01 March 2014

'Touching a Nerve' by Patricia Churchland (2013):

 A personal, non-academic review of the life physical.  In general I found 'Touching a Nerve' a good read - the subtitle 'The Self as Brain' is a kind of undertone to her (largely common-sensical) look at a variety of subjects, all based on a neuroscientific outlook.  Here are a few points of special interest to me.

On free will - she comes out pretty strongly against the Harris line that "free will is an illusion" - she says if it means there's no "contra-causal free will" then the observation is "only marginally interesting."
But what if free will is illusory means something else? What if it means, for example, that because there is a neural substrate for our deliberations and choices, we cannot have free will? Now I am totally at a loss. Why would anyone say such a thing? So what do they think is required to make genuine choices? A non-physical soul? Says who? (184)
What is not illusory is self-control, even though it can vary as a function of age, temperament, habits, sleep, disease, food and many other factors that affect how nervous systems function. (185) 
Churchland gives credit to Freud for being an early adopter (circa 1895) of the view that the unconscious processes are both mental and physical.
He understood that unconscious reasoning and intentions and thoughts need to be invoked to explain such things as complex perception (for example, heard speech as having a specific meaning) and complex motor acts (for example, speaking intelligibly and purposefully).
[...] 
He realized that he had essentially no idea what a vocabulary spanning the brain and behavioral science would look like. His conclusion was that we have no choice but to make do with what we know is a flawed and misleading vocabulary, namely, that of intentions, reasons, beliefs, and so on, to describe unconscious states. (201)
I liked this bit, on the interplay of conscious and unconscious:
Your conscious brain needs your unconscious brain, and vice versa. The character and features of your conscious life depend on your unconscious activities. And of course, conscious events can in turn have an effect on unconscious activities. (207) 
And this bit on conscious decision-making as a constraint satisfaction process:
Precisely what my dear old brain is doing as I go through these exercises is not entirely known. That is, we can think of it in terms of constraint satisfaction, but we are still a big vague about what constraint satisfaction is in neural terms. Roughly speaking, we do know that in constraint satisfaction operations, the brain integrates skills, knowledge, memories, perceptions, and emotions and somehow, in a manner we do not precisely understand, comes to a single result. (219)
She disputes Dennett's position that language has to be part of consciousness, partly on personal grounds:
A further problem is that consciousness - mine, anyhow - involves so much more than speech. Indeed, we may experience much for which we have no precise linguistic characterization at all, such as the difference between the smell of cinnamon and the smell of cloves or the difference between feeling energetic and feeling excited, or what an orgasm is like. (250)
While other mammals do not have our kind of language, they do seem to communicate, and in terms of brain structure, they have very similar organs and patterns of activity.  She feels this indicates that many animals have some level of conscious awareness.

The overall picture she draws is of the brain as a looping structure, with some highly networked neurons able to convey signals to many other areas, to support the type of integration that we see.

I noticed that the book initially got a number of one-star reviews at Amazon, mostly short critiques of her overly reductionist viewpoint (an organized effort I presume!).  I did not find her to be overly reductionist in this book.  While she doesn't explicitly take on emergence as a topic, in the epilogue she does make this argument:
If, as seems increasingly likely, dreaming, learning, remembering, and being consciously aware are activities of the physical brain, it does not follow that they are not real. Rather, the point is that their reality depends on a neural reality. If reductionism is essentially about explanation, the lament and the lashing out are missing the point. Nervous systems have many levels of organization, from molecules to the whole brain, and research on all levels contributes to our wider and deeper understanding. (262)
Accessible, personal, and a good overview - I recommend it.






19 February 2014

Dennett and Harris wrestle on 'Free Will'

My take on the recent essays by Daniel Dennett and Sam Harris on the short Harris book 'Free Will' (2012, my original thoughts here).  Dennett wrote a 22 page review of the book in late January, and Harris put out his reply about a week later.  These are my brief notes on the exchange.

Dennett's main claims:

1. Harris is fighting a strawman - everyone basically agrees that the folk free will (i.e. libertarian free will) is wrong.  Dennett makes case for compatabilist notions (without claiming determinism is settled matter - says it is up to science to decide).

2. Harris is not taking the compatibilist position seriously and/or not in informed way.  Dennett does certainly appeal to the 'vast library' in a condescending way.

3. Harris seems fixed on one point in time, not dealing with dynamics over time.  Dennett rejects the Exact Replay scenario (rewind the clock, put literally everything back in place - see also #4 below in Harris section).  I liked this passage:
Harris ignores the reflexive, repetitive nature of thinking. My choice at time t can influence my choice at time t’ which can influence my choice at time t”.  How?  My choice at t can have among its effects the biasing of settings in my brain (which I cannot directly inspect) that determine (I use the term deliberately) my choice at t’. I can influence my choice at t’. I influenced it at time t (without “inspecting” it).  Like many before him, Harris shrinks the me to a dimensionless point, “the witness” who is stuck in the Cartesian Theater awaiting the decisions made elsewhere. That is simply a bad theory of consciousness.
4. Claims Harris is inconsistent about whether we can 'grab hold of our puppet strings' - perhaps also about how influence can work.

5. Dennett acknowledges we can't be 'ultimate cause' - infinite regress issue.  But over time we can "influence ourselves" (and others) in meaningful ways.

6. Takes issue with what Dennett claims is an evasion of responsibility.  I think this is the main area where probably the two men are actually probably not far apart practically, but are accusing each other of allowing for bad results.  Key lines:
Harris should take more seriously the various tensions he sets up in this passage.  It is wise to hold people responsible, he says, even though they are not responsible, not really. But we don’t hold everybody responsible; as he notes, we excuse those who are unresponsive to demands, or in whom change is impossible. That’s an important difference, and it is based on the different abilities or competences that people have.  Some people (are determined to) have the abilities that justify our holding them responsible, and some people (are determined to) lack those abilities. But determinism doesn’t do any work here; in particular it doesn’t disqualify those we hold responsible from occupying that role.  In other words, real responsibility, the kind the everyday folk think they have (if Harris is right), is strictly impossible; but when those same folk wisely and justifiably hold somebody responsible, that isn’t real responsibility!
Overall:  I actually found Dennett fairly straightforward, somewhat condescending, and probably drawing some unwarranted conclusions about the Harris position.  I found his points to be pretty interesting and worthy of consideration.

Harris main claims:

1. Says Dennett misunderstands his arguments.  Claims that libertarian free will is quite widely held still.

2. Harris is fully focused on taking down libertarian free will. He feels that removing that illusion will remove any rational reason for hatred - but leaves in place reasons for removing dangerous folks from society. Key lines:
And accepting incompatibilism has important intellectual and moral consequences that you ignore—the most important being, in my view, that it renders hatred patently irrational (while leaving love unscathed). If one is concerned about the consequences of maintaining a philosophical position, as I know you are, helping to close the door on human hatred seems far more beneficial than merely tinkering with a popular illusion.
3. Harris says he's not fully convinced of determinism, but thinks it must be nearly true.

4. There's a weird line about indeterminism re: the putt replay.  Harris writes:
That is, whatever his ability as a golfer, Austin would miss that same putt a trillion times in a row—provided that every atom and charge in the universe was exactly as it had been the first time he missed it. You think this fact (we can call it determinism, as you do, but it includes the contributions of indeterminism as well, provided they remain the same[3]) says nothing about free will.  
This seems to me to indicate the 'pseudo-random case' here, not a truly random indeterminism.  Not a big deal, but I found it odd to have the "provided they remain the same" qualifier.

5. As Dennett argues, I think Harris does not really grapple with the compatibilist argument. Does not engage the ideas of the dynamic system changing (influencing its future direction) over time.
Key lines: "In other words, your compatibilism seems an attempt to justify the conventional notion of blame, which my view denies. This is a difference worth focusing on."

Overall: Actually seems a bit more whiney than Dennett. Says he wanted debate or conversation, not to trade essays.  I think that Dennett mostly understands exactly where Harris stands.  Harris has his reasons for not wanting to grapple with compatibilism, but personally I think he hasn't shown that he really has a grip on Dennett's points.

25 November 2013

How much neuroscience in 'Social'?

Psychologist Matthew Lieberman does like the fMRI!  In his new book 'Social' (2013) the UCLA professor and Director of the Social Cognitive Neuroscience Lab makes the case for the neural underpinnings of our social learning and behavior.  The question that came to my mind though was how much of the message was basically social psychology (which is valuable, don't get me wrong, but not dependent on fMRI findings).

The book features many diagrams of brains, pointing out various regions that are active during different cognitive tasks.  In general the correlations of active areas to cognitive tasks can be very useful to better understand the brain structures, if not to actually understand how the cognitive tasks are achieved. Most illuminating are the findings where either the same area is used during different types of tasks, or where different areas are used for what seem to be very similar tasks.  I think it's probably valuable to combine these types of findings with traditional psychology to see what may be illuminated.

Lieberman's key claim is that our 'default' brain mode is used for so-called 'mentalizing' - sorting through the social world, trying to understand other people's motives and intentions. This is shown by the activation of certain brain areas both while explicitly thinking about social problems and when not attempting to do other cognitive tasks.

We typically use a particular prefrontal brain region for general cognition (reading, memorizing, computing, etc.), and it was thought that these areas were the critical to all learning.  But various studies have found a 'social encoding advantage' in learning using the mentalizing system to form overall impressions of people and their intentions rather than simple memorization of people's behavior.  The finding was that 'the folks making sense of the information socially have done better on memory tests than the folks intentionally memorizing the material.' (284)  From the neuroscience angle:
Jason Mitchell, a social neuroscientist at Harvard University, ran an fMRI version of the social encoding advantage study. As in a dozen studies before his, he found that when people were asked to memorize the information, activity in the lateral prefrontal cortex and the medial temporal lobe predicted successful remembering of that information later on. According to the standard explanation of the social encoding advantage, the same pattern should have been present or event enhanced when people did the social encoding task, but that isn't what happened. The traditional learning network wasn't sensitive to effective social encoding. Instead the central node of the mentalizing network, the dorsomedial prefrontal cortex, was associated with successful learning during social encoding. (284-5)
Lieberman suggests a number of interesting applications of this finding to change and hopefully improve the way we teach kids, who are intensely interested in the social world and not so interested in memorizing facts - such as by teaching history more in terms of the social dramas (rather than actions and dates), and math by engaging students as both tutors and tutees.

The book has sections on three stages of social development, which he terms connection, mindreading (theory of mind), and harmonizing - and argues that significant brain resources are devoted to maintaining connection with other people.  Harmonizing is about taking on many of the goals and behaviors of our social group (particularly active during adolescence).  The idea here is that our sense of self as supported in the brain is very susceptible to the social messages we receive.

Overall I liked this book - not that it really lives up to the subtitle 'Why Our Brains Are Wired to Connect' - it's more about 'How' than 'Why'. At its best it reminds us that we are truly social creatures, and the neuroscience helps illustrate that point.

Will we understand science in the future?

Tyler Cowen suggests not in his book 'Average Is Over' (2013).  The book is a bit of prognostication about the near future, looking mainly at how the use of computers is and will change our world.  The basic idea is that the people who can add value to computer work in some way will reap most of the rewards.

For the purposes of this blog, I thought the part about computer-driven science was most interesting. Cowen lists three reasons why science may become harder to understand:
1. In some (not all) scientific areas, problems are becoming more complex and unsusceptible to simple, intuitive, big breakthroughs.
2. The individual scientific contribution is becoming more specialized, a trend that has been running for centuries and is unlikely to stop.
3. One day soon, intelligent machines will become formidable researchers in their own right. (206)
And here's one attempt at a summary:
The remaining human knowledge of science will be very practical, very prediction-oriented, and well geared for improving our lives.  Of course those are all positive developments. Still, as a general worldview, science will not always be very inspiring or illuminating. The general educated public will to some extent be shut out from a scientific understanding of the world, and we will run the risk that they might detach from a long-term loyalty to scientific reasoning. (219)
It will be interesting to see how much of this thinking will apply to neuroscience.

23 October 2013

Brain decoding - how far can it go?

Kerri Smith has a good overview of the topic in "Brain decoding: Reading minds" at Nature.  The range of investigation goes from identifying the content of dreams to verifying whether someone is lying, to trying to understand the full process of how the brain can encode information.  But the starting point is fairly modest - trying to identify what object someone is looking at based on patterns in the visual area of the brain.  There's a good reason to start there:
Applying their techniques beyond the encoding of pictures and movies will require a vast leap in complexity. "I don't do vision because it's the most interesting part of the brain," says Gallant. "I do it because it's the easiest part of the brain. It's the part of the brain I have a hope of solving before I'm dead." But in theory, he says, "you can do basically anything with this."
But of course theory and practice are two different things, and there may be practical limits:
Devising a decoding model that can generalize across brains, and even for the same brain across time, is a complex problem. Decoders are generally built on individual brains, unless they're computing something relatively simple such as a binary choice — whether someone was looking at picture A or B. But several groups are now working on building one-size-fits-all models. "Everyone's brain is a little bit different," says Haxby, who is leading one such effort. At the moment, he says, "you just can't line up these patterns of activity well enough."
Using this kind of research to detect 'secret' product preferences seems pretty misguided to me.  But that doesn't stop some from trying!

01 October 2013

Decide what you think - it matters!

Tom Stafford at mindhacks.com writes on free will studies that indicate some interesting side effects of reading about a deterministic model.  Here's the bottom line:
This is a young research area. We still need to check that individual results hold up, but taken all together these studies show that our belief in free will isn’t just a philosophical abstraction. We are less likely to behave ethically and kindly if our belief in free will is diminished.
Personally I do think that regardless of the exact underlying physical mechanisms, one's choices help set the pattern for future behaviors, so best to act carefully and with fore-thought!

24 September 2013

Follow-up on the brain-to-brain experiments

Mind Hacks blog presents a nice short analysis of the UW experiment ("It is mind control but not as we know it"), written by Tom Stafford.  Previously I logged an entry for the brain-to-brain communication experiment conducted at University of Washington by Rajesh Rao.  Here's the gist from Stafford:
In information terms, this is close to as simple as it gets. Even producing a signal which said what to fire at, as well as when to fire, would be a step change in complexity and wasn’t attempted by the group. TMS is a pretty crude device. Even if the signal the device received was more complex, it wouldn’t be able to make you perform complex, fluid movements, such as those required to track a moving object, tie your shoelaces or pluck a guitar. But this is a real example of brain to brain communication.

As the field develops the thing to watch is not whether this kind of communication can be done (we would have predicted it could be), but exactly how much information is contained in the communication.

27 August 2013

Human-to-human brain communication

A very limited form of brain-to-brain communication is described in a story on research at the University of Washington: "Researcher controls colleague’s motions in 1st human brain-to-brain interface" by Doree Armstrong and Michelle Ma, Aug 27, 2013. The experiment used EEG signals via Skype to transmit signals of thoughts of simple movement, which the receiver got via transcranial magnetic stimulation - "a noninvasive way of delivering stimulation to the brain to elicit a response.... in this case, it was placed directly over the brain region that controls a person’s right hand."

I believe there are quite severe limits to the type of signal which could actually be transmitted and received via this mechanism, and the researchers confirm:

At first blush, this breakthrough brings to mind all kinds of science fiction scenarios. Stocco jokingly referred to it as a “Vulcan mind meld.” But Rao cautioned this technology only reads certain kinds of simple brain signals, not a person’s thoughts. And it doesn’t give anyone the ability to control your actions against your will.

Both researchers were in the lab wearing highly specialized equipment and under ideal conditions. They also had to obtain and follow a stringent set of international human-subject testing rules to conduct the demonstration.

“I think some people will be unnerved by this because they will overestimate the technology,” Prat said. “There’s no possible way the technology that we have could be used on a person unknowingly or without their willing participation.”