Free will and neurosurgical resections of the supplementary motor area: a critical review

Sjöberg, Rickard L.

doi:10.1007/s00701-021-04748-9

Cited by 12 publications

(6 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Anatomically and functionally, the SMA region is interlocked between these two neural networks. As such, the SMA complex can be seen as a gateway between the more rostral systems of executive function and the PMC [54].…”

Section: Anatomy and Function Of The Sma Regionmentioning

confidence: 99%

The supplementary motor area syndrome: a neurosurgical review

et al. 2021

View full text Add to dashboard Cite

The supplementary motor area (SMA) syndrome is a frequently encountered clinical phenomenon associated with surgery of the dorsomedial prefrontal lobe. The region has a known motor sequencing function and the dominant pre-SMA specifically is associated with more complex language functions; the SMA is furthermore incorporated in the negative motor network. The SMA has a rich interconnectivity with other cortical regions and subcortical structures using the frontal aslant tract (FAT) and the frontostriatal tract (FST). The development of the SMA syndrome is positively correlated with the extent of resection of the SMA region, especially its medial side. This may be due to interruption of the nearby callosal association fibres as the contralateral SMA has a particular important function in brain plasticity after SMA surgery. The syndrome is characterized by a profound decrease in interhemispheric connectivity of the motor network hubs. Clinical improvement is related to increasing connectivity between the contralateral SMA region and the ipsilateral motor hubs. Overall, most patients know a full recovery of the SMA syndrome, however a minority of patients might continue to suffer from mild motor and speech dysfunction. Rarely, no recovery of neurological function after SMA region resection is reported.

show abstract

Section: Anatomy and Function Of The Sma Regionmentioning

confidence: 99%

The supplementary motor area syndrome: a neurosurgical review

et al. 2021

View full text Add to dashboard Cite

show abstract

“…In line with the above argument, resection of the SMA typically causes a transient inability to perform non-stimulus-driven, voluntary actions, but it does not appear to be associated with a loss of sense of volition or willpower—only with a profound disruption of executive function and/or cognitive control (Sjöberg, 2021). That is, the RP is not required for the subjective experience of free will.…”

Section: The Neurobiology Of Free Willmentioning

confidence: 91%

“…Later experiments appear to confirm that activity in the SMA is sufficient when performing a voluntary action (Sjöberg, 2021). That is, low intensity stimulation of the SMA (in connection with epilepsy evaluation) causes the patient to experience an urge to move contralateral body parts; while if the stimulation is more intense, movements are typically initiated, and they are perceived as voluntary.…”

Section: The Neurobiology Of Free Willmentioning

confidence: 99%

An evolutionary perspective on free will and self-consciousness.

Grinde¹

2022

Psychology of Consciousness: Theory, Research, and Practice

View full text Add to dashboard Cite

The sense of free will is a consequence of having a brain with the capacity of rational thoughts and self-consciousness; that is, humans have the power of volition and agency. This sense of free will is underpinned by a true level of willfulness of behavior based on conscious (or cognitive) deliberation. Conscious deliberation is one of several strategies devised by evolution to execute behavior. Other strategies, such as reflexes and instincts, can be engaged simultaneously; our free will is therefore constrained by the relative dominance of the various strategies, as well as by the obvious limits of mental and physical abilities. The question of whether we have a free will may be answered by stating that we have a sufficient amount to choose "yes" or "no" as an answer; that is, we can set the arbitrary cutoff required to qualify either above or below the level of free will evolution happened to install. Our sense of free will is likely to exceed our actual capacity of willfulness. Conscious content needs to be generated by unconscious activity; but at the same time, conscious input is needed to make a cognitive decision. If the conscious input itself must be formed by the unconscious, which of the two comes first? The answer may reflect that of the chicken-or-egg-dilemma; conscious and unconscious activity develop gradually and interdependently culminating in the awareness of a willed decision.

show abstract

“…From there on, the ongoing movement is constantly monitored by parietal and frontal areas, likely with some contribution from insular cortex' (Dominik et al, 2023, pp., 78-79). However, Sjöberg (2021) introduced a different analysis of the role of the SMA. Indeed, SMA removal seems not to be associated with a loss of sense of volition but with a deep disruption of executive functions and cognitive control, 'suggesting a view that is compatible with concepts of personal responsibility' .…”

Section: The Current Physiology Of Free Willmentioning

confidence: 99%