Long-term memory survives nerve injury and the subsequent regeneration process

A three-neuron network (a central pattern generator [CPG]) is both sufficient and necessary to generate aerial respiratory behavior in the pond snail, Lymnaea stagnalis. Aerial respiratory behavior is abolished following a specific nerve crush that results in axotomy to one of the three CPG neurons, RPeD1. Functional regeneration of the crushed neurite occurs within 10 days, allowing aerial respiratory behavior to be restored. Functional regeneration does not occur if the connective is cut rather than crushed. In unaxotomized snails, aerial respiratory behavior can be operantly conditioned, and following memory consolidation, long-term memory (LTM) persists for at least 2 weeks. We used the Lymnaea model system to determine (1) If in naive animals axotomy and the subsequent regeneration result in a nervous system that is competent to mediate associative learning and LTM, and (2) if LTM survives RPeD1 axotomy and the subsequent regenerative process. We show here that (1) A regenerated nervous system is competent to mediate associative memory and LTM, and (2) LTM survives axotomy and the subsequent regenerative process.     

Correlations for timing consistency among tapping and drawing tasks: evidence against a single timing process for motor control.

Three experiments were conducted to examine whether timing processes can be shared by continuous tapping and drawing tasks. In all 3 experiments, temporal precision in tapping was not related to temporal precision in continuous drawing. There were modest correlations among the tapping tasks, and there were significant correlations among the drawing tasks. In Experiment 3, the function relating timing variance to the square of the observed movement duration for tapping was different from that for drawing. The conclusions drawn were that timing is not an ability to be shared by a variety of tasks but instead that the temporal qualities of skilled movement are the result of the specific processes necessary to produce a trajectory. These results are consistent with the idea that timing is an emergent property of movement.     

Modelling decisions to undergo genetic testing for susceptibility to common health conditions: an ancillary study of the Multiplex Initiative

New genetic tests reveal risks for multiple conditions simultaneously, although little is understood about the psychological factors that affect testing uptake. We assessed a conceptual model called the multiplex genetic testing model (MGTM) using structural equation modelling. The MGTM delineates worry, perceived severity, perceived risk, response efficacy and attitudes towards testing as predictors of intentions and behaviour. Participants were 270 healthy insured adults aged 25-40 from the Multiplex Initiative conducted within a health care system in Detroit, MI, USA. Participants were offered a genetic test that assessed risk for eight common health conditions. Confirmatory factor analysis revealed that worry, perceived risk and severity clustered into two disease domains: cancer or metabolic conditions. Only perceived severity of metabolic conditions was correlated with general response efficacy (β?=?0.13, p<0.05), which predicted general attitudes towards testing (β?=?0.24, p<0.01). Consistent with our hypothesised model, attitudes towards testing were the strongest predictors of intentions to undergo testing (β?=?0.49, p<0.01), which in turn predicted testing uptake (OR 17.7, β?=?0.97, p<0.01). The MGTM explained a striking 48% of the variance in intentions and 94% of the variation in uptake. These findings support use of the MGTM to explain psychological predictors of testing for multiple health conditions.     

125 years of perceptual-motor skill research

This article celebrates the contribution that the American Journal of Psychology (AJP) has made to the area of perceptual-motor skill over its 125-year history. We highlight the articles published in AJP and trace the technical and theoretical developments that stem from this groundbreaking work. Included in our overview are AJP articles on the excitability of the motor system, motor learning, adaptation to visual rearrangement, the ecological approach to perception and action, and the measurement of human handedness. We conclude by identifying a number of areas associated with perceptual-motor skill where AJP continues to make an important contribution.     

Your heart makes my heart move: Cues of social connectedness cause shared emotions and physiological states among strangers

Two experiments tested the hypothesis that cues of social connectedness could lead even new interaction partners to experience shared emotional and physiological states. In Experiment 1, a confederate prepared for a stress-inducing task. Participants who had been led to feel socially connected to the confederate reported feeling greater stress than participants who had not. In Experiment 2, a confederate ran vigorously in place. Socially-connected participants had greater cardiovascular reactivity (heart rate and blood pressure) than controls. Each study held constant exposure to the confederate. The results suggest that the sharing of psychological and physiological states does not occur only between long-standing relationship partners, but can also result from even subtle experiences of social connectedness. These findings illustrate the dynamic and fluid ways in which important aspects of self can change in response to cues of social relatedness.     

Social eye gaze modulates processing of speech and co-speech gesture

In human face-to-face communication, language comprehension is a multi-modal, situated activity. However, little is known about how we combine information from different modalities during comprehension, and how perceived communicative intentions, often signaled through visual signals, influence this process. We explored this question by simulating a multi-party communication context in which a speaker alternated her gaze between two recipients. Participants viewed speech-only or speech + gesture object-related messages when being addressed (direct gaze) or unaddressed (gaze averted to other participant). They were then asked to choose which of two object images matched the speaker’s preceding message. Unaddressed recipients responded significantly more slowly than addressees for speech-only utterances. However, perceiving the same speech accompanied by gestures sped unaddressed recipients up to a level identical to that of addressees. That is, when unaddressed recipients’ speech processing suffers, gestures can enhance the comprehension of a speaker’s message. We discuss our findings with respect to two hypotheses attempting to account for how social eye gaze may modulate multi-modal language comprehension.