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Let’s explain away

What is the difference between explaining and explaining away? If I watch a magician do a trick and I witness some object appear from nowhere or simply disappear before my eyes, I of course want to know how these things happen. I want an explanation. But do I want an explanation of how matter can be created or destroyed or do I want an explanation of how the magician made it appear to me what matter appeared and disappeared in a flash? It depends on whether I believe that magic happens or whether I believe that magic is a misleading performance. So someone could say, “you have not explained the magic, you have just explained it away.” To this the answer is, “I have not explained the magic because it never happened and was an illusion but I have explained the actual events that caused the illusion.”

When Dennett published his book ‘Consciousness Explained’, the clever retort was that the book should have been called ‘Consciousness Explained Away’. There have been a few people lately explaining consciousness, that appear to be doing the same thing, explaining it away. Consciousness is not the problem – it is the insistent on a conscious mind that has to be explained away. As soon as people believe that they consciously think as opposed to being consciously aware of thoughts, then the problems occur. Wanting to know how we consciously think is like wanting to know how real magical magic happens. So it would be wise and reasonable to stop trying to explain how we have a conscious mind and concentrate on explaining how we are aware of our thoughts.

The latest explainer-away the I have encountered is a paper by Oakley and Halligan, Chasing the Rainbow: The Non-conscious nature of being, Frontiers in Psychology Nov 2017 here and a blog post by the same authors in Brainfactor, What if Consciousness is not what drives the Human Mind here . One of the first things they do is to change the names so that their meaning is clear. The contents of consciousness they refer to as the personal narrative and the experience of consciousness is a product of internal broadcasting resulting in personal awareness. The contents and experience are the result of a completely non-conscious system; they use the name non-conscious rather than un-conscious.

The model is illustrated by a figure – the Oakley-Halligan model. (click to enlarge)

The schematic diagram shows all current CES functions and other psychological activities as non-conscious processes and their products. The most task-relevant of these psychological products are selectedby a Central Executive Structure (CES) to create an ongoing personal narrative via the process of Internal Broadcasting. This personal narrative is passively accompanied by personal awareness – a by-product of Internal Broadcasting. Some components of this narrative are selected by the CES for further transmission (External Broadcasting) via spoken or written language, music, and art to other individuals. The recipients in turn transmit (internally then externally) their own narrative information, which may contain, or be influenced by, the narrative information they have received. The CES also selects some contents of the current personal narrative for storage in autobiographical memory. The contents of external broadcasts contribute (via Cultural Broadcasting) to an autonomous pool of images, ideas, facts, customs, and beliefs contained in folklore, books, artworks, and electronic storage systems (identified as “Culture” in the Figure) that is accessible to others in the extended social group but is not necessarily dependent on direct interpersonal contact. The availability of culturally based resources is a major adaptive advantage to the social group and ultimately to the species as a whole. The CES has access to self- and other-generated externally broadcast content as well as to cultural information and resources, all of which have the potential to provide information that supports the adaptedness of the individual and to be reflected in the contents of their personal narrative. As a passive phenomenon, personal awareness exerts no influence over the CES, the contents of the personal narrative or on the processes of External and Cultural Broadcasting. In the Figure non-conscious process are identified in green and personal awareness (subjective experience) in blue.

There is a great deal of interesting information and ideas in this paper – comparison of varies models, historical progress, clarification of the absence of conscious control, models of self. And I will probably write another post on some aspects. But I also have a couple of reservations. The authors seem to deal exclusively with human consciousness and put great stress on the social and cultural role of consciousness. I would have liked a little hint to how they thought other animals might differ. One might think from reading the paper that they thought other animals were not conscious. I also thought they played down the very important relationship between personal narrative and memory. I continue to suspect that one of the most important aspects of conscious awareness is in laying down memories. And one of the most important aspects of thought is the use of memory.

We can hope that there is much more coming to explain consciousness by explaining away the conscious mind.

Notice

i have just lost my husband and will not have time or inclination to post for a while. I will be back in a a few months.

Why sleep

It would be surprising if there were a single function for sleep, but there are often articles implying that the mystery is solved and THE reason for sleep has been found. Recently there was one in the New Scientist which prompted my post (https://www.newscientist.com/article/2096921-mystery-of-what-sleep-does-to-our-brains-may-finally-be-solved/).

We can look logically at reasons why we sleep. For any biological behaviour or process, there can be a spectrum of causes. At the one end of the spectrum are the ultimate causes – the evolutionary reason, the function being carried out, and the ‘why’. At the other end are the proximate causes – the individual immediate cause, the trigger, and the ‘how’.

The thing that seems the most distance and universal ultimate cause is probably that it is evolutionarily difficult to be well fitted to two dissimilar niches at the same time. There are animals that are active in the day and adapted to that; they hid and conserve their energy at night because they are not adapted to night. Or an animal can be adapted to night and hid in the day. This idea applies to animals that hibernate through a cold season every year to which they are not well adapted. There are animals that go dormant in dry seasons and are active when it is wet. It would be a good bet that all other functions of sleep are built on this mechanism of being inactive during recurring periods. Sleep is widespread amongst animals.

If there is an inactive time, that is the time to do all the things that cannot be done easily when active. Growth and repair would be immensely easier during rest. Imagine growing new muscle cells in a walking leg – much easier to wait until the leg is not moving. Growth and repair is best done on all the organs when they are just ticking over at most. This would include any maintenance needed in the brain.

These ultimate causes produce, during evolution, a proximate mechanism: an oscillating function that produces drowsiness and than sleep and followed by awakening and activity. Hormones and signals can work this rhythm without triggers, but do use light and darkness to get the timing right. The mechanism also affects the working of the body to make it suitable for growth and repair – the temperature, heart and breathing rates and many hidden levels have different sleep and wake settings. This sort of mechanism causes sleep but it is the ‘how’ of sleep not the ‘why’.

The brain is a complex organ with many functions. It is not a simple concept to say that the brain is inactive, resting and recuperating. There may be many processes in the brain taking advantage of sleep; there are a number of different types of sleep which obviously have different functions.

One function that has been investigated is waste removal. During parts of sleep some of the brain cells become physically smaller and this allow the movement of liquid through the brain, clearing out waste. It probably would interfere with the working of the brain to have cells temporarily lose volume – better to do this during sleep.

Another function that sleep houses is REM phase/dreaming. Dreaming is not completely understood but it is clearly needed for the successful integration of new memories into the web of established memories in the cortex. In this process the memories seem to be partially activated and re-experienced in combination with previous memories. For this process to be safe (without sleep walking or worse) the brain disconnects the possibility of skeletal muscle movement. This paralysis could only be acceptable in the safe inactive state of sleeping.

Another function that is known but not completely understood is the resetting of the brain’s level of activity. This is the one outlined in the NewScientist article. Consider that during the day, there has been continuous firing of neurons as a result of continuous signaling through the synapses of the brain. The synapses that are not used do not lose any strength while the ones that are used increase in strength. We end the day with a very excitable brain. During sleep this is brought down to a lower level to start the next day. All the synapses lose strength so that the new difference between strong ones and weaker ones remains but the overall strength is lower. As a photographic metaphor, it is like lowering the ‘brightness’ while maintaining the ‘contrast’ on a washed out over exposed photo. If this is not done, due to sleep deprivation, then the brain finds it more and more difficult to function. It seems that sleep alternates between strengthening particular synapses and weakening all synapses.

Of course, this is probably only the tip of the iceberg for finding sleep functions in the brain. I would not be surprised at a number of others being identified. There may even be processes that apply to insects but not to humans, as insects can sleep too. That is why an article that implies that there is a single function, THE reason for sleep, and that single reason has finally been found, is annoying. All the causes of, reasons for, functions of sleep are important and unlikely to be all found or understood.

Language in the right hemisphere

Language in the right hemisphere

I am going to write two posts: this one on the right hemisphere and prosody in language, and a later one on the left hemisphere and motor control of language. Prosody is the fancy word for things like rhythm, tone of voice, stress patterns, speed and pitch. It is not things like individual phonemes, words or syntax. In order to properly understand language, we need both.

A recent paper (Sammler, Grosbras, Anwander, Bestelmeyer, and Belin; Dorsal and Ventral Pathways for Prosody; Current Biology, Volume 25, Issue 23, p3079–3085, 7 December 2015) gives evidence of the anatomy of the auditory system in the right hemisphere that is like that in the left. Of course the two hemispheres collaborate in understanding and producing language but the right side processes the emotional aspects while the left processes the literal meaning.

Here is the abstract:

Our vocal tone—the prosody—contributes a lot to the meaning of speech beyond the actual words. Indeed, the hesitant tone of a “yes” may be more telling than its affirmative lexical meaning. The human brain contains dorsal and ventral processing streams in the left hemisphere that underlie core linguistic abilities such as phonology, syntax, and semantics. Whether or not prosody—a reportedly right-hemispheric faculty—involves analogous processing streams is a matter of debate. Functional connectivity studies on prosody leave no doubt about the existence of such streams, but opinions diverge on whether information travels along dorsal or ventral pathways. Here we show, with a novel paradigm using audio morphing combined with multimodal neuroimaging and brain stimulation, that prosody perception takes dual routes along dorsal and ventral pathways in the right hemisphere. In experiment 1, categorization of speech stimuli that gradually varied in their prosodic pitch contour (between statement and question) involved (1) an auditory ventral pathway along the superior temporal lobe and (2) auditory-motor dorsal pathways connecting posterior temporal and inferior frontal/premotor areas. In experiment 2, inhibitory stimulation of right premotor cortex as a key node of the dorsal stream decreased participants’ performance in prosody categorization, arguing for a motor involvement in prosody perception. These data draw a dual-stream picture of prosodic processing that parallels the established left-hemispheric multi-stream architecture of language, but with relative rightward asymmetry.

The ventral and dorsal pathways are also found in both hemispheres in vision. The ventral is often called the ‘what’ pathway and identifies objects and conscious perception while the dorsal is called the ‘where’ pathway and is involved in spatial location for motor accuracy. The auditory pathways appear to also have the dorsal path going to motor centers and the ventral to perceptual centers. And although they deal with different processing functions the pair of auditory pathways appear in both hemispheres, like the visual ones.

 

Misjudging criteria

Most people think of memory as the ‘past’ and judge it by how well it preserves the past. But that is not its function. Memory is material to be used in the ‘present’ and the ‘future’. What happened in the past is not important except to help understand the present and predict/plan the future. Bits of memory out of historical context are the ingredients of imagination. With more context they are the tools we use to identify things in the present and understand their dangers and opportunities. We need to know if we are encountering the old or the new. We need to remember whether someone is trustworthy when we deal with them. When we look at what we remember, how and how long we remember it, and how closely we keep it to the original memory, we should think of what is the point of all of it.

What seems a fault with memory – that memories are not fixed but can change or be lost altogether – is only a side effect of their being modified to stay relevant and useful. We need memories that help us perceive the present and model the future and that is the real criteria, not absolute accuracy. The criteria for a well constructed memory system are biological evolutionary survival ones.

Colour vision is not about accurately perceiving the frequencies of light coming into the eye. It is not about the light; it is about the surface that reflected the light and how it can be identified. There is no use in saying that our vision is not giving us accurate colour, because accurate colour would interfere with accurate characterization of surfaces and identification of objects. The many optical illusions are not faults in the system – they are due to the ways that the visual system protects the stability of our vision so that things do not appear to change colour or size.

Language is not about meaning or logic; it is about communication. People worry about changes in the meaning of words and the use of grammatical forms. Well, here is what happens generation after generation: if people have difficulty communicating, they will change their language. If their way of life changes, if they move to a different region, if the people they are talking to change, then they will change their language. Our language is not the result of biological evolution so much as cultural evolution. But the same idea applies and the criteria have to do with communication. Is language logical? It may seem so from within that language but talk to anyone learning it as a new language and see the illogical, arbitrary quirks in it. There are languages that count negatives and there must be an odd number to be negative. There are languages that have to have all or no words carry a negative marking. Both types of negation seem logical to the speakers. Is language a good communication tool? Without doubt it is better than anything else we have ever tried to invent. No artificial language has ever made a dent on a natural language no matter how clear was the meaning or logical the grammar of the new language.

When we look at biological and even social systems it is important to consider what is their real, primary reason for existence. We have a tendency to misjudge the criteria and need to watch out for this trap.

 

 

First and last syllables

Have you wondered why rhyme and alliteration are so common and pleasing, why they assist memorization? They seem to be taking advantage of the way words are ‘filed’ in the brain.

A ScienceDaily item (here) looks at a paper on how babies hear syllables. (Alissa L. Ferry, Ana Fló, Perrine Brusini, Luigi Cattarossi, Francesco Macagno, Marina Nespor, Jacques Mehler. On the edge of language acquisition: inherent constraints on encoding multisyllabic sequences in the neonate brain. Developmental Science, 2015; DOI: 10.1111/desc.12323).

It is known that our cognitive system recognizes the first and last syllables of words better than middle syllables. For example there is a trick of being able to read print where the middle of the words are changed. It has also been noted that the edges of words are often information rich, especially with grammatical information.

This paper shows that this is a feature of our brains from birth – no need to learn it.At just two days after birth, babies are already able to process language using processes similar to those of adults. SISSA researchers have demonstrated that they are sensitive to the most important parts of words, the edges, a cognitive mechanism which has been repeatedly observed in older children and adults.” The babies were also sensitive to the very short pause between words as a way to tell when one word ends and another begins.

Here is the abstract: “To understand language, humans must encode information from rapid, sequential streams of syllables – tracking their order and organizing them into words, phrases, and sentences. We used Near-Infrared Spectroscopy (NIRS) to determine whether human neonates are born with the capacity to track the positions of syllables in multisyllabic sequences. After familiarization with a six-syllable sequence, the neonate brain responded to the change (as shown by an increase in oxy-hemoglobin) when the two edge syllables switched positions but not when two middle syllables switched positions (Experiment 1), indicating that they encoded the syllables at the edges of sequences better than those in the middle. Moreover, when a 25ms pause was inserted between the middle syllables as a segmentation cue, neonates’ brains were sensitive to the change (Experiment 2), indicating that subtle cues in speech can signal a boundary, with enhanced encoding of the syllables located at the edges of that boundary. These findings suggest that neonates’ brains can encode information from multisyllabic sequences and that this encoding is constrained. Moreover, subtle segmentation cues in a sequence of syllables provide a mechanism with which to accurately encode positional information from longer sequences. Tracking the order of syllables is necessary to understand language and our results suggest that the foundations for this encoding are present at birth.

Carving Nature at its joints

If you have done any butchery or even carved the meat at the table, you will understand this metaphor. In order not to hack and end up with a terrible mess, you must follow the actual anatomy of the meat. In particular, the place to separate two bones leaving their muscles attached is at the joint. That is where you cut and break the two bones apart. This was Plato’s metaphor for making valid categories, ones that fit with the underlying ‘anatomy’ of nature.

It seems to me that we are not cutting at the joint in neuroscience. How does a science know if its concepts, categories, technical terms, contrasts/opposites are mirroring nature? Well, strictly speaking, there is no way to know that our categories are in keeping with nature. However, we can tell ways in which they are not. Perfection may not be possible but improvement almost always is. When we have to make room for odd little exceptions, when we can’t use the categories to make good predictions, when they are not easy to use, when they seem fragile to cultural or semantic differences, when they seem part of a slippery slope, when they do not fit with our theories – we have to think again about where the joints might be.

Why should neuroscience be in trouble with its categories? First, it is a very new science. It only really started in the last century; some would say it didn’t get going until into the 1980s and that would be 30 years ago. It does not have any overarching theory (not like Relativity, Quantum mechanics, Molecular theory, Plate Techonics, Cell theory, Evolution and the like). Its territory is more in ignorance than in light. Finding the joints is almost a matter of luck.

Second, it is immensely complex.

Third, neuroscience has inherited a lot of folk psychology; a great burden of Freudian psychology and other older theories; medical terminology and theories to do with mental illness; dated biological theories; attempts to simulate thought with computers; philosophical, legal and religious notions and theories. It is little wonder that agreed categories are next to impossible at the present time.

Take schizophrenia as an example. Most people treat that name as denoting a single disease. But it is more likely to be denoting a variety of diseases with differing causes, courses, symptoms, treatments, outcomes. There is no reason to accept, and many reasons to doubt, that it is a single disease. So what exactly does a statement like, “people suffering from schizophrenia hear voices”, mean. Not all schizophrenics hear voices and not everyone who hears voices is schizophrenic. And so it is with most symptoms of this ‘disease’. The same problem dogs ‘autism’ and some other conditions.

Intelligence is also hard to see as a clean category. How can it be measured? Is it one general thing or many specific one? Which specific ones? Do we know what personality is? Can we agree on subdividing it? What is its relationship to other things? There are so many, many words with such vague meanings. Neuroscience has words acquired from many sources. I read a philosophical paper and I wonder where do these words touch physical reality? What, I wonder, is a ‘mental state’; could it be a real thing? The popular press and some academics talk of ‘ego’. That is a Freudian concept and his division of the brain (ego, superego, id) is very clearly not at any ‘joints’? The computer set uses ‘algorithm’; just where are we likely to find algorithms in the brain?

It would seem that the closer a scientist is working to the level of cells and cell assemblies, the more likely they are to see the joints. But they would be less likely to be answering questions that people outside of neuroscience want answered. But unless people want to wade through oceans of muddy water, they may have to wait for answers to ‘important’ questions until after many boring questions have been investigated. My guess would be that the semantic arguments will continue because the words in which people are thinking are not doing a good job of the carving.

 

Vacation

I will not be posting to my blog for a while for various reasons including a holiday – see you in a few weeks.

Ravens can play politics

Ravens are often featured in mythology – spirit, god, creator, trickster, fortune teller and so on – heroes and villains. They are one of the most intelligent birds. A recent paper by Massen et al (citation below) shows that they are even more remarkable than science has so far shown.

The social brain hypothesis is the idea that intelligence and large brain size is an adaptation to social behavior. The more complex an animal’s social life is, the more intelligence they need to be successful. Social animals are more intelligent than their related non-social ones. But animal societies can vary in complexity and that demands extra skills. One of the first things a social animal needs is the ability to recognize all the individuals in its group and to know which are more dominant than itself and which less. It is an advantage to not fight with those that can beat you and also an advantage to not let a weaker opponent bluff you. It is an advantage to have a non-competitive bond, an alliance with kin and special friends. It is an advantage to know the etiquette and group tactics, to communicate, to be deceptive, and so on. All this takes memory, cognitive skills, and emotional control plus some theory of mind if the social adaptations include predicting others behaviour.

We have some social behaviours that have not yet been found in other animals, but the list has been getting shorter. Another area to be found not exclusively ours is a ‘political’ skill: to be able to observe but not interact with another group and figure out the dominance structure in that group. Primates can do this other group trick but they need to react with at least some of the strangers directly. The Mason paper shows that ravens can do it with just observation. They can observe another group, learn to tell the individuals apart and learn the dominance hierarchy in that group. Raven’s “cognitive skills are expressed primarily in the social domain: on one hand, they flexibly switch between group foraging (including active recruitment) and individual strategies (like providing no or false information about food, attributing perception and knowledge states about food caches to others); on the other hand, they form and maintain affiliate social relations aside from reproduction and engage in primate-like social strategies like support during conflicts, and reconciliation and consolation after conflicts. Understanding social relations of others may be key in those behaviours. Ravens also remember former group members and their relationship valence over years.” And this new skill to that list.

Massen and the other researchers had a group of young ravens in a pen (for other reasons) and another group within sight. They staged fake encounters between pairs of ravens that were just out of sight using recorded sounds. Sometimes the staged encounters matched the dominance relationship between the hidden birds and sometimes they were opposite to the expected interaction. The reaction of the test raven to these staged encounters was studied. In this way the researchers could note which dominance relationships the raven knew and which they didn’t by their reaction to incongruous events. There were differences between male and female birds in their reactions, and which staged encounters that most surprised them. But overall, ravens can very often learn the dominance hierarchy of another group by just observing them. This may be found in other animals (when it is looked for) but until now we only knew that humans could do this bit of social behavior.

Here is the abstract:

A core feature of social intelligence is the understanding of third-party relations, which has been experimentally demonstrated in primates. Whether other social animals also have this capacity, and whether they can use this capacity flexibly to, for example, also assess the relations of neighbouring conspecifics, remains unknown. Here we show that ravens react differently to playbacks of dominance interactions that either confirm or violate the current rank hierarchy of members in their own social group and of ravens in a neighbouring group. Therefore, ravens understand third-party relations and may deduce those not only via physical interactions but also by observation.”

ResearchBlogging.org

Massen, J., Pašukonis, A., Schmidt, J., & Bugnyar, T. (2014). Ravens notice dominance reversals among conspecifics within and outside their social group Nature Communications, 5 DOI: 10.1038/ncomms4679

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