Archive for the 'Neuroscience' Category

Feb 11 2019

Caring About Robots

Would you sacrifice a human to save a robot? Psychologists have set out to answer that question using the classic trolley problem.

Most people by now have probably heard about the trolley dilemma, as it has seeped into popular culture. This is a paradigm of psychology research in which subjects are presented with a dilemma – a trolley is racing down the tracks and the breaks have failed. It is heading toward 5 people who are unaware they are about to be killed. You happen to be right next to the lever that can switch the trolley to a different track, where there is only one person at risk. Would you switch the tracks to save the 5 people, but condemning the 1 person to death? Most people say yes. What if in the same situation you were on the trolley at the front of the car, and in front of you was a particularly large person – large enough that if you pushed them off the front of the trolley their bulk would stop the car and save the 5 people, but surely kill the person you pushed over (I know, this is contrived, but just go with it). Would you do it? Far fewer people indicate that they would.

The basic setup is meant to test the difference between being a passive vs active cause of harm to others in the context of human moral reasoning. We tend not to be strictly utilitarian in our moral reasoning, thinking only of outcomes (1 death vs 5), but are emotionally concerned with whether we are the direct active cause of harm to others vs allowing harm to come through inaction or as a side consequence of our actions. The more directly involved we are, the more it bothers us, not just the ultimate outcome.

The trolley problem has become so famous because you can use it as a basic framework and then change all sorts of variables to see how it affects typical human moral reasoning. You can play with the numbers, to see if there is a threshold (how many lives must be saved in order to make a sacrifice worth it?), or you can vary the age of those saved vs those sacrificed, or perhaps the person you might sacrifice is a coworker. Does that make their life more valuable? What if they are kind of a jerk?

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Jan 29 2019

The Law of Unintended Consequences

Published by under Neuroscience

Psychologists have come to recognize that, because of the complexity of human emotion and behavior, we are often motivated to engage in activity which produces the exact opposite effect that we intend. If you are fearful of losing someone, you may become clingy and possessive, driving them away.

The same is true on a societal level – interventions designed to have one effect may have the opposite effect if we are not careful. A classic example is the “scared straight” approach to public service announcements – it doesn’t work. In fact, it may have the opposite of the intended effect. Warning kids about the dangers of alcohol, for example, may just romanticize alcohol use and suggest that it is more popular or common than it is, creating social pressure to use. This is the main idea behind the social norming approach – tell kids, instead, statistics about how few of their peers are getting drunk regularly, reducing the social pressure to use.

This overall pattern is fairly consistent in the literature (although, of course, researching such questions is complex and the details matter to the outcome). Another recent example is a study which finds that fat shaming obese people does not motivate them to lose weight, which is sometimes the motivation (or at least the justification) of the person doing the fat shaming. Rather, fat shaming leads to more weight gain.

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Jan 24 2019

Yawning in Virtual Reality

Published by under Neuroscience

Psychologists are increasingly using virtual reality (VR) in their psychological experiments. It’s very convenient – they can create whatever environment they want with total control over all visual and auditory variables. It’s also safe, so they can study how people respond in traffic without the risk of subjects getting run over.

The meta-question for this research, however, is whether people will respond the same in VR as they do in physical reality? That is a research question unto itself, with implications for all other VR-based research.

Based on my personal experience in VR I would guess that it depends. Current VR technology is of sufficient resolution and fidelity that it successfully tricks the brain – your brain believes that you are in the environment you see. I say “your brain” because you consciously know it is VR and not meat-space, but your brain incorporates the visual and auditory sensory streams into its construction of reality as if they were real. So, consciously you may know the difference, but subconsciously you don’t.

Perhaps the best demonstration of this is the Planck Experience – a fun little VR demonstration in which you walk out onto a planck 40 floors high on a virtual skyscraper. You know you are safe in a room, but your subconscious brain buys the visual construction and your emotions react as if you are about to die.

A recent experiment adds a bit more data to this question. Researchers used VR to test yawning. There is a phenomenon of contagious yawning – mammals will yawn when they see other mammals yawn, about 30-60% of the time. So the researcher put subjects in VR where they were exposed to virtual yawning. Sure enough – the yawns were contagious 38% of the time, in the range of previous research.

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Jan 22 2019

New Technique to Map Brains

Published by under Neuroscience

One of the “holy grails” of neuroscience is the ability to scan a brain and create a complete detailed map, including all networks and connections. Scientists use several techniques, all with their own drawbacks, and the process is very slow – it can take a year to completely scan a single fly brain. A collaboration of scientists, however, report in Science that they have developed a new technique that can accomplish a detailed scan of an entire fly brain (or a section of mouse cortex) in 2-3 days.

The team has been described as an “Avengers” type collaboration, and it is impressive. Specialists provided the prepared fly brains. Two different types of microscopy were combined (that’s really the new bit), along with a third imaging technique. Finally, computer specialists had to figure out how to combine all the data like puzzle pieces into an image. The result was a complete map of a fly brain in three days, which is an impressive leap forward.

The core innovation of the new technique is to use a combination of expansion microscopy and lattice light-sheet microscopy. Expansion microscopy is pretty much what it sounds like – the brain sample is expanded, retaining the relative positions of neurons and connections, but creating more space to facilitate imaging. Expansion is done chemically, similar to injecting an expanding gel into a specimen. The researchers expanded their samples four-times to provide optimal results. The potential problem with this technique is that it may introduce artifacts giving spurious results, so anyone using it has to be careful and validate their techniques (by reproducing known outcomes, for example).

This expansion technique was combined with the lattice light-sheet microscopy. This is a complicated setup that illuminates the specimen with high energy thin sheet of light, only that part of the specimen that is in focus to the microscope, keeping all the out-of-focus parts dark. Finally, this is all combined with fluorescence microscopy, which tags specific biological structures (such as certain amino acids) with fluorescent molecules. This way only certain cell types or certain connections or structures can be imaged and mapped. Specifically they used confocal microscopy, which provides better resolution and contrast.

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Jan 18 2019

GM Foods and Changing Minds

The question at the core of science communication and the skeptical movement is – how do we change opinions about science-related topics? That is the ultimate goal, not just to give information but to inform people, to change the way they think about things, to build information into a useful narrative that helps people understand the world and make optimal (or at least informed) decisions.

I have been using the GMO (genetically modified food) issue as an example, primarily because the research I am discussing is using it as a topic of study. But also – GMO opposition is the topic about which there is the greatest disparity between public and scientific opinion. A new study also looks at attitudes toward GMOs, specifically, with the question of – is a convert from GMO opponent to supporter more persuasive than straightforward GMO support?

The study uses clips from a talk by Mark Lynas, an environmentalist who converted from GMO opponent to supporter. They found:

The respondents each were shown one of three video clips: 1) Lynas explaining the benefits of GM crops; 2) Lynas discussing his prior beliefs and changing his mind about GM crops; and 3) Lynas explaining why his beliefs changed, including the realization that the anti-GM movement he helped to lead was a form of anti-science environmentalism.

The researchers found that both forms of the conversion message (2 and 3) were more influential than the simple advocacy message. There was no difference in impact between the basic conversion message and the more elaborate one.

This makes sense – prior research shows that it is more effective to give someone a replacement explanatory narrative than just to tell them that they are wrong. However, it is very difficult to say how generalizable this effect is.

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Jan 14 2019

Our Memories Work Backwards

Published by under Neuroscience

One more piece to the memory puzzle seems to be falling into place. The question is – what steps do our brains go through when recalling a memory? Researchers have been focusing on visual memory, because it is easiest to model and image, and they have found that memories are recalled in a reverse of the process by which they are formed.

A recent study in Nature Communications replicates the overall findings of a previous study published in PNAS. Both studies looked at the visual system and found essentially the same thing.

When we perceive an object, first our brain receives an image from the retina. By the time this image gets to the visual cortex some basic image processing has already occurred at the subcortical level. Then the cortex puts the image together, sharpens up contrast and lines, interprets size and distance, shadows and movement, etc. The brain then tries to find a match in its catalogue of known things. Once a match is found, actually, that information is then communicated back down to the more basic visual layers and the image is adjusted to enhance the match – lines are filled in, extraneous details are suppressed, assumptions of size and distance are adjusted.

Then the now identified object is sent to even higher brain areas (higher in this network) to afford meaning to the object. If your brain thinks the object has agency, this connects to the emotional centers in order to remember what you feel about the object. Connections are also made to memories about the object. Let’s call these thematic memories. So our brains build the image up from basic details, to complex shapes, then to known objects, and finally to feelings, connections, meaning and memories.

But what about when you recall the object that you previously saw? Both of these studies, using visual memories, found that the brain works backwards. First the thematic areas of the brain light up, then progressively more basic areas of visual processing. Media reporting on these studies emphasize that this is backward from how visual memories are made in the first place. However, this is only sort-of true. Remember – even when perceiving things, information goes simultaneously from the details to the themes, but then back down from the themes to the details. Perception and memory formation is bidirectional.

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Jan 10 2019

Children and Screen Time

Most parents worry about how much time their children are spending in front of computer screens, smartphones, and other electronic devices. This is a reasonable worry – this is a fairly dramatic cultural change, and the experience is different than what most of today’s parents experienced when they were children.

Pediatricians have also been warning about excessive screen time, which has been linked to obesity. But current research and recommendations are getting more nuanced, and pediatric organizations have recently walked back or altered their recommendations.
A recent review published in the BMJ found:

We found moderately strong evidence for associations between screentime and greater obesity/adiposity and higher depressive symptoms; moderate evidence for an association between screentime and higher energy intake, less healthy diet quality and poorer quality of life. There was weak evidence for associations of screentime with behaviour problems, anxiety, hyperactivity and inattention, poorer self-esteem, poorer well-being and poorer psychosocial health, metabolic syndrome, poorer cardiorespiratory fitness, poorer cognitive development and lower educational attainments and poor sleep outcomes. There was no or insufficient evidence for an association of screentime with eating disorders or suicidal ideation, individual cardiovascular risk factors, asthma prevalence or pain. Evidence for threshold effects was weak. We found weak evidence that small amounts of daily screen use is not harmful and may have some benefits.

The evidence is weak, and correlational only. This means we cannot conclude that screen time causes obesity, anxiety, or other issues. It may be, for example, that children who are sedentary for other reasons are both overweight and engage in sedentary activities, many of which involve screen time.
Based on this review, The Royal College of Paediatrics and Child Health said that there is insufficient evidence to conclude that screen time in itself is “toxic.”

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Jan 08 2019

Misunderstanding Dunning-Kruger

Published by under Neuroscience

There is, apparently, an increase recently in interest in the Dunning-Kruger effect. The Washington Post writes about this recently, making the obvious political observation (having to do with the current occupant of the White House). It’s great that there is public interest in an important psychological phenomenon, one central to critical thinking. I have discussed DK before, and even dedicated an entire chapter to discussing it in my book.

Unfortunately the Post misinterpret the DK effect in the common way that it is most often misinterpreted. They write:

Put simply, incompetent people think they know more than they really do, and they tend to be more boastful about it.


Time after time, no matter the subject, the people who did poorly on the tests ranked their competence much higher. On average, test takers who scored as low as the 10th percentile ranked themselves near the 70th percentile. Those least likely to know what they were talking about believed they knew as much as the experts.

The first sentence makes it seem like the DK effect applies only to people who are “incompetent.” This is wrong on two levels. The first is that the DK effect does not apply only to “incompetent people” but to everyone, with respect to any area of knowledge. To be fair the author also writes, “it is present in everybody to some extent,” but this does not really capture the reality, and is undone by the sentences above. Second, the effect applies not just in the range of incompetence, but even for average or moderately above average competence.

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Dec 21 2018

Radical Political Views Correlates with Poor Metacognition

The usual caveats apply – this is one study in a limited context showing only correlation and using a psychological construct. I also have to be careful because the study confirms what I already believe. Having said all that, it is interesting and is probably telling us something about people with extreme political views, especially when other research is considered.

The study involves individuals with radical political beliefs, as measured by a standard questionnaire. It has already been established that those with more extreme beliefs espouse greater confidence in their knowledge and beliefs. However, it is not clear how much this is due to an overconfidence bias vs a failure of metacognition. In other words – do people who are overconfident about their political beliefs like to portray themselves to others as being confident, or do they simply lack insight into the correctness of their own beliefs (a metacognitive failure). The current study tests the latter factor.

The researchers, lead by Steven Flemming at University College London, looked at, “two independent general population samples (n = 381 and n = 417).” He gave them a challenge in which they had to estimate the number of dots on two images, and decide which one had more. They also had to say how confident they were in their judgement. Further, if they got the answer wrong, they were given further information in the form of another image with dots which should have helped them improve their estimate. They were then asked to restate their confidence.

The study found that those with more radical political views indicated higher confidence in their choices, even when they were wrong, and less of a tendency to update their confidence with new information. In other words – you might say they are opinionated and stubborn.  This comes as absolutely no surprise if you have ever interacted with someone with extreme political views.

What this study cannot tell us about is the arrow of cause and effect. One possibility is that those who lack the metacognitive ability to properly assess and correct their own confidence levels will tend to fall into more extreme views. Their confidence will allow them to more easily brush off dissenting opinions and information, more nuanced and moderate narratives, and the consensus of opinion.

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Dec 13 2018

Delay School Start Times

Published by under Neuroscience

Living in a complex society means that some decisions are made for us. In a representative democracy, this means our elected officials, at every level, can have incredible power over our lives. The social contract, however, is that these elected officials should know what they are doing, act in the public interest, listen to their constituents, and engage in due diligence based on valid evidence-based processes. Well, that’s the ideal, and it’s pretty clear that we generally fall far short.

One limitation is that people are flawed and have complex motivations and often fall prey to ideology. However, there is also a collective problem of political will, with often perverse incentives baked into the system itself.

These inherent flaws in the system become increasingly frustrating as there are obviously better ways to do things, and yet we can’t seem to get out of our own way. On the bright side it is possible to slowly build the political will in response to a growing body of evidence. Scientific evidence on the risks of second-hand smoke, for example, supported the political will to ban smoking in many public locations, which has led to an improvement in health.

But there are other areas where the science is increasingly clear, the arguments seem one-sided, and yet we seem to be stuck in paralysis. Changing from Daylight Savings time to Standard time is hazardous. It is linked to worse sleep, more accidents, and even more heart attacks. There is also no good reason for the change. It’s just dumb. It seems that we are long past the time of having enough evidence, arguments, and political will to just ditch the change – so what’s the holdup?

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