A method to monitor upper limb movement direction encoding in the corticomotor pathway

ABSTRACT Abnormal shoulder and elbow muscle coactivation patterns, or muscle synergies, are commonly present following stroke and may arise through dysfunctional descending neural control from the cortex. The authors evaluated a novel technique for examining corticomotor movement encoding of the upper limb in three dimensions. A 6-degree-of-freedom loadcell recorded arm twitch responses in healthy adults following stimulation over the cortex or over Erb's point in the periphery. Stimuli were delivered while the arm generated a 5 N preload in each of the 6 axial directions. The initial force twitch response to stimulation was used to construct twitch direction vectors for each preload direction. General linear mixed model analyses were used to determine the influence of stimulation location, preload direction, posture, and stimulation intensity on twitch direction. Cortical stimulation gave rise to arm twitch responses that were predictably modified by preload direction. Peripheral stimulation elicited stereotypical twitches that were not influenced by preload. Our stimulation, recording, and analysis techniques were able to capture movement encoding of the upper limb in three dimensions. Such techniques could be utilized in the stroke population to determine and monitor the presence of upper limb synergies during muscle activation.     

Pigeons are attracted to a perceived gain without an actual gain

Reference dependence refers to the reduced value of a reward that is less than expected, or the added value of a reward that is greater than expected. There is evidence that when pigeons are offered an alternative that has 1 pellet versus an alternative that has 2 pellets, but one of the two pellets offered will be removed, the pigeons prefer the originally presented 1 pellet (loss aversion). In the present research, we tested for the opposite effect (gain attraction). In Experiments 1 and 2, pigeons could choose between 2 pellets, each one on a distinctive background. If they chose the optimal alternative, they received a second pellet. In Experiment 2, the second pellet obtained was the one not initially chosen (a task sometimes referred to as the ephemeral reward task). Pigeons learned to choose optimally in both experiments. In Experiment 3, we tested the pigeons for reference dependence. Pigeons were given an alternative that offered them one pellet or two pellets, if they chose the one-pellet alternative, they received an additional pellet, and if they chose the two-pellet alternative, they received the two pellets. In keeping with the reference dependence hypothesis, the pigeons preferred the 1-pellet alternative that gave them an extra pellet. These effects are related to similar findings with humans, including the endowment effect.

     

Evidence for the Big Five in analyses of familiar English personality adjectives

Studies of the natural language are a prime source of the Big-Five model, yet the factor analysis of a large, representative, and non-clustered set of English-language personality adjectives in a large sample has not yet been published. In order to test the hypothesis that finding the Big Five depends on biasing the variable selection with an investigator's preferred non-familiar terms, we present the factor analysis of 435 familiar adjectives in a combined sample (N=899) of 507 self- and 392 peer ratings. The five-factor solution reproduced the Big Five with high clarity, demonstrating generally very high correlations with Goldberg's adjective markers of the Big Five. The Intellect factor had a more moderate correlation, due to its de-emphasis of the creativity components of Factor V, a phenomenon that may occur commonly with the lexical Intellect factor.     

A defense of the very idea of moral deference pessimism

Philosophical Studies - Pessimists think that there is something wrong with relying on deference for one’s moral beliefs—at least if one is morally mature. Call this no deference. They...     

The use of consultation in psychological practice: ethical, legal, and clinical considerations

The importance of consulting with other professionals to maintain acceptable standards of care is well documented in many health care professions. However, evidence indicates that many psychologists fail to utilize consultation when needed, and that consultation use varies along dimensions such as the education and training of the consultee, the type of setting, number of years in practice, and proximity to available consultants. In this article, we review the research on the use of consultation by psychologists as well as other health care professionals. We discuss the clinical, ethical, and legal implications of seeking consultation as a professional psychologist. Finally, a detailed and practical model for the regular use of consultation is given to improve the routine use of consultation in clinical practice.     

Aggression Observation Scale for Group Psychotherapy

An observational scale to record aggressive behaviors, defenses, and interventions that occur during a psychotherapy group has been developed. Content and process items were included. The content items focus on the spoken material and are on a continuum of increasing group members' awareness of and responsibility for their anger. The process items are directed to underlying psychodynamic issues on a continuum from avoiding anger, to indirect and then expression of anger. Leader interventions (responses) are also included. The development of the scale, the Aggression Observation Scale for Group Psychotherapy (AOSGP), is described including pilot testing and reliability and validity findings.     

The mechanics of reinforcement

Mathematical principles of reinforcement were developed in order to (1) account for the interaction of target responding and other behavior; (2) provide a simple graphical representation; (3) deal with measurement artifacts; and (4) permit a coherent transition from a statics to a dynamics of behavior. Rats and pigeons were trained to make a target response while general activity was measured with a stabilimeter. The course of behavioral change was represented as a trajectory through a two-dimensional behavior space. The trajectories rotated toward or away from the target dimension as the coupling between the target response and the incentive was varied. Higher rates of reinforcement expanded the trajectories; satiation and extinction contracted them. Concavity in some trajectories provided data for a dynamic generalization of the model.