After providing all the funding for The Brain from Top to Bottom for over 10 years, the CIHR Institute of Neurosciences, Mental Health and Addiction informed us that because of budget cuts, they were going to be forced to stop sponsoring us as of March 31st, 2013.

We have approached a number of organizations, all of which have recognized the value of our work. But we have not managed to find the funding we need. We must therefore ask our readers for donations so that we can continue updating and adding new content to The Brain from Top to Bottom web site and blog.

Please, rest assured that we are doing our utmost to continue our mission of providing the general public with the best possible information about the brain and neuroscience in the original spirit of the Internet: the desire to share information free of charge and with no adverstising.

Whether your support is moral, financial, or both, thank you from the bottom of our hearts!

Bruno Dubuc, Patrick Robert, Denis Paquet, and Al Daigen




Tuesday, 25 June 2024
Earworms as an excuse to talk about mental simulations and working memory

This week I’d like to talk about an intriguing phenomenon: earworms, those bits of songs that start playing in your head for hours and sometimes even days on end. More specifically, I’d like to talk about a comment that biologist John Medina makes about earworms in an entry entitled “As the Worm Turns” in his substack “John Medina’s Brain Rules”. I call it a comment because, as Medina admits right off, no one really knows much about what causes earworms. But the two neurological considerations that he raises are still interesting. They relate to two key concepts that I of course discuss on my website: mental simulation and working memory.

As Medina relates, when experimenters used functional magnetic resonance imaging (fMRI) to scan subjects’ brains while playing certain well known tunes for them, their auditory cortexes showed up as activated in the scans. And when the researchers suddenly stopped playing the music but told the subjects to start imagining the next parts of the songs, their auditory cortexes were activated again in much the same way.

There’s nothing surprising about any of this today, when we know that the brain’s sensory and motor areas are invariably recruited in the process of mental simulation. But it would probably have seemed quite surprising to scientists in the late 20th century, when they swam in a sea of cognitivist metaphors that equated thinking and imagining with manipulating abstract symbols, and hence with activating high-level associative areas in the brain, rather than sensory or motor areas. Since then, however, scientists have realized that our thinking is “embodied”— in other words, that it is grounded far more deeply in our sensorimotor functions than was once thought.

The second point that Medina makes is that in the case of earworms, the brain network that is activated is the one associated with working memory—the buffer where a few items are normally stored for a few seconds and then vanish. Except, it seems, in the case of earworms, in which a subset of brain regions constitute the phonological loop— a circuit where earworms reverberate for an unusually long time. Why? For now, no one seems to have the least idea, except that earworms are usually simple, catchy tunes.

As for how to get rid of earworms, let’s just say that they will go away eventually, and that singing another song in your head can sometimes help, unless it turns into an earworm too!

 

Memory and the Brain | Comments Closed


Tuesday, 30 April 2024
The so-called second brain in your intestines

After I deliver lectures about the human brain, one question that people often ask me is, “Is there really a ‘second brain’ in my belly, and if so, how is that possible?” I have to tell them that for someone like me, who many years ago did his master’s research on an invertebrate—more specifically, on a marine mollusk called the sea slug—there’s nothing surprising about finding neurons in parts of the body besides the brain. Because, like my sea slug, the phylogenetically oldest animals on Earth began by having clusters of neurons (what are often called ganglia) in many different parts of their bodies. For example, the sea slug has ganglia in its mouth, feet, and brain (where the ganglia are no bigger than anywhere else) as well as in its abdomen . It was only later in evolution, and especially in vertebrates, that increasing cephalization occurred: a concentration of neurons in the rostral portion of the neural tube (in other words, in the head). But that doesn’t mean that the other neurons, such as those in the abdomen, disappeared! (more…)

From the Simple to the Complex | Comments Closed


Thursday, 4 April 2024
The Brain Is Not a Space Shuttle

Recently, someone made me aware of an impressive graphic that attempts to use current neuroanatomical data to show how the brain’s circuits are interconnected, somewhat like the graphics that biochemists use to represent cellular metabolism.

I have never before seen any schematic representation of the brain’s circuits that pulls together so much information, both in its detailed version and in its simplified version, which shows the brain’s main circuits in the sagittal plane. The box in the lower left-hand corner of this graphic states that the research required to develop it was done by an aerospace engineer who had worked on the design of the space shuttle’s guidance system and who spent over four years analyzing over 1000 neuroscientific studies to prep this schematic. (more…)

From the Simple to the Complex | Comments Closed


Tuesday, 12 March 2024
How “awe” contributes to our well-being

In November 2023, many music fans in Quebec and elsewhere were saddened to hear that Karl Tremblay, lead singer of the folk-rock group Cowboys Fringants, had died of prostate cancer at age 47. Many of his fans remembered the moments of magic that they had experienced at the group’s concerts—the feelings of true oneness that only music can provide. People often have similar, fleeting experiences of wonder when out in nature—for example, beholding a beautiful sunset, or a sky full of stars or the view from the top of a mountain—or with the help of magic mushrooms or other psychedelic substances. The term “awe” is often used quite aptly to refer to these experiences when we feel part of something greater than ourselves, with a mixture of admiration and amazement, along with some fear, reverence and respect. (more…)

The Emergence of Consciousness | Comments Closed


Monday, 19 February 2024
Determined: A Science of Life without Free Will

This week I’d like to tell you about one of my “travelling companions” who has had a huge influence on me for as long as I’ve been writing popular science. His name is Robert Sapolsky, he’s a neurobiologist and primatologist, and I’ve posted about him before here and here. He has just published a new book, Determined: A Science of Life without Free Will , following his earlier, sensational book Behave, published in 2017. (more…)

From Thought to Language | Comments Closed