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Consciousness in humans and non-human animals: recent advances and future directions.

Boly M, Seth AK, Wilke M, Ingmundson P, Baars B, Laureys S, Edelman DB, Tsuchiya N - Front Psychol (2013)

Bottom Line: In addition, much progress has been made in the understanding of non-vertebrate cognition relevant to possible conscious states.Finally, major advances have been made in theories of consciousness, and also in their comparison with the available evidence.Along with reviewing these findings, each author suggests future avenues for research in their field of investigation.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, University of Wisconsin Madison, WI, USA ; Department of Psychiatry, Center for Sleep and Consciousness, University of Wisconsin Madison, WI, USA ; Coma Science Group, Cyclotron Research Centre and Neurology Department, University of Liege and CHU Sart Tilman Hospital Liege, Belgium.

ABSTRACT
This joint article reflects the authors' personal views regarding noteworthy advances in the neuroscience of consciousness in the last 10 years, and suggests what we feel may be promising future directions. It is based on a small conference at the Samoset Resort in Rockport, Maine, USA, in July of 2012, organized by the Mind Science Foundation of San Antonio, Texas. Here, we summarize recent advances in our understanding of subjectivity in humans and other animals, including empirical, applied, technical, and conceptual insights. These include the evidence for the importance of fronto-parietal connectivity and of "top-down" processes, both of which enable information to travel across distant cortical areas effectively, as well as numerous dissociations between consciousness and cognitive functions, such as attention, in humans. In addition, we describe the development of mental imagery paradigms, which made it possible to identify covert awareness in non-responsive subjects. Non-human animal consciousness research has also witnessed substantial advances on the specific role of cortical areas and higher order thalamus for consciousness, thanks to important technological enhancements. In addition, much progress has been made in the understanding of non-vertebrate cognition relevant to possible conscious states. Finally, major advances have been made in theories of consciousness, and also in their comparison with the available evidence. Along with reviewing these findings, each author suggests future avenues for research in their field of investigation.

No MeSH data available.


Related in: MedlinePlus

Mental imagery paradigm used to detect covert awareness in non-communicating patients. An activation of motor cortex in response to a motor imagery task instruction (“imagine playing tennis,” on the left) or an activation of parahippocampal gyrus in response to the instruction to perform a spatial navigation mental imagery task (“imagine visiting your home,” right) can be considered as evidence of response to command, and thus of the presence of awareness, in patients unresponsive at the bedside. Reproduced with permission from (Owen et al., 2006).
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Figure 3: Mental imagery paradigm used to detect covert awareness in non-communicating patients. An activation of motor cortex in response to a motor imagery task instruction (“imagine playing tennis,” on the left) or an activation of parahippocampal gyrus in response to the instruction to perform a spatial navigation mental imagery task (“imagine visiting your home,” right) can be considered as evidence of response to command, and thus of the presence of awareness, in patients unresponsive at the bedside. Reproduced with permission from (Owen et al., 2006).

Mentions: Another revolutionary advance in the field of neuroimaging of non-communicative brain damaged patients has been the design of active paradigms, in which responses to commands are probed while bypassing motor outputs [(Boly et al., 2007b); see Boly and Seth (2012) for a review]. The first paradigms employed in this context probed motor or spatial navigation imagery using functional magnetic resonance imaging (fMRI) (Owen et al., 2006; Monti et al., 2010) (Figure 3). Some EEG equivalents for these paradigms have also been designed to enable communication with patients outside of the MRI-scanner, even at their home (Bekinschtein et al., 2009; Cruse et al., 2011; Scott et al., 2011). Active paradigms typically reveal that about 20% of VS patients can respond to commands in an intentional manner (Monti et al., 2010; Cruse et al., 2011). While those responding patients are likely to be conscious, non-responsive patients in these paradigms might also be conscious, but not recognized as such due to the insensitivity of these methods. Active paradigms (asking the patients to perform a task, even without motor output) indeed heavily rely on the collaboration of the patients, as well as on intact language capabilities. In fact, it has been shown that some MCS or locked-in syndrome patients, who are conscious, can respond to commands at the bedside, however, they occasionally do not show task-relevant brain activation in response to the instruction to perform the task (Bardin et al., 2011). This finding reinforces the need for more specific identification potentially sufficient neural correlates of conscious level in order to detect awareness in patients who do not respond to these tasks. Such research would also inform psychophysiological measures of awareness that do not rely on preserved language comprehension and volition in patients (Scott et al., 2011). As we will see later, the criterion of “sufficiency” regarding neural correlates of consciousness is where recent advances in theory are extremely pertinent.


Consciousness in humans and non-human animals: recent advances and future directions.

Boly M, Seth AK, Wilke M, Ingmundson P, Baars B, Laureys S, Edelman DB, Tsuchiya N - Front Psychol (2013)

Mental imagery paradigm used to detect covert awareness in non-communicating patients. An activation of motor cortex in response to a motor imagery task instruction (“imagine playing tennis,” on the left) or an activation of parahippocampal gyrus in response to the instruction to perform a spatial navigation mental imagery task (“imagine visiting your home,” right) can be considered as evidence of response to command, and thus of the presence of awareness, in patients unresponsive at the bedside. Reproduced with permission from (Owen et al., 2006).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3814086&req=5

Figure 3: Mental imagery paradigm used to detect covert awareness in non-communicating patients. An activation of motor cortex in response to a motor imagery task instruction (“imagine playing tennis,” on the left) or an activation of parahippocampal gyrus in response to the instruction to perform a spatial navigation mental imagery task (“imagine visiting your home,” right) can be considered as evidence of response to command, and thus of the presence of awareness, in patients unresponsive at the bedside. Reproduced with permission from (Owen et al., 2006).
Mentions: Another revolutionary advance in the field of neuroimaging of non-communicative brain damaged patients has been the design of active paradigms, in which responses to commands are probed while bypassing motor outputs [(Boly et al., 2007b); see Boly and Seth (2012) for a review]. The first paradigms employed in this context probed motor or spatial navigation imagery using functional magnetic resonance imaging (fMRI) (Owen et al., 2006; Monti et al., 2010) (Figure 3). Some EEG equivalents for these paradigms have also been designed to enable communication with patients outside of the MRI-scanner, even at their home (Bekinschtein et al., 2009; Cruse et al., 2011; Scott et al., 2011). Active paradigms typically reveal that about 20% of VS patients can respond to commands in an intentional manner (Monti et al., 2010; Cruse et al., 2011). While those responding patients are likely to be conscious, non-responsive patients in these paradigms might also be conscious, but not recognized as such due to the insensitivity of these methods. Active paradigms (asking the patients to perform a task, even without motor output) indeed heavily rely on the collaboration of the patients, as well as on intact language capabilities. In fact, it has been shown that some MCS or locked-in syndrome patients, who are conscious, can respond to commands at the bedside, however, they occasionally do not show task-relevant brain activation in response to the instruction to perform the task (Bardin et al., 2011). This finding reinforces the need for more specific identification potentially sufficient neural correlates of conscious level in order to detect awareness in patients who do not respond to these tasks. Such research would also inform psychophysiological measures of awareness that do not rely on preserved language comprehension and volition in patients (Scott et al., 2011). As we will see later, the criterion of “sufficiency” regarding neural correlates of consciousness is where recent advances in theory are extremely pertinent.

Bottom Line: In addition, much progress has been made in the understanding of non-vertebrate cognition relevant to possible conscious states.Finally, major advances have been made in theories of consciousness, and also in their comparison with the available evidence.Along with reviewing these findings, each author suggests future avenues for research in their field of investigation.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurology, University of Wisconsin Madison, WI, USA ; Department of Psychiatry, Center for Sleep and Consciousness, University of Wisconsin Madison, WI, USA ; Coma Science Group, Cyclotron Research Centre and Neurology Department, University of Liege and CHU Sart Tilman Hospital Liege, Belgium.

ABSTRACT
This joint article reflects the authors' personal views regarding noteworthy advances in the neuroscience of consciousness in the last 10 years, and suggests what we feel may be promising future directions. It is based on a small conference at the Samoset Resort in Rockport, Maine, USA, in July of 2012, organized by the Mind Science Foundation of San Antonio, Texas. Here, we summarize recent advances in our understanding of subjectivity in humans and other animals, including empirical, applied, technical, and conceptual insights. These include the evidence for the importance of fronto-parietal connectivity and of "top-down" processes, both of which enable information to travel across distant cortical areas effectively, as well as numerous dissociations between consciousness and cognitive functions, such as attention, in humans. In addition, we describe the development of mental imagery paradigms, which made it possible to identify covert awareness in non-responsive subjects. Non-human animal consciousness research has also witnessed substantial advances on the specific role of cortical areas and higher order thalamus for consciousness, thanks to important technological enhancements. In addition, much progress has been made in the understanding of non-vertebrate cognition relevant to possible conscious states. Finally, major advances have been made in theories of consciousness, and also in their comparison with the available evidence. Along with reviewing these findings, each author suggests future avenues for research in their field of investigation.

No MeSH data available.


Related in: MedlinePlus