17 February 2017

Distractions Revisited

Welcome back. Here’s one to ponder. You know how I’ve been going on about aging and distractions? That getting old reduces the ability to ignore distractions (Brain Focusing with Sound). That the learning decline may be due to a reduced ability to ignore irrelevant information (i.e., we take in too much), not to a reduced ability to learn (Age Learning Decline).

Well, a recently published paper from investigators at the University of Toronto and Harvard kind of turned that around. They reviewed behavioral and neuroimaging studies on the subject and concluded that the reduction in cognitive abilities that accompany aging can sometimes be advantageous. I’ll explain.

Cognitive Control

Let’s start with the idea of cognitive control, how well one can focus attention and suppress distractions.


Lower cognitive control, older adults
playing a video game, where higher
cognitive control, young adults excel.
(Photo from multiple websites.)
Clearly, individuals with high cognitive control will excel on explicit, goal-driven tasks that require selective attention and a narrow focus on specific, targeted information. They do a better job at storing relevant information in their memory and managing interference from competing memories.

But what if the task to be accomplished isn’t goal-driven? What if you’ve got a stimulus-driven task? One that would benefit from processing and extracting knowledge derived from a variety of sources--information that was previously irrelevant? Accomplishing these tasks will normally benefit from a broader focus. In fact, completion of these tasks might even be hindered by greater cognitive control, because non-targeted, formerly irrelevant information would have been suppressed, ignored.

Get it? Reduced cognitive control might be more effective when dealing with non-goal-driven tasks. Which is to say, older adults, with their lower cognitive control, might do better than younger adults, who normally have higher cognitive control.

Advantages of Reduced Cognitive Control

Breaking it down, the researchers judge that lower cognitive control seems to help on tasks that might use previously acquired environmental information, learning regularities and creative problem solving.

Reduced cognitive control offers older adults the opportunity to learn more about the world around them. They tend to take in more information about how items and events vary together in time and space. This might allow easier inferences regarding cause and effect. Overall, the greater ability to extract structure and patterns over time and changing contexts should contribute to more prudent decision-making.

It’s interesting that older adults are more likely to opt for simple strategies over complex strategies. One study showed that lower cognitive control individuals did better than those with higher cognitive control on math problems solvable with simple, computationally straightforward strategies. They fixated less on applying more complex algorithms.

On open-ended tasks that benefit from spontaneous thought, older adults’ lower cognitive control may increase their creativity and ability to solve insight problems. But don’t carry that too far. Creativity typically relies on both generating and evaluating cool ideas, and evaluating normally benefits from higher cognitive control.

Wrap Up
Although I appreciate there apparently being some advantages to having reached my present lower cognitive control state, I wouldn’t have minded spending more years with higher cognitive control. Perhaps my level of cognitive control was never high enough to reduce my creative thoughts, but I certainly thought my thoughts were more creative in my youth. Of course, I may not be remembering correctly. I suppose those thoughts are all irrelevant now.

Thanks for stopping by.

P.S.

Cognitive control study in Trends in Cognitive Sciences journal:
www.cell.com/trends/cognitive-sciences/fulltext/S1364-6613(16)30155-3
Article on study on Science Daily website:
www.sciencedaily.com/releases/2016/11/161115150726.htm

10 February 2017

New Medicine: Placebos

Welcome back. Have you heard about the amazing cure-all? It’s called Placebo.

Oh, come on. You know what a placebo is, right? A fake treatment, such as a sugar pill. Placebos are used in testing to determine if a real treatment has an effect that’s any better than no treatment, the placebo.

The placebo effect, as I described in Placebo Sleep, is where the outcome of a treatment is attributed to the belief in the treatment--mindset, perception or expectation--rather than to the treatment itself.

For the test to have any value, the participants must be unaware if they’re receiving a placebo or the real treatment. The results are most reliable if they’re obtained with a double-blind test, where those giving and receiving the treatments are both unaware.

Open-label placebos. (Photo
 from multiple websites)

Well, that’s how placebos are normally used. But in a study published last fall, the researchers tried something different, an open-label placebo. The researchers told the test participants they were receiving a placebo, explained the placebo effect and compared outcomes of the placebo and the usual treatment for chronic low back pain. Guess what. The placebo worked better.

Open-Label Placebo Experiment
The study was conducted by researchers from Portugal’s Instituto Superior de Psicologia Aplicada, Universidade Nova de Lisboa and Centro Hospitalar de Lisboa Ocidental, and Harvard Medical School’s Beth Israel Deaconess Medical Center.

Study participants were recruited via referrals and advertisements for “a novel mind–body clinical study of chronic low back pain.” All were at least 18 years old; had experienced persistent lower back pain for over 3 months, which was confirmed by medical specialists; and had not medicated with opioids in the previous 6 months. Over 85% of the participants were taking pain medications, mostly non-steroidal anti-inflammatories.

The participants were placed randomly into either the treatment-as-usual group or the open-label placebo group. For three weeks, they all continued doing exactly what they had been doing for pain, except those in the placebo group added a placebo (two capsules of microcrystalline cellulose twice daily). Treatment outcomes were measured on 83 participants (41-placebo, 42-usual treatment) at 11 days and 21 days.

After the 21 days, a subset of those who had been in the treatment-as-usual group continued for an additional three weeks, but adding the open-label placebo pills to their usual treatment. Treatment outcomes were measured on 31 participants after 21 days.

Pain Measures and Outcomes
Pain measures included the participants’ ratings of maximum, minimum and usual pain from 0 to 10; 24 yes-or-no statements about difficulties in daily activities (Roland–Morris Disability Questionnaire); and how bothersome their pain had been, from 0 to 10, during the previous week.

For the first three weeks, the open-label placebo group reported improvements that exceeded those of the treatment-as-usual group by a wide margin. Pain scores were better by about double or more and disability by nearly 30% more. Bothersomeness differences were not significant.

After adding the placebo for three weeks, participants who had been in the treatment-as-usual group reported pain reductions ranging from 29% for maximum pain to 46% for minimum pain, a disability decrease of 40% and a bothersomeness decrease of 34%.

Wrap Up
How could the participants improve knowing that the pain reliever they were receiving wasn’t really a pain reliever? Among possible reasons discussed in the paper as well as in a 2013 U.C. Berkeley Wellness report on placebos was that participation in the study implies a belief or hope that the treatment might be helpful.
 

The placebo effect.
(Photo from multiple
 websites)
Since ancient times, it’s been known that the hope and expectation patients experience when treated--even with a placebo--by a trusted practitioner can play a large role in recovery. Although a placebo is fake, the physical responses to it are real. Sensing pain, the brain can release pain-relieving chemicals.

I still thought it was remarkable that 17 participants requested prescriptions for the placebo at the end of the study. Thanks for stopping by.

P.S.
I am indebted to the University of California, Berkeley Wellness Letter (Feb. 2017) for reporting this study, which was first published online during my break from blogging.
Placebo study in Pain journal: www.ncbi.nlm.nih.gov/pmc/articles/PMC5113234/
Article on the study on Beth Israel Deaconess Medical Center website: www.ncbi.nlm.nih.gov/pmc/articles/PMC5113234/
Earlier article (2013) on placebo effect on U.C. Berkeley Wellness website: www.berkeleywellness.com/self-care/preventive-care/article/placebo-effect

03 February 2017

Climate-Related Extinctions

Welcome back. Actually, you may not want to visit. Today’s blog post is a downer, magnified by what’s going on in Washington. I’m going to review the recently published findings of a University of Arizona researcher, who determined that climate change has already been responsible for the local extinctions of hundreds of animal and plant species. 

Species extinction defined.
Local extinctions impact biodiversity, the variability among living organisms from all sources. A reduction in biodiversity can impact the dynamics and functions of ecosystems and have severe consequences for human well-being.

Climate Change
A different recent study--this one by collaborators from the UK’s University of Cambridge and Yale and George Mason universities--suggests ways to open this discussion. Because of the increasing politicization of climate change and the “disinformation campaigns” organized by vested interest groups, I should at least note that 97% of climate scientists have concluded that human-caused climate change is happening.

That 97% consensus came from a 2013 study which examined abstracts of peer-reviewed scientific literature and authors’ self ratings. Updating that report, a 2016 paper summarized six independent studies that found 90% to 100% of publishing climate scientists shared the consensus that humans are causing recent global warming. (I emphasized climate scientists because the tally does not include the opinions of non-climate scientists, such as the Princeton physicist, who met with the new president, or of nonscientists, such as the president.)

Nevertheless, whether the change is driven primarily by humans or not, the Earth is getting warmer. The change is a threat to global biodiversity if the world’s animal and plant species can’t adapt, for example, by moving to cooler environments.

Local Species Extinctions
The University of Arizona researcher’s findings regarding local extinctions were derived from 27 published studies that documented shifts in the geographic ranges of species in response to climate change.

Such shifts typically encompass overall movement of a species toward higher latitudes and elevations, with expansion at the cool edge of the species range (higher latitudes and elevations) or contraction at the warm edge (lower latitudes and elevations), or both expansion and contraction.

A warm-edge contraction indicates that the species is not shifting enough to tolerate the new conditions and is instead going extinct.

The researcher identified the 27 studies by searching the Web of Science, an online subscription-based scientific citation-indexing service, between December 2014 and March 2016. He included all studies that both monitored the warm edge of at least one species’ range and linked their results statistically to climate change.

In all, 976 unique species were surveyed (716 animals, 260 plants), distributed over a variety of climates, regions and habitats (e.g., Asia = 332; Europe = 268; Madagascar = 30; Oceania = 58; North America = 233; South America = 55). Of the 976 species, 460 or 47% had warm-edge contractions indicative of local extinctions.

Wrap Up
The loss of 460 species, even if local, sounds like a lot, but I needed some perspective. I found a 2011 study that estimated the total number of species on Earth to be about 8.7 million (give or take 1.3 million), with 6.5 million on land and 2.2 million in oceans.

Losing 460 out of 8.7 million species wouldn’t even be noticed, or would it? Although the 27 studies were not performed or selected randomly to represent the population of all species, they did show a 47% loss. That’s high enough to get my attention. Plus, the 47% loss was not experienced uniformly. Tropical species, for example, showed a 55% loss.


Species extinction vs human population over time. (From presentation by J.M. Scott, 2008; scholar.law.colorado.edu/cgi/viewcontent.cgi?article=1014&context=water-resources-and-transformation-of-American-West)
Most important, those local extinctions were in response to a small increase in global mean annual temperature. What will be the response if the predicted increase in global warming over the coming decades occurs, especially if we continue to remove habitats and paths of dispersal, thus interfering with the ability of species to adjust?

Oh well, maybe those climate scientists are wrong. Thanks for stopping by.

P.S.
Study on climate-related local extinctions in PLOS Biology journal: journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.2001104
Article on study on TIME website: time.com/4595361/climate-change-extinction-animals/?xid=newsletter-brief
Review of biodiversity loss and humanity in Nature journal: www.nature.com/nature/journal/v486/n7401/full/nature11148.html or pub.epsilon.slu.se/10240/7/wardle_d_etal_130415.pdf
Study on counteracting climate-change misinformation in Global Challenges journal: onlinelibrary.wiley.com/doi/10.1002/gch2.201600008/full
2013 and 2016 studies on climate-scientist consensus in Environmental Research Letters journal:
iopscience.iop.org/article/10.1088/1748-9326/11/4/048002
iopscience.iop.org/article/10.1088/1748-9326/8/2/024024
2011 study estimating total number of species in PLOS Biology journal: journals.plos.org/plosbiology/article?id=10.1371/journal.pbio.1001127

27 January 2017

Genders Gaze Differently

“See, there’s a difference” is
also “There’s a difference in
how we see.” (Graphic from
multiple websites)
Welcome back. In case you were wondering, men and women are different. OK, you probably knew that. But I bet you didn’t know that the difference extends to how men and women gaze at faces. That’s what investigators from the UK’s University College London, Queen Mary University of London and University of Nottingham found recently.

This all began when earlier research showed that everyone has their own eye-scanning pattern when gazing at faces. Who cares? Well, gaze-based models have significance for fields varying from computer vision to clinical psychology. Since the face is central to social interactions, quantifying the nature of face processing is critical to understanding and diagnosing disorders, such as schizophrenia, autism and attention deficit hyperactivity disorder.

Face-Gazing Study Design
To learn that eye-scanning patterns vary with gender, the investigators collected data on 405 visitors to the Science Museum of London. These test participants included 203 males, 202 females, ages 18 to 69 (average 31), of 58 nationalities. Testing of each participant took about 15 minutes and involved three phases.

First, the participants completed a 10-item questionnaire that provided a measure of their personality traits.

Second, an eye-tracking device monitored the participants as they looked at computer-hosted video clips of the face of an actor. The actor gazed briefly toward the bottom of the display, then forward directly at the participant, and finally back toward the bottom of the display. In all, each participant viewed 40 videos, 35 of which varied only in the length of time the actor spent gazing forward at the participant. After each of the 40 videos, the participant indicated via a mouse button if the length of time the actor gazed forward felt uncomfortably short or uncomfortably long for a real interaction.

Third, the participants completed another questionnaire, rating the attractiveness, threat, dominance and trustworthiness of the actor in the video. (The actor viewed by each participant was one of eight chosen randomly. The eight actors were Caucasian, ages 20 to 40, split evenly by gender.)

Study Results
To characterize gender differences in gaze behavior, the investigators grouped the data as male watching male (119 cases), male watching female (84), female watching male (106) and female watching female (96).

As you might expect, the results showed that males watching females showed the largest increase in eye pupil diameter. But the analysis also showed: female observers made shorter fixations and larger rapid eye movements between fixation points (saccades); female gazing was more scattered or exploratory than that of males; females watching females were biased toward looking at the actors’ left eye; and males and females were both more likely to gaze at the eyes of an actor of the opposite gender than of the same gender.


Images depict where representative males (left) and females (right) gazed at actors’ faces, with lighter color indicating more intense focus. Note that females explored faces more than males did and that females watching females have the strongest left-eye bias. (Figure from paper, licensed under a Creative Commons Attribution 4.0 International License.)
Wrap Up
The study demonstrated that gender is a key variable influencing gaze patterns during face exploration. Despite employing the largest, most diverse eye-tracking database, the study had too many limiting factors to establish that gender is the key variable in all cases (e.g., the use of video clips, having only Caucasian actors, and having the actors keep their head still and maintain a neutral facial expression without speaking).

Nevertheless, it’s an interesting study and one more reminder--in case you forget--there is a difference between women and men. Thanks for stopping by.

P.S.
Face exploration study published in Journal of Vision: jov.arvojournals.org/article.aspx?articleid=2587793
Article on study on MedicalXPress website:
medicalxpress.com/news/2016-11-eyes-women-men-differently.html

20 January 2017

Careless Cooking

Welcome back. Now that you’re here, how should I begin? I could point out that I’m big on hygiene, as evidenced by multiple blog posts (see Blog Post Topics on right of website). Or I could just say that I’m not big on cooking. Unlike my wife, Vicki, and our son, Noah, I have zero interest in cooking. (Noah telephoned once, excited that he’d prepared a red velvet cake. I was happy for his cooking success, though I neither knew nor cared what a red velvet cake was.)
 

These thoughts about hygiene and cooking rushed to mind when I came across a study on television cooking shows and celebrity chef food safety. 

TV Cooking Shows
Philip Harben, the first TV cooking show
chef; began 1946, BBC. (Photo from
BBC Genome Blog)
Before I jump into the study, I should note that only 1 in 5 American adults are like me and never watch TV cooking shows, which is to say 4 in 5 adults do watch the shows, even if rarely. (These statistics are from a 2010 survey, but since the number and availability of the shows have increased, I’ll assume the statistics are still reasonable.)

One more statistic. About 1 in 6 Americans experience foodborne illnesses each year. Television is one of the many sources that provide or could provide information on how they could be prevented.

Celebrity Chef Food Safety
To evaluate food safety behaviors conveyed by television cooking shows, researchers from Kansas State and Tennessee State universities watched 100 episodes of 24 different celebrity chefs preparing meat dishes. They chose the shows randomly from cable or online services (e.g., Hulu, Netflix or Amazon) and evaluated each episode using a checklist they developed based on expert food safety knowledge and prior studies.

Their checklist had some 20 food safety practices categorized after the Fight Bac! Program: “Clean,” wash hands and surfaces often; “Separate,” don’t cross-contaminate; “Cook” to safe temperatures; and “Chill,” refrigerate promptly.

Celebrity Chef Behaviors

Dione Lucas, the first female TV
cooking show chef; began 1947,
New York City station.(Photo
from CQUnivNews Archive)
The researchers discovered that the TV chefs either ignored food safety or demonstrated very limited positive behaviors. If viewers adopted the chefs’ practices, there could be a rash of foodborne illnesses.

Some of the most commonly observed poor behaviors were that 88% of the chefs did not wash their hands after handling uncooked meat (or were not shown washing or mentioning handwashing); 79% added food with their hands; 50% ate while cooking; 75% did not use a thermometer to determine if the meat was ready; and 25% used the same cutting board to prepare ready-to-eat items and uncooked meat.

The behavior that won my Oh, come on! prize was that 21% of the chefs licked their fingers while cooking. The same number touched their hair, but that would have slipped by me.

Wrap Up
The study was intended to highlight the problem with food television culture, not shame the celebrity chefs. The chefs may have sterling food safety behaviors when off-camera, or perhaps their good practices were edited out of the shows for time or entertainment. What was broadcast, however, was poor food safety behaviors, which viewers might mistakenly believe are acceptable.

Cooking shows and celebrity chefs are popular with TV viewers. Instead of taking the opportunity to demonstrate or discuss good food safety--to promote the idea that good food and safe food are inseparable--the shows too often promote the opposite behavior.

Thanks for stopping by. Bon app├ętit.

P.S.
Celebrity chef food safety study in Journal of Public Health: jpubhealth.oxfordjournals.org/content/early/2016/04/18/pubmed.fdw026.full
Article on celebrity chef study on Science Daily website:
www.sciencedaily.com/releases/2016/12/161214100737.htm
Harris Poll statistics on TV cooking show viewers: www.marketingcharts.com/television/8-in-10-us-adults-watch-cooking-shows-13719/
Fight Bac! Program’s clean, separate, cook, chill: www.fightbac.org/wp-content/uploads/2015/08/Basic_Fight_BAC_Brochure_Oct_2011.pdf
The first TV chefs: www.history.com/news/hungry-history/lights-camera-action-the-first-tv-chefs