Neuroscience of free will , part of neurophilosophy, is the study of the linkage between free will and neuroscience.
Because it becomes possible to study a living human brain, researchers have begun to observe the decision-making process at work. Findings can have implications for our agency's sense of agency, moral responsibility, and our understanding of consciousness in general. One of the pioneering studies in this field was designed by Benjamin Libet, while other studies have tried to predict participants' actions before they make them.
This field is still very controversial. There is no consensus among researchers about the significance of the findings, their meanings, or what conclusions can be drawn. However, the precise role of consciousness in decision making remains unclear.
Thinkers like Daniel Dennett or Alfred Mele consider the language used by researchers. They explain that "free will" means many different things for different people (eg some sense of free will is dualistic, some do not). Dennett insisted that many important and general conceptions of "free will" are compatible with the emerging evidence of neuroscience.
Video Neuroscience of free will
Overview
One of the significant findings of modern research is that a person's brain seems to be committed to a certain decision before the person is aware of having made it. Researchers have found a delay of about half a second (discussed in the section below). With contemporary brain scanning technology, other scientists in 2008 were able to predict with an accuracy of 60% whether 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, such as Patrick Haggard, to reject some form of "free will." To be clear, no single study will disprove all forms of free will. This is because the term "free will" can summarize hypotheses, each of which must be considered on the basis of existing empirical evidence.
There are also a number of issues concerning the study of free will. Particularly in previous studies, the study was too dependent on introspection of the participants, but the introspective estimates of the timing of events were found to be inaccurate. Many of the brain activity steps are insufficient and primitive because there is no good independent measurement of brain function of conscious, intentional, or decision-making generation. Conclusions drawn from measurements that have been made are also debatable, as they do not necessarily say, for example, what suddenly appears in the reading represents. In other words, the tilt may have nothing to do with the unconscious decision, as many other mental processes are happening while performing the task. Some of the studies mentioned here have become more advanced, however, even recording individual neurons in conscious volunteers. Researcher Itzhak Fried says that the available studies at least show consciousness coming in a further decision-making stage than previously thought - challenging each version of "free will" in which intentions occur at the beginning of the human decision process.
Free desire as an illusion
It is likely that a large number of cognitive operations are required to freely press a button. Research at least shows that our conscious self does not start all behaviors. Instead, the conscious self is somehow alerted to certain behaviors that other parts of the brain and body are already planning and performing. This finding does not forbid the conscious experience to play the role of moderation, although it may also be that some form of unconscious process is what causes modification in our behavioral response. Unconscious processes can play a larger role in behavior than previously thought.
Perhaps, then, that our intuition of our conscious "conscious" role has led us astray; it may be that we have a confusing correlation with cause and effect by believing that conscious awareness always causes body movement. This possibility is supported by findings in neurostimulation, brain damage, but also studies of introspection illusions. Such illusions show that humans do not have full access to internal processes. The discovery that humans have a determination that will inevitably have implications for moral responsibility. Neurologist and author Sam Harris believes that we are wrong in believing the intuitive idea that the intention of initiating action. In fact, Harris is even critical of the idea that free will is "intuitive": he says careful introspection can cast doubt on free will. Harris thinks "Thoughts only appear in the brain.What else can they do? The truth about us is even more bizarre than we thought: The illusion of free will is itself an illusion". Neurologist Walter Jackson Freeman III keeps talking about the power of even the unconscious systems and actions to change the world according to our intentions. He wrote "our deliberate actions continue to flow into the world, changing the world and our bodily relationships with it.This dynamic system is each of us, it is the responsible agent, not our consciousness, who is constantly trying to follow what we do. "For Freeman, the power of intent and action can be detached from consciousness.
Disputed relevance to scientific research
Some thinkers such as neurologists and philosophers, Adina Roskies, think that this study can still show, not surprisingly, that the physical factors in the brain are involved before decision making. Instead, Haggard believes that "We feel we choose, but we do not". Researcher John-Dylan Haynes adds, "How can I call my 'wish' if I do not even know when it happened and what has been decided to do?". The philosopher Walter Glannon and Alfred Mele think that some scientists get the knowledge right, but misrepresented modern philosophers. This is mainly because "free will" can mean many things: It is not clear what one means when they say "free will does not exist". Mele and Glannon say that the available research is more proof of any dualistic idea of ​​free will - but it is "an easy target for neurologists to break down". Mele says that much of the discussion on free will now exists in materialistic terms. In these cases, "free will" means something more like "not forced" or that "the person can do the opposite at the last moment". The existence of this type of free will is debatable. Mele agrees, however, that science will continue to reveal important details about what happens in the brain during decision making.
This problem may be controversial for good reason: There is evidence to suggest that people usually associate beliefs in free will with their ability to influence their lives. Philosopher Daniel Dennett, author of the Elbow Room and a proponent of deterministic free will, believes that scientists risk making serious mistakes. He says that there is a kind of free will that is incompatible with modern science, but he says such free will is not worth it. Other types of "free will" are crucial to the sense of responsibility and purpose of others (see also "belief in free will"), and many of these genres are perfectly compatible with modern science.
The other studies described below have just begun to explain the role played by consciousness in action and too early to draw strong conclusions about certain types of "free will". It should be noted that such an experiment - so far - only dealings with free will decisions made within a short span of time (seconds) and may have no direct relationship to the free will decision made ("with due consideration" ) by subject for many seconds, minutes, hours or longer. Scientists have also so far studied only very simple behaviors (eg moving fingers). Adina Roskies shows five areas of neuroscience research: 1.) initiation of action, 2.) intentions, 3). decisions, 4.) Inhibition and control, and 5.) agency phenomenology, and for each of these areas Roskies concludes that science may develop our understanding of volition or "will," but has not offered anything to develop a "free" of the "free will" discussion.
There is also the question of the influence of such an interpretation in people's behavior. In 2008, psychologists Kathleen Vohs and Jonathan Schooler published a study of how people behave when they are asked to think that determinism is right. They ask their subjects to read one of two parts: one indicates that the behavior leads to environmental or genetic factors that are not under personal control; neutral about what influences behavior. The participants then did some math problems on the computer. But just before the test begins, they are told that because of a computer error, sometimes they show an answer by accident; if this happens, they should click on it without looking. Those who have read the deterministic message are more likely to cheat on the exam. "Perhaps, denying freedom will only give the main reason for behaving as it likes," Vohs and Schooler suggested.
Maps Neuroscience of free will
Key experiments
Libet Experiment
The pioneering experiment in this field was conducted by Benjamin Libet in the 1980s, where he asked each subject to choose random moments to flick their wrists while he measured related activity in their brains (in particular, the buildup of electrical signals called Bereitschaftspotential (BP) which was discovered by Kornhuber & Deecke in 1965). Although it is known that Bereitschaftspotential (sometimes also called "potential readiness") precedes physical action, Libet asks how Bereitschaftspotential relates to perceived intent to move. To determine when the subject feels the intention to move, he asks them to watch the second hand and report his position when they feel that they have felt the conscious desire to move.
Libet found that subconscious brain activity leading to a conscious decision by the subject to flick his wrist began approximately half a second of before the subject consciously. feeling that he has decided to move. The Libet findings show that decisions made by the first subject are made at the subconscious level and only after it is translated into "conscious decisions", and that the belief of the subject that it occurs at the command of his will is only because of his retrospective perspective. at the event.
The interpretation of these findings has been criticized by Daniel Dennett, who argues that people should divert their attention from their intentions to the clock, and that this introduces a temporal mismatch between the feel experience of will and the perceived position of the hands of the clock. Consistent with this argument, subsequent research shows that appropriate numerical values ​​vary depending on attention. Despite differences in precise numerical values, however, key findings have been held. The philosopher Alfred Mele criticized this design for other reasons. After trying the experiment itself, Mele explained that "awareness of the intention to move" is an ambiguous feeling. For this reason he remains skeptical in interpreting the subjects' reported time for comparison with their 'Bereitschaftspotential'.
Criticism
In this variation of tasks, Haggard and Eimer ask subjects to decide not only when to move their hands, but also to decide which hand moves . In this case, perceived intentions correlate much more closely with the lateralized readiness potential (LRP), an ERP component that measures the difference between left and right brain hemisphere activity. Haggard and Eimer argue that the conscious feeling will therefore have to follow the decision that the hand to move, because the LRP reflects the decision to raise a certain hand.
A more direct test of the relationship between Bereitschaftspotential and "awareness of intent to move" was done by Banks and Isham (2009). In their study, participants performed a variant of the Libet paradigm in which a delayed tone followed the keystrokes. Subsequently, study participants reported time of their intention to act (eg, "W" from Libet). If W time-locked into Bereitschaftspotential, W will remain unaffected by post-action information. However, the findings of this study indicate that W is in fact systematically shifted by the time of tone presentation, implying that W is, at least in part, reconstructed retrospectively rather than predetermined by Bereitschaftspotential.
A study conducted by Jeff Miller and Judy Trevena (2009) suggests that the Bereitschaftspotential (BP) signal in the Libet experiment does not represent a decision to move, but that is only a sign that the brain is paying attention. In this experiment the classical Libet experiment was modified by playing an audio tone that showed the volunteers to decide whether to tap the lock or not. The researchers found that there were similar RP signals in both cases, regardless of whether the volunteers were actually selected to be tapped, indicating that the RP signal did not indicate that a decision had been made.
In the second experiment, the researchers asked volunteers to decide where to use their left or right hand to press the lock while monitoring their brain signals, and they did not find any correlation between the signal and the selected hand. This criticism itself has been criticized by free-will researcher Patrick Haggard, who mentions the literature that distinguishes two different circuits in the brain that lead to action: a "stimulus-response" circuit and a "voluntary" circuit. According to Haggard, researchers who apply external stimuli may not test the proposed volunteer series, or the Libet hypothesis of internally triggered actions.
Libet's interpretation of the increase in brain activity before the conscious "consciousness" report continues to attract harsh criticism. Studies have questioned participants' ability to report on their "wish" time. The author has found that preSMA activity is modulated by attention (attention precedes signal movement by 100ms), and previously reported activity can therefore be a motion-bearing product. They also found that the onset of perceived intentions depended on neural activity that occurred after the implementation of the action. Transcranial magnetic stimulation (TMS) is applied over the preSMA after the participant performs a preliminary shift action of the motor intention backwards in time, and the time felt from the execution of the forward action in time.
Others speculate that the earlier neural activity reported by Libet might be the average artifact of "will" time, in which neural activity does not always precede the reported "will". In similar replication they also reported no difference in electrophysiological signs before the decision to move, and before the decision to move.
Regardless of his findings, Libet himself does not interpret his experiment as evidence of the inability of conscious free will - he points out that although the tendency to press the keys may increase for 500 milliseconds, awareness will still have the right to veto anything. action at the last moment. According to this model, the unconscious impulse to perform an act of open will is to be suppressed by the conscious effort of the subject (sometimes referred to as "not free"). The comparison was made with the golfer, who may have swung the club several times before hitting the ball. The action only got the approval stamp in the last millisecond. But Max Velmans argues that "free will not" may turn out to require as many nerve preparations as "free will" (see below).
But some studies have replicated Libet's findings, while discussing some of the original criticisms. A recent study found that individual neurons were found firing 2 seconds before "willingness" to act (long before EEG activity predicted such a response). Itzhak Fried replicates Libet's findings in 2011 on a single-neuron scale. This is achieved with the help of volunteer epilepsy patients, who require electrodes planted deep in their brains for evaluation and treatment. Now able to monitor conscious and mobile patients, the researchers replicated the timing anomalies discovered by Libet and discussed in the following study. Similarly for these tests, Chun Siong Soon, Anna Hanxi He, Stefan Bode and John-Dylan Haynes have conducted a study in 2013 that claims to predict the choice to be added or subtracted before the subject reports.
William R. Klemm shows the inclusion of these tests due to the limitations of design and data interpretation and proposes a less ambiguous experiment, while asserting standing on the existence of free will like Roy F. Baumeister or a Catholic neurologist such as Tadeusz Pacholczyk. Adrian G. Guggisberg and AnnaÃÆ'¯s Mottaz also challenged the findings of Itzhak Fried.
A study by Aaron Schurger and colleagues published in PNAS challenged assumptions about the causal nature of Bereitschaftspotential itself (and "pre-movement buildup" of nerve activity in general), thus denying the conclusions drawn from such studies as Libet and Fried's. See The Information Philosopher and New Scientist for comments on this study.
Unconscious action
Timing intentions compared to
actionsA study by Masao Matsuhashi and Mark Hallett, published in 2008, claims to have replicated Libet's findings independent of the subjective reports or clock memorization on the part of participants. The authors believe that their method can identify the time (T) in which the subject becomes aware of his own movement. Matsuhashi and Hallet argue that this time not only varies, but often occurs after the initial phase of the genesis of movement has begun (as measured by potential readiness). They conclude that one's consciousness can not be the cause of the movement, and on the contrary it may be concerned only with movement.
Trial
Matsuhashi and Hallett's research can be summarized so. The researchers hypothesize that, if our conscious intentions are what causes the genesis of movement (ie the beginning of an action), then naturally, our conscious intentions must always occur before any movement begins. Otherwise, if we become aware of a movement only after the movement has begun, our consciousness is unlikely to be the cause of that particular movement. Simply put, conscious intentions must precede action if that is the cause.
To test this hypothesis, Matsuhashi and Hallet have volunteers performing fast finger movements at random intervals, while not counting or planning when to make that movement (the future), but immediately doing the moves as soon as they think about it. An externally controlled "stop-signal" is played at random pseudo intervals, and volunteers must cancel their intention to move if they hear a signal while realizing their immediate intent to move. Whenever an is an action (finger motion), the authors document (and graph) every note that occurs before the action. The tone graph before action therefore only shows the tone (a) before the subject even realizes its "genesis movement" (or they will stop or "vocalize" the movement), and (b) after it is too late to veto the action. The second set of pictorial tones is not very important here.
In this work, the "movement genesis" is defined as the process of the motion-making brain, in which physiological observations have been made (via electrodes) indicating that it may occur before awareness of consciousness of intent to move (see Benjamin Libet).
By finding out when the tone starts to prevent the action, the researchers should know the length of time (in seconds) that exists between when the subject holds the conscious intention to move and perform the motion action. When this consciousness (as seen in the graph below) is dubbed "T" (meaningful time of conscious intention to move). This can be found by looking at the border between notes and notes. This allows researchers to estimate the time of conscious intent to move without relying on subject knowledge or demanding them to focus on the clock. The final step of this experiment is to compare T times for each subject with their Event-related potential (ERP) action (eg seen on the main picture of this page), which reveals when the genesis of their finger movement was first started.
The researchers found that when conscious intentions to move T usually occur late the cause of motion origin. See example of subject graph below on the right. Although it is not shown on the chart, the potential readiness of the subject (ERP) tells us that its action starts at -2.8 seconds, but this is much earlier than the conscious intention to move, time "T" (-1.8 seconds). Matsuhashi and Hallet concluded that the feeling of conscious intention to move does not cause the genesis of movement; both the feeling of intent and the movement itself is the result of the subconscious process.
Analysis and interpretation
This research is similar to Libet in some ways: volunteers are asked again to perform finger extensions in short intervals that are fast-paced. In this experimental version, the researchers introduced a random "stop tone" during a fast-paced movement. If participants are not aware of the intention to move, they ignore the tone. On the other hand, if they realize their intention to move at a moment of tone, they should try to veto the action, then relax for a moment before continuing the moves that move on their own. This experimental design allows Matsuhashi and Hallet to see when, once the subject moves his finger, any note occurs. The goal is to identify their own similarities with Libet's W, their own estimates of the timing of the conscious intent to move, which they will call "T" (time)
Testing the hypothesis that 'conscious intentions occur after the genesis of movement has begun' required the researchers to analyze the distribution of responses to tone before action. The idea is that, after time T, the tone will cause vetoing and thus the representation is reduced in the data. There will also be a point of no return where the tone is too close to the initial movement for the motion to be vetoed. In other words, researchers expect to see the following on the graph: many responses are not pressed against the tone while the subject is not yet aware of the genesis of their movement, followed by a decrease in the number of unresponsive responses to the tone over a given period of time in which the subject is conscious of their intent and stop any movement, and finally a short increase again in the unresponsive response to the tone when the subject has no time to process the tone and prevent the action - they have passed the "point of no return" action. That is exactly what the researchers found (see graph on the right, below).
The graph shows the time at which a response that is not pressed against a tone occurs when the volunteer moves. He showed many unresponsive responses to the tone (dubbed "tone events" on the graph) averaging up to 1.8 seconds before motion onset, but a significant drop in tone events soon after that time. Maybe this is because the subject usually realizes its intention to move about -1.8 seconds, which is then labeled point T. Because most of the action is voiced if the tone comes after the T point, there is very little tone activity represented during that range.. Finally, there is a sudden increase in the number of tone events at 0.1 seconds, which means that this subject has passed the point P. Matsuhashi and Hallet can thus set an average time T (-1.8 seconds) without a subjective report. This, they were compared with the measurement of ERP movement, which had detected movement ranging about -2.8 seconds on average for this participant. Because the original T-like Libet W - often found after the genesis of movement has already begun, the authors conclude that the generation of consciousness occurs after or in parallel to the action, but most importantly, that it may not be the cause of movement..
Criticism
Haggard describes other studies at the neuronal level as providing a "convincing confirmation of previous studies that record the nervous population" as just described. Note that these results are collected using finger movements, and may not need to generalize other actions such as thinking, or even other motor acts in different situations. Indeed, human planning acts have implications for free will and so this ability must also be explained by any unconscious decision-making theory. The philosopher Alfred Mele also doubts the conclusions of this study. He explains that just because a movement may have begun before our "conscious self" becomes aware of it does not mean our consciousness can not still approve, modify, and possibly cancel (called vetoing) actions.
Unconscious action undo
The possibility that "human beings are not free" is also a prerogative of the unconscious being explored.
Retrospective appraisal of free choice
Recent research by Simone KÃÆ'¼hn and Marcel Brass suggests that our consciousness may not be what caused some action to be vetoed at the last moment. First of all, their experimentation depends on the simple idea that we must know when we consciously cancel an action (ie we must have access to that information). Second, they suggest that access to this information means that humans should find it easy to say, only after completing an action, whether it is impulsive (no time to decide) and when there is time to negotiate (the participants decide to allow/not veto action). This study found evidence that the subject could not say this important difference. This again leaves behind some conceptions of free will that are vulnerable to the illusion of introspection. Researchers interpret their results to mean that the decision to "veto" an action is determined unconsciously, just as the initiation of the action may have become unconscious in the first place.
Trial
This experiment involves asking a volunteer to respond to a signal signal by pressing the "go" electronically as fast as possible. In this experiment the go-sign is represented as a visual stimulus displayed on the monitor (eg the green light as shown in the figure). The reaction time of the participants (RT) is collected at this stage, in what is described as a "major response test".
The primary response test is then modified, where 25% of the go-signal is then followed by an additional signal - either "stop" or "disconnect" the signal. Additional signals occur after "signal delay" (SD), the amount of random time up to 2 seconds after the initial incoming signal. They also occur equally, each representing 12.5% ​​of the experimental cases. These additional signals are represented by an initial stimulus color change (eg to red or orange light). 75% of other signals are not followed by additional signals - and therefore are considered the "default" mode of the experiment. The task of the participants responds as quickly as possible to the initial signal (ie pressing the "go") key nonetheless.
After viewing the initial signal, participants will immediately intend to press the "go". Participants are instructed to cancel their intentions to press the "go" button if they see a stop signal. Participants are instructed to choose randomly (at leisure) between pressing the "go" button, or not pressing it, if they see a deciding signal. The test in which the deciding signal is indicated after the initial signal ("deciding the test"), for example, requires that participants prevent themselves from acting impulsively on the initial signal and then deciding what to do. Due to various delays, this is sometimes impossible (eg some disconnected signals just appear too late in the process, both intend and press the go button to be obeyed).
The test in which the subject reacts to the impulsive movable signal without seeing the next signal indicates a fast RT of about 600 ms. The test in which the deciding signal is displayed is too late, and the participants have already issued a push to press the go-button (ie not decided to do so), it also shows a fast RT of about 600 ms. The test in which the signal stops showing and the participant successfully answers it, does not show the response time. The test where the deciding signal is displayed, and the participant decides not to press the go button, nor does it show the response time. The trials in which the deciding signal is displayed, and the participants have not enacted their encouragement to press the go-button, but (where it theorizes that they) have had a chance to decide what to do, indicating a relatively slow RT, in this case closer to 1400 ms.
Participants are required at the end of "deciding on an experiment" in which they actually push the go button if they have acted impulsively (without enough time to register a deciding signal before enacting their intention to press the go-button in response to the initial go-signal stimulus) or have acted on the conscious decisions made after seeing the deciding signal. However, based on response time data, there seems to be a difference between when users think they have a chance to decide (and therefore do not act on their push) - in this case decides to press the go-button, and when they think they are acting impulsively initial signal) - where the deciding signal arrives too late to obey.
Rationale
Kuhn and Brass wanted to test the participants' self-knowledge. The first step is that after each session, the participants are then asked if they really have time to decide. In particular, volunteers are required to label each of the court decisions as one that fails to decide (the action is the result of an impulsive action on the initial signal) or a successful decision (the result of a deliberate decision). Look at the diagram on the right for this to decide on the separation of the experiment: failing to decide and decide on success; the next section in this diagram (true or false participants) will be explained at the end of this experiment. Note also that the researchers sequenced the success of the participants deciding the trials to "decide to go" and "decide nogo", but did not care about the nogo test because they did not generate RT data (and not shown anywhere in the diagram on the right). Note that successful stop trials do not generate RT data either.
Kuhn and Brass now know what to expect: a primary response test, every failed test stop, and a "fail to decide" test are all instances where participants clearly act impulsively - they will show the same fast RT. Conversely, a "successful" decide "(where the decision was" gone "and subject moved) should show a slower RT. Presumably, if deciding whether to veto is a deliberate process, volunteers should have no difficulty distinguishing impulsivity from continuing instances of deliberate movement. Again, this is important because deciding on a test requires that participants rely on self-knowledge. Note that stopping the experiment can not test self-knowledge because if the subject performs acts, it is clear to them that they are reacting impulsively.
Results and implications
Not surprisingly, RTs recorded for primary response trials, failed trials, and "failed deciding" experiments all showed the same RT: 600 ms seems to indicate impulsive actions that were made without time to be completely deliberate. What the two researchers found hereinafter is not easy to explain: while some "deciding success" trials actually show slow RT discussions (on average about 1400 ms), the participants also labeled many impulsive actions as "deciding success". This result is surprising because the participants should have no trouble identifying which action is the result of "I will not veto", and which action is not discussed, the impulsive reaction to the initial signal. As the authors explain:
In deciding the trials the participants, it seems, can not identify whether they really have time to decide - at least, not based on internal signals. The authors explain that this result is difficult to reconcile with the idea of ​​a conscious veto, but it is simple to understand if the veto is considered an unconscious process. Thus it seems that the intention to move may not only arise from the subconscious, but may only be hampered if the subconscious says so. This conclusion can show that the phenomenon of "consciousness" is more than narrative rather than direct arbitrage (ie the unconscious process causes all thoughts, and these thoughts are again processed unconsciously).
Criticism
After the above experiments, the authors conclude that subjects sometimes can not distinguish between "generating action without stopping and stopping action before voluntarily proceeding", or in other words, they can not distinguish between direct and impulsive action compared to delays under consideration. To be clear, one assumption from the author is that all initial actions (600 ms) are not realized, and all actions are subsequently realized. These conclusions and assumptions have not been debated in the scientific literature or even replicated (this is a very early study).
The results of experiments in which so-called "deciding success" data (with measured longer periods) are observed may have possible implications for our understanding of the role of consciousness as a modulator of the action or response given - and these possible implications can not be ignored so alone or ignored for no legitimate reason, especially when the experimenter's authors declared that the end deciding the trial was actually discussed.
It should be noted that Libet consistently refers to the veto of endogenously initiated actions. That is, a veto that occurs in the absence of an external clue, rather than relying on internal cues (if any). This veto may be a different kind of veto than that explored by KÃÆ'¼hn and Brass using the signals they decide.
Daniel Dennett also argues that no clear conclusions about willingness can be derived from the Benjamin Libet experiment that purportedly demonstrates the unconscious of conscious will. According to Dennett, ambiguity in the timing of the various events involved. Libet says when potential readiness occurs objectively, using electrodes, but depends on subjects who report clockwise to determine when conscious decisions are made. As Dennett pointed out, this is just a report in which it seems to be on the subject that things come together, not from the objective time in which they actually occur.
Suppose Libet knows that your potential readiness peaked in the 6.810 milliseconds of the experimental experiment, and the point of the clock straight down (which you report you see) on a 7.005 milisecond. How many milliseconds should he add to this number to get the time you realize? The light comes from your face clock to your eyeballs almost instantly, but the signal path from the retina through the geniculate lateral nucleus to form the cortex takes 5 to 10 milliseconds - a crushed fraction of 300 milliseconds is balanced, but how much longer take them to get to < i> you . (Or are you in the striate cortex?) Visual signals must be processed before they arrive wherever they need to arrive for you to make a conscious decision about synchronization. The Libet method presupposes, in a nutshell, that we can find the intersection of two paths:
so these events occur side by side like in places where their simultaneity can be recorded.
- increased signal awareness representing the snapping decision
- signal awareness raising representing sequential clock-face orientation
The point without reply
In early 2016, PNAS published a paper by researchers in Berlin, Germany, The point of no return in vetoing self-initiated movements, in which the authors set out to investigate whether human subjects have the ability to veto an action (in this study, leg movement) after detecting Bereitschaftspotential (BP). Bereitschaftspotential, invented by Kornhuber & amp; Deecke in 1965, is an example of unconscious electrical activity within the motor cortex, measured by the use of EEG, occurring moments before a movement is performed by a person: it is considered a signal that the brain "prepares" for movement. This study finds evidence that this action can be vetoed even after BP is detected (i.E. After that it can be seen that the brain has already begun preparing the action). The researchers maintain this is evidence of the existence of at least some degree of free will in humans: previously, it has been argued that, given the subconscious nature of BP and its usefulness in predicting a person's movement, it is a movement initiated by the brain without the conscious involvement of the person. This study shows that subjects are able to "overwrite" these signals and stop doing the motion that BP is anticipating. Next, the researchers identified what is called a "point of no return": once BP is detected for a movement, the person can refrain from doing the motion only if they try to cancel it 200 milliseconds or longer before the start of the movement. After this point, the person can not avoid making moves. Previously, Kornhuber & amp; Deecke underlines that the absence of conscious will during the earliest Bereitschaftspotential (termed BP1) is not evidence of the absence of free will, as also the unconscious agenda may be free and non-deterministic. According to their advice, humans have relative freedom, which is freedom in degrees, which can be in- derived through deliberate choices involving the conscious and unconscious (panencephalic) process.
Neuronal prediction of free will
Despite criticism, researchers are still trying to gather data that could support the case that consciously predictable "wills" of brain activity. The fMRI machine that studies brain activity (multivariate pattern analysis) has been used to predict the choice of key (left/right) users up to 7 seconds before they report will do so. Areas of the brain that have been trained for prediction include the frontopolar cortex (anterior prefrontal cortex anterior) and the precuneus/posterior cingulate cortex (medial parietal cortex). To ensure the time of conscious "conscious" reporting to act, they show participants a series of frames with single letters (500ms apart), and after pressing the selected button (left or right) they are required to show the letter they have. visible at the time of decision. The study reported a statistically significant 60% accuracy rate, which may be limited by experimental settings; limitations of machine learning data (time spent in fMRI) and instrument precision.
Another version of the multivariate pattern analysis experiments fMRI performed using the problem of abstract decisions, in an attempt to override the possibility of predictive capability into a product of capturing a motor drive built-up. Each frame contains the central letter as before, but also the center number, and about 4 possible "answer numbers". Participants first choose in their minds whether they want to perform addition or difference (subtraction) operations (and note the central letter on the screen at the time of this decision). Participants then perform mathematical operations based on the central figures shown in the next two frames. In the following frames, the participant then selects the "answer number" associated with the results of the operation. They are further presented with a frame that allows them to show the central mail that appears on screen at the time of their initial decision. This trial version found the brain's prediction capacity up to 5 seconds before being aware of the action.
Multivariate pattern analysis using EEG has suggested that evidence-based perceptual decision models may apply to free decisions. It was found that decisions can be predicted by neural activity soon after perception of stimulus. Furthermore, when participants can not determine the nature of the stimulus, recent decision history predicts neural activity (decisions). The initial point of evidence accumulation is essentially shifted towards the previous choice (indicating priming bias). Other studies have found that subliminal priming participants for a particular decision result (indicating cues for 13ms) can be used to influence the outcome of a free decision. Likewise, it has been found that decision history alone can be used to predict future decisions. The prediction ability of Soon et al. (2008) experiments were successfully replicated using a linear SVM model based on participant's decision history alone (without brain activity data). Nevertheless, recent research has sought to confirm the application of a perceptual decision model to free will decisions. When masked stimuli are shown and therefore invisible, participants are asked to guess between categories or make free decisions for a particular category. Multivariate pattern analysis using fMRI can be trained on "free decision" data to successfully predict "guess decisions", and be trained on "forecast data" to predict "free decisions" (in precuneus and cuneus areas).
The task of predicting contemporary voluntary decisions has been criticized on the basis of the possibility of neuronal signatures for pre-conscious decisions can actually correspond to a lower conscious process than unconscious processing. People may be aware of their decision before making their report but need to wait a few seconds to be sure. Such a model does not explain what is left unconscious if everything can be realized at some level (and the purpose of defining a separate system). But the limitations remain free will be a prediction of research to date. In particular, the predictive assessment judgment of brain activity involving the thought process begins minutes rather than seconds before the conscious will to act, including rejection of conflicting desires. These are generally seen as a sequence of evidence products that collect judgments.
Retrospective construction
It has been suggested that wisdom authorship is an illusion. Unconscious thoughts and actions can facilitate thoughts and actions, while agents experience thoughts and actions as dependent on the conscious will. We can excessively assign agents because of the evolutionary advantages that once come by always suspecting there may be an agent doing something (eg a predator). The idea behind retrospective construction is that, while part of the "yes, I do" agency feeling seems to occur during the course of action, there also seems to be processing after the fact - once the action is done - to build a feeling of full agency.
The processing of an unconscious agent can even change, at this point, how we perceive the time of sensation or action. KÃÆ'¼hn and Brass apply a retrospective construct to explain the two peaks in the "successful deciding" RT. They suggested that the deceased decided the trial was actually discussed, but that an impulsive initial decision that should have been labeled "failed decides" was wrong during the processing of an unconscious agent. They say that people "continue to believe that they have access to their own cognitive processes" when in fact we do a lot of automatic unconscious processing before conscious perception takes place.
It should be noted that criticism of Wegner's claim on the importance of illusions of introspection for the idea of ​​free will has been made public.
Manipulate options
Several studies have shown that TMS can be used to manipulate the authors' perceptions of a particular choice. Experiments show that neurostimulation can affect the hands of people in motion, although the experience of free will is intact. A preliminary TMS study revealed that a single-sided activation of the neocortex could be used to deviate from one arm to another in a forced decision-making task. Ammon and Gandevia find that it is possible to influence the hands of the people to move by stimulating the frontal areas involved in planning the movement using transcranial magnetic stimulation in the left or right hemispheres of the brain.
People who use the right hand will usually choose to move their right hand 60% of the time, but when the right hemisphere is stimulated, they will choose their left hand 80% of the time (remember that the right hemisphere of the brain is responsible for the left side of the body, and the left hemisphere to the right). Despite the external influences on their decision-making, subjects continue to report that they believe their choice of hand has been made freely. In a follow-up experiment, Alvaro Pascual-Leone and colleagues found similar results, but also noted that transcranial magnetic stimulation should occur within 200 milliseconds, consistent with time derived from the Libet experiment.
By the end of 2015, a team of researchers from the UK and the US published a paper showing similar findings. The researchers concluded that "motor responses and hand choices can be modulated using tDCS". However, different attempts by Sohn et al. failed to replicate the result; then, Jeffrey Gray wrote in his book Awareness: Crawling on Difficult Problems that tested the search for the influence of electromagnetic fields on brain function has been universally negative in their results.
Manipulating perceived intent to move
Various studies show that the intentions felt to move (have moved) can be manipulated. Research has focused on pre-supplementary (pre-SMA) motor areas of the brain, where the potential readiness that indicates the onset of motion genesis has been noted by EEG. In one study, directly stimulating pre-high school causes volunteers to report feelings of intent, and sufficient stimulation of the same area causes physical movement. In a similar study, it was found that people who do not have visual awareness of their bodies can make their feet move without awareness of this movement, by stimulating the premotor brain region. When their parietal cortex is stimulated, they report a drive (intention) to move certain limbs (that they want to do). Furthermore, the strong stimulation of the parietal cortex results in the illusion of having moved without doing so.
This shows that awareness of an intention to move can actually be a "sensation" of the body's early movements, but certainly not the cause. Other studies at least show that "Greater activation of SMA, SACC, and parietal areas during and after the implementation of internally generated actions suggests that important features of an internal decision are certain neural processes that occur during and after appropriate action. , awareness of time of intent seems to be fully established only after the implementation of appropriate action, according to the time course of nerve activity observed here. "
Another experiment involved an electronic ouija board in which the device's movements were manipulated by experimentation, while the participants were led to believe that they were entirely self-perpetrated. Experiments stop the device at certain times and ask the participants how much they feel like quitting. Participants also listen to words on headphones; and it was found that if the experiment stops next to the object coming through headphones, they are more likely to say that they want to stop there. If the participant is considered to have thought at the time of the action, then it is set as intentional. It was concluded that a strong illusion of perception of causality requires; priority (we assume the thinking must precede action), consistency (thought is about action), and exclusivity (no real cause or alternative hypothesis).
Lau et al. set up an experiment in which the subject will see an analog-style clock, and a red dot will move around the screen. Subjects are told to click the mouse button whenever they feel the intention to do so. One group was given a transcranial magnetic stimulation pulse (TMS), and the other was given a fake TMS. Subjects in a condition of intent were told to move the cursor to a place where they felt a tendency to press a button. Under motion conditions, the subject moves the cursor to its place when they physically press the key. The results showed TMS was able to shift the felt intention to the front of 16 ms, and shifted back 14 ms for the condition of movement. The perceived intentions can be manipulated up to 200 ms after the implementation of spontaneous action, indicating that perceptions of intentions occur after executive motor movements. It is often assumed that free will exists, it will require intent to be the source of the cause of behavior. These results suggest that intent may not be the source of all causes of behavior.
Related models
The idea that intentions coincide with movement (not cause) reminds us of the "front motor control model" (or FMMC, which has been used to try to explain inner speech). FMMC describes parallel circuits: movements are processed in parallel with other motion predictions; if the movement is in accordance with the prediction - the feeling of the agent occurs. FMMC has been applied in other related experiments. Metcalfe and his colleagues used FMMC to explain how volunteers determine if they are in control of computer game duties. On the other hand, they recognize other factors as well. The authors attribute agency feelings to the outcome wishes (see self-serving bias) and top-down processing (reasoning and conclusions about the situation).
In this case, with the forward-looking modeling imaginable how other conscious processes can be the result of efficient, predictive processing. If self-consciousness is a copy of the action and veto done, then consciousness is a kind of narrator of what has happened inside the body, and an incomplete narrator at the time. Haggard, summarizing data taken from recent neuron records, said "this data suggests that conscious intentions are merely subjective consequences of an action to take place". Parallel processing helps explain how we can experience some kind of counter-causal freedom even if it is determined.
How the brain builds consciousness is still a mystery, and breaking it open will have a significant influence on the question of free will. Many different models have been proposed, for example, the Multiple Draft Model which states that there is no central Cartesian theater in which the conscious experience is represented, but that consciousness lies throughout the brain. This model will explain the delay between decision and conscious realization, as experiencing everything as 'filmstrip' is constantly behind the real conscious decisions. In contrast, there is a Cartesian model of materialism that has gained recognition by neuroscience, implying that there may be a special brain area that stores the contents of consciousness; this does not, however, rule out the possibility of the conscious will. Other models such as epiphenomenalism argue that the conscious will is an illusion, and that consciousness is a by-product of the physical state of the world. Working in this sector is still highly speculative, and researchers are not fond of single awareness models. (See also: The philosophy of the mind.)
Related brain disorders
Various brain disorders involve the role of unconscious brain processes in decision-making tasks. Hearing hallucinations produced by Schizophrenia seem to indicate differences in desire and behavior. The left hemisphere of the hemispheric person has been interrupted to be observed to create an explanation for body movements initiated by the opposite (right) hemisphere, probably based on the assumption that their actions are consciously desired. Likewise, people with 'foreign hand syndrome' are known to perform complicated motor moves that conflict with their desires.
Neural model of voluntary action
The nerve model for the voluntary action proposed by Haggard consists of two main circuits. The first involves early preparatory signals (basal ganglia substantia nigra and striatum), previous intentions and deliberations (medial prefrontal cortex), motor preparation/potential readiness (preSMA and SMA), and motor execution (primary motor cortex, spinal cord and muscle). The second involves a pre-motorized parietal circuit for object-guided action, such as grasping (premotor cortex, primary motor cortex, primary somatosensory cortex, parietal cortex, and returning to the premotor cortex). He proposes that voluntary action involves the input of the external environment ('when decisions'), motivation/reason for action (initial 'whether the decision'), task and selection of actions ('what decisions'), final predictive checks (end 'whether decisions') and action execution.
Other neural models for voluntary action also involve what decisions, when, and whether (WWW). The 'what' decision component is considered a function of the anterior cingulate cortex, which is involved in conflict monitoring. Time ('when') decisions are considered as a function of preSMA and SMA, who are involved in motor preparation. Finally, the 'what' component is considered a function of the medial dorsal prefrontal cortex.
Prospects
Martin Seligman and others criticized the classical approach to science that views animals and humans as "driven by the past," and suggests instead that humans and animals use experience to evaluate their prospects, and act accordingly. Claims are made that this purposive action includes an unprecedented evaluation of the possibility, and can be tested experimentally.
Seligman and others argue that free will and the role of subjectivity in consciousness can be better understood by taking a "prospective" attitude to cognition, and that "gathering evidence in various studies shows a shift [this] within the framework".
See also
- Adaptive unconscious
- Dick Swaab
- Neural decodean
- Sam Harris
- Identify the mind, through the use of technology
- Unconscious mind
References
External links
Fate, Freedom and Neuroscience - the debate over whether neuroscience has proven that free will is an illusion by the Institute of Art and Ideas featuring neuroscientist Oxford Nayef Al-Rodhan, East End psychiatrist and broadcaster Mark Salter, and LSE philosopher Kristina Musholt debates the limits of science.Source of the article : Wikipedia
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