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Binding binding: Departure points for a different version of the perceptual retouch theory.

Bachmann T - Adv Cogn Psychol (2008)

Bottom Line: In the perceptual retouch theory, masking and related microgenetic phenomena were explained as a result of interaction between specific cortical representational systems and the non-specific sub-cortical modulation system.This article presents some premises for modification of the retouch theory, where instead of the cumulative presynaptic spike activities and EPSPs of single cells, the oscillatory activity in the gamma range of the participating systems is considered and shown to be consistent with the basic ideas of the retouch theory.In this conceptualisation, O-binding refers to specific encoding which is based on gamma-band synchronised oscillations in the activity of specific cortical sensory modules that represent features and objects; C-binding refers to the gamma-band oscillations in the activity of the non-specific thalamic systems, which is necessary for the O-binding based data to become consciously experienced.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology and Institute of Law, University of Tartu.

ABSTRACT
In the perceptual retouch theory, masking and related microgenetic phenomena were explained as a result of interaction between specific cortical representational systems and the non-specific sub-cortical modulation system. Masking appears as deprivation of sufficient modulation of the consciousness mechanism suffered by the target-specific signals because of the temporal delay of non-specific modulation (necessary for conscious representation), which explicates the later-coming mask information instead of the already decayed target information. The core of the model envisaged relative magnitudes of EPSPs of single cortical cells driven by target and mask signals at the moment when the nonspecific, presynaptic, excitatory input arrives from the thalamus. In the light of the current evidence about the importance of synchronised activity of specific and non-specific systems in generating consciousness, the retouch theory requires perhaps a different view. This article presents some premises for modification of the retouch theory, where instead of the cumulative presynaptic spike activities and EPSPs of single cells, the oscillatory activity in the gamma range of the participating systems is considered and shown to be consistent with the basic ideas of the retouch theory. In this conceptualisation, O-binding refers to specific encoding which is based on gamma-band synchronised oscillations in the activity of specific cortical sensory modules that represent features and objects; C-binding refers to the gamma-band oscillations in the activity of the non-specific thalamic systems, which is necessary for the O-binding based data to become consciously experienced.

No MeSH data available.


A schematic of a cortical slice where interaction between O-binding						(left-side loop) and C-binding (right-side loop) systems takes place at the						single-unit level. (The central part of this picture is adapted from Llinas,						R.R., Urbano, F.J., Leznik, E., Ramirez, R.R., & van Marle, H.J.F.							(2005). Rhythmic and dysrhythmic						thalamocortical dynamics: GABA systems and the edge effect. TINS, 28(6),						325-333.) The specific pathway activates pyramidal neurons and inhibitory						interneurons (upper red), producing cortical oscillations by direct						activation and feedforward inhibition. Collaterals from this pathway produce						thalamic feedback inhibition through the reticular nucleus (lower red). The						return corticothalamic pathway (curved green arrow) from pyramidal cells						returns this oscillatory loop to specific and reticular thalamic nuclei						(yellow and red lower circles). The non-specific thalamocortical pathway						projects to the cortex and gives collaterals to the reticular nucleus.						Pyramidal neurons return the oscillation to the non-specific and reticular						thalamic nuclei (green and red lower circles). This forms the second						resonant loop (curved green arrow on the right). The conjunction of the						specific and non-specific loops is hypothesised to generate functional						binding by temporal coincidence.
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Figure 2: A schematic of a cortical slice where interaction between O-binding (left-side loop) and C-binding (right-side loop) systems takes place at the single-unit level. (The central part of this picture is adapted from Llinas, R.R., Urbano, F.J., Leznik, E., Ramirez, R.R., & van Marle, H.J.F. (2005). Rhythmic and dysrhythmic thalamocortical dynamics: GABA systems and the edge effect. TINS, 28(6), 325-333.) The specific pathway activates pyramidal neurons and inhibitory interneurons (upper red), producing cortical oscillations by direct activation and feedforward inhibition. Collaterals from this pathway produce thalamic feedback inhibition through the reticular nucleus (lower red). The return corticothalamic pathway (curved green arrow) from pyramidal cells returns this oscillatory loop to specific and reticular thalamic nuclei (yellow and red lower circles). The non-specific thalamocortical pathway projects to the cortex and gives collaterals to the reticular nucleus. Pyramidal neurons return the oscillation to the non-specific and reticular thalamic nuclei (green and red lower circles). This forms the second resonant loop (curved green arrow on the right). The conjunction of the specific and non-specific loops is hypothesised to generate functional binding by temporal coincidence.

Mentions: One of the best models so far to describe SP/NSP oscillatory interaction in generating conscious representation has been offered by Rodolfo Llinás (e.g., Llinás, 2001; Llinás et al., 2002, 2005). A neuronal loop, including specific sensory units, contains projections onto cortical pyramidal neurons and inhibitory interneurons, and also collaterals to the NSP. A different loop includes NSP neurons located in the thalamus, which project to deeper and superficial layers of the cortex and give collaterals to the reticular nucleus and striatum and putamen. Collaterals of these two looping local circuits produce also feedback inhibition via the reticular nucleus and globus pallidus. The return pathway returns oscillations back to the reticular, specific thalamic and non-specific thalamic nuclei. When excited to respond to sensory input, both circuits produce gamma-frequency oscillations, but conscious awareness requires that these oscillations become synchronised. (See Figure 2 for an illustration of the elementary cortical module that exemplifies such an interaction.) Supralinear summation of SP- and NSP-inputs at the cortical effect layer demonstrates coincidence detection along the apical dendrites, the very mechanism of synchronised oscillatory activity. Llinás explains that coincidence detection by coactivation of SP- and NSP units provides the basis for temporal conjunction that supports cognitive binding in the conscious brain (for the details of summation and modulation see Llinás et al., 2002, 2005; coincidence detection mechanisms are well explained in detail, for instance by Börgers et al., 2005, Matell & Meck, 2004, Wang & Slotine, 2005).


Binding binding: Departure points for a different version of the perceptual retouch theory.

Bachmann T - Adv Cogn Psychol (2008)

A schematic of a cortical slice where interaction between O-binding						(left-side loop) and C-binding (right-side loop) systems takes place at the						single-unit level. (The central part of this picture is adapted from Llinas,						R.R., Urbano, F.J., Leznik, E., Ramirez, R.R., & van Marle, H.J.F.							(2005). Rhythmic and dysrhythmic						thalamocortical dynamics: GABA systems and the edge effect. TINS, 28(6),						325-333.) The specific pathway activates pyramidal neurons and inhibitory						interneurons (upper red), producing cortical oscillations by direct						activation and feedforward inhibition. Collaterals from this pathway produce						thalamic feedback inhibition through the reticular nucleus (lower red). The						return corticothalamic pathway (curved green arrow) from pyramidal cells						returns this oscillatory loop to specific and reticular thalamic nuclei						(yellow and red lower circles). The non-specific thalamocortical pathway						projects to the cortex and gives collaterals to the reticular nucleus.						Pyramidal neurons return the oscillation to the non-specific and reticular						thalamic nuclei (green and red lower circles). This forms the second						resonant loop (curved green arrow on the right). The conjunction of the						specific and non-specific loops is hypothesised to generate functional						binding by temporal coincidence.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2864979&req=5

Figure 2: A schematic of a cortical slice where interaction between O-binding (left-side loop) and C-binding (right-side loop) systems takes place at the single-unit level. (The central part of this picture is adapted from Llinas, R.R., Urbano, F.J., Leznik, E., Ramirez, R.R., & van Marle, H.J.F. (2005). Rhythmic and dysrhythmic thalamocortical dynamics: GABA systems and the edge effect. TINS, 28(6), 325-333.) The specific pathway activates pyramidal neurons and inhibitory interneurons (upper red), producing cortical oscillations by direct activation and feedforward inhibition. Collaterals from this pathway produce thalamic feedback inhibition through the reticular nucleus (lower red). The return corticothalamic pathway (curved green arrow) from pyramidal cells returns this oscillatory loop to specific and reticular thalamic nuclei (yellow and red lower circles). The non-specific thalamocortical pathway projects to the cortex and gives collaterals to the reticular nucleus. Pyramidal neurons return the oscillation to the non-specific and reticular thalamic nuclei (green and red lower circles). This forms the second resonant loop (curved green arrow on the right). The conjunction of the specific and non-specific loops is hypothesised to generate functional binding by temporal coincidence.
Mentions: One of the best models so far to describe SP/NSP oscillatory interaction in generating conscious representation has been offered by Rodolfo Llinás (e.g., Llinás, 2001; Llinás et al., 2002, 2005). A neuronal loop, including specific sensory units, contains projections onto cortical pyramidal neurons and inhibitory interneurons, and also collaterals to the NSP. A different loop includes NSP neurons located in the thalamus, which project to deeper and superficial layers of the cortex and give collaterals to the reticular nucleus and striatum and putamen. Collaterals of these two looping local circuits produce also feedback inhibition via the reticular nucleus and globus pallidus. The return pathway returns oscillations back to the reticular, specific thalamic and non-specific thalamic nuclei. When excited to respond to sensory input, both circuits produce gamma-frequency oscillations, but conscious awareness requires that these oscillations become synchronised. (See Figure 2 for an illustration of the elementary cortical module that exemplifies such an interaction.) Supralinear summation of SP- and NSP-inputs at the cortical effect layer demonstrates coincidence detection along the apical dendrites, the very mechanism of synchronised oscillatory activity. Llinás explains that coincidence detection by coactivation of SP- and NSP units provides the basis for temporal conjunction that supports cognitive binding in the conscious brain (for the details of summation and modulation see Llinás et al., 2002, 2005; coincidence detection mechanisms are well explained in detail, for instance by Börgers et al., 2005, Matell & Meck, 2004, Wang & Slotine, 2005).

Bottom Line: In the perceptual retouch theory, masking and related microgenetic phenomena were explained as a result of interaction between specific cortical representational systems and the non-specific sub-cortical modulation system.This article presents some premises for modification of the retouch theory, where instead of the cumulative presynaptic spike activities and EPSPs of single cells, the oscillatory activity in the gamma range of the participating systems is considered and shown to be consistent with the basic ideas of the retouch theory.In this conceptualisation, O-binding refers to specific encoding which is based on gamma-band synchronised oscillations in the activity of specific cortical sensory modules that represent features and objects; C-binding refers to the gamma-band oscillations in the activity of the non-specific thalamic systems, which is necessary for the O-binding based data to become consciously experienced.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology and Institute of Law, University of Tartu.

ABSTRACT
In the perceptual retouch theory, masking and related microgenetic phenomena were explained as a result of interaction between specific cortical representational systems and the non-specific sub-cortical modulation system. Masking appears as deprivation of sufficient modulation of the consciousness mechanism suffered by the target-specific signals because of the temporal delay of non-specific modulation (necessary for conscious representation), which explicates the later-coming mask information instead of the already decayed target information. The core of the model envisaged relative magnitudes of EPSPs of single cortical cells driven by target and mask signals at the moment when the nonspecific, presynaptic, excitatory input arrives from the thalamus. In the light of the current evidence about the importance of synchronised activity of specific and non-specific systems in generating consciousness, the retouch theory requires perhaps a different view. This article presents some premises for modification of the retouch theory, where instead of the cumulative presynaptic spike activities and EPSPs of single cells, the oscillatory activity in the gamma range of the participating systems is considered and shown to be consistent with the basic ideas of the retouch theory. In this conceptualisation, O-binding refers to specific encoding which is based on gamma-band synchronised oscillations in the activity of specific cortical sensory modules that represent features and objects; C-binding refers to the gamma-band oscillations in the activity of the non-specific thalamic systems, which is necessary for the O-binding based data to become consciously experienced.

No MeSH data available.