Dana Foundation Blog

Brain Oddities: All You Need Is Love

Several months ago, my roommate and I were sitting in our kitchen talking about our various relationship issues. After a lengthy discussion, we finally concluded that feelings were just too complicated, and we’d rather be robots.

“But really,” my roommate pointed out, “without love, there would be no, like, books.”

At first this struck me as a pretty bold, sweeping statement, but then I thought, she’s kind of right. Most works of literature (and music, and film, and visual art) that came to my mind are about one form of love or another—love for a partner, or a child, or a place of origin. It’s a cross-cultural universal that can be a source of deep pain or immense joy, and it can dominate your mind.

Brain Oddities: Where Did I Put My Keys?

If I had a dollar for every absentminded thing I’ve done, I’d probably have a couple hundred dollars by now, which actually doesn’t seem like much when you consider how many times I’ve thrown my house keys in the trash and walked out with a banana peel.

Absentmindedness is one of seven “sins of memory,” a term coined by Dana Alliance member Daniel Schacter in his book The Seven Sins of Memory: How the Mind Forgets and Remembers. The other six sins of memory are: transience, or the deterioration of memory over time; blocking, when you try to retrieve or store information but another memory interferes (like tip-of-the-tongue); misattribution, or the recollection of information but the inaccurate recollection of where the information came from; suggestibility, when memories are influenced by how they’re recalled; bias, when feelings and worldview distort memories; and persistence, or the unwanted recall of disturbing information (think middle school).

Brain Oddities: Collector’s Item

In recent months, I have become somewhat of a minimalist. I have come to the belief that less is more simply because, like many New York residents, I live in a shoebox. Due to severely limited space and a desire to see my floor, I’ve had to shed many things I collected in my pre-New York years.

Fortunately, I’ve had an easier time getting rid of belongings than some people might. An estimated 2-5 percent of the U.S. population suffers from compulsive hoarding (CH) [1], which is defined as “an accumulation of an excessive number of objects due to an inability to discard things of little value” [2]. In 2009, A&E began showing a television series called "Hoarders," which profiles people whose lives have been severely and detrimentally affected by CH. Over the course of more than 60 episodes, "Hoarders" has illustrated that what some people consider merely a personality quirk is actually much more serious.

The DSM-V Task Force, the most-superhero-sounding body of scientists responsible for overseeing the development of the fifth edition of the APA’s Diagnostic and Statistical Manual of Mental Disorders, is deciding whether to classify CH as a standalone disorder or as part of a broad definition of obsessive-compulsive disorder (OCD). Between 20 percent and 40 percent of people diagnosed with OCD report hoarding compulsions, meaning it could be a symptom of their disorder; however, hoarding is the major symptom of fewer than 5 percent of those cases. Furthermore, CH is often present alone or with other psychiatric disorders. The lack of CH’s clear placement in the DSM has caused some shortcomings in research on diagnoses and treatments; most studies on the disorder do not differentiate between people with OCD and hoarding tendencies and those whose only symptom is compulsive hoarding.

What is known about CH, however, is that it’s usually chronic and progressive, which means it has a higher prevalence in older people. Furthermore, although it seems to be genetically influenced, it can also be triggered by a stressful life event [3]. Whatever its origin, CH appears to be related to dysfunction in the frontal lobe. One study of patients with focal brain lesions found that 13 participants out of 86 displayed hoarding behavior; all 13 of those participants had lesions in the mesial frontal region of the brain [4]. Some studies have also found that hoarders perform more poorly than controls on tests of memory, attention, planning, and decision-making.

Regardless of how it's classified, finding treatments to ameliorate its symptoms is important. After hours of scientific research—watching "Hoarders" on Netflix streaming— I’ve learned that it’s an illness that needs understanding and visibility. I hope the Task Force will make the right decision to help the millions of Americans who suffer from compulsive hoarding.

In the meantime, enjoy this DSM-V Superhero Task Force logo I drew:

 

1. Pertusa, A., Frost, R.O., Fullana, M. A., Samuels, J., Steketee, G., Tolin, D., Saxena, S., Leckman, J.F., Mataix-Cols, D. 2010. Refining the boundaries of compulsive hoarding: A review. Clinical Psychology Review, 30, 371-386.
2. Blom, R.M., Samuels, J.F., Grados, M.A., Chen, Y., Bienvenu, O.J., Riddle, M.A., Liang, K., Brandt, J., Nestadt, G. 2011. Cognitive functioning in compulsive hoarding. J  Anxiety Dis.
3. Grisham, J.R., Norberg, M.M. 2010. Compulsive hoarding: current controversies and new directions. Dialogues Clin Neurosci, 12:233-240.
4. Anderson, S.W., Damasio, H., Damasio, A.R. 2005. A neural basis for collecting behaviouir in humans. Brain, 128:201-212.

-- Caitlin Schneider

Brain Oddities: Reading Rainbow

Yesterday, a coworker showed me an interesting internet phenomenon that I’d seen some years before but had completely forgotten. You may recognize it from when it began circulating via email in 2003 (you know, those chain emails that threatened horrible things if you didn't forward them):

Aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a toatl mses and you can sitll raed it wouthit porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe.

I, like most people who read this, found it incredibly interesting, and decided to investigate further. It turns out that, although this passage holds a few grains of truth, there are a few substantial errors.

The first issue with the passage is that, according to an actual language researcher at Cambridge University, while there are several groups at the school studying language, this particular topic was not being investigated at the time of the passage’s release. The second problem is its claim that the middle letters can be in any order without affecting reading comprehension—this is only partially true. Take, for example, the following sentences:

1. Big ccunoil tax ineesacrs tihs yaer hvae seezueqd the inmcoes of mnay pneosenirs

2. A dootcr has aimttded the magltheuansr of a tageene ceacnr pintaet who deid aetfr a hatospil durg blender

You probably found these two sentences much more difficult to read than the first example (if you got stuck, you can check the translations at the bottom of this post). There are several potential reasons why the “Cambridge University” passage is easier to read: firstly, the words in the passage still largely maintain the shape of the correct word; secondly, the distance between where the letters actually belong and where they have been displaced is usually small. For example, the “bridge" in “Cambridge” (“Cmabrigde”) remains largely unchanged, so it’s easy for us to infer the entire word based on our recognition of “bridge.”

Although we usually do not read letter-by-letter, as claimed in the passage, we also do not necessarily process each word as a whole. There are a variety of factors that allow us to read efficiently. As mentioned above, one theory holds that we attend to the shapes of words (that is, letter placement) as part of our visual processing. Additionally, one-, two-, and three-letter words are often skipped entirely, so our reading is not as linear as one might think:

(Credit: Kevin Larson)

The arrows represent saccades, or short eye movements, analyzed with an eye-tracking device. The eye skips over the small words and, in the case of the last sentence, sometimes doubles back. Another interesting thing to note is that when we read,

You probably deciphered the first half of that to say “we focus on the top of the letters,” but you probably couldn’t tell (apart from context) that the second half says “rather than the bottom.” This could either be an efficiency tactic or a by-product of the fact that the top halves of letters appear to be more distinctive than the bottom halves.

Unfortunately, I was unable to find any studies that shed light on the neural underpinnings of reading comprehension tactics. But discovering that reading is a much more complicated process than I thought made me feel marginally better about the shame I endured when stumbling through passages that I was forced to read aloud in grade school. I’m gald thsoe dyas are gnoe.

--Caitlin Schneider

Translation Answers:

1. Big council tax increases this year have squeezed the incomes of many pensioners.

2. A doctor has admitted the manslaughter of a teenage cancer patient who died after a hospital drug blunder.

Source: Larson, Kevin. 2004. The Science of Word Recognition.

Brain Oddities:The Weirdness of Sleep

During my freshman year of college, I took a supremely boring class called La Belle Epoque. In fact, it was so dull that I almost always nodded off during the lectures. Unfortunately, while drifting to sleep, I often experienced that unpleasant full-body convulsion that jerks you awake in the most embarrassing way possible. Good thing it was a 200-person lecture.

It turns out that this phenomenon has a name, and it is not, as I usually call it, “that awkward sleep twitch thing.” It’s actually known as hypnic myoclonia or a hypnic jerk, and is often preceded by a sensation of falling. (In my case, I usually dream of tripping—I guess the brain likes to pull from real life experience.) The majority of the population experiences this, although it is more commonly reported in those with irregular sleep schedules.

Like many brain-related conditions, the exact cause of hypnic myoclonia is unknown. In fact, the only thing we know for certain is that it’s super annoying. For now, the popular theory among sleep scientists is that as we drift off to sleep, our brain misinterprets our slackening muscles as falling and forces us to react.

Even more puzzling than hypnic myoclonia is periodic limb movement disorder (PLMD), previously known as nocturnal myoclonus. People with this condition suffer from excessive daytime sleepiness and have trouble falling asleep at night. When they do fall asleep, they display involuntary limb movements at bizarrely precise intervals, usually between 20 and 40 seconds. These intervals are so precise that you can extrapolate out five minutes and predict perfectly when they will twitch. Like hypnic myoclonia, the cause of PLMD is unknown, but it is related to stress, snoring, sleep apnea, and narcolepsy.

And finally, speaking of uncontrollable sleep movements, let’s discuss sleepwalking. I have only seen someone sleepwalk once in my life, and I will never forget it. What began as a high school, basketball-team-bonding, hair-brushing, boy-discussing sleepover eventually took a turn for the creepy. We were all awoken to one of our teammates walking around the dark house saying, “Mom, don’t leave me! I’m cold!” over and over in a strange voice. It was all very Exorcist.

The specific cause of sleepwalking is unknown, but we do know that it generally occurs during non-REM (NREM) sleep. Brain-wise, sleep is divided into REM sleep, during which we sometimes experience vivid dreams, and four stages of NREM sleep, distinguishable by their EEG rhythms. During REM sleep, the brain stem systems responsible for sleep processes actively inhibit spinal motor neurons, essentially leaving us paralyzed. The inhibition keeps us from acting out our dreams, thus protecting ourselves and others. During NREM, the inhibition stops and we are no longer paralyzed. However, with the exception of the occasional position shift, the brain does not usually send movement signals to the body during NREM.

I hope, for the sake of those who suffer from these sleep disorders (and of course, future generations of basketball-playing high school girls), sleep scientists can develop effective therapies and treatments. In the meantime, maybe we should just follow the example of bottlenose dolphins and put only one brain hemisphere to sleep at a time—it would certainly give a whole different meaning to being half-asleep.

--Caitlin Schneider

Sources:

American Academy of Sleep Medicine

Bear, M.F, Connors, B.W., Paradiso, M.A. (2006). Neuroscience: Exploring the Brain (3^rd edition). Lippincott Williams & Wilkins.