Tag Archives: Psychological Science

Is brain training a placebo?

25 Jul

The word “placebo” comes from the Latin and means  “I shall please.” A recent paper in the Proceedings of the National Academy of Sciences suggests that claims about the benefits of brain training may simply be placebo effects:

“Placebo effects pose problems for some intervention studies, particularly those with no clearly identified mechanism. Cognitive training falls into that category, and yet the role of placebos in cognitive interventions has not yet been critically evaluated. Here, we show clear evidence of placebo effects after a brief cognitive training routine that led to significant fluid intelligence gains. Our goal is to emphasize the importance of ruling out alternative explanations before attributing the effect to interventions. Based on our findings, we recommend that researchers account for placebo effects before claiming treatment effects.”

(Hat tip to Deric’s MindBlog).

 

 

Micronutrients and insomnia

22 Jul

The most recent issue of Clinical Psychological Science includes a paper titled “Effect of Micronutrients on Insomnia in Adults.” Here is the abstract:

Insomnia is a debilitating condition causing psychological distress and frequently comorbid with other mental health conditions. This study examined the effect of 8 weeks of treatment by broad spectrum micronutrients (vitamins and minerals) on insomnia using a multiple-baseline-across-participants open-label trial design. Seventeen adults were randomized to 1-, 2-, or 3-week baseline periods (14 completed). Self-report measures were the Consensus Sleep Diary–Morning (CSD-M), the Pittsburgh Insomnia Rating Scale (PIRS), and the Depression, Anxiety, Stress Scale (DASS). Baselines were generally stable. Treatment completers reported reliable and clinically significant change in insomnia severity (PIRS), in depression, stress, and anxiety (DASS), and on at least two aspects of sleep measured by the CDS-M. All completers were treatment-compliant, and side effects were minimal. Nutritional supplementation is shown to be a novel, beneficial treatment for insomnia in adults. Follow-up research using placebo-controlled designs as well as comparisons to cognitive-behavioral and other treatments is recommended.

I think the paper is quite interesting and it is consistent with some other research. I do, however, have some concerns. The researchers use a commercial brand name supplement, DSD (Daily Self Defense). Here is their description:

DSD contains all the B vitamins identified as being important for stress reduction (Table S1 in the Supplemental Material available online provides a full list of ingredients).

As a subscriber, I have access to the supplementary material, yet when I checked s1 it did not contain that information. I found a list of ingredients on line and I think the researchers should be clearer about why they thought this formulation would be more effective than other commercially available products. The main ingredients are very similar to what you would find in many commercially available multiple vitamin pills, plus 460 milligrams of a proprietary herbal blend.

 

 

Correlation is not causation (nudge, nudge, wink, wink)

4 Jul

There is no end to the media presenting correlations as causation. I was struck by this piece in Monitor on Psychology a publication of the American Psychological Society. I think I see a pattern here:

  1. Point out some correlation
  2.  Say that the researchers “controlled for other variables” (always a dubious claim)
  3.  Quickly acknowledge that correlation is not causation
  4. Never report the magnitude of the effect
  5. Write the rest of the article as if causation has been established

 

Bayesian reasoning and the South Park Hypothesis

3 Jun

There were many good presentations at APS this year, but by far the best was the three hour workshop I attended on JASP and Bayesian analysis run by Eric-Jan Wagenmakers. This led me to look up some of his writings including this great paper: “Bayesian Benefits for the Pragmatic Researcher.”

As way of illustration, the paper test the South Park Hypothesis: the contention that there is no correlation between the box office success and the quality of Adam Sandler movies. Quality is operationalized as freshness rating at Rottentomatoes.com.

Sandler

It is called the South Park hypothesis from this bit of dialog:

“Producer: Watch this. A.W.E.S.O.M-O, given the current trends of the movie going public, can you come up with an idea for a movie that will break $100 million box office?
Cartman: [as A.W.E.S.O.M.-O] Um… Okay, how about this: Adam Sandler is like in love with some girl. But it turns out that the girl is actually a golden retriever or something.
Mitch: Oh! Perfect!
Executive: We’ll call it “Puppy Love”.
Mitch: Give us another movie idea, A.W.E.S.O.M.-O.
Cartman: Um… How about this: Adam Sandler inherits like, a billion dollars, but first he has to become a boxer or something.
Mitch: “Punch Drunk Billionaire”.”

Pyschologists study telomeres

19 Dec

Telomeres are structures at the end of chromosomes that shorten with each cell division. They are restored through the action of an enzyme. Shorter telomeres is a sign of aging and stress.

The Observer, a publication of the Association for Psychological Science, reports on the psychological study of telomeres.

“Over the last decade, these scientists and others have investigated how protracted psychological stress lowers telomerase activity, leading to shorter telomeres. This line of research represents the height of integrative science, incorporating disciplines that include psychology, immunology, epidemiology, genetics, and even nutrition.”

The entire piece is worth reading.

telomere-863617441

Sleep deprivation increases false memories

29 Jul

Because of several notorious cases, false memories have attracted a great deal of research attention. Here is a study published in Psychological Science suggesting that sleep deprivation can play a role in the formation of false memories; additional evidence that sleep is vital to memory.

Here is the abstract:

“Many studies have investigated factors that affect susceptibility to false memories. However, few have investigated the role of sleep deprivation in the formation of false memories, despite overwhelming evidence that sleep deprivation impairs cognitive function. We examined the relationship between self-reported sleep duration and false memories and the effect of 24 hr of total sleep deprivation on susceptibility to false memories. We found that under certain conditions, sleep deprivation can increase the risk of developing false memories. Specifically, sleep deprivation increased false memories in a misinformation task when participants were sleep deprived during event encoding, but did not have a significant effect when the deprivation occurred after event encoding. These experiments are the first to investigate the effect of sleep deprivation on susceptibility to false memories, which can have dire consequences.”

 

 

Psychology’s replication crisis

15 Jun

Chris Chambers at Psychology Today has written a good post on the replication crisis in psychology:

“For the first time in history, we are seeing a co-ordinated effort to make psychology more robust, repeatable, and transparent.”

 

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