Wednesday Round Up #38

Toward Clinically-Viable Brain-Machine Interfaces – Krishna Shenoy

Shenoy’s talk starts around 3:25, and the first part really is about dynamical approaches to understanding neural functions. So great basic science on how mammals accomplish tasks in real-time, before turning to how to apply that type of approach to help people who have disabilities.

Beyond reductionism – systems biology gets dynamic

Real biological systems – in the wild, as it were – simply don’t behave as they do under controlled lab conditions that isolate component pathways. They behave as systems – complex, dynamic, integrative systems. They are not simple stimulus-response machines. They do not passively process and propagate signals from the environment and react to them. They are autopoietic, homeostatic systems, creating and maintaining themselves, accommodating to incoming information in the context of their own internal states, which in turn reflect their history and experiences, over seconds, minutes, hours, days, years, and which even reflect the histories of their ancestors through the effects of natural selection.

Living things do things – they are proactive agents, not merely reactive systems. This is widely acknowledged in a general sort of way, but the problem is that the conceptualisation of cells or organisms as proactive systems has remained largely philosophical, even metaphorical, and disconnected from experimental study. It’s just not easy to study cells or organisms as systems.

Bad Dog

Schenkel’s language found its way into popular culture, and his work was still influential in the late eighties, when a scientist named L. David Mech began spending his summers on Ellesmere Island, in the Arctic Circle. By observing wolves in the wild, Mech discovered that packs are, in fact, simply families, with dynamics that change as pups reach mating age. The competition that Schenkel had observed, Mech found, was a result of the wolves’ conditions in captivity. Mech published two papers correcting the record, and the “alpha” terminology fell out of scientific use. Still, the myth has stuck. For many people, training a dog is an exercise in proving our power and authority, in vying for the position of the alpha…

The problem with using fear and pain in behavior modification is that fear is also at the root of aggression. For dogs, biting, snarling, and lunging are designed to create distance from a threat. The scientific literature of the past thirty years shows that dogs subjected to “dominant” or punishing training techniques—striking, kicking, staring, spraying water, shock and prong collars, choke chains, raised voices—have the highest incidence of aggression. These dogs also have elevated levels of cortisol, a greater fear of humans, and an inhibited ability to learn.

Teacher Demoralization Isn’t the Same as Teacher Burnout

It is worth distinguishing teacher demoralization from burnout. Teachers’ ongoing value conflicts with the work (demoralization) cannot be solved by the more familiar refrain for teachers to practice self-care in order to avoid exhaustion (burnout). Demoralization occurs when teachers cannot reap the moral rewards that they previously were able to access in their work. It happens when teachers are consistently thwarted in their ability to enact the values that brought them to the profession.

Burnout, on the other hand, happens when teachers are pushed to the brink of exhaustion and are entirely depleted. The rhetoric of teacher resilience offers a clear culprit in the scenario of burnout—the teachers themselves who failed to conserve their energy and internal resources.

Phenotypic covariance across the entire spectrum of relatedness for 86 billion pairs of individuals

Excellent study using an extremely large sample to examine how common models impact estimates of heritability. Well-worth the entire read, but a couple things stand out: twin-studies overestimate genetic influences on traits, and assortative mating makes a difference for several traits in humans. We tend to marry/have children with people who are a similar height to us, and we tend to marry/mate with people who are a similar social class to us.

We find that non-random mating had a measurable effect on the phenotypic correlation of close relatives for some traits. The phenotypic correlation of close relative pairs was higher than what would be expected under a simple AE model, and the AE model predicted that unrelated pairs to have a non-zero phenotypic correlation for height, income, lung capacity and Educational Attainment…
We observe that the twin estimate assessing the equilibrium heritability for height is significantly greater than our estimate of h^2EQ from close relatives (χ21 = 5.9, p = 0.01; Table 4). This finding adds further to evidence for the systematic inflation of heritability estimates from classic twin studies.

To Avoid Getting Duped By Fake News, Think Like A Fact Checker

The first reader’s opinion, and maybe even his vote, were swayed by a site whose backing he failed to uncover. This reader needs a tutorial in critical thinking, right?

After watching groups of intelligent adults navigate and flounder on the web, we’ve come to a different conclusion. Often, it’s not more critical thinking that they need. It’s less.

For more, see this NYT’s piece Don’t Go Down the Rabbit Hole.

Specialized coding of sensory, motor and cognitive variables in VTA dopamine neurons

There is increased appreciation that dopamine neurons in the midbrain respond not only to reward1 and reward-predicting cues1,2, but also to other variables such as the distance to reward3, movements4,5,6,7,8,9 and behavioural choices10,11. An important question is how the responses to these diverse variables are organized across the population of dopamine neurons. Whether individual dopamine neurons multiplex several variables, or whether there are subsets of neurons that are specialized in encoding specific behavioural variables remains unclear. This fundamental question has been difficult to resolve because recordings from large populations of individual dopamine neurons have not been performed in a behavioural task with sufficient complexity to examine these diverse variables simultaneously. Here, to address this gap, we used two-photon calcium imaging through an implanted lens to record the activity of more than 300 dopamine neurons from the ventral tegmental area of the mouse midbrain during a complex decision-making task. As mice navigated in a virtual-reality environment, dopamine neurons encoded an array of sensory, motor and cognitive variables. These responses were functionally clustered, such that subpopulations of neurons transmitted information about a subset of behavioural variables, in addition to encoding reward. These functional clusters were spatially organized, with neighbouring neurons more likely to be part of the same cluster. Together with the topography between dopamine neurons and their projections, this specialization and anatomical organization may aid downstream circuits in correctly interpreting the wide range of signals transmitted by dopamine neurons.

4 Work-From-Home Tech Tricks I Learned From Twitch Streamers

Upgrade Your Space—in Order

As quarantine drags on, I’ve seen a lot of Facebook ads for small pieces of equipment to improve your video calls. If the number one goal is that you can contribute to meetings and be understood by your coworkers, clip-on lights and mini webcams shouldn’t be the first thing to buy. Consider upgrading your setup in this order.

Persuading the Unpersuadable

Let a Stubborn Person Seize the Reins

A second obstacle to changing people’s opinions is stubbornness. Intractable people see consistency and certainty as virtues. Once made up, their minds seem to be set in stone. But their views become more pliable if you hand them a chisel…

A solution to this problem comes from a study of Hollywood screenwriters. Those who pitched fully formed concepts to executives right out of the gate struggled to get their ideas accepted. Successful screenwriters, by contrast, understood that Hollywood executives like to shape stories. Those writers treated the pitch more like a game of catch, tossing an idea over to the suits, who would build on it and throw it back.

Not long ago I was introduced to a former Apple engineer named Mike Bell, who knew how to play catch with Steve Jobs. In the late 1990s Bell was listening to music on his Mac computer and getting annoyed at the thought of lugging the device with him from room to room. When he suggested building a separate box to stream audio, Jobs laughed at him. When Bell recommended streaming video, too, Jobs fired back, “Who the f— would ever want to stream video?”

Bell told me that when evaluating other people’s ideas, Jobs often pushed back to assert his control. But when Jobs was the one generating ideas, he was more open to considering alternatives. Bell learned to plant the seeds of a new concept, hoping that Jobs would warm to it and give it some sunlight.

Research shows that asking questions instead of giving answers can overcome people’s defensiveness. You’re not telling your boss what to think or do; you’re giving her some control over the conversation and inviting her to share her thoughts. Questions like “What if?” and “Could we?” spark creativity by making people curious about what’s possible.

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