Monday, April 14, 2008

How Much Control Do We Have Over Decisions and Opinions?

[This schematic shows the brain regions (green) from which the outcome of a participant's decision can be predicted before it is made. Courtesy John-Dylan Haynes.]

The answer to the question in the title is dependent on whom one is asking the question. Many neuroscientists insist that we have very little control over how we make decisions. They tend to reject the whole notion that we are conscious beings and contend that the illusion of consciousness is merely a by-product of unconscious brain functions.

Because that is what they are looking for, that is what they are finding. This current article in Wired looks at what brain scans (fMRI) can tell us about the decision making process. It seems our brains often make decisions well before we are aware of them, implying we have little or no control over the process.

You may think you decided to read this story -- but in fact, your brain made the decision long before you knew about it.

In a study published Sunday in Nature Neuroscience, researchers using brain scanners could predict people's decisions seven seconds before the test subjects were even aware of making them.

The decision studied -- whether to hit a button with one's left or right hand -- may not be representative of complicated choices that are more integrally tied to our sense of self-direction. Regardless, the findings raise profound questions about the nature of self and autonomy: How free is our will? Is conscious choice just an illusion?

"Your decisions are strongly prepared by brain activity. By the time consciousness kicks in, most of the work has already been done," said study co-author John-Dylan Haynes, a Max Planck Institute neuroscientist.

Haynes updated a classic experiment by the late Benjamin Libet, who showed that a brain region involved in coordinating motor activity fired a fraction of a second before test subjects chose to push a button. Later studies supported Libet's theory that subconscious activity preceded and determined conscious choice -- but none found such a vast gap between a decision and the experience of making it as Haynes' study has.

In the seven seconds before Haynes' test subjects chose to push a button, activity shifted in their frontopolar cortex, a brain region associated with high-level planning. Soon afterwards, activity moved to the parietal cortex, a region of sensory integration. Haynes' team monitored these shifting neural patterns using a functional MRI machine.

Taken together, the patterns consistently predicted whether test subjects eventually pushed a button with their left or right hand -- a choice that, to them, felt like the outcome of conscious deliberation. For those accustomed to thinking of themselves as having free will, the implications are far more unsettling than learning about the physiological basis of other brain functions.

Caveats remain, holding open the door for free will. For instance, the experiment may not reflect the mental dynamics of other, more complicated decisions.

It doesn't look good for free will, but then (as they point out), complex decisions might be more within our control. The prefrontal cortex is considered the seat of executive function (among other things), and if there is a place in the brain where we make decisions, it is likely in the PFC.

Over at Not Exactly Rocket Science, Ed Yong posted an article the other day which looks at the research in this area, Unconscious brain activity shapes our decisions. He's looking at the same research in the Wired article, but he's a cancer researcher and science writer, so he has a better grasp of the material than the average writer. He refers more specifically to the frontopolar cortex, part of Broadmann Area 10, which is in the anterior portion of the frontal cortex.

The involvement of the frontopolar cortex isn't surprising. It fulfills the role of an executive manager and is involved in retrieving memories and controlling other high-level parts in the brain. Soon thinks that it is the source of the decision itself, with the precuneus simply storing the decision until it reaches a conscious level. When he changed his experiment so that volunteers were shown a cue to tell them when to make their choice, the frontopolar cortex still showed predictive activity before the signal, but the precuneus only did so in the time between signal and action.

Soon found, as Libet did, that the SMA was also active before the volunteers became conscious about their intentions. But he also showed that its pattern of activity can predict when the final decision is made. Again, this information is available at an unconscious level about 5 seconds before the volunteers actually move. The frontopolar and parietal cortex aren't involved in timing until the few milliseconds before the movement, so it seems that the two parts of the brain have different and complementary duties. One shapes the outcome of a choice and the other affects its timing.

Soon tentatively suggests that the sparks of a decision begin in the frontopolar cortex. From there, the decision is 'prepared' by the buildup of activity in the precuneus and later, the SMA. It is held there for a short while before we become consciously aware of it and act. This unconscious part of the decision-making process may be for our own good. At least one experiment showed that people with damage to the relevant parts of the brain don't show any signs of unconscious preparation and make poorer decisions in a gambling experiment.

Studies like these have important philosophical implications. If our brains unconsciously make our decisions for us, is there any room for free will? Libet himself thinks so, but only in a restricted way. He asserts that for all the brain's unconscious preparation, people can still consciously decide to stop performing an action in the final milliseconds before thought becomes deed. In this view, it's more a case of "free won't" than free will.

At the Toward a Science of Consciousness conference last week, Alfred Levinson presented a paper that argues in favor of Global Workspace Theory to explain the results of Benjamin Libet's research in this area. Here is a description of what GWT argues:

GWT resembles the concept of Working Memory, and is proposed to correspond to a "momentarily active, subjectively experienced" event in working memory (WM) –-- the "inner domain in which we can rehearse telephone numbers to ourselves or, more interestingly, in which we carry on the narrative of our lives. It is usually thought to include inner speech and visual imagery."

The easiest way to think about GWT is in terms of a "theater metaphor" --- which is not to say that the brain contains a theater in any concrete way, of course. In the "theater of consciousness" a "spotlight of selective attention" shines a bright spot on stage. The bright spot reveals the contents of consciousness, actors moving in and out, making speeches or interacting with each other. The audience is not lit up --- it is in the dark (i.e., unconscious) watching the play. Behind the scenes, also in the dark, are the director (executive processes), stage hands, script writers, scene designers and the like. They shape the visible activities in the bright spot, but are themselves invisible. (See Figure 1).

GWT involves a fleeting memory with a duration of a few seconds (much shorter than the 10-30 seconds of classical working memory). GWT contents are proposed to correspond to what we are conscious of, and are broadcast to a multitude of unconscious cognitive brain processes, which may be called receiving processes. Other unconscious processes, operating in parallel with limited communication between them, can form coalitions which can act as input processes to the global workspace. Since globally broadcast messages can evoke actions in receiving processes throughout the brain, the global workspace may be used to exercise executive control to perform voluntary actions. Individual as well as allied processes compete for access to the global workspace, striving to disseminate their messages to all other processes in an effort to recruit more cohorts and thereby increase the likelihood of achieving their goals.

Baars (1997) suggests that the global workspace "is closely related to conscious experience, though not identical to it." Conscious events may involve more necessary conditions, such as interacting with a "self" system, and executive interpreter in the brain, such as has been suggested by a number of authors including Michael A. Gazzaniga.

Under the terms of GWT, since we can only hold a single idea or concept in the "spotlight" at any one given moment, the fact that we are concentrating on the task of "choosing" whether to hit the button with our left or right hand would necessarily relegate the actual decision to an unconscious process. Does that make sense?

The cool thing about GWT is that it explains how the brain can engage whole series of networks while the "mind" is engaged in some other task. This view allows that the brain is an integrated system, not merely a collection of autonomous sub-routines.

Another key consideration, I think, is whether the task is exogenous or endogenous (or extrinsic versus intrinsic). Exogenous tasks, those that deal with the external environment, are more likely, from an evolutionary perspective, to be automated. When we were dependent on our (often somatic-based) awareness for survival in a wild and unpredictable world, having to consciously make a decision could be fatal. It makes sense that those systems became preconscious.

However, endogenous decisions -- such as whether or not I want to vote for A versus B -- are not likely to be automated and are probably handled within the prefrontal cortex -- by executive function.

However, not all exogenous stimuli is handled by sub-routines, as this explanation of EF demonstrates.

The executive system is thought to be heavily involved in handling novel situations outside the domain of some of our 'automatic' psychological processes that could be explained by the reproduction of learned schemas or set behaviors. Psychologists Don Norman and Tim Shallice have outlined five types of situation where routine activation of behavior would not be sufficient for optimal performance[4]:

  1. Those that involve planning or decision making.
  2. Those that involve error correction or troubleshooting.
  3. Situations where responses are not well-learned or contain novel sequences of actions.
  4. Dangerous or technically difficult situations.
  5. Situations which require the overcoming of a strong habitual response or resisting temptation.

Any situation in the which the input is novel, unique, or complex is likely to trigger executive function. Choosing which hand to press a button with does not fit these criteria and was undoubtedly handled by sub-routines.

For more on the conscious versus unconscious processing of information, see this cool (but difficult) article by Bernard Baars at the University of Arizona.

* * * * *

A related topic to decision-making is how we form opinions. looked at some new research into how our opinions are formed as a result of our environment more than our internal beliefs. In Physicists model how we form opinions, Lisa Zyga examines the role of cultural context in forming our opinions.

As a team of researchers explains, our individual opinions both influence and are influenced by our surroundings. By following a set of rules, the researchers have modeled the opinion formation process in societies where individuals’ opinions are strongly influenced by others they interact with. The scientists found that, depending on two criteria – how strongly individuals are influenced by each other and how many connections individuals have – a society’s overall state can exhibit either large segregated patches of consensus, or areas with closely intermingled opinions.

Peter Klimek from the Medical University of Vienna, Renaud Lambiotte from the University of Liege and the Catholic University of Louvain in Belgium, and Stefan Thurner of the Medical University of Vienna and the Santa Fe Institute in the US have published their study in a recent issue of Europhysics Letters.

In their model, individuals are represented as nodes in a network. The nodes are binary, and they display an individual’s opinion on some subject, such as yes/no, liberal/conservative, Clinton/Obama, or any other choice.

Then, the society’s overall stance on a subject can be determined for the future by evolving the system. First, an algorithm checks the state of all nodes connected to the node in question. If the fraction of the state of neighboring nodes exceeds a certain threshold (which the researchers call the “laggard parameter” and must be above 50%), then the central node adopts that state. If not, the node remains in its original state. This process is iterated several times, until it can no longer be updated, and the society freezes.

“The original opinions of the individuals are 'a priori' inclinations toward some subject,” Thurner told “To stay within the Clinton/Obama example, although most of my peers may be democrats, some of them may consider political experience to be more important, while others think that a fresh start is needed. Given such individual initial dispositions, our work shows under which circumstances individuals will stick to them or change their mind.”

Depending on the laggard parameter and the system’s average connectivity, the model produces societies with different features. For example, as the laggard parameter increases (when individuals require a greater fraction of neighbors holding the opposite opinion in order to change their opinions), the regions of consensus shrink, and the society’s diverse views intermingle. In other words, individuals stubbornly hold on to their opinions, even if many of their neighbors have the opposite view. But the more that people are influenced by others, the less likely it is that the society will ever reach such an intermixed state.

This is basic systems theory, but it provides a relatively new lens for explaining cultural beliefs and opinions. The same processes likely hold true in many other areas of our psychological lives, from opinions to beliefs to values.

I recently looked at a related article on The Collective Mind, by Jonah Lehrer.

One of the tremendous biases and blind spots of modern neuroscience is that it's almost always forced to see the mind in a social vacuum. While there have been some rudimentary attempts to study human interaction, or what happens to the cortex when it's not by itself - see, for instance, some of the work by Read Montague - our theories of the brain are almost entirely based on brains in isolation. The reasons for this are straightforward: other people are confounding variables. They make everything too complicated. Nevertheless, even a cursory glance at human existence is a reminder that we are profoundly social animals, that our minds are largely shaped by the minds of others.

These concepts -- collective mind and the idea that individuals are represented as nodes in a network -- likely influence many other areas of thought and decision making, not just how we form opinions. Which brings us back to the notion that we may not be as conscious as we think we are.

* * * * *

So, does free will actually exist? Buddhists believe it does, sort of , and that it operates alongside determinism. For the most part, Buddhism teaches that most of us are not awake, and therefore we are controlled by automated responses in our thinking (what we might consider unconscious processes). However, through following the Eightfold Path and engaging in the process of waking up, we can wake up and have conscious control over our thoughts and our lives.

Here is a brief summary on the Buddhist concept of free will:

Buddhism believes in neither absolute free will, nor determinism. It preaches a middle doctrine called pratitya-samutpada in Sanskrit, which is often translated as "inter-dependent arising". It is part of the theory of karma in Buddhism. The concept of karma in Buddhism is different from the notion of karma in Hinduism. In Buddhism, the idea of karma is much less deterministic. The Buddhist notion of karma is primarily focussed on the cause and effect of moral actions in this life, while in Hinduism the concept of karma is more often connected with determining one's destiny in future lives.

In Buddhism it is taught that the idea of absolute freedom of choice (i.e. that any human being could be completely free to make any choice) is foolish, because it denies the reality of one's physical needs and circumstances. Equally incorrect is the idea that we have no choice in life or that our lives are pre-determined. To deny freedom would be to undermine the efforts of Buddhists to make moral progress (through our capacity to freely choose compassionate action). Pubbekatahetuvada, the belief that all happiness and suffering arise from previous actions, is considered a wrong view according to Buddhist doctrines.

Because Buddhists also reject agenthood, the traditional compatibilist strategies are closed to them as well. Instead, the Buddhist philosophical strategy is to examine the metaphysics of causality. Ancient India had many heated arguments about the nature of causality with Jains, Nyayists, Samkhyists, Cārvākans, and Buddhists all taking slightly different lines. In many ways, the Buddhist position is closer to a theory of "conditionality" than a theory of "causality", especially as it is expounded by Nagarjuna in the Mūlamadhyamakakārikā.[89]

So where does that leave us? Is it possible to expand our "consciousness"?

Let's bring it back to the level of individuals. According to neuroscience, we have little or no ability to purposefully make decisions -- most or all of them happen outside our conscious intention.

Yet some neuroscientists and psychologists are looking at ways in which we might become more conscious and less asleep. John Stewart, one of the presenters at Toward a Science of Consciousness, used GWT to suggest that we have allowed our minds to be "colonized" by thinking, which inherently takes us out of the present moment (where the action is) and into our heads.

In a paper that is available online, Stewart argues that we can, indeed, increase our consciousness through the implementation of contemplative traditions, including Buddhism and others. [Many of the terms in this section are explained earlier in the paper, but I have tried to provide Wikipedia links where possible.]

What capacities must individuals acquire if the declarative transition is to occur for the processes that set goals and regulate sequences of thought? Obviously, individuals would need to acquire declarative knowledge about what goals to pursue and about when it is optimal to have consciousness unloaded by sequences of thought. But this would not be enough. Merely having declarative knowledge about the optimal outputs of conscious processes will not change those processes. For the transition to occur, individuals will need to develop the capacity to modify the processes so that they produce the outputs identified by declarative modelling. In particular, to implement alternative goals, individuals would have to be able to prevent pre-existing goals that are supported by the hedonic system [brain stem and limbic system] from continuing to control behaviour by regulating recruitment to the GW. And to prevent sequences of thought from loading consciousness, individuals would need to be able to stop sequences of thought from gaining access to the GW and perpetuating themselves.

How could an individual develop these capacities? What sources of declarative knowledge are available to guide their acquisition?

Knowledge and practices of religious and contemplative traditions

In general, the development of these sorts of capacities has not been a goal of western empirical psychology and it has not devised practices and procedures for developing them. However, various religious and contemplative traditions more or less explicitly seek to produce key aspects of these capacities in their adherents. In particular, they pursue capacities that appear synonymous with an ability for individuals to free themselves from the dictates of goals established by their hedonic system. They seek, for example, to have their adherents ‘resist temptation’ and ‘turn the other cheek’ (Christianity), free themselves from all desires (Buddhism), and experience equanimity in the face of pleasure or pain (Hinduism).

Most traditions also attempt to develop capacities that enable individuals to consciously regulate their engagement in sequences of thought and imagining. For example, nearly all contemplative traditions seek to produce a mode of functioning that is now commonly referred to as ‘being in the present’. The key characteristic of such a mode appears to be that consciousness is not loaded by sequences of thought. It is referred to as ‘being in the present’ because the individual is ‘on-line’ and able to attend to stimuli arising at each moment, rather than off-line engaged in thoughts that are nearly always about the past or future.

The contemplative traditions teach a wide range of practices and techniques that are explicitly intended to develop these capacities. Broadly, the practices can be understood as operating to disengage the pre-existing processes that enable the hedonic system to control behaviour and that perpetuate sequences of thought, replacing them with new processes that embody the desired capacities.

Stewart believes strongly in the ability of humans to shape their evolutionary trajectory, and one way of doing so is to develop the skills needed to remain fully in the present as much as possible (obviously, we need to be able to plan and remember, but few of us spend ANY time in present space).

So what would being in the present look like and how do we get there?

[W]e will identify some of the key elements that are common to many of the practices and techniques, and show how their reported effects are consistent with the framework developed here. In doing so I will draw on general accounts of the practices of Buddhism (Sogyal Rinpoche 1992; Surya Das 1997; and Bucknell and Kang 1997), Hinduism (Mascaro 1962; Mascaro 1965; and Goleman 1988), the Gurdjieff system (Nicoll 1996; Ouspensky 1949) and on surveys of other contemplative traditions (Wilber 1995 and 2000; Combs 2002). I will also draw on the extensive work being done to integrate key practices such as mindfulness meditation into empirical clinical psychology, and to interpret their injunctions and effects within the theories and models of western scientific psychology (for recent reviews see Breslin et al. 2002; Kabat-Zinn 2003; Baer 2003; Lau and McMain 2005; Walsh and Shapiro 2006; and Shapiro et al. 2006).

The central elements in many of these practices are:

(i) to rest attention on a stimulus that is not associated with any goal and that does not recruit any sequences of thought or other resources (an ‘inert’ stimulus); and to

(ii) bring attention back to the stimulus whenever it is realised that attention has become to be occupied with thoughts or feelings.

The traditions emphasise that the entire practice, including the realisation by the practitioner that consciousness is occupied by thoughts or feelings, and the movement of attention back to the inert stimulus, is to be undertaken non-deliberatively and non-judgementally. In contrast to cognitive behavioural therapy, thoughts and feelings are not disputed, challenged or evaluated (Lau and McMain 2005). To do so would train further engagement with thoughts and feelings, not disengagement. If elaborative thoughts or judgements arise, these too are disengaged from, and attention returned to the inert stimulus.

A very wide range of internal and external phenomenon can serve as the inert stimulus. One of the most common recommendations is to focus attention on sensations of the breath. Other foci of attention recommended by various contemplative traditions include external objects, visualised objects, internal or external sounds (including chanting and mantras), other physical and mental sensations (including resting attention on awareness itself), repetitious cognitive tasks such as counting or prayer, and goalless emotional states such as reverence, love or feelings of surrender.

The essential effects of this core practice are to train processes that:

(i) disengage attention from sequences of thought and from the recruitment of resources by the hedonic system; and that

(ii) maintain consciousness free from on-going loading and from domination by the hedonic system.

In circumstances where these processes are trained, the individual will have the capacity to choose when consciousness is loaded by sequences of contents, and will be able to access any resources to devise suitable responses, not just those dictated by the hedonic system.

Standard learning theory is capable of fully explaining the ability of the core practice to train these capacities (see, for example, Breslin et al. 2002; and Baer 2003).

Most contemplative traditions supplement a core practice of this type with a range of other activities and teachings that enhance its effectiveness, including:

(i) Adherents are taught to undertake the core practice initially in stimulus-controlled circumstances that require less skill and motivation to be effective. For example, the adherent might withdraw from the distractions and challenges of ordinary life for a period in a retreat, pilgrimage, or monastery (or at least withdraw for short periods each day), and the practice is undertaken as formal sitting meditation in a quite place with a physical posture that is consistent with un-distracted alertness.

(ii) Particularly in traditions that seek to produce these capacities in the midst of everyday life, steps are subsequently taken to generalise the skills learnt through this initial practice to a progressively wider range of stimulus conditions. This is done to ensure the capacities are not trained only in the limited circumstances in which they are learnt—e.g. on the meditation cushion. The capacities are generalised by performing the core practice while engaged in a progressively wider range of normal daily activities.

(iii) A number of traditions include practices and teachings that have the effect of reducing the difficulties associated with extending the core practice to daily life. For example, they may reduce the likelihood that adherents experience strong negative emotions by promoting acceptance, forgiveness, surrender and an attitude of loving kindness towards all others.

(iv) Some traditions encourage adherents to perform the core practice while putting themselves in situations that they would otherwise avoid because, for example, the situations would produce negative affect (e.g. the Gurdjieff system). Without intentionally experiencing such situations, individuals would not have the opportunity to practice disengagement from the impact of aversive stimuli and negative affect, and their behaviour could continue to be controlled by them. These approaches seem to be founded on similar principles to the desensitization and related therapies developed by clinical psychology (e.g. see Breslin et al. 2002).

(v) Traditions generally provide adherents with a set of narratives and beliefs that motivate the performance of the practices, including by pointing to benefits they supposedly will bring. Claimed benefits range from internal peace and bliss to various forms of eternal life. Traditions are also often accompanied by teachings that question the efficacy of continual involvement in thought, as well as the wisdom of a life spent in the pursuit of self-centred desires and motivations. These teachings are directed at overcoming reluctance to continually disengage from sequences of thought and from responses dictated by feelings and emotions. Until individuals gain some proficiency in disengaging from thought and stilling the mind they are unlikely to discover for themselves the limitations of thought—they will be unable to acquire direct knowledge about the lack of utility of most thought while their consciousness is continually loaded by sequences of thought and imagining.

(vi) Mindfulness meditation (also known as insight meditation and self-observation) is a particularly effective practice common to a number of traditions. It combines the core practice with processes that enable the acquisition of knowledge about the efficacy of thought and the operation of the hedonic system. In mindfulness meditation, perceptions of thoughts and feelings can serve as the inert stimulus. Attention is given to these perceptions as they arise from moment to moment, non-deliberatively and non-judgementally. Whenever the meditator realises that consciousness has come to be occupied with thoughts or feelings, rather than only with inert perception of them, the thoughts or feelings are noted (again non-deliberatively and non-judgementally), and attention is taken back to them as objects of inert perception. Alternatively, attention can be returned to another inert stimulus such as the breath.

This practice facilitates the accumulation of resources and knowledge about the efficacy of thinking and feelings without conflicting with the central objective of the practice—to disengage from thought and from recruitment dictated by the hedonic system. This knowledge is accumulated non-deliberatively and non-judgementally during the practice itself, but can be further analysed deliberatively and judgementally during periods set aside for this purpose when the practice is not being undertaken. This process will eventually produce procedural resources that can be recruited and used by consciousness for adaptive purposes without loading consciousness for extended periods.

I highly recommend reading the whole paper -- The Future Evolution of Consciousness -- for those who are interested.

I want to mention one other recent study, although I could mention several. Stephen Whitmarsh, also at Toward a Science of Consciousness, looked at the effects of meditation on the processing and anticipation of visual stimuli.

Whitmarsh found that meditation affects the default state of mind (lack of being present, lack of free will) by quieting emotional, narrative, and self-reference functions of the mind in daily life. Over time, there is a structural difference in the brains of meditators versus non-meditators.

* * * * *

What does all of this mean?

Well, mostly it means that the average person walking around is little more than a zombie with only partial and fleeting consciousness. We have limited control of our decision-making processes, especially those that involve simple or repetitive behaviors. We also have limited ability to shape our own opinions when we are embedded in social systems (which we generally are). Our biological brains are designed to keep us alive, so much of what goes on there is beyond our control most of the time.

But biology is not destiny.

The good news is that we can change our brain habits (and structures) by simply sitting down and counting breathes, or watching our thoughts drift by without attaching to them, or whatever version of meditation one wants to use. We can initiate and participate in our own conscious evolution, and that can process can offer us greater degrees of consciousness. As Stewart argues in one of his books, evolution is directional, and we can become a part of that process by becoming more fully present to our lives.

1 comment:

Hokai said...

Bill, this is a balanced and informative article. Thank you!