K. S. Lashley

Bio: K. S. Lashley is an academic researcher from Yerkes National Primate Research Center. The author has contributed to research in topics: Generalization & Order (business). The author has an hindex of 13, co-authored 14 publications receiving 3897 citations. Previous affiliations of K. S. Lashley include University of Chicago & Harvard University.

Persistent problems in the evolution of mind.

Abstract: Harward University and The Yerkes Laboratories of Primate Biology T H HE comparative psychologist must try to ask questions of his animals and to understand their answers. When Pfungst (1911) demonstrated that the horses of Elberfeld, who were showing marvelous linguistic and mathematical ability, were merely reacting to movements of the trainer's bead, Mr. Krall, (1912), their owner, met the criticism in the most direct manner. He asked the horses whether they could see such small movements and in answer they spelled out an emphatic \"NO.\" Unfortunately, we cannot all be so sure that our questions are understood or obtain such clear answers. In 1913 Szymanski tried to find out whether the dog can recognize pictures of objects. The dogs not only failed to recognize the pictures but even failed to distinguish the objects. After long testing with the best methods that he could devise, Szymanski conduded that the dog's vision is so poor that he can only distinguish light from darkness. A number of us in this country were equally unsuccessful in demonstrating detail vision in dogs and rodents. For a period of ten years we were forced to believe these animals practically blind, in spite of common experience to the contrary. Then by chance we hit upon the method of having the animal jump against the objects to be distinguished. This \"look before you leap\" method put the questions in a way that was intelligible even to rats. They learned in 1 trial discriminative reactions that had formerely taken more than 100; they learned in 10 trials, tasks that they had previously failed after 7000 trials of training. Except for differences in acuity, their perception of visual form turned out to be almost as good as my own. Dogs did equally well. Evidently when an animal fails in a task, it is not safe to conclude that he lacks capacity for that task, unless we can be sure that the question was properly asked. Sometimes the answers are unexpected and often ambiguous. When I started work with chimpanzees, I presented what seemed a very simple problem: to associate a white box with food. I placed a white and a black box on a table before the cage, each box attached to a rope extending to the bars of the cage. The white box alone always contained food and if the black box were pulled in, I snatched away the other rope. When this had happened half a dozen times, my subject, Mimi, a husky female, grasped a rope in each hand, pulled one in until she could wrap it around her foot for a firm grip. She thus freed both hands to pull in one rope, while retaining complete control of the other. If the first box were empty, she usually won the tug of war for the second. Her solution of the problem was better than my own, so I judge it highly intelligent. But when I finally regained control of the situation, Mimi took more than 200 trials to form the simple association between the white box and food, a task which the rat, under optimal conditions, can learn in a single trial. I describe these misadventures in animal training to emphasize the tentative character of the conclusions to be drawn from the accumulated mass of studies of animal behavior. It has been said that American rats learn only by trial and error, whereas European rats learn by insight. Certainly, investigators in America have been only too prone to put a rat in a dark box where it can do nothing but press a lever and, because it does nothing else, to conclude that all its behavior is of the same character. Unless the experimenter has wide experience with the animals that he studies and adapts his questions

Sources of Method Bias in Social Science Research and Recommendations on How to Control It

Abstract: Despite the concern that has been expressed about potential method biases, and the pervasiveness of research settings with the potential to produce them, there is disagreement about whether they really are a problem for researchers in the behavioral sciences. Therefore, the purpose of this review is to explore the current state of knowledge about method biases. First, we explore the meaning of the terms “method” and “method bias” and then we examine whether method biases influence all measures equally. Next, we review the evidence of the effects that method biases have on individual measures and on the covariation between different constructs. Following this, we evaluate the procedural and statistical remedies that have been used to control method biases and provide recommendations for minimizing method bias.

The role of deliberate practice in the acquisition of expert performance.

Abstract: because observed behavior is the result of interactions between environmental factors and genes during the extended period of development. Therefore, to better understand expert and exceptional performance, we must require that the account specify the different environmental factors that could selectively promote and facilitate the achievement of such performance. In addition, recent research on expert performance and expertise (Chi, Glaser, & Farr, 1988; Ericsson & Smith, 1991a) has shown that important characteristics of experts' superior performance are acquired through experience and that the effect of practice on performance is larger than earlier believed possible. For this reason, an account of exceptional performance must specify the environmental circumstances, such as the duration and structure of activities, and necessary minimal biological attributes that lead to the acquisition of such characteristics and a corresponding level of performance. An account that explains how a majority of individuals can attain a given level of expert performance might seem inherently unable to explain the exceptional performance of only a small number of individuals. However, if such an empirical account could be empirically supported, then the extreme characteristics of experts could be viewed as having been acquired through learning and adaptation, and studies of expert performance could provide unique insights into the possibilities and limits of change in cognitive capacities and bodily functions. In this article we propose a theoretical framework that explains expert performance in terms of acquired characteristics resulting from extended deliberate practice and that limits the role of innate (inherited) characteristics to general levels of activity and emotionality. We provide empirical support from two new studies and from already published evidence on expert performance in many different domains.

The coordination of arm movements: an experimentally confirmed mathematical model.

Abstract: This paper presents studies of the coordination of voluntary human arm movements. A mathematical model is formulated which is shown to predict both the qualitative features and the quantitative details observed experimentally in planar, multijoint arm movements. Coordination is modeled mathematically by defining an objective function, a measure of performance for any possible movement. The unique trajectory which yields the best performance is determined using dynamic optimization theory. In the work presented here, the objective function is the square of the magnitude of jerk (rate of change of acceleration) of the hand integrated over the entire movement. This is equivalent to assuming that a major goal of motor coordination is the production of the smoothest possible movement of the hand. Experimental observations of human subjects performing voluntary unconstrained movements in a horizontal plane are presented. They confirm the following predictions of the mathematical model: unconstrained point-to-point motions are approximately straight with bell-shaped tangential velocity profiles; curved motions (through an intermediate point or around an obstacle) have portions of low curvature joined by portions of high curvature; at points of high curvature, the tangential velocity is reduced; the durations of the low-curvature portions are approximately equal. The theoretical analysis is based solely on the kinematics of movement independent of the dynamics of the musculoskeletal system and is successful only when formulated in terms of the motion of the hand in extracorporal space. The implications with respect to movement organization are discussed.