Ioannis Pappas

The Prefrontal Cortex Organizes Visual Evidence by Representational Abstraction

The paper shows that prefrontal cortex organizes visual evidence by representational abstraction, with distinct regions processing lower- and higher-level similarity during decision-making.

Recurrent Neural Network Exploration Strategies During Reinforcement Learning Depend on Network Capacity

This study examines how RNN capacity affects exploration strategies in reinforcement learning, finding that higher capacity networks exhibit more human-like strategies but still differ in perseveration and switch rates.

Emotional arousal enhances narrative memories through functional integration of large-scale brain networks

The paper shows emotional arousal improves memory recall by enhancing functional integration of brain networks during narrative processing.

Arousal increases locus coeruleus blood flow, salience-related brain responses, and modulates negative-valence attentional biases

This study shows that arousal increases locus coeruleus blood flow and modulates brain responses to negative-valence stimuli, while the amygdala shows valence-general responses.

Temporal fMRI Dynamics Map Dopamine Physiology

The paper maps dopamine physiology using hemodynamic latency from fMRI, showing distinct patterns in the nucleus accumbens and linking them to addictive behaviors and substance use disorders.

Exploration-exploitation mechanisms in recurrent neural networks and human learners in restless bandit problems

This study compares human and recurrent neural network performance in restless bandit tasks, finding human-level RNN performance and distinct exploration strategies.

A meta reinforcement learning account of behavioral adaptation to volatility in recurrent neural networks

The paper shows that recurrent neural networks trained with medium or meta-volatility regimes adapt better to environmental volatility than those trained in low volatility.

Cortical timescales and the modular organization of structural and functional brain networks

The paper examines the relationship between BOLD fMRI timescales and modular organization of structural and functional brain networks, finding associations with within-community connectivity and structural connectivity degree.

Age-Related Decline in Blood-Brain Barrier Function is More Pronounced in Males than Females in Parietal and Temporal Regions

The paper investigates age and sex differences in BBB function using MRI in 186 participants, finding more pronounced decline in males starting in the early 60s, particularly in parietal and temporal regions.

Distributed harmonic patterns of structure-function dependence orchestrate human consciousness

The paper identifies harmonic patterns of structure-function dependence in the human connectome that correlate with different states of consciousness.

Cerebral perfusion in post-stroke aphasia and its relation to residual language abilities

This study examines cerebral perfusion in chronic aphasia and finds reduced perfusion in left hemisphere language areas and a link between perfusion and language abilities.

A Precuneal Causal Loop Mediates External and Internal Information Integration in the Human Brain

This study identifies a functional division in the precuneus that connects internally and externally oriented networks, modulated by task difficulty.

Consciousness is supported by near-critical cortical electrodynamics

The paper identifies the edge-of-chaos critical point as the state of cortical dynamics during conscious states and shows it is disrupted during unconsciousness.

Resting-state based prediction of task-related activation in patients with disorders of consciousness

This study uses resting-state fMRI and a deep learning model to predict task-related activation in DOC patients, finding that frontoparietal control network connectivity is key for volitional capacity classification.

Differential Contributions of Static and Time-Varying Functional Connectivity to Human Behavior

The paper compares static and time-varying functional connectivity measures to their associations with personality and cognitive ability, finding time-varying measures capture additional behavioral variability.

Consciousness & Brain Functional Complexity in Propofol Anaesthesia

The paper investigates algorithmic and process complexity measures in functional MRI data from propofol sedation, showing they correlate with sedation levels and support a complexity-based hypothesis of consciousness.