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Mind Time: The Temporal Factor in Consciousness
Our subjective inner life is what really matters to us as human beings--and yet we know relatively little about how it arises. Over a long and distinguished career Benjamin Libet has conducted experiments that have helped us see, in clear and concrete ways, how the brain produces conscious awareness. For the first time, Libet gives his own account of these experiments and their importance for our understanding of consciousness.
Most notably, Libet's experiments reveal a substantial delay--the "mind time" of the title--before any awareness affects how we view our mental activities. If all conscious awarenesses are preceded by unconscious processes, as Libet observes, we are forced to conclude that unconscious processes initiate our conscious experiences. Freely voluntary acts are found to be initiated unconsciously before an awareness of wanting to act--a discovery with profound ramifications for our understanding of free will.
How do the physical activities of billions of cerebral nerve cells give rise to an integrated conscious subjective awareness? How can the subjective mind affect or control voluntary actions? Libet considers these questions, as well as the implications of his discoveries for the nature of the soul, the identity of the person, and the relation of the non-physical subjective mind to the physical brain that produces it. Rendered in clear, accessible language, Libet's experiments and theories will allow interested amateurs and experts alike to share the experience of the extraordinary discoveries made in the practical study of consciousness.
Most notably, Libet's experiments reveal a substantial delay--the "mind time" of the title--before any awareness affects how we view our mental activities. If all conscious awarenesses are preceded by unconscious processes, as Libet observes, we are forced to conclude that unconscious processes initiate our conscious experiences. Freely voluntary acts are found to be initiated unconsciously before an awareness of wanting to act--a discovery with profound ramifications for our understanding of free will.
How do the physical activities of billions of cerebral nerve cells give rise to an integrated conscious subjective awareness? How can the subjective mind affect or control voluntary actions? Libet considers these questions, as well as the implications of his discoveries for the nature of the soul, the identity of the person, and the relation of the non-physical subjective mind to the physical brain that produces it. Rendered in clear, accessible language, Libet's experiments and theories will allow interested amateurs and experts alike to share the experience of the extraordinary discoveries made in the practical study of consciousness.
272 pages, Paperback
First published January 1, 2004
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Displaying 1 - 14 of 14 reviews
February 9, 2009
The scientific evidence that not only is our conscious perception of the world shifted back in time to compensate for the .5 second delay that is an effect of our perceptual apparatus, but that our conscious "decisions" may actually originate in the unconscious and that we live an illusion of being in control. Or rather, the only control we may have is a veto power that allows us to select from a shower of impulses that trickle down out of our unconsciousness. Subliminal or sublime?
April 17, 2016
An excellent book for exploring Libet's experiments in human consciousness, but it isn't interested in going much beyond that. There's some philosophy and discussion of free will, but I didn't find that nearly as useful.
August 8, 2024
EXPERIMENTAL RESEARCH RELATING TO OUR CONSCIOUS AWARENESS
Neuroscientist Benjamin Libet wrote in the Preface to this 2004 book, “How did I come to write this book? We had made some surprising discoveries of how the brain is involved in the production of conscious subjective experience and of unconscious mental functions. Where and how conscious experience arises, and how that differs from unconscious mental activities, are questions of profound interest… to many others. Our discoveries were arrived at experimentally… I thought, therefore, that our discoveries and the many important implications that they generate should be made available to a wide general audience as well as to philosophers, scientists and clinicians… An equally important feature of this presentation is the demonstration that mind-brain problems and cerebral bases for conscious experience can be studied experimentally.”
He continues in the first chapter, “It is not the intention of this book to present a full review of the literature… The goal of the book is to show that it is possible to deal experimentally with the problems in the relation between brain and conscious experience. Our own studies … form the major coverage in the book.” (Pg. 3-4)
He explains, “All of [our] feelings and awarenesses are part of your subjective inner life. They are subjective in the sense that they are accessible ONLY to the individual subject who is experiencing them. They are NOT evident in and cannot be described by observations of the physical brain. Our subjective inner life is what really matters to us as human beings. Yet we know and understand little of how it arises and how it functions in our conscious will to act. We do know that the physical brain is essential to and intimately involved in the manifestations of our conscious, subjective experiences.” (Pg. 1-2)
He states, “At one pole is the determinist materialist position. In this philosophy, observable matter is the only reality and everything, including thought, will and feeling, can be explained only in terms of matter and the natural laws that govern matter… Is this position a ‘proven’ scientific theory? I shall state, straight out, that this determinist materialist view is a belief system; it is not a scientific theory… At the opposite pole … are beliefs that the mind is separable from the brain (dualism)… the latter is absolutely tenable as a BELIEF. The same is true for most other philosophical and religious proposals.” (Pg. 5-6)
He suggests, “there is no need to invent different kinds or categories of consciousness or of conscious experiences to deal with all the kinds of experiences. The common feature in all cases is awareness. The differences lie in the different CONTENTS of awareness. As I will argue from the experimental evidence, awareness per se is a unique phenomenon, and it is associated with unique neuronal activities that are a necessary condition for all conscious experiences.” (Pg. 13-14)
He explains, “If we look at some of the ramifications of our findings for a delay in sensory awareness, the implications are quite astounding… I mention a few obvious ones here. First, if awareness of all sensory stimuli is delayed by about 0.5 sec[onds]., following the pattern found for somatic sensations, then our awareness of our sensory world is substantially delayed from its actual occurrence. What we become aware of has already happened about 0.5 sec earlier. We are not conscious of the actual moment of the present… If that is so, how can one explain the fact that subjectively we feel that we are aware at the actual moment of a sensory event?” (Pg. 70-71) Later, he adds, “subjects report that subjectively the sensation appears without any significant delay… They are not aware that the sensory experience did not ACTUALLY BEGIN until adequate cerebral stimulation of up to 0.5 sec in duration had taken place.” (Pg. 80-81)
He explains, “the ‘TIME-ON THEORY’ has two simple components: (1) to produce a conscious sensory experience… appropriate brain activities must proceed for a minimum duration of… about 0.5 sec… (2) We proposed that when these same brain activities have durations shorter than those required for awareness, they could nevertheless be involved in producing an unconscious mental function, without awareness. An unconscious function might then be transformed into a conscious one simply by increasing the duration (time-on) of the appropriate brain activities… We don’t know yet that brain mechanism ‘decides’ to focus attention on one signal and not on others…” (Pg. 101-102)
He continues, “Thoughts of various kinds, imaginations, attitudes, creative ideas, solving of problems, and so on initially develop unconsciously. Such unconscious thoughts only reach a person’s conscious awareness if the appropriate brain activities last a long enough time.” (Pg. 107) He goes on, “Perhaps it is the attention mechanism that allows a given selected response to last long enough to elicit awareness; but attention itself is apparently not a sufficient mechanism for awareness.” (Pg. 115)
He proposes, “We may view voluntary acts as beginning with unconscious initiatives being ‘burbled up’ by the brain. The conscious will would then select which of these initiatives may go forward with an action, or which ones to veto and abort so no motor act appears.” (Pg. 139) He continues, “What we are sure of is the ability of the conscious will to block or veto the volitional process and prevent the appearance of any motor act. In other words, conscious free will could control the outcome of an unconsciously initiated process. Whether it has an additional role in enabling a nonvetoed acat to proceed to consummation is not presently established experimentally.” (Pg. 45) Later, he adds, “The role of conscious free will would be, then, not to initiate a conscious process… However, conscious will definitely can control whether the act takes place. We may view the unconscious initiatives for voluntary actions as ‘burbling up’ unconsciously in the brain. The conscious will then selects which of these initiatives may go forward to an action, or which ones to veto and abort so no act occurs.” (Pg. 149)
He summarizes, “My conclusion about free will … is that its existence is at least as good, if not a better, scientific option than its denial by natural law determinist theory … why not adopt the view that we do have free will (until some real contradictory evidence appears, if it ever does)? Such a view would at least allow us to proceed in a way that accepts and accommodates our own deep feeling that we do have free will. We would not need to view ourselves as machines that act in a manner completely controlled by known physical laws.” (Pg. 156)
He suggests, “As one possible experimentally testable solution to both features of the mind-brain relationship. I have proposed that we may view conscious subjective experience as if it were a FIELD, produced by appropriate though multifarious neuronal activities of the brain…. Such a field would provide communication within the cerebral cortex without the neural connections and pathways in the cortex. A conscious mental field (CMF) would provide the mediator between the physical activities of nerve cells and the emergence of subjective experience. It thus offers an answer to the profound question of the nonphysical mental arising from the physical.” (Pg. 168)
He notes, “you might ask, What would be the role of all the massive and complex neural interconnections… and hemisphere to hemisphere? And here is a possible answer: to subserve all the cerebral functions other than those directly related to the appearance of the conscious subjective experience dan its role in conscious will… it is only the phenomenon of conscious subjective experience… that is modeled in the CMF, in an admittedly speculative manner.” (Pg. 180)
He suggests, “the experience of selfhood may represent a kind of content added to awareness. Theorists have produced a variety of selves to account for the actual variety in phenomenological displays of a self. It is simpler to view these varieties of self as variations of the CONTENTS of basic awareness rather than as different levels and kinds of awareness.” (Pg. 206)
He points out, “The attack by the philosophers Gilbert Ryle on the Cartesian concept of a separable soul called that proposed entity ‘the ghost in the machine.’ But Ryle’s attack is based on his belief that we are just machines. How does Ryle KNOW there is no ghost in our cerebral makeup? The fact is he does not know. There is no direct evidence that contradicts the possible existence of a Cartesian-type soul. But there is also no evidence that contradicts a nonphysical phenomenon that is not separable from the brain… Nor is there evidence that confirms it, as yet.” (Pg. 221)
He concludes, “Even these limited discoveries that center on the time factor would appear to have a profound effect on how we view our mental selves. If all conscious awarenesses are preceded by unconscious processes, we are forced to conclude that we do not actually live in the present and that unconscious processes play a predominant role in the production of our conscious life. We found that this can be extended even to an unconscious initiation of a voluntary act and appears to restrict the role of free will to controlling the performance of actions. We have also seen that subjective experiences of all kinds involve a subjective referral of the responsible brain activities into images or thoughts that give a conscious order and meaning to the complicated neural activities that elicit them.” (Pg. 222)
This book will be of great interest to those studying Mind/Brain issues.
Neuroscientist Benjamin Libet wrote in the Preface to this 2004 book, “How did I come to write this book? We had made some surprising discoveries of how the brain is involved in the production of conscious subjective experience and of unconscious mental functions. Where and how conscious experience arises, and how that differs from unconscious mental activities, are questions of profound interest… to many others. Our discoveries were arrived at experimentally… I thought, therefore, that our discoveries and the many important implications that they generate should be made available to a wide general audience as well as to philosophers, scientists and clinicians… An equally important feature of this presentation is the demonstration that mind-brain problems and cerebral bases for conscious experience can be studied experimentally.”
He continues in the first chapter, “It is not the intention of this book to present a full review of the literature… The goal of the book is to show that it is possible to deal experimentally with the problems in the relation between brain and conscious experience. Our own studies … form the major coverage in the book.” (Pg. 3-4)
He explains, “All of [our] feelings and awarenesses are part of your subjective inner life. They are subjective in the sense that they are accessible ONLY to the individual subject who is experiencing them. They are NOT evident in and cannot be described by observations of the physical brain. Our subjective inner life is what really matters to us as human beings. Yet we know and understand little of how it arises and how it functions in our conscious will to act. We do know that the physical brain is essential to and intimately involved in the manifestations of our conscious, subjective experiences.” (Pg. 1-2)
He states, “At one pole is the determinist materialist position. In this philosophy, observable matter is the only reality and everything, including thought, will and feeling, can be explained only in terms of matter and the natural laws that govern matter… Is this position a ‘proven’ scientific theory? I shall state, straight out, that this determinist materialist view is a belief system; it is not a scientific theory… At the opposite pole … are beliefs that the mind is separable from the brain (dualism)… the latter is absolutely tenable as a BELIEF. The same is true for most other philosophical and religious proposals.” (Pg. 5-6)
He suggests, “there is no need to invent different kinds or categories of consciousness or of conscious experiences to deal with all the kinds of experiences. The common feature in all cases is awareness. The differences lie in the different CONTENTS of awareness. As I will argue from the experimental evidence, awareness per se is a unique phenomenon, and it is associated with unique neuronal activities that are a necessary condition for all conscious experiences.” (Pg. 13-14)
He explains, “If we look at some of the ramifications of our findings for a delay in sensory awareness, the implications are quite astounding… I mention a few obvious ones here. First, if awareness of all sensory stimuli is delayed by about 0.5 sec[onds]., following the pattern found for somatic sensations, then our awareness of our sensory world is substantially delayed from its actual occurrence. What we become aware of has already happened about 0.5 sec earlier. We are not conscious of the actual moment of the present… If that is so, how can one explain the fact that subjectively we feel that we are aware at the actual moment of a sensory event?” (Pg. 70-71) Later, he adds, “subjects report that subjectively the sensation appears without any significant delay… They are not aware that the sensory experience did not ACTUALLY BEGIN until adequate cerebral stimulation of up to 0.5 sec in duration had taken place.” (Pg. 80-81)
He explains, “the ‘TIME-ON THEORY’ has two simple components: (1) to produce a conscious sensory experience… appropriate brain activities must proceed for a minimum duration of… about 0.5 sec… (2) We proposed that when these same brain activities have durations shorter than those required for awareness, they could nevertheless be involved in producing an unconscious mental function, without awareness. An unconscious function might then be transformed into a conscious one simply by increasing the duration (time-on) of the appropriate brain activities… We don’t know yet that brain mechanism ‘decides’ to focus attention on one signal and not on others…” (Pg. 101-102)
He continues, “Thoughts of various kinds, imaginations, attitudes, creative ideas, solving of problems, and so on initially develop unconsciously. Such unconscious thoughts only reach a person’s conscious awareness if the appropriate brain activities last a long enough time.” (Pg. 107) He goes on, “Perhaps it is the attention mechanism that allows a given selected response to last long enough to elicit awareness; but attention itself is apparently not a sufficient mechanism for awareness.” (Pg. 115)
He proposes, “We may view voluntary acts as beginning with unconscious initiatives being ‘burbled up’ by the brain. The conscious will would then select which of these initiatives may go forward with an action, or which ones to veto and abort so no motor act appears.” (Pg. 139) He continues, “What we are sure of is the ability of the conscious will to block or veto the volitional process and prevent the appearance of any motor act. In other words, conscious free will could control the outcome of an unconsciously initiated process. Whether it has an additional role in enabling a nonvetoed acat to proceed to consummation is not presently established experimentally.” (Pg. 45) Later, he adds, “The role of conscious free will would be, then, not to initiate a conscious process… However, conscious will definitely can control whether the act takes place. We may view the unconscious initiatives for voluntary actions as ‘burbling up’ unconsciously in the brain. The conscious will then selects which of these initiatives may go forward to an action, or which ones to veto and abort so no act occurs.” (Pg. 149)
He summarizes, “My conclusion about free will … is that its existence is at least as good, if not a better, scientific option than its denial by natural law determinist theory … why not adopt the view that we do have free will (until some real contradictory evidence appears, if it ever does)? Such a view would at least allow us to proceed in a way that accepts and accommodates our own deep feeling that we do have free will. We would not need to view ourselves as machines that act in a manner completely controlled by known physical laws.” (Pg. 156)
He suggests, “As one possible experimentally testable solution to both features of the mind-brain relationship. I have proposed that we may view conscious subjective experience as if it were a FIELD, produced by appropriate though multifarious neuronal activities of the brain…. Such a field would provide communication within the cerebral cortex without the neural connections and pathways in the cortex. A conscious mental field (CMF) would provide the mediator between the physical activities of nerve cells and the emergence of subjective experience. It thus offers an answer to the profound question of the nonphysical mental arising from the physical.” (Pg. 168)
He notes, “you might ask, What would be the role of all the massive and complex neural interconnections… and hemisphere to hemisphere? And here is a possible answer: to subserve all the cerebral functions other than those directly related to the appearance of the conscious subjective experience dan its role in conscious will… it is only the phenomenon of conscious subjective experience… that is modeled in the CMF, in an admittedly speculative manner.” (Pg. 180)
He suggests, “the experience of selfhood may represent a kind of content added to awareness. Theorists have produced a variety of selves to account for the actual variety in phenomenological displays of a self. It is simpler to view these varieties of self as variations of the CONTENTS of basic awareness rather than as different levels and kinds of awareness.” (Pg. 206)
He points out, “The attack by the philosophers Gilbert Ryle on the Cartesian concept of a separable soul called that proposed entity ‘the ghost in the machine.’ But Ryle’s attack is based on his belief that we are just machines. How does Ryle KNOW there is no ghost in our cerebral makeup? The fact is he does not know. There is no direct evidence that contradicts the possible existence of a Cartesian-type soul. But there is also no evidence that contradicts a nonphysical phenomenon that is not separable from the brain… Nor is there evidence that confirms it, as yet.” (Pg. 221)
He concludes, “Even these limited discoveries that center on the time factor would appear to have a profound effect on how we view our mental selves. If all conscious awarenesses are preceded by unconscious processes, we are forced to conclude that we do not actually live in the present and that unconscious processes play a predominant role in the production of our conscious life. We found that this can be extended even to an unconscious initiation of a voluntary act and appears to restrict the role of free will to controlling the performance of actions. We have also seen that subjective experiences of all kinds involve a subjective referral of the responsible brain activities into images or thoughts that give a conscious order and meaning to the complicated neural activities that elicit them.” (Pg. 222)
This book will be of great interest to those studying Mind/Brain issues.
January 27, 2024
Libet provided experimental evidences for some discoveries in the mind brain problem. If I understood correctly, the main points basically are:
- concious awareness are preceded about 400ms by unconcious processes.
- concious will would then decide to go forward, modify the content or "veto" the action.
- we are forced to conclude that we do not actually live in the present; concious free will does not initiate the volitional process but the brain initiate it unconciously.
- this leads to discussions about the notions of "free will" versus determinism.
I overally enjoyed the book and the way he organized his ideas.
- concious awareness are preceded about 400ms by unconcious processes.
- concious will would then decide to go forward, modify the content or "veto" the action.
- we are forced to conclude that we do not actually live in the present; concious free will does not initiate the volitional process but the brain initiate it unconciously.
- this leads to discussions about the notions of "free will" versus determinism.
I overally enjoyed the book and the way he organized his ideas.
February 17, 2020
This book should be read by everyone who believes that humans have no free will. Libet's neurological work is often cited by those (ie Sam Harris) who think free will is a myth. And yet when you read what Libet himself writes, it becomes clear that his research validates just the opposite. The first half of this book is quite tedious as Libet outlines his research and the various findings. But the last half is surprisingly philosophical and addresses some fascinating issues all related to the philosophy of mind (consciousness, ethics, etc).
October 17, 2017
Who are we? Are our actions driven by our conscious or unconscious minds? Are "we" just observers of our bodies actions or are we in charge of what we do? With scientific studies, Libet shows us that our actions are not as simple and immediate as we are have been taught. This book will make you think!
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May 23, 2021My critique of this book can be accessed here. This is paper titled “A Critical Analysis of Libet and Wegner on Free Will.” This essay includes a slightly revised draft of the section on “The Libet and Successor Experiments” in my forthcoming book Free Will and Human Life.
June 19, 2025
I really enjoyed this book.
It gave me valuable insight into what happens between a stimulus and a response — a topic I’ve been deeply curious about.
I think this book will be especially helpful for anyone on a spiritual journey, as it explores the subtle boundary between unconscious processes and conscious will.
It gave me valuable insight into what happens between a stimulus and a response — a topic I’ve been deeply curious about.
I think this book will be especially helpful for anyone on a spiritual journey, as it explores the subtle boundary between unconscious processes and conscious will.
June 17, 2012
Embarrassingly, I'll admit that The main reason for me reading this book, was for its contribution to the free will vs. determinism debate. This made me feel biased to pick up only the details that suited my purpose and expectations, which is not intellectually honest at all. Nevertheless, I am genuinely interested in neuroscience but lack knowledge the technicalities and experimental procedures of the field. Hence, the descriptions of experimental neoroscience in this book, were way above my level.
Moving back to the reason of why Libet's writing caught my interest, the experiments actually provides insight into how consciousness works, and what the implications are regarding decision-making. If I understood it correctly, the gist is basically that 'voluntary' processes are initiated unconsciously, but are, after about 400 msec available for the conscious mind to alter. That is, decide either to act, or not to act (on the so called "Readiness Potential" developed by the unconscious mind). This means that our experience of being in control of our actions does not entirely correspond to the reality of how the brain works. The 'control' function of conciousness is merely a a 'veto' process.
Libet is careful not to mix scientific descriptions with philosophical implications, and leaves the latter for separate chapters, which makes it much more clear and comprehensible. Although being consistent, there were, at least in my opinion, quite a few repetitions and digressions into details that seemed to state the same things as previous sections had already said, but in different words. Although this is most likely a consequence of my own limited understanding in the subtleties of this research, and I suppose that Libet's intended audience is primarily experienced neuroscientists..? It was quite hard to get through this book, but the imagined dialogue with Descartes at the end was an entertaining little reward, despite the implausibility of e.g a common (contemporary) definition of 'free will' with someone who lived four centuries ago, lol.
Moving back to the reason of why Libet's writing caught my interest, the experiments actually provides insight into how consciousness works, and what the implications are regarding decision-making. If I understood it correctly, the gist is basically that 'voluntary' processes are initiated unconsciously, but are, after about 400 msec available for the conscious mind to alter. That is, decide either to act, or not to act (on the so called "Readiness Potential" developed by the unconscious mind). This means that our experience of being in control of our actions does not entirely correspond to the reality of how the brain works. The 'control' function of conciousness is merely a a 'veto' process.
Libet is careful not to mix scientific descriptions with philosophical implications, and leaves the latter for separate chapters, which makes it much more clear and comprehensible. Although being consistent, there were, at least in my opinion, quite a few repetitions and digressions into details that seemed to state the same things as previous sections had already said, but in different words. Although this is most likely a consequence of my own limited understanding in the subtleties of this research, and I suppose that Libet's intended audience is primarily experienced neuroscientists..? It was quite hard to get through this book, but the imagined dialogue with Descartes at the end was an entertaining little reward, despite the implausibility of e.g a common (contemporary) definition of 'free will' with someone who lived four centuries ago, lol.
May 20, 2010
Based mainly on experiments done in Libet's lab on task-performing humans. Not a substitute for reading the primary literature, but highly engaging, accessible and thoughtful, and pointedly logical. A good book to recommend to non-neuroscientist friends who are intrigued about (or have never previously contemplated) the differences between various components of awareness (detection of sensory input to the brain, assembly of signals into non-conscious and/or conscious awareness).
Reminds you of the fact that when it comes to cutting-edge studies in consciousness and higher-level cognition, the ability to conceptualise and examine individual processes in detail depends almost entirely on our systematic development of a corresponding vocabulary to delineate concepts that have never before been quite this carefully elucidated and verbalised.
Reminds you of the fact that when it comes to cutting-edge studies in consciousness and higher-level cognition, the ability to conceptualise and examine individual processes in detail depends almost entirely on our systematic development of a corresponding vocabulary to delineate concepts that have never before been quite this carefully elucidated and verbalised.
December 29, 2016
Un saggio discretamente interessante che presenta in maniera comprensibile i risultati sperimentali del gruppo di ricerca coordinato dall'Autore sulle relazioni temporali fra uno stimolo sensoriale sopraliminare e la sua consapevolezza. Purtroppo quando il discorso si sposta sulla genesi dei processi volontari (arrivando addirittura a lambire il "libero arbitrio") gli argomenti, pur restando comprensibili, diventano molto meno convincenti.
September 30, 2010
The writing is stilted and at times redundant. He's not much of an author. It gets five stars because the research he talks about is pretty mind-blowing (pun partially intended). Our consciousness has a time delay. Life is reverbed before it reaches us. No kidding!
June 20, 2022
i tried my best. i just don‘t believe in free will and to me it looks like libets experiment proves that there is no free will even though he tries to argument against his own results? that‘s all i got from this book.
January 21, 2008
It contains pretty much information and no suggestions which are not proven by experiments. The experiments are well described and the conclusions are good explained!
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