Showing posts with label Neuroscience. Show all posts
Showing posts with label Neuroscience. Show all posts

Thursday, October 1, 2015

Quote Of The Day: Does Quantum Indeterminacy Allow Free Will?


Today's QOTD is by Caltech physcist Sean Carroll. Many people, theists and atheist alike, think that quantum indeterminacy allows for libertarian free will to take place. But this is a misunderstanding of quantum mechanics and the way probability works in it. On his blog, Carroll explains:

[I]f you want to use the lack of determinism in quantum mechanics to make room for supra-physical human volition (or, for that matter, occasional interventions by God in the course of biological evolution, as Francis Collins believes), then let’s be clear: you are not making use of the rules of quantum mechanics, you are simply violating them. Quantum mechanics doesn’t say “we don’t know what’s going to happen, but maybe our ineffable spirit energies are secretly making the choices”; it says “the probability of an outcome is the modulus squared of the quantum amplitude,” full stop. Just because there are probabilities doesn’t mean there is room for free will in that sense.

Wednesday, September 30, 2015

Quote Of The Day: Does Consciousness Collapse The Wave Function?


There are so many purveyors of woo-woo out there that it's enough to drive an atheist mad. One of the most common claims is that the famous double slit experiment shows that consciousness collapses the wave function because it seems that observing the quantum particles changes their behavior from waves to particles. This is often used by spiritualists and theists as evidence that there is a soul, because, it is argued, physical reality seems to exist only when we're looking at it, and so the soul must be fundamental.

But most working physicists will tell you that consciousness has nothing to do with wave function collapse, often described as decoherence. Here's a quote from an actual physicist David Simmons-Duffin on what really collapses the wave function:

Decoherence occurs whenever a quantum mechanical system interacts with another system with a large number of degrees of freedom (like a human, or a house cat, or a chair). It has absolutely nothing to do with consciousness, and can be described rigorously from the Schrodinger equation without any extra axioms.

Monday, September 21, 2015

Free Will, Science, And Religion Podcast


On the weekend I participate in a podcast called Free Will, Science, and Religion that talks about, well, free will, science, and religion, and how they all intermingle. Although we're all on the same page that libertarian free will doesn't exist, we differ on many other things. We're not all atheists; at least one of the participants is a pantheist. We differ on politics, like on the topic of abortion. Most are hard determinists/incompatibilists, but I'm the only one a bit sympathetic to compatibilism.


Here is the first episode introducing the podcast:



We've piled through over a hundred episodes, although I haven't participated in most of them. Here is the hundredth episode, on how understanding that we have no free will be the biggest revolution in human history ever.



I'll be listing all the episodes from now on on my blog, maybe not all of them, but I'll have to see how it goes.

Wednesday, June 24, 2015

Miracles: Humean or Leibnizian?


Every religion has miracle claims. The purpose of these claims can vary from religion to religion and from within religions. Sometimes the purpose is to demonstrate god's awesome power. Other times it's to establish the authority and validity of a prophet. Regardless of the reasons, the miracle itself is a demonstration of the natural laws of physics being violated. This view of miracles is so common that the definition of a miracle in its popular usage is "an event not explicable by natural or scientific laws."

Or is it? Miracles of this kind — the law violating type, are sometimes called Humean miracles, after the 18th century Scottish philosopher David Hume. In Section X in his 1748 book An Enquiry concerning Human Understanding, titled Of Miracles, he defined a miracle as "a transgression of a law of nature by a particular volition of the Deity, or by the interposition of some invisible agent". Though a source of great debate, this general notion of miracles violating natural law such that they could not happen without the interference of a deity or something outside nature is what we commonly think of when we claim a miracle occurred (despite the fact that colloquially we loosely throw the term around to describe anything unlikely, such as surviving a terrible car crash).

But the Humean definition is only one of many. One of its great rivals is the lesser known Leibnizian miracle, and fits into the view philosopher Kenny Pearce calls Christian naturalism. Leibniz was the 17th/18th century philosopher and mathematician known mostly to apologists as the creator of the argument from contingency. Pearce describes what a miracle is on his blog following Leibniz's insights:

A miracle is an event in which the "higher functions" of the divine consciousness, i.e. the part equivalent to the conscious functioning of the human mind, that makes plans and designs regarding human lives and the like, are more apparent than the "lower functions" which are the laws of nature. To put it more simply (but less precisely) a miracle occurs when the laws of nature conspire together to acheive [sic] some intelligent end. These sorts of miracles are a definite argument not just for the existence of a spiritual being in general, but for the existence of the God of the Judeo-Christian Scriptures.

Um, what? I have to honestly say that I have no idea what he really means in his first sentence. How do the higher functions of the divine consciousness become more apparent than the laws of nature without violating them? It's not clear, especially since earlier in the post Pearce had written:

What I do mean, is the belief that every occurence [sic] in the physical world is governed by a set of fundamental laws to which there are no exceptions.

Except of course that one time, an under-aged virgin girl in Palestine gave birth to a son, who walked on water and turned it into wine without technology, and he died for a few days and came back to life. Yeah, no exceptions. But anyway...

Friday, June 5, 2015

The Evidence From Neuroscience That Free Will Is An Illusion



Starting with Benjamin Libet's experiments in 1983 which gave some of the earliest evidence that conscious decisions are preceded by unconscious neural activity, there have been numerous scientific studies recently that have confirmed this to a much higher degree. Here is a list of some of those tests:


Unconscious determinants of free decisions in the human brain

Highlights:

  • Taken together, two specific regions in the frontal and parietal cortex of the human brain had considerable information that predicted the outcome of a motor decision the subject had not yet consciously made. This suggests that when the subject’s decision reached awareness it had been influenced by unconscious brain activity for up to 10 seconds.
  • The temporal ordering of information suggests a tentative causal model of information flow, where the earliest unconscious precursors of the motor decision originated in frontopolar cortex, from where they influenced the buildup of decision-related information in the precuneus and later in SMA, where it remained unconscious for up to a few seconds.

Tracking the Unconscious Generation of Free Decisions Using UItra-High Field fMRI

Highlights:

  • Researchers show that it was possible to decode the decision outcomes of such free motor decisions from the pole of anterior medial prefrontal cortex (BA 10) and the precuneus/posterior cingulate cortex (PCC), up to 7 s before subjects were aware of their intention.
  • Taking into account the temporal delay of the BOLD signal (which is in the order of a few seconds), it is possible that these signals reflect processes up to 10 seconds before the actual decision.

Predicting free choices for abstract intentions

Highlights:

  • Researchers are able to show that the outcome of a free decision to either add or subtract numbers can already be decoded from neural activity in medial prefrontal and parietal cortex 4 s before the participant reports they are consciously making their choice.
  • Previous findings have been mostly restricted to simple motor choices.
  • In the current study, participants were not cued to make decisions at specific points in time but were allowed to make decisions spontaneously. By asking participants to report when they first consciously decided, we could investigate what happened in the brain before the decisions were consciously made. We found that both medial frontopolar cortex and posterior cingulate/precuneus started to encode the specific outcome of the abstract decisions even before they entered conscious awareness. Our results suggest that, in addition to the representation of conscious abstract decisions, the medial frontopolar cortex was also involved in the unconscious preparation of abstract decisions.

Reading My Mind

Highlights:

  • CBS 60 minutes report from 2009 showing how fMRI imaging can recognize with a high degree of accuracy the contents of thoughts about objects like a hammer, a window, an apartment etc. 
  • Report reveals there are enough similarities between different people such that once enough people's brains are measured when thinking about an object, a person who never scanned can have their thoughts predicted with 100 percent accuracy when thinking about those objects. 

Internally generated preactivation of single neurons in human medial frontal cortex predicts volition.

Highlights:

  • Recording the activity of 1019 neurons while twelve subjects performed self-initiated finger movement, this study shows progressive neuronal recruitment over ∼1500 ms before subjects report making the decision to move.
  • A population of 256 SMA (supplementary motor area) neurons is sufficient to predict in single trials the impending decision to move with accuracy greater than 80% already 700 ms prior to subjects' awareness. Furthermore, they predict, with a precision of a few hundred ms, the actual time point of this voluntary decision to move.
  • Using an SVM classifier to predict the time point at which the subject reported making the decision to move, the algorithm detected the occurrence of the decision in 98% of the trials and only missed W in 2% of the trials.

There Is No Free Won’t: Antecedent Brain Activity Predicts Decisions to Inhibit

Highlights:

  • Our main argument is as follows: Libet et al, (1983) had suggested that decisions to inhibit action have an important role in freedom of will, because, he argued, they do not have any obvious unconscious neural precursors. In Libet’s view, this makes decisions to inhibit crucially different from decisions to act, for which, he claimed, there is a clear unconscious precursor. Libet’s dualistic notion of “free won’t” has been criticised on theoretical grounds. However, in our view, a stronger rejection of “free won’t” could come from actually showing that a decision to act or not can be driven by a preceding, presumably unconscious neural activity. Our results identify, for the first time, a candidate unconscious precursor of the decision to inhibit action. These results count as evidence against Libet’s view that the decision to inhibit action may involve a form of uncaused conscious causation.
  • The dualistic view that decisions to inhibit reflect a special “conscious veto” or “free won’t” mechanism is scientifically unwarranted.

As the data keeps piling up the evidence against free will gets stronger and stronger. If mental phenomena were caused by electro-chemical brain states as the data shows, the traditional dualistic picture of mind causing physical states is empirically ruled out by the data. Libertarian free will, and dualistic interactionism have no empirical support. The question now is whether you're a compatibilist or an incompatibilist. This is not to say that this evidence alone is absolute proof free will is an illusion, or that we've resolved the hard problem of consciousness. We still don't know how the brain causes consciousness, and it is possible we may never. But, we don't need to know how the brain causes consciousness in order to know that the brain causes consciousness. 

*This list will grow as I find more studies.

Sunday, April 19, 2015

Thoughts On The Randal Rauser/Justin Schieber Debate



So the debate between Randal Rauser and Justin Schieber from last month is online and having just watched it I thought I'd weigh in. Randal Rauser is a trained theologian and Christian apologist. What I like about him is that he isn't just another William Lane Craig clone, of which there are far too many. He makes his own arguments for god his own way and I always want to see the real reasons why theists believe what they do. Here, Randal offers a few of the arguments that help convince him god is real. I'll offer some thoughts on why I don't find them convincing.

First, Randal defines god as a "necessarily existent, non-physical agent, who is omniscient, omnipotent, and perfectly good." This is the basic god of classical theism which I think was a good idea for Randal to define upfront so there's no confusion. The only problem I have of course is the "necessarily existent" part. I know that many classical theists view god as necessarily existent, but there is often an attempt to define god into existence this way that I think is little more than wordplay. Thankfully, Randal does not try to make that argument for god in this debate.

Randal outlines his three main arguments:

  1. Rational belief in god doesn't require evidence
  2. God is a legitimate philosophical explanation
  3. God best accounts for the cognitive faculty of moral intuition

Let's go over them one by one.

1. Rational belief in god doesn't require evidence


Randal first defends the idea that rational belief in god doesn't require evidence. He tries to argue that it is properly basic, much like the belief in an external world. "One need not have evidence for god to believe rationally that god exists," Randal declares. He later says, "Belief in god can be produced in conditions which qualify it as properly basic." He tells the story about a non-religious Canadian rock musician who walked into a church in New York one day and was "struck by overwhelming spiritual presence." But so what? As Randal himself observes, "Millions of people have formed belief about god with the same naturalness and immediacy, the same phenomenology of self-presentation that [the Canadian rock musician] experienced." In other words, millions of people have formed belief in other gods as well as non-gods as a result of spiritual experience. There is no special power Christianity has in the spiritual domain. 

Sunday, April 5, 2015

What To Make Of The Evidence For An Afterlife?



What are we to make of the evidence for an afterlife? Here are your options.

There is either:

  • Some ill-defined metaphysical substance, not subject to the known laws of physics, that interacts with the atoms of our brains in ways that have thus far eluded every controlled experiment ever performed in the history of science

or 

  • People hallucinate when they are nearly dead

Which option do you think makes the most sense?

Sunday, March 1, 2015

Hyperactive Agency Detection — A Just-So Story?


The hyperactive agency detection (HAAD), or hyperactive agent-detection device (HADD), is the most widely accepted explanation for religious belief in biology, psychology and sociology. It offers us a naturalistic explanation of the origin of beliefs which form the basis of every religion. Because of this, you can expect that many religious believers are skeptical of its claims. Some of them claim that this is a "just-so" story, part of "atheist mythology." The irony of religionists making this claim, when their religious beliefs are often backed up on the mere testimony of religious texts, which are chalk full of just-so stories, is stupendous. A just-so story is "an unverifiable and unfalsifiable narrative explanation for a cultural practice, a biological trait, or behavior of humans or other animals." Is the HADD hypothesis unverifiable and unfalsifiable? It must be both in order to meet the criterion of a just-so story. Here I want to list some of the evidence supporting the HADD hypothesis and support the view that it is a valid scientific explanation.

In their 2008 paper The evolution of superstitious and superstition-like behaviour, Harvard biologist Kevin R. Foster and Helsinki biologist Hanna Kokko test for the origin of superstitious behavors through an incorrect assignment of cause and effect, where they "conclude that behaviours which are, or appear, superstitious are an inevitable feature of adaptive behaviour in all organisms, including ourselves."

This is experimental evidence for what Michael Shermer termed patternicity, or the tendency to find meaningful patterns in both meaningful and meaningless noise. He writes:

Unfortunately, we did not evolve a baloney-detection network in the brain to distinguish between true and false patterns. We have no error detecting governor to modulate the pattern-recognition engine. The reason has to do with the relative costs of making Type I and Type II errors in cognition, which I describe in the following formula:

P = C(TI) < C(TII) Patternicity (P) will occur whenever the cost (C) of making a Type I error (TI) is less than the cost (C) of making a Type II error (TII). 

The problem is that assessing the difference between a Type I and Type II error is highly problematic—especially in the split-second timing that often determines the difference between life and death in our ancestral environments—so the default position is to assume that all patterns are real; that is, assume that all rustles in the grass are dangerous predators and not the wind.

This is the basis for the evolution of all forms of patternicity, including superstition and magical thinking. There was a natural selection for the cognitive process of assuming that all patterns are real and that all patternicities represent real and important phenomena. We are the descendants of of the primates who most successfully employed patternicity. The Believing Brain (60)

A Type I error is a false positive, and is "believing something is real when it is not." A Type II error is a false negative, and is "believing something is not real when it is." For a short explanation of how this affected our hominid ancestors, see here.

Sunday, August 24, 2014

Cool Idea For Neuroscience Experiment


I love the recent experiments in neuroscience that are shedding light on the nature and origin of consciousness. I just thought of a cool test I would love neuroscientists to do if it hasn't been done already.

Sniper Target Confirmed - Wallpaper

Imagine if instead of asking the subjects to flicker their wrist, or push between one of two buttons, why not have them viewing a hostage crisis and being put in a sniper's position where they have their hand on a mock gun with a trigger and they're asked to save a person who is being held with a gin to their head, and they have to either do nothing, or try to shoot the perpetrator in order to save the hostage. Then we can monitor their brain patters and ask them to acknowledge when they had the desire to kill the kidnapper, the same basic way we do in other experiments. This would be more challenging of course because the subject would have to be thinking about whether or not to shoot a kidnapper, and they'd have to try and remember to note what letter appeared on the screen at the time they thought of it. I'm not saying it can be done without problems but it's a nice idea to see if the same kinds of predictable signals occur before conscious knowledge of a choice when there is a moral factor to the decision.

Dear Theists, A Question About Dualism And Neuroscience



Dear Theists,

So you believe we have an immaterial soul in addition to our physical bodies, don't you? What's that? No, you don't believe in dualism? OK, fine. Then I'm not talking to you. I want to talk to the substance dualist. Imagine that you're a neuroscientist right now and you want to be the person who finds out something groundbreaking in the field about consciousness. What epistemological framework are you going to adopt while in your work? - that there are parts of the immaterial and/or supernatural world interacting with and causing neurological or conscious activity, or that there are natural and physical explanations to seek in order to help shed more light on consciousness?

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