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
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!
Biological systems, such as the circulatory, respiratory, and nervous systems, are groups of organs that function together to perform a common task. Some can also participate in crosstalk with other organ systems. The respiratory system, for example, brings in the oxygen that the circulatory system delivers to all the cells of the body, and maintains blood pH. The endocrine and nervous systems are signaling systems that facilitate communication between different parts of the body by use of hormones and neurotransmitters, respectively. These connections are numerous and complex, but it was previously thought that the immune system and the nervous systems were separate and largely autonomous.
In June 2010, Mauricio Vargas and colleagues from Stanford University School of Medicine reported research in Proceedings of the National Academy of Sciences showing that endogenous antibodies play an important role in repairing peripheral nervous system (PNS) damage. Antibodies are a principal part of the adaptive immune response to infection, but this research suggested that antibodies are also able to clear degenerating myelin which inhibits axon regeneration, akin to a homeostasis function. This repair was only present after PNS injury, whereas myelin debris remained in the central nervous system (CNS) white matter for years. The well known blood-brain barrier concurs with this separation in responses, as it is understood to be impermeable to large proteins such as antibodies.
Sammy Maloney was a happy and outgoing 12-year-old boy. In 2002, however, his mother started to notice curious deviations in his personality. In six months, he underwent complete mental deterioration and was diagnosed with obsessive compulsive disorder and Tourette’s syndrome. Shortly afterwards, he was found to be harboring a streptococcal infection, although he exhibited no physical symptoms of one. Interestingly, when he started taking the prescribed antibiotics, his behavior markedly improved.
Madeline Cunningham at the University of Oklahoma has spent several years investigating various behavioral disorders associated with streptococcal infections. Cunningham has shown that antibodies against one group of streptococcal bacteria are able to bind to a site in the brain that controls movement, and consequently trigger the release of dopamine. This could explain the emotional disturbances associated with these types of disorders (1).
Studies also suggest that an activated immune system has other perceivable effects on the nervous system. For example, Jonathan Kipnis of the University of Virginia and his colleagues have shown that learning triggers a stress response in the brain, which causes CD4 cells, a type of T lymphocytes, to gather at the meninges and release interleukin-4. IL-4 switches off the stress response and causes a release of brain-derived neurotrophic factor, which facilitates memory formation. Interestingly, cancer patients treated with chemotherapy drugs often experience various cognitive defects and some memory loss. This is commonly called “chemobrain”, and these studies raise the possibility that it is a consequence of immunosuppression. Finally, an immune response against Mycobacterium vaccae has been shown to improve mood by causing neurons in the prefrontal cortex to release excess seratonin.
So it could be that the blood-brain barrier is kind of leaky after all. Understanding the connections between the immune system and the brain could lead to all sorts of ingenious treatments for various disorders. Perhaps those scientists at Stanford will utilize antibodies to develop a treatment for central nervous system repair. Perhaps we’ll one day be faced with immuno-emotive treatments for depression. Who knows? Anything is possible when a long-standing “truth” turns out not to be absolute – I’m optimistic since scientific advancement is often built on the refinement of prior knowledge.
Happiness is Catching – New Scientist
Endogenous Antibodies Promote Rapid Myelin Clearance and Effective Axon Regeneration after Nerve Injury – Proceedings of the National Academy of Sciences
(1) Antibodies raised against the Streptococcal M protein and human myocardial tissue, and Guillain-Barre syndrome in response to Campylobacter infection, are well studied examples of cross-reactivity between anti-pathogen antibodies with host tissues.
Scientists from the U.S. Department of Energy’s Lawrence Berkeley National Laboratory and the University of California Berkeley have delineated an alternative pathway for antidepressant function. Fluoxetine, the active compound in the widely-prescribed antidepressant drug Prozac, primarily acts as a selective serotonin reuptake inhibitor (SSRI). Many pharmaceutical agents, however, are known to exhibit multiple functions, and fluoxetine is now thought to act by a second mechanism. TREK1, a potassium channel expressed in reward-related basal ganglia, has been associated with symptoms of depression and implicated in mood regulation. Notably, it is inhibited by fluoxetine. Earlier studies have shown that TREK1 “knock out” mice display a depression-resistant phenotype, their behavior being similar to mice treated with fluoxetine. This newfound beneficial role of fluoxetine may open up a new vessel for antidepressant treatments.
Ehud Isacoff, a neurobiophysicist in UC Berkeley’s Department of Molecular and Cell Biology, and Guillaume Sandoz, a TREK1 specialist, looked at the molecular mechanisms underlying the TREK1 channel’s function. When its C-terminal domain is bound to the plasma membrane, the TREK1 channel remains open, but when the tail is unbound, the channel closes. Isacoff and his research team separated the C-terminal domain from the rest of the protein, and tagged it with green fluorescent protein. They then used voltage clamps to measure electrical currents, and fluorescence to observe the status of the channel, finding that the addition of fluoxetine causes the isolated C-terminal domain to dissociate from the membrane. This prevents current from flowing through the channel, and effectively inhibits TREK1 function. Although the effects of the C-terminal domain’s position still need to be observed with a completely intact protein, Isacoff and his team foresee promising results.
The cerebral cortex, a layer of neural tissue surrounding the cerebrum of the mammalian brain, has been known to play various roles in memory, language, thought, attention, and consciousness. Up until now, no invertebrate equivalent
to the cerebral cortex has been encountered, but Detlev Arendt, Raju Tomer, and colleagues may have found an evolutionary counterpart. The obvious answer is hidden in one simple creature– the worm. Wait, what? Yeah, you heard me. The marine ragworm, found at all water depths, has been shown to possess a tissue resembling that of our mysterious cerebral cortex.
Arendt and his colleagues used a technique called cellular profiling to determine a molecular footprint for each kind of cell in this particular type of ragworm. By utilizing this technique, they were able to uncover which genes were turned on and off in each cell, providing a means for cellular categorization. Surprisingly, mushroom bodies, regions of the ragworm’s brain that are thought to control olfactory senses, show a striking similarity to tissue found in our cerebral cortex. This intriguing discovery may provide remarkable insight into the evolutionary basis of what has developed into an incredibly important cerebral structure.
Read more about this review here, or see the original article in Cell.
To see how Suzana Herculano-Houzel thwarted the conventional correlation of brain size to intelligence, read more here.
As my good friend Cobb once told me, “Dreams feel real while we’re in them. It’s only when we wake up that we realize something was actually strange.”
OK, fine, Leonardo DiCaprio’s character from Inception isn’t real, but he does make a valid point. Oneirologists, those who study dreams, have traditionally viewed dreams as uncontrollable streams of sounds and images with the ability to induce a tremendous spectrum of emotion. However, the idea of lucid dreaming has caused the conventional understanding of dreams to collapse. A “lucid dream,” terminology coined by the Dutch psychiatrist Frederik van Eeden, is one in which the sleeper is aware that he or she is dreaming. This example of dissociation is wonderfully paradoxical in that it exhibits components of both waking and dreaming consciousness.
An American psychiatrist and dream researcher named Allan Hobson specializes in the quantification of mental events and their corresponding brain activities. Although he vehemently dismisses the idea of hidden meanings in dreams, he has embarked on a search along with other neurobiologists and cognitive scientists to decipher the neurological basis of consciousness. Hobson hypothesizes that subjects may learn to become lucid, self-awaken, and regulate plot control by intercalating voluntary decisions into the involuntary nature of the dream.
The validation of this idea would imply that the mind is capable of experiencing a waking and a dreaming state at the same time. Consequently, Hobson states, “…it may be possible to measure the physiological correlates of three conscious states, waking, non-lucid dreaming, and lucid dreaming in the laboratory.” If there is a psychological distinction between the three, there should also be a physiological difference.
The advent of lucid dreaming experimentation has not only benefitted Hollywood, but it has also provided possible treatment options for those hindered by frequent nightmares or post-traumatic stress disorder (PTSD). Methodologically speaking, the study of lucid dreaming presents a formidable challenge, but it is becoming an important component of the cognitive neurosciences.
Josefin Gavie and Antti Revonsuo have built on Hobson’s theories by proposing a technique termed lucid dreaming treatment (LDT). The key to this treatment is that the subject learns how to identify cues that facilitate lucidity during a dream, and the subject learns to manipulate the environment once lucidity is attained. The phenomenon of lucidity may prove to be a useful device in that it offers the sleeper a method to control components of the dream – altering and diminishing any threatening situation. Although the investigation of LDT is extremely new and incontestably controversial, it has shown promising preliminary results in its ability to lower the frequency of nightmares in the selected subjects.
The premise of the film Inception may be wildly hypothetical, but it has expertly amplified the current research on lucid dreams. However, researchers in the field should take a word of advice from the character of Eames: “You mustn’t be afraid to dream a little bigger, darling.”
The Neurobiology of Consciousness: Lucid Dreaming Wakes Up – J. Allan Hobson
The Future of Lucid Dreaming Treatment (PDF) – Josefin Gavie and Antti Revonsuo
Regardless of the outcome of the NBA finals this year, one team had to go home empty handed. It’s difficult to fathom how athletes immediately get back on their feet and start training for the next round of emotionally tortuous ups and downs. Even though they’re getting paid an absurd amount of money to play the game that they love, there must be some emotional consequences, right? On the surface, viewers can clearly see the bond a sports team has as evidenced by their chest bumps, high-fives, “OH YEAH”s, and less-than-tender slaps on the butt, but there must be another aspect of these superficial rituals that isn’t seen.
So, here comes sports psychology, which aims to improve performance by mediating the psychological effects of injury and loss. Naturally, sports psychology began as a way to increase positive attitudes in individual athletes, as well as entire teams. Later, this branch of psychology went from questioning how to instill positive attitudes in athletes, to wondering what relationship psychological well-being had to strenuous physical activity.
In 1975, the neurological world discovered compounds now known as endorphins – endogenous opioid polypeptides released during exercise, excitement, and orgasm, and known to produce analgesia. But what happens when outside stressors, like losing and injury, interfere with the natural high created by exercise? This connection between brain psychology and kinesiology has recently been researched with the development of the field of psychophysiology, which attempts to solidify the link between psychology and physiology. With the advent of multiple neuroimagery techniques, such as MRI, fMRI, and PET, psychophysiologists have been able to move on from exploring organ systems innervated by the autonomic nervous system, to examining the central nervous system and monitoring brain activity. The illumination of the relationship between stress, physical activity, competition, recovery from an injury, and the underlying cognitive processes could have great implications for the future of professional sports.
More advanced technology has provided insight into the relationship between body and mind. A biofeedback loop can be utilized to facilitate awareness between physiological functions and their activities. Using a variety of precise instruments and an integrating computer system, the user can measure brain waves, skin conductance, muscle tone, and heart rate, just to name a few. Once this information reaches the user, he or she can consciously manipulate the activities of these processes. These changes can be used to heighten performance and boost health. Eventually, the user can learn to manipulate these activities without using these devices.
The fourth quarter of game seven was obviously not the best quarter the Celtics have ever played. What if the field of sports psychology, in combination with psychophysiology, found a way to allow each player to consistently perform to his or her best ability? Then, would the real competition begin? Or would this take the excitement out of the game?
Watch a video on biofeedback here: