Categorization is the brain's tool to organize nearly everything we encounter in our daily lives. Grouping information into categories simplifies our complex world and helps us to react quickly and effectively to new experiences. Scientists at the Max Planck Institute of Neurobiology have now shown that also mice categorize surprisingly well. The researchers identified neurons encoding learned categories and thereby demonstrated how abstract information is represented at the neuronal level.
A toddler is looking at a new picture book. Suddenly it points to an illustration and shouts 'chair'. The kid made the right call, but that does not seem particularly noteworthy to us. We recognize all kinds of chairs as 'chair' without any difficulty. For a toddler, however, this is an enormous learning process. It must associate the chair pictured in the book with the chairs it already knows - even though they may have different shapes or colors. How does the child do that?

The answer is categorization, a fundamental element of our thinking. Sandra Reinert, first author of the study explains: "Every time a child encounters a chair, it stores the experience. Based on similarities between the chairs, the child's brain will abstract the properties and functions of chairs by forming the category 'chair'. This allows the child to later quickly link new chairs to the category and the knowledge it contains."

Our brain categorizes continuously: not only chairs during childhood, but any information at any given age. What advantage does that give us? Pieter Goltstein, senior author of the study says: "Our brain is trying to find a way to simplify and organize our world. Without categorization, we would not be able to interact with our environment as efficiently as we do." In other words: We would have to learn for every new chair we encounter that we can sit on it. Categorizing sensory input is therefore essential for us, but the underlying processes in the brain are largely unknown.

Few topics in psychology are more controversial than sex differences [1]. Debates can be classified into two main types: (a) The description of sex differences, including both the size and variability of sex differences across a multitude of physical and psychological traits, and (b) The origins and development of sex differences, including the complex interplay between social, cultural, genetic, and biological factors that influence sex differences.

These lines often get blurred. Researchers who emphasize sociocultural factors in their research tend to conceptualize sex differences as small and worry that if we exaggerate the differences, then all hell will break loose in society. On the other side, those who emphasize biological influences tend to emphasize how differences in personality and behavior can be quite large.

I believe that this blurring between the descriptive and the explanatory levels of analysis has stunted the field and distorted public debates over these complex and sensitive issues. In order to make real long-lasting changes that actually have an effect on desired outcomes, our knowledge of the truth needs to be as clear as possible.

In this article I will focus on the personality domain, which has made some truly fascinating advances in only the past few years. I will argue that while the science still has a long way to go to fully flesh out the complex interplay of nature and nurture in creating these differences, it's nevertheless time to take sex differences in personality seriously.

When the Nazis came to power, the writer Charlotte Beradt began collecting dreams. What did she learn?

Not long after Hitler came to power, in 1933, a thirty-year-old woman in Berlin had a series of uncanny dreams. In one, her neighborhood had been stripped of its usual signs, which were replaced with posters that listed twenty verboten words; the first was "Lord" and the last was "I." In another, the woman found herself surrounded by workers, including a milkman, a gasman, a newsagent, and a plumber. She felt calm, until she spied among them a chimney sweep. (In her family, the German word for "chimney sweep" was code for the S.S., a nod to the trade's blackened clothing.) The men brandished their bills and performed a Nazi salute. Then they chanted, "Your guilt cannot be doubted."

These are two of about seventy-five dreams collected in "The Third Reich of Dreams," a strange, enthralling book by the writer Charlotte Beradt. Neither scientific study nor psychoanalytic text, "The Third Reich of Dreams" is a collective diary, a witness account hauled out of a nation's shadows and into forensic light. The book was released, in Germany, in 1966; an English translation, by Adriane Gottwald, was published two years later but has since fallen out of print. (Despite ongoing interest from publishers, no one has been able to find Beradt's heir, who holds the rights.) But the book deserves revisiting, not just because we see echoes today of the populism, racism, and taste for surveillance that were part of Beradt's time but because there's nothing else like it in the literature of the Holocaust. "These dreams — these diaries of the night — were conceived independently of their authors' conscious will," Beradt writes. "They were, so to speak, dictated to them by dictatorship."

Today on MindMatters we interview Thomas Costello, Emory University PhD candidate and lead author of a groundbreaking new study on leftwing authoritarianism. Long thought by social psychologists to be the exclusive of social conservatives (RWA), studies of authoritarianism on the left have been few and far between. Until now. Despite the almost willful ignorance about the subject in the field, LWA really does exist, and Costello and colleagues are clarifying its structure as a valid construct. It turns out that rightwing and leftwing authoritarians have a lot in common - and some differences too.

Join us as we pick Tom's brain about the history of the study of authoritarianism, how it became associated exclusively with conservatism, and what the latest studies are revealing about authoritarians on the left: those anti-conventionalists who channel their aggression against existing hierarchies and favor top-down censorship, and who are more willing to participate in political violence than their peers.


Running Time: 01:03:04

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In a newly published study, researchers say the Dunning-Kruger Effect can cause low-performers to overestimate their judgments during the intuitive decision-making process.

According to the study published in the journal Frontiers in Psychology on April 8, 2021, researchers found that persons with the highest number of errors demonstrated the highest degree of miscalibration, or overconfidence, in their actual performance on the cognitive reflection test.

Researchers say study results have potential implications for the theoretical cognitive bias that persons with low abilities tend to overestimate their actual capabilities, also known as the Dunning-Kruger effect.

Speaking with The Debrief, Dr. Justin Couchman, professor of psychology at Albright College and co-author of the recent study, says the ability to make correct intuitive decisions is increasingly becoming one of the most critical skills to have in the modern information-technology age.

According to a Finnish study, the structure and function of the brain areas involved in emotions and their regulation are altered in both psychopathic criminal offenders and otherwise well-functioning individuals who have personality traits associated with psychopathy.

Psychopathy is a personality disorder characterized by persistent antisocial behavior, impaired empathy, and bold, disinhibited and egotistical traits. However, similar antisocial traits are also common, yet less pronounced, with people who are well-off psychologically and socially. It is possible that the characteristics related to psychopathy form a continuum where only the extreme characteristics lead to violent and criminal behavior.

The collaborative study of Turku PET Center, Karolinska Institutet, and Psychiatric Hospital for Prisoners in Finland examined the brain structure and function in psychopathic prisoners and healthy volunteers. Brain structure was measured with magnetic resonance imaging. The participants also viewed violent and non-violent films while their brain activity was monitored with functional magnetic resonance imaging.

A trio of Stoics from Ancient Greece offer philosophical opposition to today's turbo capitalism in this excerpt from Raging Twenties, Great Power Politics Meets Techno-Feudalism.

Stoicism, in Ancient Greece, was pop culture — reaching out in a way that the sophisticated Platonic and Aristotelian schools could only dream of. Like the Epicureans and the Skeptics, the Stoics owed a lot to Socrates — who always stressed that philosophy had to be practical, capable of changing our priorities in life.

The Stoics were very big on ataraxia (freedom of disturbance) as the ideal state of our mind. The wise man cannot possibly be troubled because the key to wisdom is knowing what not to care about. So the Stoics were Socratic — in the sense that they were striving to offer peace of mind to Everyman. Like a Hellenistic version of the Tao. The great ascetic Antisthenes was a companion of Socrates — and a precursor of the Stoics.

The first Stoics took their name from the porch — stoa — in the Athenian market where official founder Zeno of Citium (333-262 B.C.) used to hang out. But the real deal was in fact Chrysippus, a philosopher specialized in logic and physics, who may have written no fewer than 705 books, none of which survived. The West came to know the top Stoics as a Roman trio — Seneca, Epictetus and Marcus Aurelius. They are the role models of Stoicism as we know it today.

Thousands of our daily activities, from making coffee to taking a walk to saying hello to a neighbor, are made possible through an ancient collection of brain structures tucked away near the center of the cranium.

The cluster of neurons known as the basal ganglia is a central hub for regulating a vast array of routine motor and behavior functions. But when signaling in the basal ganglia is weakened or broken, debilitating movement and psychiatric disorders can emerge, including Parkinson's disease, Tourette's syndrome, attention deficit hyperactivity disorder (ADHD) and obsessive-compulsive disorder.

Despite its central importance in controlling behavior, the specific, detailed paths across which information flows from the basal ganglia to other brain regions have remained poorly charted. Now, researchers at the University of California San Diego, Columbia University's Zuckerman Institute and their colleagues have generated a precise map of brain connectivity from the largest output nucleus of the basal ganglia, an area known as the substantia nigra pars reticulata, or SNr. The findings offer a blueprint of the area's architecture that revealed new details and a surprising level of influence connected to the basal ganglia.

The results, spearheaded by Assistant Project Scientist Lauren McElvain and carried out in the Neurophysics Laboratory of Professor David Kleinfeld at UC San Diego, and the laboratory of Zuckerman Institute Principal Investigator Rui Costa, are published April 5 in the journal Neuron.

We're all familiar with the phrase "healthy body, healthy mind". But this doesn't just refer to physical fitness and muscle strength: for a healthy mind, we need healthy senses, too. Fortunately, there's now a wealth of evidence that we can train our many senses, to improve not only how we use our bodies, but how we think and behave, as well as how we feel. Trapped as we are in our own "perceptual bubbles", it can be hard to appreciate not only that other people sense things differently — but that so can we, if we only put in a little effort.

But if we're going to make the most of using and improving our senses to enhance our wellbeing, we have to consider more than sight, hearing, taste, touch and smell. Aristotle's desperately outdated five sense model may still be popular, but it vastly under-estimates our extraordinary human capacity for sensing.

Proprioception

Proprioception — the sensing of the location of our body parts in space — has been relatively ignored, but it's critical for confidence in using our bodies. If you now shut your eyes, and extend a leg, it's thanks to this sense that you know exactly where your leg is. To go for a run, then, or work out in the gym, and not fall or injure yourself, you need a good sense of proprioception. Our sedentary lifestyles are a threat to this sense (and the Covid-19 lockdowns certainly did not help). But climbing trees, walking along balance beams, navigating obstacles, crossing stepping stones (which you can simulate at home, using small mats placed on the floor) are all proprioceptively demanding, and so train this sense. According to research led by a team at the University at North Florida, these kinds of exercises not only improve physical coordination but also working memory.

Gad Saad, a psychologist who specializes in applying evolutionary biology to the study of consumer behavior, has written a book of great value, and moreover, it is a book that required great courage to write. The book is filled with interesting ideas, and I have space here to mention only a few of them.

What most draws me to the book is that Saad has a philosophical turn of mind, and as such, he is concerned with fashionable attempts to deny the existence of objective truth. He says,

The central focus of this book is to explore another set of pathogens that are as dangerous [as biological parasites] to the human condition: parasitic pathogens of the human mind. These are composed of thought patterns, belief systems, attitudes, and mindsets that parasitize one's ability to think properly and accurately. Once these mind viruses take hold of one's neuronal circuitry, the afflicted victim loses the ability to use reason, logic, and science to navigate the world. Instead, one sinks into an abyss of infinite lunacy best defined by a dogged and proud departure from reality, common sense, and truth. (p. 17)