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This paper explores the shift from static logic gates to dynamic logic gates (DLGs) for modeling neuronal activity. Traditional static logic gates, while influential in machine learning and artificial neural networks, have limitations in reflecting the complexities of neuronal behavior. DLGs, which depend on historical activity, stimulation frequencies, and interconnections, present a more accurate framework. The work builds on foundational theories by McCulloch and Pitts, Neumann, and Shannon, proposing new systematic methods for understanding neural dynamics and their latency responses.
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A computational paradigm for dynamic logic-gates in neuronal activity Sander Vaus 15.10.2014
Background • “A logical calculus of the ideas immanent in nervous activity” (Mcculloch and Pitts, 1943)
Background • “A logical calculus of the ideas immanent in nervous activity” (Mcculloch and Pitts, 1943) • Neumann’s generalized Boolean framework (1956)
Background • “A logical calculus of the ideas immanent in nervous activity” (Mcculloch and Pitts, 1943) • Neumann’s generalized Boolean framework (1956) • Shannon’s simplification of Boolean circuits (Shannon, 1938)
Problems • Static logic-gates (SLGs)
Problems • Static logic-gates (SLGs) • Influencial in developing artificial neural networks and machine learning
Problems • Static logic-gates (SLGs) • Influencial in developing artificial neural networks and machine learning • Limited influence on neuroscience
Problems • Static logic-gates (SLGs) • Influencial in developing artificial neural networks and machine learning • Limited influence on neuroscience • Alternative: • Dynamic logic-gates (DLGs)
Problems • Static logic-gates (SLGs) • Influencial in developing artificial neural networks and machine learning • Limited influence on neuroscience • Alternative: • Dynamic logic-gates (DLGs) • Functionality depends on history of their activity, the stimulation frequencies and the activity of their interconnetcions
Problems • Static logic-gates (SLGs) • Influencial in developing artificial neural networks and machine learning • Limited influence on neuroscience • Alternative: • Dynamic logic-gates (DLGs) • Functionality depends on history of their activity, the stimulation frequencies and the activity of their interconnetcions • Will require new systematic methods and practical tools beyond the methods of traditional Boolean algebra
Elastic response latency • Neuronal response latency • The time-lag between a stimulation and its corresponding evoked spike
Elastic response latency • Neuronal response latency • The time-lag between a stimulation and its corresponding evoked spike • Typically in the order of several milliseconds
Elastic response latency • Neuronal response latency • The time-lag between a stimulation and its corresponding evoked spike • Typically in the order of several milliseconds • Repeated stimulations cause the delay to stretch
Elastic response latency • Neuronal response latency • The time-lag between a stimulation and its corresponding evoked spike • Typically in the order of several milliseconds • Repeated stimulations cause the delay to stretch • Three distinct states/trends
Elastic response latency • Neuronal response latency • The time-lag between a stimulation and its corresponding evoked spike • Typically in the order of several milliseconds • Repeated stimulations cause the delay to stretch • Three distinct states/trends • The higher the stimulation rate, the higher the increase of latency
Elastic response latency • Neuronal response latency • The time-lag between a stimulation and its corresponding evoked spike • Typically in the order of several milliseconds • Repeated stimulations cause the delay to stretch • Three distinct states/trends • The higher the stimulation rate, the higher the increase of latency • In neuronal chains, the increase of latency is cumulative
Δ (Vardi et al., 2013b)
Experimentally examined DLGs • Dyanamic AND-gate
Experimentally examined DLGs • Dyanamic AND-gate • Dynamic OR-gate
Experimentally examined DLGs • Dyanamic AND-gate • Dynamic OR-gate • Dynamic NOT-gate
Experimentally examined DLGs • Dyanamic AND-gate • Dynamic OR-gate • Dynamic NOT-gate • Dynamic XOR-gate
Theoretical analysis • A simplified theoretical framework
Theoretical analysis • A simplified theoretical framework l(q) = l0 + qΔ(1) l0– neuron’s initial response latency q – number of evoked spikes Δ – constant (typically in range of 2-7 μs
Theoretical analysis • A simplified theoretical framework l(q) = l0 + qΔ (1) τ(q) = τ0 + nqΔ(2) τ0 – initial time delay of the chain n –number of neurons in the chain
Theoretical analysis • A simplified theoretical framework l(q) = l0 + qΔ (1) τ(q) = τ0 + nqΔ(2) Simplifying assumption: The number of evoked spikes of a neuron is equal to the number of its stimulations
Theoretical analysis • Dynamic AND-gate
Theoretical analysis • Dynamic AND-gate • Generalized AND-gate
Theoretical analysis • Dynamic AND-gate • Generalized AND-gate • number of intersections of k non-parallel lines: 0.5k(k – 1)
Theoretical analysis • Dynamic AND-gate • Generalized AND-gate • number of intersections of k non-parallel lines: 0.5k(k – 1) • Dynamic XOR-gate
Theoretical analysis • Dynamic AND-gate • Generalized AND-gate • number of intersections of k non-parallel lines: 0.5k(k – 1) • Dynamic XOR-gate • Transitions among multiple modes
Theoretical analysis • Dynamic AND-gate • Generalized AND-gate • number of intersections of k non-parallel lines: 0.5k(k – 1) • Dynamic XOR-gate • Transitions among multiple modes • Varying inputs
Multiple component networks and signal processing Basic edge detector: (Vardi et al., 2013b)
Suitability of DLGs to brain functionality • Short synaptic delays
Suitability of DLGs to brain functionality • Short synaptic delays • The examined cases set the synaptic delays to a few tens of milliseconds, as opposed to those of several milliseconds in the brain
Suitability of DLGs to brain functionality • Short synaptic delays • The examined cases set the synaptic delays to a few tens of milliseconds, as opposed to those of several milliseconds in the brain • Can be remedied with the help of long synfire chains
Suitability of DLGs to brain functionality • Short synaptic delays • The examined cases set the synaptic delays to a few tens of milliseconds, as opposed to those of several milliseconds in the brain • Can be remedied with the help of long synfire chains • Population dynamics • DLGs assume