Delayed auditory feedback and rhythmic tapping: evidence for a critical interval shift

Delayed auditory feedback (DAF) impairs performance in speech, music, and tapping, with maximal impairment in speech occurring at a delay of about 200 msec. This critical interval has played a central role in many explanations of the DAF effect, including both closed-loop feedback explanations and alternative proposals. We investigated the nature of the critical interval in rhythmic tapping--in particular, whether the critical interval has a constant value or is dependent on performance rate. Three experiments in which a synchronization-continuation paradigm was used consistently showed that the critical interval shifted with different tapping rates, with maximal impairment occurring when the delay approximately equaled the tapping rate. We address the implications of these results for theories of DAF.     

A bit-addressable I/O interface for microcomputers

An input/output (I/O) interface design based on the 6522 VIA is described. This design is enhanced with additional circuitry to provide such features as latched input, bit-addressable I/O line control, and provisions for expansion.     

A versatile memory-mapped I/O interface for microcomputers

An inexpensive and easy-to-bulid input/output interface capable of driving the electromechanical loads (relays, solenoids, dc motors, etc.) and incandescent lamps is described. The interface hardware is based on the Commodore VIC-20 microcomputer. The design is adaptable to most 8-bit microcomputers.     

A comparison of inexpensive statistical packages for microcomputers running MS-DOS

The purpose of the present paper is to describe and compare some inexpensive software packages that calculate a variety of statistics on microcomputers running MS-DOS. For each package, hardware requirements, program capabilities, limitations, accuracy, error handling, and other features are considered.     

A comparison of inexpensive statistical packages for apple II microcomputers

The purpose of this paper is to describe and compare some inexpensive software packages that calculate a variety of statistics on the Apple II microcomputer. For each package, hardware requirements, program capacity, limitations, constraints, accuracy, editing, error handling, and other features were studied.     

Bivar: A program for generating correlated random numbers

This article describes Bivar, a program that generates random numbers from a wide variety of bivariate distributions. Numbers are written to an ASCII output file, from which they can be read as needed by programs simulating stochastic processes. The program runs under the DOS operating system on IBM-PC compatibles with a 386 or later processor, and it is free for educational and noncommercial use.     

A pseudo-dynamic search ant colony optimization algorithm with improved negative feedback mechanism

To solve low convergence precision and slow convergence speed, a pseudo-dynamic search ant colony optimization algorithm with improved negative feedback mechanism (PACON) is proposed. Firstly, the algorithm introduces an angle in the pheromone transfer rule. Through the rule for calculating the angle, multiple cities with smaller angles are also included in the next candidate city list. It affects the probability of city selection and enhances the algorithm’ performance to avoid local optimization. Secondly, the algorithm updates the pheromone concentrations on the worst and optimal path simultaneously, and enhances the weights of the pheromone concentrations on the optimal path. It improves the convergence speed of the algorithm. Based on experiments adopting TSPLIB data sets, the results demonstrate the improved algorithm improves the convergence accuracy by at least 1.26% and increases the convergence speed by at least 9.5%, both on large-scale and small-scale urban data. The novel algorithm will improve convergence precision and speed better.     

A test for psychometric function shift

A nonparametric, small-sample-size test for the homogeneity of two psychometric functions against the left- and right-shift alternatives has been developed. The test is designed to determine whether it is safe to amalgamate psychometric functions obtained in different experimental sessions. The sum of the lower and upper p-values of the exact (conditional) Fisher test for several 2 × 2 contingency tables (one for each point of the psychometric function) is employed as the test statistic. The probability distribution of the statistic under the null (homogeneity) hypothesis is evaluated to obtain corresponding p-values. Power functions of the test have been computed by randomly generating samples from Weibull psychometric functions. The test is free of any assumptions about the shape of the psychometric function; it requires only that all observations are statistically independent.