Target-size influences on reaction time with movement time controlled

The variable that affect motor programming time may be studied by changing the nature of the response and measuring the subsequent changes in reaction time (RT). One notion of motor programming suggests that aiming responses with reduced target size and/or increased target amplitude require more "complex" motor programs that require longer RTs. In a series of five experiments which movement time (MT) was experimentally varied target size neither influences RT when the movement amplitude was 2 or 30 cm nor when the target sizes differed by as much as a factor of 16:1. Increasing the movement amplitude from 15 to 30 cm also had no influence on RT. Movement time, however, did affect RT, with 200-msec movements having longer RTs than 120-msec movements. Target size and movement amplitude did not appear to be factors that influence programming time or program complexity.     

Sleep,activity, temperature,and performance: Techniques for long-term monitoring in the mouse

This paper describes a test chamber, a food acquisition task, and a training procedure for the long-term testing of an implanted mouse in a circadian rhythm experiment. For the training phase, a special-purpose controller is provided to a single cage. For the experimental phase, behavioral, electrophysiological, and environmental measures are collected by means of a mini-computer.     

Sex of leader,leader behavior,and subordinate satisfaction

A 2×2×2 factorial design was employed to examine the influence of instructed leadership style, sex of leader, and sex of followers on leader behavior, subordinate satisfaction, and productivity in a simple task. In general, male and female leaders were equally able and equally willing to display autocratic and democratic leadership styles if so instructed. Similarly, leader sex did not have a significant influence on subordinate satisfaction or productivity either by itself or in interaction with leadership style or follower sex.     

Task dynamics and resource dynamics in the assembly of a coordinated rhythmic activity.

Task dynamics corresponding to rhythmic movements emerge from interactions among dynamical resources composed of the musculature, the link segments, and the nervous and circulatory systems. This article investigated whether perturbations of interlimb coordination might be effect over circulatory and nervous elements. Stiffness of wrist-pendulums oscillated at a common tempo and at 180 degrees relative phase was perturbed through the use of tonic activity about an ankle. Left and right stiffnesses, the common period, and the phase relation all changed. Stiffnesses increased with ankle torque in proportion to the wrist's inertial load. Despite different changes in stiffness at the two wrists, isochrony was preserved. The stability was shown to be consistent with the proportionality of changes in stiffness to the inertial loads. The phase departed from antiphase in proportion to the asymmetry of inertial loads. The size of departures decreased with increasing ankle torque. An account was developed in terms of muscular, circulatory, and nervous functions.     

Ambiversion: characteristics of midrange responders on the Introversion-Extraversion continuum

Sixty-nine midrange responders on the Introversion-Extroversion (IE) scale of the Eysenck Personality Questionnaire (EPQ) were given an experimental measure to assess tendency toward ambivalence (i.e., both strongly introverted and strongly extraverted responses) vs. moderation (i.e., midrange responses), and degree of importance given to IE types of activities. The participants were divided into those showing ambivalence vs. those showing moderate responses, and into those reporting high vs. low importance of such activities. As was predicted, the ambivalent group showed significantly higher scores on the neuroticism scale of the EPQ, while the low importance group tended to show more psychoticism, but not to a significant degree. Both of the midrange scores were unrelated to the Bem Sex Role Inventory. Based on the findings, at least two groups are posited in the midrange of the IE dimension: an ambivalent group with mixed strong introversive and extraversive tendencies, and an ambiverted group with midrange scores.     

On the spread of semantic excitation

Summary Access to word-representations in memory was studied in two experiments. A lexical decision paradigm was used in both: Ss had to decide whether a string of letters shown to them was a word or a nonword. Decision time was the main dependent variable. Independent variables were context-similarity and context-intensity. The former is defined in terms of the categorical relationship that holds between a set of context-words and a subsequently presented test-word. The latter is defined by the number of highly related context-words, all sampled from a small semantic subcategory, that preceded the test-stimulus. In theory, the presentation of the context-words generates semantic excitation that spreads over memory and activates other memory representations. Differences in mean decision time, as a function of experimental conditions, are attributed to differences in the activation of test-words. Two hypotheses about the course or gradient of excitation-spread in lexical memory were studied. The results indicate that a simple spread-of-excitation hypothesis as proposed by Meyer, Schvaneveldt and Ruddy (1972, 1974) is sufficient to account for the data. For the conditions studied in the experiments, there was no reliable evidence of inhibitory processes that confine spread of excitation to a small region of lexical memory.This paper reports work that was conceived and begun at Stanford University, Calif., USA, where the author spent a year as a postdoctoral fellow. The fellowship was made possible by the Deutsche Forschungsgemeinschaft, Bad Godesberg, West Germany, Grant Schm 350/1. I thank Prof. Richard G. Atkinson and Dr. Stephan Monsell for discussing aspects of this work with me. I further thank Paul Matthews for introducing me to the art of running computerized experiments.