Limits...
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

Neurophysiological correlates of visual awareness measured in different studies by intracranial recordings in monkeys and humans. Color code depicts the reported percentage of sites modulated for a given signal: Single Unit/Multiunit (upper row), Local Field Potentials (LFP) (lower row) Gamma band (40–100 Hz), Alpha/Beta (8–30 Hz). Stimulus paradigms used in the depicted studies are in brackets next to the area label (see Figure 5). Unavailable information for a given area is given as white circle. Data were derived from following publications: V1-V4 (Leopold and Logothetis, 1996; Gail et al., 2004; Wilke et al., 2006; Maier et al., 2008; Keliris et al., 2010), LGN (Lehky and Maunsell, 1996; Wilke et al., 2009), STS/IT (Sheinberg and Logothetis, 1997; Kreiman et al., 2002), MT/MST (Logothetis and Schall, 1989; Williams et al., 2003; Maier et al., 2007; Wang et al., 2009), LIP (Williams et al., 2003), pulvinar (Wilke et al., 2009), FEF (Libedinsky and Livingstone, 2011), and LPFC (Panagiotaropoulos et al., 2012). Abbreviations: BR, Binocular Rivalry; BRFS, Binocular Rivalry Flash Suppression; GFS, Generalized Flash Suppression; SfM, Structure-from-Motion; AM, Apparent Motion Quartet.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC3814086&req=5

Figure 6: Neurophysiological correlates of visual awareness measured in different studies by intracranial recordings in monkeys and humans. Color code depicts the reported percentage of sites modulated for a given signal: Single Unit/Multiunit (upper row), Local Field Potentials (LFP) (lower row) Gamma band (40–100 Hz), Alpha/Beta (8–30 Hz). Stimulus paradigms used in the depicted studies are in brackets next to the area label (see Figure 5). Unavailable information for a given area is given as white circle. Data were derived from following publications: V1-V4 (Leopold and Logothetis, 1996; Gail et al., 2004; Wilke et al., 2006; Maier et al., 2008; Keliris et al., 2010), LGN (Lehky and Maunsell, 1996; Wilke et al., 2009), STS/IT (Sheinberg and Logothetis, 1997; Kreiman et al., 2002), MT/MST (Logothetis and Schall, 1989; Williams et al., 2003; Maier et al., 2007; Wang et al., 2009), LIP (Williams et al., 2003), pulvinar (Wilke et al., 2009), FEF (Libedinsky and Livingstone, 2011), and LPFC (Panagiotaropoulos et al., 2012). Abbreviations: BR, Binocular Rivalry; BRFS, Binocular Rivalry Flash Suppression; GFS, Generalized Flash Suppression; SfM, Structure-from-Motion; AM, Apparent Motion Quartet.

Mentions: In parallel work involving human subjects, a particularly fruitful approach has employed “multistable visual stimuli,” where the same physical stimulus can give rise to multiple conscious interpretations (Leopold and Logothetis, 1999). Familiar examples of methodologies employing such stimuli include the Necker-Cube, Binocular Rivalry or Flash Suppression paradigms (Blake and Logothetis, 2002; Wilke et al., 2003; Kim and Blake, 2005; Tsuchiya and Koch, 2005) (Figure 5). Electrophysiological studies in monkeys employing such paradigms have revealed that neuronal spiking in a wide range of cortical areas is correlated with subjective perception, including retinotopically organized visual areas (Logothetis and Schall, 1989; Leopold and Logothetis, 1996; Bradley et al., 1998; Wilke et al., 2006), inferotemporal (IT) cortex (Sheinberg and Logothetis, 1997; Kreiman et al., 2002), medial temporal lobe (Kreiman et al., 2002) and fronto-parietal areas (Williams et al., 2003; Panagiotaropoulos et al., 2012). From a multitude of studies, a view has emerged that the proportion of neurons that reflect conscious perception gradually increases from early stages of visual processing (i.e. V1/V2) toward “higher-order” association areas (i.e., V4/IT) (Figure 6). Correspondingly, the few studies that have investigated spiking activity in thalamic visual nuclei have reported perceptual modulation in “second-order” (i.e., pulvinar), but not in first-order, thalamic nuclei [e.g., lateral geniculate nucleus (LGN)] (Lehky and Maunsell, 1996; Wilke et al., 2009). Interestingly, a recent study found that pulvinar neurons signaled “confidence” during motion perception judgments in a random-dot-motion paradigm, suggesting a further connection with subjective responses (Komura et al., 2013).


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)

Neurophysiological correlates of visual awareness measured in different studies by intracranial recordings in monkeys and humans. Color code depicts the reported percentage of sites modulated for a given signal: Single Unit/Multiunit (upper row), Local Field Potentials (LFP) (lower row) Gamma band (40–100 Hz), Alpha/Beta (8–30 Hz). Stimulus paradigms used in the depicted studies are in brackets next to the area label (see Figure 5). Unavailable information for a given area is given as white circle. Data were derived from following publications: V1-V4 (Leopold and Logothetis, 1996; Gail et al., 2004; Wilke et al., 2006; Maier et al., 2008; Keliris et al., 2010), LGN (Lehky and Maunsell, 1996; Wilke et al., 2009), STS/IT (Sheinberg and Logothetis, 1997; Kreiman et al., 2002), MT/MST (Logothetis and Schall, 1989; Williams et al., 2003; Maier et al., 2007; Wang et al., 2009), LIP (Williams et al., 2003), pulvinar (Wilke et al., 2009), FEF (Libedinsky and Livingstone, 2011), and LPFC (Panagiotaropoulos et al., 2012). Abbreviations: BR, Binocular Rivalry; BRFS, Binocular Rivalry Flash Suppression; GFS, Generalized Flash Suppression; SfM, Structure-from-Motion; AM, Apparent Motion Quartet.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 6: Neurophysiological correlates of visual awareness measured in different studies by intracranial recordings in monkeys and humans. Color code depicts the reported percentage of sites modulated for a given signal: Single Unit/Multiunit (upper row), Local Field Potentials (LFP) (lower row) Gamma band (40–100 Hz), Alpha/Beta (8–30 Hz). Stimulus paradigms used in the depicted studies are in brackets next to the area label (see Figure 5). Unavailable information for a given area is given as white circle. Data were derived from following publications: V1-V4 (Leopold and Logothetis, 1996; Gail et al., 2004; Wilke et al., 2006; Maier et al., 2008; Keliris et al., 2010), LGN (Lehky and Maunsell, 1996; Wilke et al., 2009), STS/IT (Sheinberg and Logothetis, 1997; Kreiman et al., 2002), MT/MST (Logothetis and Schall, 1989; Williams et al., 2003; Maier et al., 2007; Wang et al., 2009), LIP (Williams et al., 2003), pulvinar (Wilke et al., 2009), FEF (Libedinsky and Livingstone, 2011), and LPFC (Panagiotaropoulos et al., 2012). Abbreviations: BR, Binocular Rivalry; BRFS, Binocular Rivalry Flash Suppression; GFS, Generalized Flash Suppression; SfM, Structure-from-Motion; AM, Apparent Motion Quartet.
Mentions: In parallel work involving human subjects, a particularly fruitful approach has employed “multistable visual stimuli,” where the same physical stimulus can give rise to multiple conscious interpretations (Leopold and Logothetis, 1999). Familiar examples of methodologies employing such stimuli include the Necker-Cube, Binocular Rivalry or Flash Suppression paradigms (Blake and Logothetis, 2002; Wilke et al., 2003; Kim and Blake, 2005; Tsuchiya and Koch, 2005) (Figure 5). Electrophysiological studies in monkeys employing such paradigms have revealed that neuronal spiking in a wide range of cortical areas is correlated with subjective perception, including retinotopically organized visual areas (Logothetis and Schall, 1989; Leopold and Logothetis, 1996; Bradley et al., 1998; Wilke et al., 2006), inferotemporal (IT) cortex (Sheinberg and Logothetis, 1997; Kreiman et al., 2002), medial temporal lobe (Kreiman et al., 2002) and fronto-parietal areas (Williams et al., 2003; Panagiotaropoulos et al., 2012). From a multitude of studies, a view has emerged that the proportion of neurons that reflect conscious perception gradually increases from early stages of visual processing (i.e. V1/V2) toward “higher-order” association areas (i.e., V4/IT) (Figure 6). Correspondingly, the few studies that have investigated spiking activity in thalamic visual nuclei have reported perceptual modulation in “second-order” (i.e., pulvinar), but not in first-order, thalamic nuclei [e.g., lateral geniculate nucleus (LGN)] (Lehky and Maunsell, 1996; Wilke et al., 2009). Interestingly, a recent study found that pulvinar neurons signaled “confidence” during motion perception judgments in a random-dot-motion paradigm, suggesting a further connection with subjective responses (Komura et al., 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