The Utility of the Connectome

As a new-comer to the world of neuropsychology I was surprised to see the number of fields which work directly with neuropsychology. There is a perfect illustration of this in the textbook being used in PS233 Biological Basis of Behavior this semester– The Mind’s Machine- Foundations of Brain and Behavior (Watson & Breedlove, 2012) which lists a range of areas of study from anthropology and evolutionary biology to computer science and psychiatry and demonstrates how they relate right back to biological psychology.

In discussing the introduction of Sebastian Seung’s book Connectome and his TEDTalk, the influence of ethics and philosophy was impossible to ignore. But it became clear to me that the connectome itself is also multifaceted. There seems to be a multitude of  directions in which the connectome and the future knowledge we gain about the connectome will become increasingly important. Seung mentioned memories as well as learning about various disorders as two large areas of interest concerning connectomes. It is clear that the properties of the connectome also play a role in many other areas of the human experience.

Over JanPlan I took in a class centered around Behavioral Medicine. The professor of this class–a clinical psychologist from the Waterville area, Dr. Ferguson–seamlessly demonstrated the connection between psychology and biology. While reading the introduction of Connectome and watching Seung discuss his concept I couldn’t help but think back to my JanPlan class. We spent some time discussing Cognitive Behavioral Therapy (CBT) and it seems to me that the connectome would play an integral part in the success of this and similar treatment approaches.

In discussing CBT, Dr. Ferguson spoke of the importance of strengthening the mental pathways of more adaptive thought patterns, rather than reinforcing the maladaptive thinking patterns that clients describe to him. These pathways are part of the connectome. As soon as more is known about the connectome we will better understand how to mold it. While reading the introduction of Connectome and considering  the importance of strengthening adaptive pathways for CBT I started to wonder about the strength of the connectome and if in mapping the connectome researchers will be able to also shed light on the relative strength of specific connections within the connectome. Also, if researchers are able to mold the connectome, CBT and other treatments will become more simple if not entirely obsolete.

The connectome’s potential application to treatment approaches is just one interesting implication that Seung’s vision brings to light. I am interested to see what other implications of mapping connectomes come with the addition of more knowledge to this area of research.

The Immune System can produce depression?!?

When I was in 6th grade, I was diagnosed with a form of juvenile arthritis, a chronic autoimmune disorder that causes inflammation and pain in any number of joints.  Causes may be hereditary and the onset often involves an accident.  My arthritis began in my left wrist, but it spread to my right wrist, ankles, knees, back, hips quickly.  Since it is a relatively uncommon disease, it took 9 months for a proper diagnosis, in which we had no idea what was wrong with me.  I missed a lot of school to go to doctor’s appointments and my teachers were not happy.  I began to develop symptoms of depression do to the isolation I felt on a daily basis.  My parents and doctors were not surprised by this since I had just learned that I would probably have chronic pain for the rest of my life; however, when I was doing research for my third paper, I came across an article that explained another reason for these sudden symptoms.  This article explains that cancer and rheumatoid (juvenile) arthritis can lead depression due to the effects of the immune system’s cytokines on the brain.

In 1990, scientists noticed that some patients suffering from clinical depression had higher concentration of inflammatory biomarkers in their blood, which led to the hypothesis that pro-inflammatory cytokines released from the immune system are responsible for many of the clinical aspects of depression like sleep disturbance, decreased energy, changes in eating patterns, and hyperactivity of the hypothalamus-pituitary-adrenal axis. When the body is infected with disease, the immune system releases pro-inflammatory cytokines that are able to cross the blood-brain barrier.  The cytokines affect the central amygdala, hypothalamus, medulla, which not only causes “sick behavior” but also increases the risk of major depressive disorder.  Additionally, stimulation of the immune system by injecting certain cytokines (IL-1ß and TNF-α) creates depression-like disorders in humans and animals, which can be relieved with anti-depressants that work on dopamine, norepinephrine, and serotonin.

Although this cannot be the only explanation for depression (since not all depressed patients also have autoimmune disorders), I found this incredibly interesting and personally relevant.

Ghandi Neurons

Last week, my Neurobiology class was assigned to watch this TED Talk by Vilayanur Ramachandran (link posted below).  He discusses many of the themes we have discussed this semester, such as evolution, the neurological process of learning, and what constitutes the self.  Ramachandran attributes the evolution of human culture to the emergence and development of mirror neurons, a type of interneuron that allows individuals to mimic one another.      The use of tools, fire, shelters, language, and theories of mind, all developed from interpersonal process emulation by mirror neurons.  Once these neurons evolved, skills could spread horizontally through a population at an unprecedented rate.

Ramachandran also discusses these mirror neurons as being the fundamental source of interpersonal experience on a neurological level.  These “Ghandi Neurons” allow us to neurologically empathize with others, a finding that integrates cultural and social experience to the biological world.

He explains it much better than I can… Its a great seven minutes!

The Neurons that Shaped Civilization

The Brain and Sexual Assault?

Due to all the recent talk/civil discourse on sexual assault, I thought it would be really interesting to look at the neural pathways underlying the perpetrators actions.  Most of the articles I found, were about various actions of date rape drugs on the brain and the amount of victims who later suffered PTSD-like symptoms.  Finally after days of searching, I stumbled across a few case study articles that found a correlation between frontal and temporal lobe damage in sexual offenders.

In this paper, they explore the neurobiological basis for sexual deviance through neuropsychiatry, structural neuroimaging, neuropsychological assessments, and by comparing neuroimages of controls and sex offenders. The frontal and temporal cortices are important for modulation of sex drive, initiation, and sexual activation, which subcortical regions (including the hippocampus, amygdala, hypothalamus, and septal cortex) play a significant role in the modulation of sexual behavior and the endocrine messengers to other parts of the body.  They found that damage to any of these areas often caused hypersexuality, paraphilia, fetishes, or other types of sexual deviance (note, sometimes brain damage may result in a lower sexual drive; however, this paper did not focus on these individuals).  While interesting, these statements seem slightly odd to me since there are so many brain areas involved.  Does disruption to any one of them really produce similar results in behavior?  We must also remember that brain injuries to these areas can result in other differences as well, such as being more impulsive and more violent.

They also found that more pedophiles had dysfunctions in higher cognitive abilities than sexual offenders who target adults.  However, the researchers claim that many of these brain abnormalities are clear in all types of criminals.

Another important fact to consider that was not brought up in this paper is the large number of sexual offenders that have experienced some form of sexual abuse in their life.  Obviously, having a neurobiological basis for committing a crime should not be a get-out-of-jail-free card.  Crimes are crimes, and victims of sexual assault are often left feeling helpless, guilty, and worthless for years and years after an attack.  I know that there are now defendants who claim to have suffered from dissociation or amnesia when committing acts of crime, and the neural pathways should not be used as a similar plea.  But understanding the neurobiology can give us the tools for change. The researchers tried not to make generalizations by breaking down groups into non-violent sexual offenders, violent non-sexual offenders, pedophiles, paraphilias, sadistic and nonsadistic sexual offenders.  This made the paper more complicated and also significantly decreased the sample size in each category.

My Phantom (broken) Limb

Last December I was plagued with pulsing pain searing through my left shin. The throbbing, sometimes piercing, feeling became a constant in my daily life. I absentmindedly would run my hand over the aching spot during class, and automatically hold my weight on my right leg when standing around; my mom even caught me standing (unknowingly) entirely on one leg, with my left leg bent up so my foot wasn’t touching the ground. The pain wasn’t much of a mystery, I’m a runner, and I knew the diagnosis was inevitable for my symptoms: a medial tibial stress fracture. 6 months of cross-training, 1 week on crutches, 4 weeks of immobilization and exercise-restriction got me back to having the top half of my shin play nice with the bottom half of my shin. What a glorious reunion, like long-lost lovers meeting again for the first time, I only hope they never separate again.

Throughout this process I was often told by others who had similar injuries, that the pain would “never completely go away”. That I would always sort of feel that throbbing, broken feeling, even when my bone was completely healed, even years after the area had returned to normal. The funny thing is, I just accepted these comments as truths. And after feeling some of these familiar twinges of pain, I finally started to think about how a weird a phenomenon this is. What a terrible psychneuro major I am. How come, until now I hadn’t given much thought into this absurd observation?! Here’s my chance for redemption, some scientific musings….

This lingering feeling of pain made me think of phantom limbs.  When a person has their limb amputated they often continue to feel pain in what is no longer a part of their body, and this perception of pain can persist indefinitely, it’s called phantom limb pain. There are some factors that determine how likely you are to have phantom limb pain, such as how intense and how long your actual pain was in the limb before amputation. However, these factors DO NOT play a role in whether or not your phantom limb pain persists for many years after amputation. That is more of a mystery.

So if we can experience pain in a limb that no longer exists, can we experience pain from an injury that no longer exists? I couldn’t find much (read: any) scientific papers on this. I read on a lot of message forums about stress fractures that residual pain can be from remodelling of the bone, but that lasts for 6-12months. So, what about after a year? The people who I have talked to had their stress fractures years ago, is it all in their head? Has the paranoia of re-injury caused us to create pain in a place that’s not in pain? How are we tricking our brain into thinking that there is pain in that spot? I don’t know that I have an answer for these questions, but I’m glad I started using my psychological noggin to think about this; sometimes I forget how nice it is to cross my psychological self with my runner self.

<—Phantom Limb by The Shins (haha get it?)

Reference:

Troels S., Børge Krebs, Jørn Nielsen, Peter Rasmussen. (1985). Immediate and long-term phantom limb pain in amputees: Incidence, clinical characteristics and relationship to pre-amputation limb pain. Pain 21(3): 267-278.

What happens when a psychologist is abducted by aliens?

The estimated number of Americans reported to have been abducted by aliens reaches into the millions (four, to be precise). This means that the support for alien existence is 4 million voices strong, sounds like a pretty big sample size to me. So why don’t we (scientists) believe any of them? Well, people with a scientific background generally look for more concrete evidence before drawing conclusions. A psychologist could offer several alternative possibilities to these outlandish claims.

1. Mental illness

People who report abductions are more likely to be open to unusual experiences, be more imaginative and creative, have more depressive thinking, be suspicious, and have suffered childhood trauma. These tendencies alone might not suffice to explain such strange experiences.

2. The fallibility of human memory

Like everything else about us, our memories are imperfect. Sometimes we incorrectly remember the facts of a situation. Other times, we end up mixing some of the aspects of a recent event with bits and pieces of information from our long-term memories. Those folks who claim to have been abducted by aliens seem to have less perfect memories than others, meaning that they are more likely to have false memory in general (Clancy et al., 2002).

3. Temporal lobe disturbance

This area of the brain may be responsible for creepy, other-worldly experiences. Placing magnets near the temporal lobes outside the head can induce feelings of fear, disorientation, and even a ‘presence’. Pretty freaky stuff.

4. Sleep Paralysis

This phenomenon was the most interesting to me. When you are sleeping and entering the REM cycle (the time when you dream), your brain kicks into body-movement blocking mode. You don’t want to act out your dreams, so you are essentially immobilized. Sometimes people sleepwalk when the system fails at keeping your muscles inactive when you’re unconscious. The opposite can also happen; your brain fails to stop blocking body movement s when consciousness is regained. Thus, you are awake, but unable to move and feel helpless. This weird state is often accompanied by hallucinogenic happenings, such as a greenish creature with an abnormally large head hovering over you.

But let’s get back to the question I posed in the title. What happens when a psychologist experiences a so-called ‘alien abduction’? Well, as anyone who has taken an intro psychology course knows, we tend to start self-diagnosing when we are aware of the specific descriptions of pathologies. So, they are probably going to self diagnose themselves as having tendencies towards imaginative behavior, creating false memories, having messed up temporal lobes, and/or being afflicted with sleep paralysis. Though, I’d love to see the statistic telling us how many of the 4 million reported abductions include anyone with a degree in psychology…

References:

http://www.kuro5hin.org/story/2002/9/1/14038/46155

Clancy, S.A., McNally, R.J., Schacter, D.L., Lenzenweger, M.F. & Pitman, R.K. (2002) Memory distortion in people reporting abduction by aliens. Journal of Abnormal Psychology, 111 (3), 455-461

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