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Dominik T, Mele A, Schurger A, Maoz U. Libet's legacy: A primer to the neuroscience of volition. Neurosci Biobehav Rev 2024; 157:105503. [PMID: 38072144 DOI: 10.1016/j.neubiorev.2023.105503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Revised: 11/09/2023] [Accepted: 12/04/2023] [Indexed: 12/23/2023]
Abstract
The neuroscience of volition is an emerging subfield of the brain sciences, with hundreds of papers on the role of consciousness in action formation published each year. This makes the state-of-the-art in the discipline poorly accessible to newcomers and difficult to follow even for experts in the field. Here we provide a comprehensive summary of research in this field since its inception that will be useful to both groups. We also discuss important ideas that have received little coverage in the literature so far. We systematically reviewed a set of 2220 publications, with detailed consideration of almost 500 of the most relevant papers. We provide a thorough introduction to the seminal work of Benjamin Libet from the 1960s to 1980s. We also discuss common criticisms of Libet's method, including temporal introspection, the interpretation of the assumed physiological correlates of volition, and various conceptual issues. We conclude with recent advances and potential future directions in the field, highlighting modern methodological approaches to volition, as well as important recent findings.
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Affiliation(s)
| | - Alfred Mele
- Department of Philosophy, Florida State University, FL, USA
| | | | - Uri Maoz
- Brain Institute, Chapman University, CA, USA
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Neafsey EJ. Conscious intention and human action: Review of the rise and fall of the readiness potential and Libet's clock. Conscious Cogn 2021; 94:103171. [PMID: 34325185 DOI: 10.1016/j.concog.2021.103171] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 06/26/2021] [Accepted: 07/04/2021] [Indexed: 11/15/2022]
Abstract
Is consciousness-the subjective awareness of the sensations, perceptions, beliefs, desires, and intentions of mental life-a genuine cause of human action or a mere impotent epiphenomenon accompanying the brain's physical activity but utterly incapable of making anything actually happen? This article will review the history and current status of experiments and commentary related to Libet's influential paper (Brain 106:623-664, 1983) whose conclusion "that cerebral initiation even of a spontaneous voluntary act …can and usually does begin unconsciously" has had a huge effect on debate about the efficacy of conscious intentions. Early (up to 2008) and more recent (2008 on) experiments replicating and criticizing Libet's conclusions and especially his methods will be discussed, focusing especially on recent observations that the readiness potential (RP) may only be an "artifact of averaging" and that, when intention is measured using "tone probes," the onset of intention is found much earlier and often before the onset of the RP. Based on these findings, Libet's methodology was flawed and his results are no longer valid reasons for rejecting Fodor's "good old commonsense belief/desire psychology" that "my wanting is causally responsible for my reaching.".
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Affiliation(s)
- Edward J Neafsey
- Loyola University Chicago Stritch School of Medicine, Department of Molecular Pharmacology and Neuroscience, 2160 S. First Ave., Maywood, IL 60153, United States.
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Schurger A, Hu P'B, Pak J, Roskies AL. What Is the Readiness Potential? Trends Cogn Sci 2021; 25:558-570. [PMID: 33931306 PMCID: PMC8192467 DOI: 10.1016/j.tics.2021.04.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2021] [Revised: 03/29/2021] [Accepted: 04/01/2021] [Indexed: 12/14/2022]
Abstract
The readiness potential (RP), a slow buildup of electrical potential recorded at the scalp using electroencephalography, has been associated with neural activity involved in movement preparation. It became famous thanks to Benjamin Libet (Brain 1983;106:623-642), who used the time difference between the RP and self-reported time of conscious intention to move to argue that we lack free will. The RP's informativeness about self-generated action and derivatively about free will has prompted continued research on this neural phenomenon. Here, we argue that recent advances in our understanding of the RP, including computational modeling of the phenomenon, call for a reassessment of its relevance for understanding volition and the philosophical problem of free will.
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Affiliation(s)
- Aaron Schurger
- Department of Psychology, Crean College of Health and Behavioral Sciences, Chapman University, One University Drive, Orange, CA 92867, USA; Institute for Interdisciplinary Brain and Behavioral Sciences, Chapman University, 14725 Alton Parkway, Irvine, CA 92618, USA; INSERM, Cognitive Neuroimaging Unit, NeuroSpin Center, Gif sur Yvette 91191, France; Commissariat à l'Energie Atomique, Direction des Sciences du Vivant, I2BM, NeuroSpin Center, Gif sur Yvette 91191, France.
| | - Pengbo 'Ben' Hu
- Department of Linguistics and Cognitive Science, Pomona College, Claremont, CA 91711, USA
| | - Joanna Pak
- Institute for Interdisciplinary Brain and Behavioral Sciences, Chapman University, 14725 Alton Parkway, Irvine, CA 92618, USA
| | - Adina L Roskies
- Department of Philosophy and Program in Cognitive Science, Dartmouth College, Hanover, NH 03755, USA.
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Suppress Me if You Can: Neurofeedback of the Readiness Potential. eNeuro 2021; 8:ENEURO.0425-20.2020. [PMID: 33568461 PMCID: PMC7986527 DOI: 10.1523/eneuro.0425-20.2020] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 12/09/2020] [Accepted: 12/15/2020] [Indexed: 11/23/2022] Open
Abstract
Voluntary movements are usually preceded by a slow, negative-going brain signal over motor areas, the so-called readiness potential (RP). To date, the exact nature and causal role of the RP in movement preparation have remained heavily debated. Although the RP is influenced by several motorical and cognitive factors, it has remained unclear whether people can learn to exert mental control over their RP, for example, by deliberately suppressing it. If people were able to initiate spontaneous movements without eliciting an RP, this would challenge the idea that the RP is a necessary stage of the causal chain leading up to a voluntary movement. We tested the ability of participants to control the magnitude of their RP in a neurofeedback experiment. Participants performed self-initiated movements, and after every movement, they were provided with immediate feedback about the magnitude of their RP. They were asked to find a strategy to perform voluntary movements such that the RPs were as small as possible. We found no evidence that participants were able to to willfully modulate or suppress their RPs while still eliciting voluntary movements. This suggests that the RP might be an involuntary component of voluntary action over which people cannot exert conscious control.
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Takashima S, Ogawa CY, Najman FA, Ramos RT. The volition, the mode of movement selection and the readiness potential. Exp Brain Res 2020; 238:2113-2123. [PMID: 32656650 DOI: 10.1007/s00221-020-05878-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2019] [Accepted: 07/08/2020] [Indexed: 11/30/2022]
Abstract
A growing body of evidence suggests that the mode of movement selection is relevant for the readiness potential, namely, internal (or free) selection of movements is associated with increased readiness potential amplitudes compared to predetermined or externally guided selection. It is little acknowledged, however, that this finding may be ascribed to the different expression of volition (i.e., conscious experience of choice) rather than to the mode of movement selection per se. To probe this issue, we conducted two experiments: in Experiment 1, a mental task was employed to distract sixteen volunteers from the selection and performance of incidental movements, which consisted of pressing one of two buttons according to either free or externally guided modes of movement selection; in Experiment 2, another sixteen individuals performed the same motor task, however, they were encouraged to attend to their intention to act. As result, the increased readiness potential amplitude before freely selected movements was found exclusively in Experiment 2. More detailed analysis suggested that the attention to the initiation of movements was associated with greater readiness potential in its medial and late portion, while the attention to the movement selection, with more global increase of the component. The study suggests that much of the higher demands on motor preparatory activities ascribed to the internal selection of movements in previous studies actually depends on individual's attention and, thus, probably corresponds to volitional processes.
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Affiliation(s)
- Shiro Takashima
- Department of Psychiatry, Faculdade de Medicina, Instituto de Psiquiatria, LIM23, Hospital das Clinicas HCFMUSP, Universidade de Sao Paulo, Rua Doutor Ovídio Pires de Campos, 785, Cerqueira César, São Paulo, SP, 05403-010, Brazil.
| | - Carolina Y Ogawa
- Department of Psychiatry, Faculdade de Medicina, Instituto de Psiquiatria, LIM23, Hospital das Clinicas HCFMUSP, Universidade de Sao Paulo, Rua Doutor Ovídio Pires de Campos, 785, Cerqueira César, São Paulo, SP, 05403-010, Brazil
| | - Fernando Araujo Najman
- Instituto de Matematica e Estatistica, RIDC NeuroMat, Universidade de Sao Paulo, Av. Prof. Luciano Gualberto, 117, Butantã, São Paulo, SP, 05508-010, Brazil
| | - Renato T Ramos
- Department of Psychiatry, Faculdade de Medicina, Instituto de Psiquiatria, LIM23, Hospital das Clinicas HCFMUSP, Universidade de Sao Paulo, Rua Doutor Ovídio Pires de Campos, 785, Cerqueira César, São Paulo, SP, 05403-010, Brazil
- Department of Psychiatry, Frederick W. Thompson Anxiety Disorders Centre, Sunnybrook Health Sciences Centre, University of Toronto, 2075 Bayview Avenue, K3W42, Toronto, ON, M4N 3M5, Canada
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Houdayer E, Lee SJ, Hallett M. Cerebral preparation of spontaneous movements: An EEG study. Clin Neurophysiol 2020; 131:2561-2565. [PMID: 32927211 DOI: 10.1016/j.clinph.2020.08.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2020] [Revised: 08/04/2020] [Accepted: 08/12/2020] [Indexed: 01/09/2023]
Abstract
OBJECTIVE The current study sought to determine whether there is a Bereitschaftspotential (BP) before uninstructed, spontaneous movements. METHODS 14 participants were seated on a comfortable armchair for one hour without any instruction except not to fall asleep and to keep their eyes open. Electroencephalography (EEG) and electromyography (EMG) activity were recorded during the whole session. EEG activity was analyzed before spontaneous movements and compared with EEG activity before repetitive, instructed movements in a separate session. RESULTS BPs were identified in most participants with the spontaneous movements. The BPs with spontaneous movements were mostly localized in the medial frontocentral regions. The BPs with the instructed movements were localized primarily in the central regions and had larger amplitude. CONCLUSION Presence of a BP before movement does not depend on instruction and may be independent of conscious volition. The amplitude of the BP may depend on the amount of attention. SIGNIFICANCE This study shows that the presence of a BP before movement is not an "artifact" of the experimental instructions.
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Affiliation(s)
- Elise Houdayer
- Human Motor Control Section, Medical Neurology Branch, NINDS, NIH, Building 10, Room 7D37, 10 Center Drive, MSC 1428, Bethesda, MD 20892-1428, USA; Department of Rehabilitation and Functional Recovery, IRCCS San Raffaele Hospital, via Olgettina 60 Milan, MI 20132, Italy
| | - Sae-Jin Lee
- Human Motor Control Section, Medical Neurology Branch, NINDS, NIH, Building 10, Room 7D37, 10 Center Drive, MSC 1428, Bethesda, MD 20892-1428, USA
| | - Mark Hallett
- Human Motor Control Section, Medical Neurology Branch, NINDS, NIH, Building 10, Room 7D37, 10 Center Drive, MSC 1428, Bethesda, MD 20892-1428, USA.
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Takashima S, Najman FA, Ramos RT. Disruption of volitional control in obsessive-compulsive disorder: Evidence from the Bereitschaftspotential. Psychiatry Res Neuroimaging 2019; 290:30-37. [PMID: 31260827 DOI: 10.1016/j.pscychresns.2019.06.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 06/24/2019] [Accepted: 06/26/2019] [Indexed: 11/19/2022]
Abstract
In the context of controversies involving possible abnormalities in the volition and action control in obsessive-compulsive disorder (OCD), the current study examined electroencephalographic correlates of automatic and volitional brain processes involved in the genesis of spontaneous movements in individuals diagnosed with OCD. For this, the amplitudes of early and late Bereitschaftspotential (early BP and late BP) from 12 patients and 12 controls were obtained while they performed spontaneous button presses under different levels of volitional experience. In the first condition, participants were distracted from their motor actions by a mental task (automatic condition) and in the second condition they were instructed to attending to their own intention to move (willed condition). The results corroborate previous report that the attention to (and, presumably, the awareness of) intention to act accounts for the expression of significant portion of the late BP in healthy individuals. More relevantly, the increased late BP in willed condition in relation to automatic condition was not present in the OCD group. Neither groups nor conditions affected the early BP. In sum, the current findings suggest the existence of abnormalities in the brain activities associated with the establishment of volitional control in OCD patients.
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Affiliation(s)
- Shiro Takashima
- Department of Psychiatry, LIM 23, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR.
| | - Fernando Araujo Najman
- Instituto de Matematica e Estatistica, RIDC NeuroMat, Universidade de Sao Paulo, Sao Paulo, SP, BR
| | - Renato Teodoro Ramos
- Department of Psychiatry, LIM 23, Hospital das Clinicas HCFMUSP, Faculdade de Medicina, Universidade de Sao Paulo, Sao Paulo, SP, BR; Frederick W. Thompson Anxiety Disorders Centre, Sunnybrook Health Sciences Centre, Department of Psychiatry, University of Toronto, Canada
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