Sleep deprivation associated with changes in brain micro-structure

9 Oct

A paper from PLOS , “Widespread Changes in White Matter Microstructure after a Day of Waking and Sleep Deprivation.”

From the PLOS Blog:

“Neuroscientists from Norway set out to answer this question in their recent PLOS ONE study, examining how a night forgoing sleep affects brain microstructure. Among their findings, sleep deprivation induced widespread structural alterations throughout the brain.”

“My hypothesis,” says first author Dr. Torbjørn Elvsåshagen, “would be that the putative effects of one night of sleep deprivation on white matter microstructure are short term and reverse after one to a few nights of normal sleep. However, it could be hypothesized that chronic sleep insufficiency might lead to longer-lasting alterations in brain structure. Consistent with this idea, evidence for an association between impaired sleep and localized cortical thinning was found in obstructive sleep apnea syndrome, idiopathic rapid eye movement sleep behavior disorder, mild cognitive impairment and community-dwelling adults. Whether chronic sleep insufficiency can lead to longer-lasting alterations in white matter structure remains to be clarified.”

Alzheimer’s and Atherosclerosis

7 Oct

Another excellent piece by Dr. Greger:


Again facilitated communication

5 Oct

Facilitated communication, a technique that is supposed to allow communication with nonverbal people with autism, is in the news again. The best overview of this topic remains the PBS documentary Prisoners of Silence.  The empirical case against facilitated communication is overwhelming, yet belief persists.

I embrace the Misfit fitness tracker

2 Oct

For years, I have worn an Omron pedometer as part of a 10,000+ step a day program. The Omron pedometer is the most accurate pedometer that I have found. Part of my reluctance to move onto a fitness tracker, such as the Fitbit, is that I found they over counted steps.

On the other hand, I have been tempted by the idea of a fitness tracker that syncs to my phone, tracks activity other than walking (including sleep), and provides a good on line interface. Omron efforts to integrate its pedometers with the newer technology has been unimpressive.

Now, I have found a fitness tracker that seems to meet my needs: The Misfit Flash. It has a number of excellent features:

It is inexpensive compared to other fitness trackers ($23.99 on Amazon).

It uses a replaceable battery (but, I am not sure if this is good for the environment), and does not have to charged frequently.

It does not over count steps as much as other fitness trackers I have tested (but is not as accurate as Omron pedometers).

It tracks both steps and other activities and assigns fitness points (I calculate that a fitness point equates to about 10 steps)

It has a nice interface available on my smart phone and computer.

It tracks sleep (although, I don’t know how I could check the accuracy of this).

One note of caution, the manufacture claims that it does not matter where you wear it. It does, if you wear in on your wrist, it will over estimate your activity. I have found it most accurate  if you wear it clipped to your waist or on your shoe.


Happy people live longer

30 Sep

From the always great Pacific Standard:

“New research finds happier people live longer, on average, while angry ones are more likely to die early.”


Replicability Ranking of 27 Psychology Journals (2015)

28 Sep Featured Image -- 4291


Given all the attention the Association for Psychological Science has given the issue of replication, it was surprising to see their flagship journal Psychological Science received a grade of D.

Originally posted on Replication-Index:

The replicability rankings below are based on post-hoc power analysis of published results. The method is explained in more detail elsewhere.  More detailed results and time trends can be found by clicking on the hyperlink of a journal.  The ranking for the average replicability score in 2010-2014 and 2015 is r = .66, indicating that there are reliable differences in replicability between journals.  Movements by more than 10 percentage points are marked with an arrow.

Rank Journal Area 2010-2014 2015 Grade
1 Developmental Psychology DEV 0.63 0.76 B↑
2 Cognitive Psychology COG 0.72 0.74 B
3 JEP: Human Percpetion and Performance COG 0.72 0.71 B
4 Judgment and Decision Making COG 0.66 0.70 B
5 J. Experimental Psych: Learning, Memory, Cognition COG 0.69 0.70 B-
6 JPSP: Personality Process & Individual Differences PER 0.56 0.70 B↑
7 Journal of Memory & Language COG 0.67 0.69 C
8 Social Psychology…

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Meditation and false memories

28 Sep

I am convinced that meditation has benefits, but could meditation also have negative consequences? A study just published in Psychological Science suggests that mindfulness meditation might increase susceptibility to false memories. Here is the abstract:

“The effect of mindfulness meditation on false-memory susceptibility was examined in three experiments. Because mindfulness meditation encourages judgment-free thoughts and feelings, we predicted that participants in the mindfulness condition would be especially likely to form false memories. In two experiments, participants were randomly assigned to either a mindfulness induction, in which they were instructed to focus attention on their breathing, or a mind-wandering induction, in which they were instructed to think about whatever came to mind. The overall number of words from the Deese-Roediger-McDermott paradigm that were correctly recalled did not differ between conditions. However, participants in the mindfulness condition were significantly more likely to report critical nonstudied items than participants in the control condition. In a third experiment, which tested recognition and used a reality-monitoring paradigm, participants had reduced reality-monitoring accuracy after completing the mindfulness induction. These results demonstrate a potential unintended consequence of mindfulness meditation in which memories become less reliable.”

Given that meditation does resemble suggestive states, such as hypnosis, I am not completely surprised by this finding. Perhaps, meditation should be supplemented with exercises in critical thinking.



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