons, particularly by the well-known neurotransmitter – dopamine. More
You’re lying on a sandy beach on a hot sunny afternoon, enjoying a few hours of much needed laziness. As you open your eyes and confront the vastness of the ocean in front of you, light of 600nm wavelength hits your retina, kindling an impossibly long cascade of events in your brain: a molecule called retinal changes shape, neurons fire action potentials down the optic nerve, arrive at the lateral geniculate nucleus deep in the brain causing more action potentials in primary visual cortex in the back of your head, and so on ad infinitum. At some point, the mechanical wonder of 100 billion neurons working together produces something special: your experience of the color blue. What’s special is not that you can discriminate that color from others; nor that you are aware of it and paying attention to it. It is not notable that you can tell us about it, or assign a name to it. It’s that you have a subjective, qualitative experience of the color; there is something it is like to experience the color blue. Some philosophers call these experiences qualia – meaning “what kind” – but it is not important what kind of experience you are having, just that you are having one at all. Modern science hypothesizes that subjective experience is a product of the brain, but has no explanation for it. More
Using the human nervous system as a representational medium, are there parts of the universe that are innately unknowable to us- are there realities that we can experience but not objectively measure? Is spirituality real, or a man-made delusion to justify ambiguous emotions and guide behavior? Is consciousness an emergent property or does it extend beyond?
These are timeless ontological questions that have been posed by both philosophers and the common man for centuries. But only recently has the new field of neurotheology, the study of correlations between neural phenomena and subjective experiences of spirituality, emerged on the scene to advance our understanding of what the brain undergoes during religious practices. Whereas before we could only rely on logic and speculation in an attempt to tackle some of these controversial issues, today neuroscientists are beginning to uncover substantial information regarding the relationship between brain activity and “the feeling of God”.
Scientists have long been intrigued by claims of mystical encounters. Though these assertions may seem to be all too uncommon and even downright outlandish in an increasingly “secular” nation, still a survey by the Pew Form on Religion and Public Life demonstrated that nearly half of American adults today have had what they consider a “religious” or “mystical experience” of some kind. In order to investigate the biological basis of these obscure episodes, scientists first explored the effects of psychedelic drugs, which have a long history of traditional use in religion. Since users of psychedelics often report of the drug’s ability to elicit a sense of the spiritual, as well as promote mental healing, researchers sought empirical support for the notion that psychedelic drugs could facilitate “religious experiences”. More
Free will is a hackneyed topic. Science seems to be telling us that free will doesn’t exist because behavior is governed by the brain and the brain operates on physical rules of cause and effect. There is no such thing as uncaused cause, which free will requires. For some people this is an unbearable notion; these folks hang on to their perceived volition as evidence that they are in fact free to do as they choose, without being constrained by their biology. Others swallow what science has espoused long ago; of these folks, some tend to be pessimistic, thinking that their lack of free will means that everything is pointless and that the best thing they can do for themselves is to blur the line between their behind and a comfortable couch, until scientists discover the new species Homo sofus. More
Ranging from the Eastern Mediterranean in the 7th century, to China in the 16th century, and finally to Europe in the 17th century, dream interpretation has been viewed as a decryption of supernatural communications and symbolic messages. Sigmund Freud, the academically (in)famous founder of the field of psychoanalysis, whole-heartedly supported the hypothesis that dreams contain deeper meaning. He consequently produced one of the seminal works on the subject, quite obviously named, The Interpretation of Dreams. Today, revelatory and efficient techniques, such as MRI and EEG, have far surpassed Freud’s interpretive dream journal methods, and allow scientists to look at dreams from a very different perspective. Although these advancements lend more credibility to the field of oneirology, it is still somewhat tainted by its psychoanalytic past. Some even go as far to say that studying dreams is “academic suicide”. Nevertheless, modern neuroscience has forced Freud’s ideas to the background, making room for new theories of memory consolidation, experience organization, and emotional stabilization.
Since dreaming occurs while sleeping, it is no surprise that the sleep cycle, during which the brain experiences patterns of varying electrical activity, has been implicated in dream theories. Each cycle consists of five stages – two stages of light sleep, followed by two stages of deep sleep, and completed with a stage of rapid eye movement sleep (REM). Unfortunately, there is no representative electrical pattern associated with dreaming, but REM and non-REM sleep have both been connected to the brain’s analysis of waking experiences. Pierre Maquet at the University of Liege, Belgium, observed deep non-REM sleep and found that the brain’s electrical activity mimicked the electrical activity elicited during waking experiences.
Not only do we replay events in our dreams, but we also seem to process, integrate, and store the information for future use. Robert Stickgold of Harvard University found that those who had non-REM dreams about a task that they were asked to complete, proceeded to do better on it. Stickgold proposes that “non-REM dreaming might be more important for stabilizing and strengthening memories, while REM dreaming reorganizes the way a memory is stored in the brain, allowing you to compare and integrate a new experience with older ones”. On a different, albeit related note, daydreaming activates a part of the brain called the default network. This region has previously been shown to be associated with memory processing. Be sure to mention this to your professor next time you’re caught not paying attention in class.
Matt Walker of the University of California acknowledges that dreaming has an important role in memory, but argues that the main function is emotional homeostasis. Walker has found that REM sleep facilitates the strengthening of negative memories. He believes that experiencing the negative emotion in a dream state can diminish the intensity of the emotion, making it easier to deal with. In those with post-traumatic stress disorder, however, this process seems to fail. Boston University’s Patrick McNamara agrees with Walkers’ speculation. He believes that “non-REM dreams help us practice friendly encounters, while REM dreams help us to rehearse threats”.
While dreaming, the brain rewires itself and forms new connections. It seems that this curious kind of consciousness does not reveal our secret desires or open windows into our hidden selves, but instead plays an integral role in making us who we are. Sorry, Siggy.
To view the original article from New Scientist, click here!