Tag Archives: plasticity

The Edge Question 6

This is the last posting on the Edge Question responses. You can find all (over 100) answers (here). The question was: What scientific idea is ready for retirement?

 

Some responses were critical of essentialist views: Barrett, essentialist views of the mind; Richerson, human nature; Shafir, opposites can’t both be right; Dawkins, essentialism.

 

Lisa Barrett (University Distinguished Professor of Psychology, Northeastern University; Research Scientist and Neuroscientist, Massachusetts General Hospital/Harvard Medical School) “In pre-Darwinian biology, for example, scholars believed each species had an underlying essence or physical type, and variation was considered error. Darwin challenged this essentialist view, observing that a species is a conceptual category containing a population of varied individuals, not erroneous variations on one ideal individual….In my field of psychology, essentialist thought still runs rampant….This (subcategorization of emotions) technique of creating ever finer categories, each with its own biological essence, is considered scientific progress, rather than abandoning essentialism as Darwin and Einstein did….Essentialism can also be seen in studies that scan the human brain, trying to locate the brain tissue that is dedicated to each emotion. At first, scientists assumed that each emotion could be localized to a specific brain region (e.g., fear occurs in the amygdala), but they found that each region is active for a variety of emotions, more than one would expect by chance. Since then, scientists have been searching for the brain essence of each emotion in dedicated brain networks, and in probabilistic patterns across the brain, always with the assumption that each emotion has an essence to be found, rather than abandoning essentialism….The data are screaming out that essentialism is wrong: individual brain regions, circuits, networks and even neurons are not single-purpose…. every psychological theory in which emotions and cognitions battle each other, or in which cognitions regulate emotions, is wrong….This discussion is more than a bunch of metaphysical musings. Adherence to essentialism has serious, practical impacts on national security, the legal system, treatment of mental illness, the toxic effects of stress on physical illness… the list goes on. Essentialism leads to simplistic “single cause” thinking when the world is a complex place.”

 

Peter Richerson (Distinguished Professor Emeritus, University of California-Davis; Visiting Professor, Institute of Archaeology, University College London)

 

The concept of human nature has considerable currency among evolutionists who are interested in humans. Yet when examined closely it is vacuous. Worse, it confuses the thought processes of those who attempt to use it. Useful concepts are those that cut nature at its joints. Human nature smashes bones. Human nature implies that our species is characterized by common core of features that define us. Evolutionary biology teaches us that this sort of essentialist concept of species is wrong. A species is an assemblage of variable individuals, albeit individuals who are sufficiently genetically similar that they can successful interbreed.The concept of human nature causes people to look for explanations under the wrong rock. Take the most famous human nature argument: are people by nature good or evil? In recent years, experimentalists have conducted tragedy of the commons games and observed how people solve the tragedy (if they do). A common finding is that roughly a third of participants act as selfless leaders, using whatever tools the experimenters make available to solve the dilemma of cooperation, roughly a tenth are selfish exploiters of any cooperation that arises, and the balance are guarded cooperators with flexible morals….In no field is the deficiency of the human nature concept better illustrated than in its use to try to understand learning, culture and cultural evolution. Human nature thinking leads to the conclusion that causes of behavior can be divided into nature and nurture. Nature is conceived of as causally prior to nurture both in evolutionary and developmental time. What evolves is nature and cultural variation, whatever it is, has to the causal handmaiden of nature. This is simply counterfactual…. Using the human nature concept, like essentialism more generally, makes it impossible think straight about human evolution.

 

Edlar Shafir (William Stewart Tod Professor of Psychology and Public Affairs Ph.D., Princeton University; Co-author, Scarcity)

 

We typically assume, for example, that happiness and sadness are polar opposites and, thus, mutually exclusive. But recent research on emotion suggests that positive and negative affects should not be thought of as existing on opposite sides of a continuum, and that, in fact, feelings of happiness and sadness can co-occur. When participants are surveyed immediately after watching certain films, or graduating from college, they are found to feel both profoundly happy and sad. …(people can be) both caring and indifferent, displaying one trait or the other depending on arbitrary twists of fate. From the little I understand, physicists question the classical distinction between wave and matter, and biologists refuse to choose between nature and nurture. But let me stay close to what I know best. In the social sciences, there is ongoing, and often quite heated, debate about whether or not people are rational, and about whether they’re selfish. And there are compelling studies in support of either camp… People can be cold, precise, selfish and calculating. Or they can be hot-headed, confused, altruistic, emotional and biased. In fact, they can be a little of both; they can exhibit these conflicting traits at the very same time.”

 

Richard Dawkins(Evolutionary Biologist; Emeritus Professor of the Public Understanding of Science, Oxford; Author, The Greatest Show on Earth, The Magic of Reality) “Essentialism—what I’ve called “the tyranny of the discontinuous mind”—stems from Plato, with his characteristically Greek geometer’s view of things. For Plato, a circle, or a right triangle, were ideal forms, definable mathematically but never realised in practice. A circle drawn in the sand was an imperfect approximation to the ideal Platonic circle hanging in some abstract space. That works for geometric shapes like circles, but essentialism has been applied to living things… The whole system of labelling species with discontinuous names is geared to a time slice, the present, in which ancestors have been conveniently expunged from our awareness…Essentialism rears its ugly head in racial terminology. The majority of “African Americans” are of mixed race. Yet so entrenched is our essentialist mind-set, American official forms require everyone to tick one race/ethnicity box or another: no room for intermediates….I mainly want to call attention to our society’s essentialist determination to dragoon a person into one discrete category or another. We seem ill-equipped to deal mentally with a continuous spectrum of intermediates. We are still infected with the plague of Plato’s essentialism. Moral controversies such as those over abortion and euthanasia are riddled with the same infection. At what point is a brain-dead accident-victim defined as “dead”? At what moment during development does an embryo become a “person”? Only a mind infected with essentialism would ask such questions…. Our essentialist urge toward rigid definitions of “human” (in debates over abortion and animal rights) and “alive” (in debates over euthanasia and end-of-life decisions) makes no sense in the light of evolution and other gradualistic phenomena. We define a poverty “line”: you are either “above” or “below” it. But poverty is a continuum. Why not say, in dollar-equivalents, how poor you actually are?

 

You can surely think of many other examples of “the dead hand of Plato”—essentialism. It is scientifically confused and morally pernicious. It needs to be retired.

 

The next group does not have much in common except that they complain about widely held opinion in science and/or the public.

 

Chalupa responded with a request to retire brain plasticity. He is not saying that the brain is not plastic but that it always is and therefore there is no need to keep saying it it.

 

Leo M. Chalupa (Ophthalmologist and Neurobiologist, George Washington University) “Brain plasticity refers to the fact that neurons are capable of changing their structural and functional properties with experience. …The field of brain plasticity primarily derives from the pioneering studies of Torsten Wiesel and David Hubel ….These studies convincingly demonstrated that early brain connections are not hard-wired, but could be modified by early experience hence they were plastic…. Since that time there have been thousands of studies showing a wide diversity of neuronal changes in virtually every region of the brain, ranging from molecular to the systems level….As a result, by the end of the 20th century our view of the brain evolved from the hard wired to the seemingly ever changeable…. the widespread use of “brain plasticity” to virtually every type of change in neuronal structure and function has rendered this term largely meaningless…. many studies invoke brain plasticity as the underlying cause of modified behavioral states without having any direct evidence for neuronal changes….There are large profits to be made as evident by the number of (brain training) companies that have proliferated in this sector in recent years….But please refrain from invoking brain plasticity, remarkable or otherwise, to explain the resulting improvements.”

 

Blackmore would like to retire the Neural Correlates of Consciousness, NCCs, and the theory behind them. This one is difficult for me because I agree with everything she says except that there may be no neural correlates of consciousness. Is the activity of the thalamo-cortical loops not part of the NCCs? I don’t think one has to be a dualist to look for the way that the brain creates each individual conscious moment or how it creates the vivid illusions that are the content of each moment.

 

Susan Blackmore (Psychologist; Author, Consciousness: An Introduction) Consciousness is a hot topic in neuroscience and some of the brightest researchers are hunting for the neural correlates of consciousness (NCCs)—but they will never find them. The implicit theory of consciousness underlying this quest is misguided and needs to be retired…the mystery of how subjective experience arises from (or is created by or generated by) objective events in a brain—then it’s easy to imagine that there must be a special place in the brain where this happens. Or if there is no special place then some kind of ‘consciousness neuron’, or process or pattern or series of connections. We may not have the first clue how any of these objective things could produce subjective experience but if we could identify which of them was responsible (so the thinking goes), then we would be one step closer to solving the mystery….The underlying intuition is that consciousness is an added extra—something additional to and different from the physical processes on which it depends. Searching for the NCCs relies on this difference. On one side of the correlation you measure neural processes using EEG, fMRI or other kinds of brain scan; on the other you measure subjective experiences or ‘consciousness itself’….Dualist thinking comes so naturally to us. We feel as though our conscious experiences are of a different order from the physical world. But this is the same intuition that leads to the hard problem seeming hard. It is the same intuition that produces the philosopher’s zombie—a creature that is identical to me in every way except that it has no consciousness. It is the same intuition that leads people to write, apparently unproblematically, about brain processes being either conscious or unconscious….Am I really denying this difference? Yes. Intuitively plausible as it is, this is a magic difference. Consciousness is not some weird and wonderful product of some brain processes but not others. Rather, it is an illusion constructed by a clever brain and body in a complex social world. We can speak, think, refer to ourselves as agents and so build up the false idea of a persisting self that has consciousness and free will….All we will ever find is the neural correlates of thoughts, perceptions, memories and the verbal and attentional processes that lead us to think we are conscious.When we finally have a better theory of consciousness to replace these popular delusions we will see that there is no hard problem, no magic difference and no NCCs.

 

Churchland goes after Brain Modules. The word ‘module’ has implications that do not fit what is known about the brain.

 

Patricia S. Churchland (Philosopher and Neuroscientist, UC San Diego; Author, Touching a Nerve: The Self as Brain)“The concept of ‘module’ in neuroscience (meaning sufficient for a function, given gas-in-the-tank background conditions) invariably causes more confusion than clarity. The problem is that any neuronal business of any significant complexity is underpinned by spatially distributed networks, and not just incidentally but essentially—and not just cortically, but between cortical and subcortical networks. ….What is poorly understood is how nervous systems solve the coordination problem; i.e. how does the brain orchestrate the right pattern of neuronal activation across networks to get the job done?…This is not all that is amiss with ‘module’. Traditionally, modules are supposed to beencapsulated–aka insulated. I think of ‘module’ in the way I think of ‘nervous breakdown’—mildly useful in the old days when we had no clue about what was going on under the skull, but of doubtful explanatory significance these days.

 

Sacktor wants to to get rid of the idea that Long-Term Memory is Immutable. My impression is that this is gone from science but still is current in the general public.

 

Todd C. Sacktor (Distinguished Professor of Physiology, Pharmacology, and Neurology, State University of New York Downstate Medical Center) For over a century psychological theory held that once memories are consolidated from a short-term into long-term form, they remain stable and unchanging. Whether certain long-term memories are very slowly forgotten or are always present but cannot be retrieved was a matter of debate…. (This made sense for 50 years.) Two recent lines of evidence have relegated this dominant theory of long-term memory ready for retirement. First is the discovery of reconsolidation. When memories are recalled, they undergo a brief period in which they are once again susceptible to disruption by many of the same biochemical inhibitors that affect the initial conversion of short- into long-term memory. This means that long-term memories are not immutable, but can be converted into short-term memory, and then reconverted back into long-term memory. If this reconversion doesn’t happen, the specific long-term memory is effectively disrupted. The second is the discovery of a few agents that do indeed erase long-term memories…. Memory reconsolidation allows specific long-term memories to be manipulated. Memory erasure is extraordinarily potent and likely disrupts many, if not all long-term memories at the same time. When these two fields are combined, specific long-term memories will be erased or strengthened in ways never conceivable in prior theories.

 

Clark goes after the Input-Output Model of Perception and Action.

 

Andy Clark (Philosopher and Cognitive Scientist, University of Edinburgh; Author: Supersizing the Mind: Embodiment, Action, and Cognitive Extension) “It’s time to retire the image of the mind as a kind of cognitive couch potato—a passive machine that spends its free time just sitting there waiting for an input to arrive to enliven its day. When an input arrives, this view suggests, the system swings briefly into action, processing the input and preparing some kind of output (the response, which might be a motor action or some kind of decision, categorization, or judgement). Output delivered, the cognitive couch potato in your head slumps back awaiting the next stimulation.The true story looks to be almost the reverse.Naturally intelligent systems (humans, other animals) are not passively awaiting sensory stimulation. Instead, they are constantly active, trying to predict the streams of sensory stimulation before they arrive. … Systems like that are already (pretty much constantly) poised to act, and all they need to process are any sensed deviations from the predicted state. Action itself then needs to be reconceived. …These hyperactive systems are constantly predicting their own upcoming states, and moving about so as to bring some of them into being. In this way we bring forth the evolving streams of sensory information that keep us viable (keeping us fed, warm, and watered) and that serve our increasingly recondite ends. As ever-active prediction engines these kinds of minds are not, fundamentally, in the business of solving puzzles given to them as inputs. Rather, they are in the business of keeping us one step ahead of the game, poised to act and actively eliciting the sensory flows that keep us viable and fulfilled.

 

Hoffman wants to lose the idea that Truer Perceptions are Fitter Perceptions.

 

Donald D. Hoffman (Cognitive Scientist, UC, Irvine; Author, Visual Intelligence) “Those of our predecessors who perceived the world more accurately enjoyed a competitive advantage over their less-fortunate peers. They were thus more likely to raise children and to become our ancestors. … But with these provisos noted, it is fair to conclude on evolutionary grounds that our perceptions are, in general, reliable guides to reality. This is the consensus of researchers studying perception via brain imaging, computational modeling and psychophysical experiments. It is mentioned in passing in many professional publications, and stated as fact in standard textbooks. But it gets evolution wrong. Fitness and truth are distinct concepts in evolutionary theory. To specify a fitness function one must specify not just the state of the world but also, inter alia, a particular organism, a particular state of that organism, and a particular action. …Monte Carlo simulations using evolutionary game theory, with a wide range of fitness functions and a wide range of randomly created environments, find that truer perceptions are routinely driven to extinction by perceptions that are tuned to the relevant fitness functions. Perceptions tuned to fitness are typically far less complex than those tuned to truth. They require less time and resources to compute, and are thus advantageous in environments where swift action is critical. …We must take our perceptions seriously. They have been shaped by natural selection to guide adaptive behaviors and to keep us alive long enough to reproduce. We should avoid cliffs and snakes. But we must not take our perceptions literally. They are not the truth; they are simply a species-specific guide to behavior. Observation is the empirical foundation of science. The predicates of this foundation, including space, time, physical objects and causality, are a species-specific adaptation, not an insight. Thus this view of perception has implications for fields beyond perceptual science, including physics, neuroscience and the philosophy of science. The old assumption that fitter perceptions are truer perceptions is deeply woven into our conception of science.”

 

Dennett wants the Hard Problem buried.

 

Daniel C. Dennett (Philosopher; Austin B. Fletcher Professor of Philosophy, Co-Director, Center for Cognitive Studies, Tufts University; Author, Intuition Pumps) “One might object that the Hard Problem of consciousness (so dubbed by philosopher David Chalmers in his 1996 book, The Conscious Mind) isn’t a scientific idea at all, and hence isn’t an eligible candidate for this year’s question, but since the philosophers who have adopted the term have also persuaded quite a few cognitive scientists that their best scientific work addresses only the “easy” problems of consciousness, this idea qualifies as scientific: it constrains scientific thinking, distorting scientists’ imaginations as they attempt to formulate genuinely scientific theories of consciousness. No doubt on first acquaintance the philosophers’ thought experiments succeed handsomely at pumping the intuitions that zombies are “conceivable” and hence “possible” and that this prospect, the (mere, logical) possibility of zombies, “shows” that there is a Hard Problem of consciousness untouched by any neuroscientific theories of how consciousness modulates behavioral control, introspective report, emotional responses, etc., etc. But if the scientists impressed by this “result” from philosophers were to take a good hard look at the critical literature in philosophy exploring the flaws in these thought experiments, they would—I hope—recoil in disbelief. (I am omitting Dennett’s discussion of the faults in zombies and other philosophical contortions.) …Is the Hard Problem an idea that demonstrates the need for a major revolution in science if consciousness is ever to be explained, or an idea that demonstrates the frailties of human imagination? That question is not settled at this time, so scientists should consider adopting the cautious course that postpones all accommodation with it. That’s how most neuroscientists handle ESP and psychokinesis—assuming, defeasibly, that they are figments of imagination.”