A little blue-and-black fish swims up to a mirror. It maneuvers its body vertically to reflect its belly, along with a brown mark that researchers have placed on its throat. The fish then pivots and dives to strike its throat against the sandy bottom of its tank with a glancing blow. Then it returns to the mirror. Depending on which scientists you ask, this moment represents either a revolution or a red herring.
Alex Jordan, an evolutionary biologist at the Max Planck Institute for Ornithology in Germany, thinks this fish — a cleaner wrasse — has just passed a classic test of self-recognition. Scientists have long thought that being able to recognize oneself in a mirror reveals some sort of self-awareness, and perhaps an awareness of others’ perspectives, too. For almost 50 years, they have been using mirrors to test animals for that capacity. After letting an animal get familiar with a mirror, they put a mark someplace on the animal’s body that it can see only in its reflection. If the animal looks in the mirror and then touches or examines the mark on its body, it passes the test.
Humans don’t usually reach this milestone until we’re toddlers. Very few other species ever pass the test; those that do are mostly or entirely big-brained mammals such as chimpanzees. And yet as reported in a study that appeared on bioRxiv.org earlier this year and that is due for imminent publication in PLOS Biology, Jordan and his co-authors observed this seemingly self-aware behavior in a tiny fish.
Jordan’s findings have consequently inspired strong feelings in the field. “There are researchers who, it seems, do not want fish to be included in this secret club,” he said. “Because then that means that the [primates] are not so special anymore.” [Continue reading…]
‘Self-aware’ fish raises questions about mirror test
The unexamined inner lives of insects
Lars Chittka and Catherine Wilson write:
René Descartes’s dog, Monsieur Grat (‘Mister Scratch’), used to accompany the 17th-century French philosopher on his ruminative walks, and was the object of his fond attention. Yet, for the most part, Descartes did not think very highly of the inner life of nonhuman animals. ‘[T]he reason why animals do not speak as we do is not that they lack the organs but that they have no thoughts,’ Descartes wrote in a letter in 1646.
Followers of Descartes have argued that consciousness is a uniquely human attribute, perhaps facilitated by language, that allows us to communicate and coordinate our memories, sensations and plans over time. On this view, versions of which persist in some quarters today, nonhuman animals are little more than clever automata with a toolkit of preprogrammed behaviours that respond to specific triggers.
Insects such as bees and ants are often held up as the epitome of the robotically mechanistic approach to animal nature. Scientists have long known that these creatures must possess a large behavioural repertoire in order to construct their elaborate homes, defend against intruders, and provision their young with food. Yet many still find it plausible to look at bees and ants as little more than ‘reflex machines’, lacking an internal representation of the world, or an ability to foresee even the immediate future. In the absence of external stimuli or internal triggers such as hunger, it’s believed that the insect’s mind is dark and its brain is switched off. Insects are close to ‘philosophical zombies’: hypothetical beings that rely entirely on routines and reflexes, without any awareness.
But perhaps the problem is not that insects lack an inner life, but that they don’t have a way to communicate it in terms we can understand. It is hard for us to prise open a window into their minds. So maybe we misdiagnose animal brains as having machine-like properties simply because we understand how machines work – whereas, to date, we have only a fragmentary and imperfect insight into how even the simplest brains process, store and retrieve information.
However, there are now many signs that consciousness-like phenomena might exist not just among humans or even great apes – but that insects might have them, too. Not all of these lines of evidence are from experiments specifically designed to explore consciousness; in fact, some have lain buried in the literature for decades, even centuries, without anyone recognising their hidden significance. [Continue reading…]
Could consciousness all come down to the way things vibrate?
agsandrew/Shutterstock.com
By Tam Hunt, University of California, Santa Barbara
Why is my awareness here, while yours is over there? Why is the universe split in two for each of us, into a subject and an infinity of objects? How is each of us our own center of experience, receiving information about the rest of the world out there? Why are some things conscious and others apparently not? Is a rat conscious? A gnat? A bacterium?
These questions are all aspects of the ancient “mind-body problem,” which asks, essentially: What is the relationship between mind and matter? It’s resisted a generally satisfying conclusion for thousands of years.
The mind-body problem enjoyed a major rebranding over the last two decades. Now it’s generally known as the “hard problem” of consciousness, after philosopher David Chalmers coined this term in a now classic paper and further explored it in his 1996 book, “The Conscious Mind: In Search of a Fundamental Theory.”
Chalmers thought the mind-body problem should be called “hard” in comparison to what, with tongue in cheek, he called the “easy” problems of neuroscience: How do neurons and the brain work at the physical level? Of course they’re not actually easy at all. But his point was that they’re relatively easy compared to the truly difficult problem of explaining how consciousness relates to matter.
Over the last decade, my colleague, University of California, Santa Barbara psychology professor Jonathan Schooler and I have developed what we call a “resonance theory of consciousness.” We suggest that resonance – another word for synchronized vibrations – is at the heart of not only human consciousness but also animal consciousness and of physical reality more generally. It sounds like something the hippies might have dreamed up – it’s all vibrations, man! – but stick with me.
Octopuses on ecstasy reveal genetic link to evolution of social behaviors in humans
Johns Hopkins University School of Medicine:
By studying the genome of a kind of octopus not known for its friendliness toward its peers, then testing its behavioral reaction to a popular mood-altering drug called MDMA or “ecstasy,” scientists say they have found preliminary evidence of an evolutionary link between the social behaviors of the sea creature and humans, species separated by 500 million years on the evolutionary tree.
A summary of the experiments is published Sept. 20 in Current Biology, and if the findings are validated, the researchers say, they may open opportunities for accurately studying the impact of psychiatric drug therapies in many animals distantly related to people.
“The brains of octopuses are more similar to those of snails than humans, but our studies add to evidence that they can exhibit some of the same behaviors that we can,” says Gül Dölen, M.D., Ph.D., assistant professor of neuroscience at the Johns Hopkins University School of Medicine and the lead investigator conducting the experiments. “What our studies suggest is that certain brain chemicals, or neurotransmitters, that send signals between neurons required for these social behaviors are evolutionarily conserved.”
Octopuses, says Dölen, are well-known to be clever creatures. They can trick prey to come into their clutches, and Dölen says there is some evidence they also learn by observation and have episodic memory. The gelatinous invertebrates (animals without backbones) are further notorious for escaping from their tank, eating other animals’ food, eluding caretakers and sneaking around.
But most octopuses are asocial animals and avoid others, including other octopuses. But because of some of their behaviors, Dölen still thought there may be a link between the genetics that guide social behavior in them and humans. One place to look was in the genomics that guide neurotransmitters, the signals that neurons pass between each other to communicate. [Continue reading…]
We are more than our brains
Brains are undoubtedly somewhat computer-like – computers, after all, were invented to perform brain-like functions – but brains are also much more than bundles of wiry neurons and the electrical impulses they are famous for propagating. The function of each neuroelectrical signal is to release a little flood of chemicals that helps to stimulate or suppress brain cells, in much the way that chemicals activate or suppress functions such as glucose production by liver cells or immune responses by white blood cells. Even the brain’s electrical signals themselves are the products of chemicals called ions that move in and out of cells, causing tiny ripples that can spread independently of neurons.
Also distinct from neurons are the relatively passive brain cells called glia (Greek for glue) that are roughly equal in number to the neurons but do not conduct electrical signals in the same way. Recent experiments in mice have shown that manipulating these uncharismatic cells can produce dramatic effects on behaviour. In one experiment, a research group in Japan showed that direct stimulation of glia in a brain region called the cerebellum could cause a behavioural response analogous to changes more commonly evoked by stimulation of neurons. Another remarkable study showed that transplantation of human glial cells into mouse brains boosted the animals’ performance in learning tests, again demonstrating the importance of glia in shaping brain function. Chemicals and glue are as integral to brain function as wiring and electricity. With these moist elements factored in, the brain seems much more like an organic part of the body than the idealised prosthetic many people imagine.
Stereotypes about brain complexity also contribute to the mystique of the brain and its distinction from the body. It has become a cliché to refer to the brain as ‘the most complex thing in the known Universe’. This saying is inspired by the finding that human brains contain something on the order of 100,000,000,000 neurons, each of which makes about 10,000 connections (synapses) to other neurons. The daunting nature of such numbers provides cover for people who argue that neuroscience will never decipher consciousness, or that free will lurks somehow among the billions and billions.
But the sheer number of cells in the human brain is unlikely to explain its extraordinary capabilities. Human livers have roughly the same number of cells as brains, but certainly don’t generate the same results. Brains themselves vary in size over a considerable range – by around 50 per cent in mass and likely number of brain cells. Radical removal of half of the brain is sometimes performed as a treatment for epilepsy in children. Commenting on a cohort of more than 50 patients who underwent this procedure, a team at Johns Hopkins in Baltimore wrote that they were ‘awed by the apparent retention of memory after removal of half of the brain, either half, and by the retention of the child’s personality and sense of humour’. Clearly not every brain cell is sacred.
If one looks out into the animal kingdom, vast ranges in brain size fail to correlate with apparent cognitive power at all. Some of the most perspicacious animals are the corvids – crows, ravens, and rooks – which have brains less than 1 per cent the size of a human brain, but still perform feats of cognition comparable to chimpanzees and gorillas. Behavioural studies have shown that these birds can make and use tools, and recognise people on the street, feats that even many primates are not known to achieve. Within individual orders, animals with similar characteristics also display huge differences in brain size. Among rodents, for instance, we can find the 80-gram capybara brain with 1.6 billion neurons and the 0.3-gram pygmy mouse brain with probably fewer than 60 million neurons. Despite a greater than 100-fold difference in brain size, these species live in similar habitats, display similarly social lifestyles, and do not display obvious differences in intelligence. Although neuroscience is only beginning to parse brain function even in small animals, such reference points show that it is mistaken to mystify the brain because of its sheer number of components.
Playing up the machine-like qualities of the brain or its unbelievable complexity distances it from the rest of the biological world in terms of its composition. But a related form of brain-body distinction exaggerates how the brain stands apart in terms of its autonomy from body and environment. This flavour of dualism contributes to the cerebral mystique by enhancing the brain’s reputation as a control centre, receptive to bodily and environmental input but still in charge.
Contrary to this idea, our brains themselves are perpetually influenced by torrents of sensory input. The environment shoots many megabytes of sensory data into the brain every second, enough information to disable many computers. The brain has no firewall against this onslaught. Brain-imaging studies show that even subtle sensory stimuli influence regions of the brain, ranging from low-level sensory regions where input enters the brain to parts of the frontal lobe, the high-level brain area that is expanded in humans compared with many other primates.
Many of these stimuli seem to take direct control of us. For instance, when we view illustrations, visual features often seem to grab our eyes and steer our gaze around in spatial patterns that are largely reproducible from person to person. If we see a face, our focus darts reflexively among eyes, nose and mouth, subconsciously taking in key features. When we walk down the street, our minds are similarly manipulated by stimuli in the surroundings – the honk of a car’s horn, the flashing of a neon light, the smell of pizza – each of which guides our thoughts and actions even if we don’t realise that anything has happened.
Even further below our radar are environmental features that act on a slower timescale to influence our mood and emotions. Seasonal low light levels are famous for their correlation with depression, a phenomenon first described by the South African physician Norman Rosenthal soon after he moved from sunny Johannesburg to the grey northeastern United States in the 1970s. Colours in our surroundings also affect us. Although the idea that colours have psychic power evokes New Age mysticism, careful experiments have repeatedly linked cold colours such as blue and green to positive emotional responses, and hot red hues to negative responses. In one example, researchers showed that participants performed worse on IQ tests labelled with red marks than on tests labelled with green or grey; another study found that subjects performed better on computerised creativity tests delivered on a blue background than on a red background.
Signals from within the body influence behaviour just as powerfully as influences from the environment, again usurping the brain’s command and challenging idealised conceptions of its supremacy. [Continue reading…]
A theory of reality as more than the sum of its parts
In his 1890 opus, The Principles of Psychology, William James invoked Romeo and Juliet to illustrate what makes conscious beings so different from the particles that make them up.
“Romeo wants Juliet as the filings want the magnet; and if no obstacles intervene he moves towards her by as straight a line as they,” James wrote. “But Romeo and Juliet, if a wall be built between them, do not remain idiotically pressing their faces against its opposite sides like the magnet and the filings. … Romeo soon finds a circuitous way, by scaling the wall or otherwise, of touching Juliet’s lips directly.”
Erik Hoel, a 29-year-old theoretical neuroscientist and writer, quoted the passage in a recent essay in which he laid out his new mathematical explanation of how consciousness and agency arise. The existence of agents — beings with intentions and goal-oriented behavior — has long seemed profoundly at odds with the reductionist assumption that all behavior arises from mechanistic interactions between particles. Agency doesn’t exist among the atoms, and so reductionism suggests agents don’t exist at all: that Romeo’s desires and psychological states are not the real causes of his actions, but merely approximate the unknowably complicated causes and effects between the atoms in his brain and surroundings.
Hoel’s theory, called “causal emergence,” roundly rejects this reductionist assumption.
“Causal emergence is a way of claiming that your agent description is really real,” said Hoel, a postdoctoral researcher at Columbia University who first proposed the idea with Larissa Albantakis and Giulio Tononi of the University of Wisconsin, Madison. “If you just say something like, ‘Oh, my atoms made me do it’ — well, that might not be true. And it might be provably not true.”
Using the mathematical language of information theory, Hoel and his collaborators claim to show that new causes — things that produce effects — can emerge at macroscopic scales. They say coarse-grained macroscopic states of a physical system (such as the psychological state of a brain) can have more causal power over the system’s future than a more detailed, fine-grained description of the system possibly could. Macroscopic states, such as desires or beliefs, “are not just shorthand for the real causes,” explained Simon DeDeo, an information theorist and cognitive scientist at Carnegie Mellon University and the Santa Fe Institute who is not involved in the work, “but it’s actually a description of the real causes, and a more fine-grained description would actually miss those causes.” [Continue reading…]
What matters
In “The Strange Order of Things” Antonio Damasio promises to explore “one interest and one idea … why and how we emote, feel, use feelings to construct our selves; how feelings assist or undermine our best intentions; why and how our brains interact with the body to support such functions.”
Damasio thinks that the cognitive revolution of the last 40 years, which has yielded cognitive science, cognitive neuroscience and artificial intelligence, has been, in fact, too cognitive, too rationalist, and not concerned enough with the role that affect plays in the natural history of mind and culture. Standard stories of the evolution of human culture are framed in terms of rational problem solving, creative intelligence, invention, foresight and linguistically mediated planning — the inventions of fire, shelters from the storms, agriculture, the domestication of animals, transportation systems, systems of political organization, weapons, books, libraries, medicine and computers.
Damasio rightly insists that a system with reason, intelligence and language does nothing unless it cares about something, unless things matter to it or, in the case of the emerging world of A.I., things matter to its makers. Feelings motivate reason and intelligence, then “stay on to check the results, and help negotiate the necessary adjustments.”
In an earlier book, “Looking for Spinoza,” Damasio developed the concept of conatus — drive, will, motive, urge — as the taken-for-granted force or catalyst that puts reason, creative intelligence and language to work. If there were no feelings, he adds now, there would be no art, no music, no philosophy, no science, no friendship, no love, no culture and complex life would not aim to sustain itself. “The complete absence of feeling would spell a suspension of being.” [Continue reading…]
The spiritual part of our brains — religion not required
Scientists seek to quantify everything—even the ineffable. And so the human search for meaning recently took a physical turn as Columbia and Yale University researchers isolated the place in our brains that processes spiritual experiences.
In a new study, published in Cerebral Cortex (paywall) on May 29, neuroscientists explain how they generated “personally relevant” spiritual experiences in a diverse group of subjects and scanned their brains while these experiences were happening. The results indicate that there is a “neurobiological home” for spirituality. When we feel a sense of connection with something greater than the self—whether transcendence involves communion with God, nature, or humanity—a certain part of the brain appears to activate.
The study suggests that there is universal, cognitive basis for spirituality, as opposed to a cultural grounding for such states. This new discovery, researchers say, could help improve mental health treatment down the line.
Previous studies have examined the brain activity of Buddhist monks or Catholic nuns, say—people who are already spiritually inclined and familiar with the practice of cultivating transcendent states. But this research analyzed subjects from different backgrounds with varying degrees of religiosity, and totally different individual notions of what constitutes a spiritual experience. [Continue reading…]
Theory of predictive brain as important as evolution — an interview with Lars Muckli
Our brains make sense of the world by predicting what we will see and then updating these predictions as the situation demands, according to Lars Muckli, professor of neuroscience at the Centre for Cognitive Neuroimaging in Glasgow, Scotland. He says that this predictive processing framework theory is as important to brain science as evolution is to biology.
Horizon magazine: You have used advanced brain imaging techniques to come up with a model of how the brain processes vision – and it says that instead of just sorting through what we see, our brains actually anticipate what we will see next. Could you tell us a bit more?
Lars Muckli: ‘We are interested to understand how the brain supports vision. A classical view had been that the brain is responding to visual information in a cascade of hierarchical visual areas with increasing complexity, but a more modern way is to realise that, actually, the brain is not meeting every situation with a clean sheet, but with lots of predictions.’
How does that work?
‘The main purpose of the brain, as we understand it today, is it is basically a prediction machine that is optimising its own predictions of the environment it is navigating through. So, vision starts with an expectation of what is around the corner. Once you turn around the corner, you are then negotiating potential inputs to your predictions – and then responding differently to surprise and to fulfilment of expectations.
‘So that’s what’s called the predictive processing framework, and it’s a proposed unifying theory of the brain. It’s basically creating an internal model of what’s going to happen next.’
Why does this happen?
‘First of all, the outside world is not in our brain so somehow we need to get something into our brain that is a useful description of what’s happening – and that’s a challenge.
‘We become painfully aware of this challenge if we try to simulate this in a computer model – how do we get information about the outside world into a computer model? The brain does that in an unsupervised way. It segments the visual input into object, background, foreground, context, people and so on, and no one ever gives the brain any kind of supervision to do so.
‘To have meaningful models of the world, you need to have something like a supervisor in your brain that says: “This is Object A. This is another object, and you need to find a name for this.” We don’t have a supervisor, but we have something – and that’s the currency of surprise. (The need) to minimise surprise is used as a supervisor.’