Advancing and Integrating the Cusp Concept to Understand Behavioral Repertoire Dynamics.

The behavioral repertoire grows and develops through a lifetime in a manner intricately dependent on bidirectional connections between its current form and the shaping environment. Behavior analysis has discovered many of the key relationships that occur between repertoire elements that govern this constant metamorphosis, including the behavioral cusp: an event that triggers contact with new behavioral contingencies. The current literature already suggests possible integration of the behavioral cusp and related concepts into a wider understanding of behavioural development and cumulative learning. Here we share an attempted step in that progression: an approach to an in-depth characterization of the features and connections underlying cusp variety. We sketch this approach on the basis of differential involvement of contingency terms; the relevance to the cusp of environmental context, accompanying repertoire, or response properties; the connections of particular cusps to other behavioral principles, processes, or concepts; the involvement of co-evolving social repertoires undergoing mutual influence; and the ability of cusps to direct the repertoire either toward desired contingencies or away from a growth-stifling repertoire. We discuss the implications of the schema for expanded applied considerations, the programming of unique cusps, and the need for incorporating cultural context into the cusp. We hope that this schema could be a starting point, subject to empirical refinement, leading to an expanded understanding of repertoire interconnectivity and ontogenetic evolution.

Using Operant Reach Chambers to Assess Mouse Skilled Forelimb Use After Stroke.

Skilled forelimb reaching and grasping are important components of rodent motor performance. The isometric pull task can serve as a tool for quantifying forelimb function following stroke or other CNS injury as well as in forelimb rehabilitation. This task has been extensively developed for use in rats. Here, we describe methods of setup and training of an operant reach chamber for mice. Using a reward of peanut oil, mice are adaptively trained to pull a handle positioned slightly outside of an operant chamber, with automated recording of the number of attempts, force generated, success rate, and latency to maximal force.

Forelimb Cortical Stroke Reduces Precision of Motor Control in Mice.

Background and Objective. Rodent models of stroke impairment should capture translatable features of behavioral injury. This study characterized poststroke impairment of motor precision separately from strength in an automated behavioral assay. Methods. We measured skilled distal forelimb reach-and-grasp motions within a target force range requiring moderate-strength. We assessed whether deficits reflected an increase in errors on only one or both sides of the target force range after photothrombotic cortical stroke. Results. Pull accuracy was impaired for 6 weeks after stroke, with errors redistributing to both sides of the target range. No decrease in maximum force was measured. Conclusions. This automated reach task measures sustained loss of motor precision following cortical stroke in mice.

The flight of the locus of selection: Some intricate relationships between evolutionary elements.

Selection has enriched our understanding of the world since it was first applied to the evolution of species. Selection stands as an alternative to essentialist thinking, as a generalized and multiply applicable concept, and as a causal explanation for current forms within biology and behavior. Attempts to describe selection processes in a generalizable way have provided clarity about their minimal elements, such as replicators and interactors. This paper discusses the interconnectedness among different levels of selection using evidence garnered from evolutionary biology, development, epigenetics, neuroscience, and behavior analysis. Currently, it appears that replicators and interactors may be more fluid than previously supposed and that selection for particular traits may rely on both multiple levels of interaction and multiple levels of replication. Replicators, interactors, and environment share influence on one another, and different replicators may exchange critical control over similar interactor variation as evolution proceeds. Our current understanding of selection continues to undergo revision, and reference to a number of disparate fields can help to account for the complexity of these processes. An understanding of their interconnectedness may help resolve some mysteries that develop in fields that exclusively focus on one or a few, such as the focused study of behavior.

Closed-loop neuromodulation restores network connectivity and motor control after spinal cord injury.

Recovery from serious neurological injury requires substantial rewiring of neural circuits. Precisely-timed electrical stimulation could be used to restore corrective feedback mechanisms and promote adaptive plasticity after neurological insult, such as spinal cord injury (SCI) or stroke. This study provides the first evidence that closed-loop vagus nerve stimulation (CLV) based on the synaptic eligibility trace leads to dramatic recovery from the most common forms of SCI. The addition of CLV to rehabilitation promoted substantially more recovery of forelimb function compared to rehabilitation alone following chronic unilateral or bilateral cervical SCI in a rat model. Triggering stimulation on the most successful movements is critical to maximize recovery. CLV enhances recovery by strengthening synaptic connectivity from remaining motor networks to the grasping muscles in the forelimb. The benefits of CLV persist long after the end of stimulation because connectivity in critical neural circuits has been restored.

An automated task for the training and assessment of distal forelimb function in a mouse model of ischemic stroke.

BACKGROUND: Behavioral models relevant to stroke research seek to capture important aspects of motor skills typically impaired in human patients, such as coordination of distal musculature. Such models may focus on mice since many genetic tools are available for use only in that species and since the training and behavioral demands of mice can differ from rats even for superficially similar behavioral readouts. However, current mouse assays are time consuming to train and score, especially in a manner producing continuous quantification. An automated assay of mouse forelimb function may provide advantages for quantification and speed, and may be useful for many applications including stroke research. NEW METHOD: We present an automated assay of distal forelimb function. In this task, mice reach forward, grip and pull an isometric handle with a prescribed force. The apparatus partially automates the training process so that mice can be trained quickly and simultaneously. RESULTS: Using this apparatus, it is possible to measure long-lasting impairment in success rate, force pulled, latency to pull, and latency to success up to 22 weeks following photothrombotic cortical strokes in mice. COMPARISON WITH EXISTING METHOD(S): This assessment measures forelimb function as do pellet reach tasks, but it utilizes a different motion and provides automatic measures that can ease and augment the research process. CONCLUSIONS: This high-throughput behavioral assay can detect long-lasting motor impairments, eliminates the need for subjective scoring, and produces a rich, continuous data set from which many aspects of the reach and grasp motion can be automatically extracted.

An Iterated Four-Player Prisoner's Dilemma Game with an External Selecting Agent: A Metacontingency Experiment / El juego del "Dilema del Prisionero" con cuatro participantes y un agente selector externo: un experimento metacontingencia

En esta serie de experimentos utilizamos un juego iterativo del "Dilema del Prisionero" (IPDG por sus siglas en inglés) para examinar el efecto de las metacontingencias sobre los productos agregados del comportamiento interrelacionado de cuatro jugadores. Los resultados del primer experimento muestran que las consecuencias de nivel cultural ("retroalimentación del mercado" en la forma de puntos entregados a todos los jugadores), contingentes con los productos agregados XXX o YYYY aumentaron la frecuencia de esas producciones. En experimentos posteriores, añadimos una condición de línea de base en la cual los jugadores experimentaron solo las contingencias conductuales individuales incorporadas en el juego. Luego impusimos la metacontingencia sobre el producto agregado XXXX, o de forma alternativa sobre YYYY. Después de varias reversiones, descontinuamos la metacontingencia y los jugadores comenzaron a experimentar nuevamente solo las contingencias individuales del juego. En un experimento utilizamos un control para evaluar el efecto de la retroalimentación del mercado de manera independiente de la relación metacontingencial. Los resultados indican que la consecuencia cultural (retroalimentación del mercado) controló la producción de productos agregados incluso cuando su magnitud era mínima, que la relación metacontingencial era necesaria, y que mantenía relaciones en el comportamiento de los individuos que tenían los peores resultados para todos los jugadores.

In these series of experiments we used an iterated prisoners' dilemma game (IPDG) to examine the effect of metacontingencies on aggregate products of the interrelated behavior of four players. Results of the first experiment showed that cultural level consequences ("market feedback" in the form of points delivered to all players) contingent on aggregate products XXXX or YYYY increased the frequency of those productions. In subsequent experiments we added a baseline condition where the players experienced only the individual behavioral contingencies embedded in the game. Then we imposed the metacontingency on the XXXX aggregate product or, alternatively, on YYYY. After several reversals, we discontinued the metacontingency and the players again experienced only the individual contingencies of the game. In one experiment we used a yoked control to assess the effect of market feedback independent from the metacontingency relation. Results indicate that the cultural consequence (market feedback) controlled production of aggregate products even when its magnitude was minimal, that the metacontingency relation was necessary, and that it maintained relations among the behavior of individuals which resulted in the worst individual outcomes for all players.