Richard Kempter

Population sparseness determines strength of Hebbian plasticity for maximal memory lifetime in associative networks

This paper investigates how population sparseness affects learning speed and memory capacity in a network model with Hebbian plasticity, finding that optimal learning speed increases with sparseness and capacity depends non-monotonically on input sparseness.

Elementary Dynamics of Neural Microcircuits

The paper derives closed-form conditions for multistability, oscillations, and paradoxical responses in neural microcircuits using threshold-linear networks and applies them to different brain circuits.

Conditions for replay of neuronal assemblies

The paper investigates conditions for replay of neuronal assemblies using simulations and analytical models, finding that weak feedforward connectivity and recurrent connections enable sequence replay.

Inhibitory inputs to avian ITD circuits

The paper investigates inhibitory inputs to the nucleus laminaris (NL) in birds, showing that GABA and glycine contribute to inhibition, with distinct synaptic dynamics and origins from SON neurons.

Sub-type specific connectivity between CA3 pyramidal neurons may underlie their sequential activation during sharp waves

The paper investigates connectivity between thorny and athorny CA3 pyramidal neurons and finds asymmetric input patterns that may explain their sequential activation during sharp waves.

Single neuron contributions to the auditory brainstem EEG

This study quantifies single neuron contributions to the auditory brainstem response (ABR) in barn owls, showing that individual neurons contribute to ABR wave II.

Quantitative modeling of the emergence of macroscopic grid-like representations

This study uses simulations to investigate how population-level hexadirectional modulation in fMRI data may arise from grid cell activity, testing three hypotheses about grid cell properties.

Intra-ripple frequency accommodation in an inhibitory network model for hippocampal ripple oscillations

The paper explains the mechanism of intra-ripple frequency accommodation (IFA) in a computational model of hippocampal ripple oscillations, showing it arises from a speed-dependent hysteresis effect in interneuron dynamics.

Experience-Dependent Plasticity in Nucleus Laminaris of the Barn Owl

The paper investigates experience-dependent plasticity in the barn owl's nucleus laminaris by altering auditory input during development and observing changes in ITD representation.

Learning accurate path integration in a ring attractor model of the head direction system

The paper proposes a network model that learns accurate path integration in the Drosophila head direction system using a biologically plausible learning rule guided by supervisory cues.

Coherent multi-level network oscillations create neural filters to favor quiescence over navigation in Drosophila

The paper shows how coherent neural oscillations in Drosophila create filters that promote quiescence over navigation by hierarchically overriding locomotion-promoting networks.

Hebbian plasticity in parallel synaptic pathways: A circuit mechanism for systems memory consolidation

The paper proposes a computational model of systems memory consolidation based on Hebbian plasticity in parallel synaptic pathways, showing how memories are transferred and transformed across brain regions.

A neural code for egocentric spatial maps in the human medial temporal lobe

The paper identifies 'anchor cells' in the human medial temporal lobe that encode egocentric spatial maps during virtual navigation.

Synaptic learning rules for sequence learning

This paper investigates how phase precession and synaptic learning windows contribute to temporal-order learning through mathematical analysis and simulations.

Interneuronal gap junctions increase synchrony and robustness of hippocampal ripple oscillations

The paper shows that gap junctions in interneurons enhance synchrony and firing rate of hippocampal ripple oscillations, though they have a mild effect on ripple frequency.

Dipolar extracellular potentials generated by axonal projections

The paper demonstrates that axonal terminal zones generate significant extracellular field potentials with dipolar characteristics and polarity reversal.

Refractoriness accounts for variable spike burst responses in somatosensory cortex

The paper shows that refractoriness explains variable spike burst responses in somatosensory cortex by combining synaptic inputs with intrinsic neural properties.

Memory Replay in Balanced Recurrent Networks

The paper investigates how sparse synaptic connections in balanced recurrent networks can enable memory replay through recurrent amplification and small sensory cues.