Biology subjects

Kralik, J. D.

Publications and source records attributed to Kralik, J. D..

3 recordsLinked to original sources

bioRxiv2024

Bilateral Symmetry and Asymmetry in the C. elegans Connectome: A Graph-Theoretic Analysis based on Redundancy Measures

Understanding the balance between symmetry and asymmetry in animal nervous systems is crucial for unraveling the complexities of neural architectures and their functions. Previous studies have primarily focused on morphological symmetry, such as neuron placement, leaving the symmetry in the functional architecture largely unexplored. The current study investigates this aspect within the Caenorhabditis elegans connectomes by introducing a graph-theoretic approach. By defining a mirror-symmetry index, we quantitatively assess the symmetry in these connectomes, revealing a significant level of bilateral symmetry alongside notable asymmetry. Our approach also incorporates measures including connectivity similarity, motif-fingerprint differences, and path-compensation index to evaluate the networks functional redundancy and its capacity to compensate for unilateral disturbances. Here we show the C. elegans connectomes robust bilateral symmetry, which not only facilitates similar functions across neuron pairs but also ensures resilience against disruptions. This redundancy is not confined to symmetrical connections; it also includes asymmetric ones, adding to the neural networks complexity. An in-depth analysis into different neuron types shows varied redundancy levels: high in interneurons, moderate in motor neurons, and low in sensory neurons. This pattern suggests a strategic neural design where diverse inputs from sensory neurons, coupled with the stable integration by interneurons, lead to coordinated actions through motor neurons. This study advances our understanding of neural connectomes, offering insights into the intricate balance of symmetry and asymmetry in neural systems and their implications for complex, adaptive behaviors.

neuroscience↗

bioRxiv2019

Effective Public Apologies

Communicating with the public after corporate crises is often necessary, yet little evidence provides guidance. To address this, our theoretical and content analyses of public apologies revealed 12 key content elements. From these, we developed a basic apology, and tested its effectiveness alone, and with additional content. In two experiments involving river contamination, the basic apology was effective and improved with additional content. In Experiment 1, effectiveness involved actions taken to reduce harm and reoccurrence. Experiment 2 increased the hazard to carcinogenic chemicals, and one apology was superior: the basic apology plus statements of recovery efforts and defense of company actions. The two experiments show that crisis severity influences apology effectiveness. Experiment 3 found that clarifying causality helps convince people that the crisis source is identified and the problem resolved. Our findings show that an optimal public apology is comprehensive, and details the causes and actions taken to prevent reoccurrence.

neuroscience↗

bioRxiv2018

Decoupling between causal understanding and awareness during learning and inference

Causal reasoning is a principal higher-cognitive ability of humans, however, much remains unknown, including (a) the type (systematic versus intermixed) and order (inductive-then-deductive or vice versa) of experience that best achieves causal-chain extraction; (b) how inferences generalize to novel problems, especially with one-shot experience; and (c) how metacognition, reflected in uncertainty of ones knowledge, relates to actual knowledge. We tested people on a realistic cancer biology task (e.g., seroc chemicals inducing tumors with subsequent effects). Systematic experience was superior, with some evidence that the inductive-then-deductive order promoted stronger one-shot generalization. Notably, uncertainty was decoupled from actual knowledge, with the deductive-then-inductive group being overconfident, likely reflecting lack of awareness of the inductive component; while those with successful one-shot generalization held lower confidence, reflecting generalization with minimal experience, while remaining skeptical. Our findings clarify processes underlying causal reasoning, and reveal a complex relationship between causal reasoning and metacognitive awareness of it.

neuroscience↗