Neuroscience of free will
The neuroscience of free will, an area within neurophilosophy, is the study of topics related to free will, using neuroscience and the analysis of how findings from such studies may impact the free will debate.
As medical and scientific technology has advanced, neuroscientists have become able to study the brains of living humans, allowing them to observe the brain's decision-making processes and revealing insights into human agency, moral responsibility, and consciousness. One of the pioneering studies in this field was conducted by Benjamin Libet and his colleagues in 1983, and has been the foundation of many studies in the years since. Other studies have attempted to predict the actions of participants before they happen, explore how we know we are responsible for voluntary movements as opposed to being moved by an external force, or how the role of consciousness in decision-making may differ depending on the type of decision being made.
File:Some brain areas.png|thumb|upright=1.35|Some areas of the human brain implicated in mental disorders that might be related to free will. Area 25 refers to Brodmann's area 25, related to major depression.
Some philosophers, such as Alfred Mele and Daniel Dennett, have questioned the language used by researchers, suggesting that "free will" means different things to different people. Dennett insisted that many important and common conceptions of "free will" are compatible with the emerging evidence from neuroscience.
Overview
The neuroscience of free will encompasses two main fields of study: volition and agency.Volition, as in the study of voluntary actions, is difficult to define. If human actions are considered as lying along a spectrum based on conscious involvement in initiating the actions, then reflexes would be on one end, and fully voluntary actions would be on the other. How these actions are initiated and consciousness' role in producing them is a major area of study in volition.
Agency is the capacity of an actor to act in a given environment. Within the neuroscience of free will, the sense of agency—the subjective awareness of initiating, executing, and controlling one's volitional actions—is usually what is studied.
One significant finding of modern studies is that a person's brain seems to commit to certain decisions before the person becomes aware of having made them. Researchers have found a delay of about half a second or more. With contemporary brain scanning technology, scientists in 2008 were able to predict with 60% accuracy whether 12 subjects would press a button with their left or right hand up to 10 seconds before the subject became aware of having made that choice. These and other findings have led some scientists, like Patrick Haggard, to reject some definitions of "free will".
However, it is very unlikely that a single study could disprove all definitions of free will. Definitions of free will can vary greatly, and each must be considered separately in light of existing empirical evidence. There have also been a number of problems regarding studies of free will. Particularly in earlier studies, research relied on self-reported measures of conscious awareness, but introspective estimates of event timing were found to be biased or inaccurate in some cases. There is no agreed-upon measure of brain activity corresponding to conscious generation of intentions, choices, or decisions, making studying processes related to consciousness difficult. The existing conclusions drawn from measurements are also debatable, as they don't necessarily tell, for example, what a sudden dip in the readings represents. Such a dip might have nothing to do with unconscious decision because many other mental processes are going on while performing the task. Although early studies mainly used electroencephalography, more recent studies have used fMRI, single-neuron recordings, and other measures. Researcher Itzhak Fried says that available studies do at least suggest that consciousness comes in a later stage of decision-making than previously expected – challenging any versions of "free will" where intention occurs at the beginning of the human decision process.
Free will as illusion
It may be possible that our intuitions about the role of our conscious "intentions" have led us astray; it may be the case that we have confused correlation with causation by believing that conscious awareness necessarily causes the body's movement. This possibility is bolstered by findings in neurostimulation, brain damage, but also research into introspection illusions. Such illusions show that humans do not have full access to various internal processes. The discovery that humans possess a determined will would have implications for moral responsibility or lack thereof.Neuroscientist, philosopher, and author Sam Harris believes that we are mistaken in believing the intuitive idea that intention initiates actions. Harris criticizes the idea that free will is "intuitive": and that careful introspection will cast doubt on free will. Harris argues: "Thoughts simply arise in the brain. What else could they do? The truth about us is even stranger than we may suppose: The illusion of free will is itself an illusion".
In contrast to this claim, neuroscientist Walter Jackson Freeman III, discusses the impact of unconscious systems and actions to change the world according to human intention. Freeman writes: "our intentional actions continually flow into the world, changing the world and the relations of our bodies to it. This dynamic system is the self in each of us, it is the agency in charge, not our awareness, which is constantly trying to keep up with what we do." To Freeman, the power of intention and action can be independent of awareness.
An important distinction to make is the difference between proximal and distal intentions. Proximal intentions are immediate in the sense that they are about acting now. For instance, a decision to raise a hand now or press a button now, as in Libet-style experiments. Distal intentions are delayed in the sense that they are about acting at a later point in time. For instance, deciding to go to the store later. Research has mostly focused on proximal intentions; however, it is unclear to what degree findings will generalize from one sort of intention to the other.
Relevance of scientific research
Some thinkers like neuroscientist and philosopher Adina Roskies think that these studies can still only show, unsurprisingly, that physical factors in the brain are involved before decision-making. In contrast, Haggard believes that "We feel we choose, but we don't". Researcher John-Dylan Haynes adds: "How can I call a will 'mine' if I don't even know when it occurred and what it has decided to do?". Philosophers Walter Glannon and Alfred Mele think that some scientists are getting the science right, but misrepresenting modern philosophers. This is mainly because "free will" can mean many things: it is unclear what someone means when they say "free will does not exist". Mele and Glannon say that the available research is more evidence against any dualistic notions of free will – but that is an "easy target for neuroscientists to knock down". Mele says that most discussions of free will are now in materialistic terms. In these cases, "free will" means something more like "not coerced" or that "the person could have done otherwise at the last moment". The existence of these types of free will is debatable. Mele agrees, however, that science will continue to reveal critical details about what goes on in the brain during decision-making.This issue may be controversial for good reason: there is evidence to suggest that people normally associate a belief in free will with their ability to affect their lives. Philosopher Daniel Dennett, author of Elbow Room and a supporter of deterministic free will, believes that scientists risk making a serious mistake. He says that there are types of free will that are incompatible with modern science, but those kinds of free will are not worth wanting. Other types of "free will" are pivotal to people's sense of responsibility and purpose, and many of these types are actually compatible with modern science.
The other studies described below have only just begun to shed light on the role that consciousness plays in actions, and it is too early to draw very strong conclusions about certain kinds of "free will". It is worth noting that such experiments so far have dealt only with free-will decisions made in short time frames and may not have direct bearing on free-will decisions made by the subject over the course of many seconds, minutes, hours or longer. Scientists have also only so far studied extremely simple behaviors. Adina Roskies points out five areas of neuroscientific research:
- Action initiation
- Intention
- Decision
- Inhibition and control
- The phenomenology of agency.
There is also the question of the influence of such interpretations in people's behavior. In 2008, psychologists Kathleen Vohs and Jonathan Schooler published a study on how people behave when they are prompted to think that determinism is true. They asked their subjects to read one of two passages: one suggesting that behavior boils down to environmental or genetic factors not under personal control; the other neutral about what influences behavior. The participants then did a few math problems on a computer. But just before the test started, they were informed that because of a glitch in the computer it occasionally displayed the answer by accident; if this happened, they were to click it away without looking. Those who had read the deterministic message were more likely to cheat on the test. "Perhaps, denying free will simply provides the ultimate excuse to behave as one likes", Vohs and Schooler suggested. However, although initial studies suggested that believing in free will is associated with more morally praiseworthy behavior, some recent studies have reported contradictory findings.