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Unconscious determinants of free decisions in the human brain

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Abstract

There has been a long controversy as to whether subjectively 'free' decisions are determined by brain activity ahead of time. We found that the outcome of a decision can be encoded in brain activity of prefrontal and parietal cortex up to 10 s before it enters awareness. This delay presumably reflects the operation of a network of high-level control areas that begin to prepare an upcoming decision long before it enters awareness.
... The findings propose that decisions occur milliseconds prior to conscious awareness, hinting that the concept of free will could be illusory. . Additionally, with the fMRI technology, they can detect brain activation patterns related to decisions making that occurred before the actual decision is made, questioning even the more about the traditional views on free will [3]. The existence or absence of free will has deep implications for our concepts of law, morality, and personal responsibility. ...
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Free will, an age-old philosophical concept, is integral to our understanding of human autonomy, ethical responsibility, and the legal system. Its presence or absence fundamentally influences our decisions and the fabric of societal norms. In recent years, the advancement of neuroscience has made re-evaluating free will increasingly important. This paper reviews philosophical perspectives from ancient to modern times, integrates neuroscientific experiments, and analyzes psychological research to comprehensively explore the issue of the existence of free will. It enumerates contemporary mainstream views on the existence of free will, discusses the sources of the sense of free will, and highlights its profound implications for both individual and collective societal structures. The paper finds that current discussions on the existence of free will remain controversial. In the end, it summarizes the findings and provides an outlook on future research. New technologies and further interdisciplinary studies are expected to offer new perspectives and evidence for understanding free will.
... It turns out the relationship between consciousness, free will, and decision making is more complicated than you might have guessed. While Libet's experiments (1985) and subsequent research by Soon et al. (2008) suggest that decisions may be initiated before conscious awareness, this doesn't necessarily negate the role of consciousness in decision making. It suggests, however, a more complex interaction between conscious and unconscious processes. ...
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One of humanity's oldest philosophical puzzles is the debate over free will vs. determinism. Do our actions proceed from prior causes, and are we therefore enslaved? Or are we free to choose? What used to be a purely philosophical question has become a scientific one, with support from neuroscience, psychology, and artificial intelligence.
... This means that the brain always tries to adjust a little in advance to possible situations that will come our way. When looking directly at the brain processes with functional magnetic resonance tomography, a rhythmic activity that jumps back and forth between different brain regions is noticeable [87][88][89]. ...
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This review presents biophysical and quantum physical aspects of informational processes coming from the early evolution till the human brain. Here, the sophistication in the layered cortex architecture as well as the functional orientation of its areas has built nearly “free” zones for associations and connections. With our self-consciousness, a further horizon is reached which represents a “membrane” or portal to other space dimensions - leading out of the narrow cage of the brain. This notion renders the brain cortex into a kind of “antenna”. Some possible ways of this linkage to these “outer space dimensions” are discussed, also looking to psychological aspects like “extended mind”, terminal lucidity” etc.
... However, establishing the link between these two is essential to finding the roots of modern insight meditation and mindfulness practices in the West. The idea that there is no free will is backed by neurological data since they observed neurological patterns of functional magnetic resonance imaging (fMRI) where they could predict what decision the person is going to make about a few seconds before the person is aware of their decision (Soon, Brass, Heinze, & Haynes, 2008). ...
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This study explores the profound questions surrounding the pursuit of Nirvana in Buddhism, examining whether it arises from the cycle of rebirth, present suffering, or future pain as depicted in early Buddhist scriptures. It also investigates the potential convergence of Buddhism with existentialism, a philosophy emphasizing individual experience, freedom, responsibility, and life’s inherent uncertainties. The primary inquiry examines whether Buddhism can harmonize with existentialist perspectives, which emphasize individuality amidst life’s enigmas. This research comprehensively investigates the reasons driving individuals in mainstream Buddhism to seek Nirvana, delving into their quest for liberation, and emphasizes the existential essence of Buddhism. Finally, It explores the plausibility of an alternative form of Buddhism that incorporates existential philosophy. Using a literature analysis approach with a thematic focus, this study critically examines the writings of prominent Buddhist scholars, existential philosophers, and researchers on the intersection of Buddhism and existentialism. The analysis reveals that Buddhists aspire for Nirvana to escape the cycle of suffering and find solace and serenity. Moreover, the juxtaposition of Buddhism and existentialism offers a fresh perspective, highlighting individual autonomy and choice in confronting life’s complexities, and providing an early Buddhist account of existential nature. By deepening the understanding of how mindfulness and meditation connect to core Buddhist principles, this research fosters more authentic engagement with Buddhist practices, enriching personal well-being. This research has vital implications for understanding the pursuit of meaning and liberation from suffering amidst life’s chaos, challenging conventional perceptions of Buddhism, and elucidating potential alignments with existential thought, inviting further research.
... Now, if any of what we naively think of as our chosen behaviour is fixed in advance, behaviour in such tasks certainly would be. Despite this, predictive neural models about what one will do on isolated trials based on changes in neural states and activities in the seconds leading up to one's action only have around 59% accuracy [54,55]. They are wrong around 41% of the time. ...
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Antiquated Classical pictures of the universe have been formative in shaping the modern idea that, to the extent change is caused, it is fixed in advance. This idea has played a role in making it seem to many that what we are discovering through science supports the exclusion of free will from models for the relevant neural and bodily changes. I argue that giving up this unwarranted notion about causation opens us to the likelihood that how a person expresses free will offers unique explanatory value. I then briefly discuss some further issues with either including or excluding expressions of free will from our explanations, as well as some implications for AI and everyday life.
... Indeed, it has been shown that the spontaneous fluctuations in brain activity preceding stimuli presentation, i.e., pre-trial or pre-stimulus brain activity, influences a wide range of behavioral and cognitive processes in humans. These include perception (Boly et al., 2007;Hesselmann et al., 2010aHesselmann et al., , 2010bVan Dijk et al., 2008;Wyart & Tallon-Baudry, 2009); cognitive flexibility (Leber et al., 2008); memory encoding (Otten et al., 2006); decision-related processes, for example, perceptual decision-making (Hesselmann et al., 2008(Hesselmann et al., , 2010a(Hesselmann et al., , 2010bHsieh et al., 2012); motor decisions and inhibition (Filevich et al., 2013;Haggard, 2005;Libet, 1985;Libet et al., 1983;Soon et al., 2008); and aesthetic judgment (Colas & Hsieh, 2014). Recent studies have shown that pre-stimulus brain activity influences the complex valuation processes involved in decisionmaking under risk (Chew et al., 2019;Huang et al., 2014). ...
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Recent studies have shown that spontaneous pre-stimulus fluctuations in brain activity affect higher-order cognitive processes, including risky decision-making, cognitive flexibility, and aesthetic judgments. However, there is currently no direct evidence to suggest that pre-choice activity influences value-based decisions that require self-control. We examined the impact of fluctuations in pre-choice activity in key regions of the reward system on self-control in food choice. In the functional magnetic resonance imaging (fMRI) scanner, 49 participants made 120 food choices that required self-control in high and low working memory load conditions. The task was designed to ensure that participants were cognitively engaged and not thinking about upcoming choices. We defined self-control success as choosing a food item that was healthier over one that was tastier. The brain regions of interest (ROIs) were the ventral tegmental area (VTA), putamen, nucleus accumbens (NAc), and caudate nucleus. For each participant and condition, we calculated the mean activity in the 3-s interval preceding the presentation of food stimuli in successful and failed self-control trials. These activities were then used as predictors of self-control success in a fixed-effects logistic regression model. The results indicate that increased pre-choice VTA activity was linked to a higher probability of self-control success in a subsequent food-choice task within the low-load condition, but not in the high-load condition. We posit that pre-choice fluctuations in VTA activity change the reference point for immediate (taste) reward evaluation, which may explain our finding. This suggests that the neural context of decisions may be a key factor influencing human behavior.
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Intention is central to the concept of voluntary action. Using functional magnetic resonance imaging, we compared conditions in which participants made self-paced actions and attended either to their intention to move or to the actual movement. When they attended to their intention rather than their movement, there was an enhancement of activity in the pre-supplementary motor area (pre-SMA). We also found activations in the right dorsal prefrontal cortexand left intraparietal cortex. Prefrontal activity, but not parietal activity, was more strongly coupled with activity in the pre-SMA. We conclude that activity in the pre-SMA reflects the representation of intention.
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Complex problem-solving and planning involve the most anterior part of the frontal lobes including the fronto-polar prefrontal cortex (FPPC), which is especially well developed in humans compared with other primates. The specific role of this region in human cognition, however, is poorly understood. Here we show, using functional magnetic resonance imaging, that bilateral regions in the FPPC alone are selectively activated when subjects have to keep in mind a main goal while performing concurrent (sub)goals. Neither keeping in mind a goal over time (working memory) nor successively allocating attentional resources between alternative goals (dual-task performance) could by themselves activate these regions. Our results indicate that the FPPC selectively mediates the human ability to hold in mind goals while exploring and processing secondary goals, a process generally required in planning and reasoning.
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Prospective memory (PM) refers to the functions that enables a person to carry out an intended act after a delay. Despite the ubiquity of this behaviour, little is known about the supporting brain structures and the roles that they play. In this study, eight healthy participants performed four different PM tasks, each under three conditions: a baseline, and two conditions involving an intention. In the first of the intention conditions, subjects were asked to make a novel response to a certain class of stimuli whilst performing an attention-demanding task. However, the expected stimuli never actually occurred. In the second intention condition subjects were expecting to see these stimuli as before, and they did occur on approximately 20% of trials. Relative to the baseline condition, increases in regional cerebral blood flow (rCBF) as estimated by oxygen-15 positron emission tomography technique across all four tasks were seen in the frontal pole (Brodmann's area 10) bilaterally, right lateral prefrontal and inferior parietal regions plus the precuneus when subjects were expecting a PM stimulus regardless of whether it actually occurred. Further activation was seen in the thalamus when the PM stimuli occurred and was acted upon, with a corresponding rCBF decrease in right lateral prefrontal cortex. It is argued that the first set of region play a role in the maintenance of an intention, with the second set involved additionally in its realisation.
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Roger Penrose has suggested that when we consider consciousness the usual physical rules for time may not apply. But that notion is based on a false interpretation of physiological observations.
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Voluntary acts are preceded by electrophysiological “readiness potentials” (RPs). With spontaneous acts involving no preplanning, the main negative RP shift begins at about—550 ms. Such RPs were used to indicate the minimum onset times for the cerebral activity that precedes a fully endogenous voluntary act. The time of conscious intention to act was obtained from the subject's recall of the spatial clock position of a revolving spot at the time of his initial awareness of intending or wanting to move (W). W occurred at about—200 ms. Control experiments, in which a skin stimulus was timed (S), helped evaluate each subject's error in reporting the clock times for awareness of any perceived event. For spontaneous voluntary acts, RP onset preceded the uncorrected Ws by about 350 ms and the Ws corrected for S by about 400 ms. The direction of this difference was consistent and significant throughout, regardless of which of several measures of RP onset or W were used. It was concluded that cerebral initiation of a spontaneous voluntary act begins unconsciously. However, it was found that the final decision to act could still be consciously controlled during the 150 ms or so remaining after the specific conscious intention appears. Subjects can in fact “veto” motor performance during a 100–200-ms period before a prearranged time to act. The role of conscious will would be not to initiate a specific voluntary act but rather to select and control volitional outcome. It is proposed that conscious will can function in a permissive fashion, either to permit or to prevent the motor implementation of the intention to act that arises unconsciously. Alternatively, there may be the need for a conscious activation or triggering, without which the final motor output would not follow the unconscious cerebral initiating and preparatory processes.
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We investigated the relation between neural events and the perceived time of voluntary actions or the perceived time of initiating those actions using the method of Libet. No differences were found in either movement-related potentials or perceived time of motor events between a fixed movement condition, where subjects made voluntary movements of a single finger in each block, and a free movement condition, in which subjects chose whether to respond with the left or the right index finger on each trial. We next calculated both the readiness potential (RP) and lateralised readiness potential (LRP) for trials with early and late times of awareness. The RP tended to occur later on trials with early awareness of movement initiation than on trials with late awareness, ruling out the RP as a cause of our awareness of movement intiation. However, the LRP occurred significantly earlier on trials with early awareness than on trials with late awareness, suggesting that the processes underlying the LRP may cause our awareness of movement initiation.
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The hypothesis is formulated that in all voluntary movements the initial neuronal event is in the supplementary motor areas (SMA) of both cerebral hemispheres. Experimental support is provided by three lines of evidence. 1. In voluntary movements many neurones of the SMA are activated probably up to 200 ms before the pyramidal tract discharge. 2. Investigations of regional cerebral blood flow by the radioactive Xenon technique reveal that there is neuronal activity in the SMA of both sides during a continual series of voluntary movements, and that this even occurs when the movement is thought of, but not excuted. 3. With voluntary movement there is initiation of a slow negative potential (the readiness potential, RP) at up to 0.8 s before the movement. The RP is maximum over the vertex, i.e. above the SMA, and is large there even in bilateral Parkinsonism when it is negligible over the motor cortex. An account is given of the SMA, particularly its connectivities to the basal ganglia and the cerebellum that are active in the preprogramming of a movement. The concept of motor programs is described and related to the action of the SMA. It is proposed that each mental intention acts on the SMA in a specific manner and that the SMA has an ‘inventory’ and the ‘addresses’ of stored subroutines of all learnt motor programs. Thus by its neuronal connectivities the SMA is able to bring about the desired movement. There is a discussion of the manner in which the mental act of intention calls forth neural actions in the SMA that eventually lead to the intended movement. Explanation is given on the basis of the dualist-interactionist hypothesis of mind-brain liaison. The challenge is to the physicalists to account for the observed phenomena in voluntary movement.
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Deciding advantageously in a complex situation is thought to require overt reasoning on declarative knowledge, namely, on facts pertaining to premises, options for action, and outcomes of actions that embody the pertinent previous experience. An alternative possibility was investigated: that overt reasoning is preceded by a nonconscious biasing step that uses neural systems other than those that support declarative knowledge. Normal participants and patients with prefrontal damage and decision-making defects performed a gambling task in which behavioral, psychophysiological, and self-account measures were obtained in parallel. Normals began to choose advantageously before they realized which strategy worked best, whereas prefrontal patients continued to choose disadvantageously even after they knew the correct strategy. Moreover, normals began to generate anticipatory skin conductance responses (SCRs) whenever they pondered a choice that turned out to be risky, before they knew explicitly that it was a risky choice, whereas patients never developed anticipatory SCRs, although some eventually realized which choices were risky. The results suggest that, in normal individuals, nonconscious biases guide behavior before conscious knowledge does. Without the help of such biases, overt knowledge may be insufficient to ensure advantageous behavior.
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The conclusions drawn by Benjamin Libet from his work with colleagues on the timing of somatosensorial conscious experiences has met with a lot of praise and criticism. In this issue we find three examples of the latter. Here I attempt to place the divide between the two opponent camps in a broader perspective by analyzing the question of the relation between physical timing, neural timing, and experiential (mental) timing. The nervous system does a sophisticated job of recombining and recoding messages from the sensorial surfaces and if these processes are slighted in a theory, it might become necessary to postulate weird operations, including subjective back-referral. Neuroscientifically inspired theories are of necessity still based on guesses, extrapolations, and philosophically dubious manners of speech. They often assume some neural correlate of consciousness (NCC) as a part of the nervous system that transforms neural activity in reportable experiences. The majority of neuroscientists appear to assume that the NCC can compare and bind activity patterns only if they arrive simultaneously at the NCC. This leads to a search for synchrony or to theories in terms of the compensation of differences in neural delays (latencies). This is the main dimension of the Libet discussion. Examples from vision research, such as "temporal-binding-by-synchrony" and the "flash-lag" effect, are then used to illustrate these reasoning patterns in more detail. Alternatively one could assume symbolic representations of time and space (symbolic "tags") that are not coded in their own dimension (not time in time and space in space). Unless such tags are multiplexed with the quality message (tickle, color, or motion), one gets a binding problem for tags. One of the hidden aspects of the discussion between Libet and opponents appears to be the following. Is the NCC smarter than the rest of the nervous system, so that it can solve the problems of local sign (e.g., "where is the event"?) and timing (e.g., "when did it occur?" and "how long did it last?") on its own, or are these pieces of information coded symbolically early on in the system? A supersmart NCC appears to be the assumption of Libet's camp (which includes Descartes, but also mystics). The wish to distribute the smartness evenly across all stages of processing in the nervous system (smart recodings) appears to motivate the opponents. I argue that there are reasons to side with the latter group.
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Trevena and Miller (2002, this issue) provide further evidence that readiness potentials occur in the brain prior to the time that participants claim to have initiated a voluntary movement, a contention originally forwarded by Libet, Gleason, Wright, and Pearl (1983). In their examination of this issue, though, aspects of their data lead them to question whether their measurement of the initiation of a voluntary movement was accurate. The current article addresses this concern by providing a direct analysis of biases in this task. This was done by asking participants to make subjective timing decisions regarding a stimulus that could be measured objectively. Our findings suggest that their timing task was indeed biased such that participants' tend to report events as happening approximately 70 ms later than they actually happened. Implications for the original Libet et al. claims are discussed.