The TeensyTap Framework for Sensorimotor Synchronization Experiments

Synchronizing movements with an external periodic stimulus, such as tapping your foot along with a metronome, is a remarkable human skill called sensorimotor synchronization. A growing body of literature investigates this process, but experiments require collecting responses with high temporal reliability, which often requires specialized hardware. The current article presents and validates TeensyTap, an inexpensive, highly functional framework with excellent timing performance. The framework uses widely available, low-cost hardware and consists of custom-written open-source software and communication protocols. TeensyTap allows running complete experiments through a graphical user interface and can simultaneously present a pacing signal (metronome), measure movements using a force-sensitive resistor, and deliver auditory feedback, with optional experimenter-specified artificial feedback delays. Movement data is communicated to a computer and saved for offline analysis in a format that allows it to be easily imported into spreadsheet programs. The present work also reports a validation experiment showing that timing performance of TeensyTap is highly accurate, ranking it among the gold standard tools available in the field. Metronome pacing signals are presented with millisecond accuracy, feedback sounds are delivered on average 2 ms following the subjects’ taps, and the timing log files produced by the device are unbiased and accurate to within a few milliseconds. The framework allows for a range of experimental questions to be addressed and, since it is open source and transparent, researchers with some technical expertise can easily adapt and extend it to accommodate a host of possible future experiments that have yet to be imagined.     

WHEN PERFORMANCE IMPROVEMENT IS THE GOAL: A NEW SET OF CRITERIA FOR CRITERIA

Weitz (1961), aware of the lure of tradition and expedience, urged the identification of evaluation standards for dependent variables, which he referred to as criteria for criteria. In this article, five criteria are proposed using the mnemonic SURF & C: the directness of sampling (S); the responsiveness of the target (i.e., making sure the dependent variable is under (U) the worker's control); the reliability (R) of observers; the frequent (F) assessment of the target during the intervention period; and the critical (C) nature of the target. Together the criteria provide guidelines for what and how targets should be assessed. Their necessity is illustrated in two year-long experiments designed to improve the preventive maintenance of heavy equipment in the U.S. Marine Corps. Although the criteria are limited to evaluating dependent variables in field experiments, they are recommended as the foundation for successful performance efforts in any applied setting.     

Kindness: A new kind of rigour for British Geographers

Let's face it, those of us who work in the academic discipline of Geography, largely work on the subject of failure. The failure of political leaders worldwide to avert disastrous climate change. The need to prevent the continuation of the fastest species extinction the world has ever known. The social and personal repercussions of enormous global income, wealth and power inequalities. We describe all this, usually, as if it were just an interesting set of observations. Then we tell students to write an essay about it. If they cogently analyse our collective failure, we give them a high mark. Many of them can then take their university degrees and head out to banking, advertising and management and make the world an even worse place, armed with the knowledge of what they might be critiqued for by those who taught them, but never convinced them. Perhaps if we were kinder to our students when they were at university, were kinder and clearer in what we wrote and taught, more of them would use what they have learnt for good, rather than seeing their degrees as stepping-stones to their allotted place in the social hierarchy.     

Influence of speed-related auditory feedback on braking in a 3D-driving simulator

Although discrete auditory stimuli have been found useful for emergency braking, the role of continuous speed-related auditory feedback has not been investigated yet. This point may though be of importance in electric vehicles in which acoustic cues are drastically changed. The present study addressed this question through two experiments. In experiment 1, 12 usual drivers were exposed to naturalistic auditory feedback mimicking those issued from electric cars, while facing dynamic visual scenes in a 3D driving simulator. After being passively travelled up to a sustained constant speed, subjects had to stop their car in front of a traffic light that unexpectedly turned to red. Modifications of the speed-related auditory feedback did not impact braking initiation and regulation. In experiment 2, synthesized auditory feedback based on the Shepard-Risset glissando was provided to a new sample of 15 usual drivers in the same task. Pitch variations of this acoustic stimulus, although not scaled to an absolute speed, were manipulated as a function of visual speed changes. Changing the mapping between pitch variations of the synthesized auditory feedback and visual speed changes induced adjustments on braking which depended on acceleration/deceleration feedback. These findings stressed the importance of the acoustic content and its dynamics for car speed control.     

The Role of Visual Feedback about Motion of the Ground on Postural Sway

Abstract

We asked whether body sway would be influenced by visual information about motion of the ground surface. On a ship at sea, standing participants performed a demanding visual search task or a simple visual inspection task. Display content was stationary relative to the ship or relative to the Earth. Participants faced the ship’s bow or its port side. Performance on the visual search task was representative of terrestrial studies. Body sway was greater during viewing of the Earth Stationary displays than during viewing of the Ship Stationary displays. We discuss possible implications of these results for theoretical and applied issues.     

Explaining social contagion in sport applying Heider's balance theory: First experimental results

A sudden collective collapse of an entire sport team is often described in terms of the social contagion of weak performance. Two experiments studied this phenomenon against the backdrop of balance theory. Experiment 1 examined whether false negative feedback on a partner's performance during a team task would lead to compensatory mechanisms as predicted by balance theory. Results showed that perceived negative performance in the partner was compensated by devaluing the relationship to the partner. Experiment 2 replicated Experiment 1 and investigated the impact of physical self-esteem. Results showed that persons with strong physical self-esteem devalued the situational value of the relationship when they perceived their partner's performance to be negative. Experiment 2 also investigated objective performance. Although failing to attain statistical significance, there was a tendency for the perceived sudden decline in the partner's performance to be contagious. It is concluded that balance theory offers promising insights into the interpersonal dynamics of social contagion.     

Jump performance and augmented feedback: Immediate benefits and long-term training effects

Drop jumps and their adaptations to training have been extensively investigated. However, the influence of augmented feedback (aF) on stretch-shortening cycle (SSC) was not scrutinized so far despite the well-known positive effects of aF on motor performance and motor learning. The aim of the present study was therefore to investigate the effects of aF by evaluating immediate within-session effects and long-term adaptations. 34 participants were assigned to three groups that trained drop jumps with different relative frequencies of aF about their jump height: 100%, 50%, or 0%. A significant within-session effect of aF on jump height was observed before and also after the training period (pre: +4.6%; post: +2.6%). In the long-term (comparing pre- to post-measurement), the 100% group showed the greatest increase in jump height (+14%), followed by the 50% (+10%) and the 0% group (+6%). The importance of aF on drop jumps is therefore twofold: (i) to immediately increase jump performance and (ii) to improve long-term training efficacy. In contrast to the proposition of the guidance hypothesis, high frequency of aF seems to be beneficial when maximizing SSC-performance. As jump height cannot be quantified without objective technical measures it is recommended to include them into daily training.     

Decreasing Adolescent Drug Use and School Failure:

Behavioral analyses of 3 adolescents show that 3 months of targeted family problem-solving training can decrease drug use and school failure by the end of a 1 1/4 year follow-up while control behaviors remain stable. Some findings, however, reflected incomplete understanding of the controlling variables: (a) lengthy delays before behavioral improvement, (b) recurrences of the problem behavior and subsequent recoveries during follow-up, and (c) correlated changes in the home and school environments. It is suggested that systematic study of relevant variables in the intervention could reduce behavioral variability and further increase understanding of adolescent drug use.