Perceptuomotor compatibility in pursuit tracking of two-dimensional movements

In a previous article, we reported an investigation of visuomanual pursuit tracking of unpredictable two-dimensional targets. This article extends the study to the tracking of predictable stimuli. In both investigations, the target trajectory was elliptical. The experimental factors we varied were the orientation of the major axis of the ellipses (horizontal or vertical), the period of the movement (9.65 to 1.61 s), and the law of motion (natural vs. transformed). In the natural condition (L), the motion results from the combination of harmonic functions, as would be the case if the target were generated by a human. In the transformed (T) condition, the law of motion departs systematically from this natural model. The main results of the study are as follows: (a) Satisfactory performance is achieved only in the natural condition. Pursuit movements obey the same constraints observed in spontaneous movements. (b) Predictability affects significantly the average delay between target and pursuit. (c) Each component of the pursuit movements depends on both components of the targets. Thus, two-dimensional tracking generalizes significantly the classical one-dimensional condition. (d) The simple model developed previously to describe performance with unpredictable targets can be generalized to cover the present case as well.     

Reminiscence and strategies of performance in rotary pursuit tracking

The maximum speed at which man detects and corrects errors is analyzed on the pursuit rotor. During the prerest performance, scores of about 220 msec. are found, for both extravertive and introvertive subjects. During the postrest performance a crossover effect appeared: extraverts had scores near 60 msec., while introverts did not surpass 100 msec. The results are discussed in the framework of Eysenck and Frith's (1977) theory of reminiscence.     

Infant attention and the development of smooth pursuit tracking.

The effect of attention on smooth pursuit and saccadic tracking was studied in infants at 8, 14, 20, and 26 weeks of age. A small rectangle was presented moving in a sinusoidal pattern in either the horizontal or vertical direction. Attention level was distinguished with a recording of heart rate. There was an increase across age in overall tracking, the gain of the smooth pursuit eye movements, and an increase in the amplitude of compensatory saccades at faster tracking speeds. One age change was an increase in the preservation of smooth pursuit tracking ability as stimulus speed increased. A second change was the increasing tendency during attentive tracking to shift from smooth pursuit to saccadic tracking when the stimulus speed increased to the highest velocities. This study shows that the development of smooth pursuit and targeted saccadic eye movements is closely related to the development of sustained attention in this age range.     

Effect of sex and joystick experience on pursuit tracking in adults

Using a joystick, adults (n = 39 males, 40 females in Experiment 1; n = 35 males, 40 females in Experiment 2; and n = 18 males, 18 females in Experiment 3) performed a computerized pursuit tracking task. Contrary to previously reported findings, the males were not more accurate than the females when performance was adjusted for prior perceptual-motor experience. Although no sex differences were found in a speeded tracking task, in an inverted tracking task the males exhibited a significant performance advantage; that advantage remained after several blocks of practice. Because participants' performance was adjusted statistically for prior perceptual-motor experience, the male advantage in inverted tracking was not related to experience. Rather, more proficient inverted tracking performance was associated with higher 3-dimensional mental rotations scores. In sum, sex differences in normal pursuit tracking may be better explained by differences in perceptual-motor experience. Inverted tracking, however, may depend on proficiency with spatial transformations.     

Effects of sine wave combinations on the development of precognitive mode in pursuit tracking

A pursuit tracking task was carried out to investigate the effects of combinations of sine waves on the development of precognitive mode, which is defined as open-loop mode with little feedback. Subjects were asked to track the targets, which contained two or three sine waves as components, and then to reproduce the target motion after the target had been removed. Frequency characteristics of tracking revealed the superiority of the faster component over the slower components in terms of both amplitude ratio and tracking lag. Subjects' reproduction after removing the target demonstrated that in general, subjects could learn and memorize also the slower component motion, which had yielded inferior performance during the tracking period. These results are discussed in terms of a model based on successive organization of perception.     

Asymmetric transfer in a pursuit tracking task related to a change of strategy

Sixty male subjects were divided into three equal groups, one control and the other two experimental. The experimental groups were given two tracking tasks in different orders. The tasks were given by distributed practice. One tracking task consisted of far and near movements at short regular intervals, while the other was of irregular longer intervals. Transfer was positive from the regular task to the irregular task. The parts of the tracking course on which far and near movements were made were the same for both tasks, but the movement pattern of the right hand was different in each case. The strategy used for the regular task could not be applied to the irregular task. For this reason the asymmetric transfer occurred.     

The pursuit of the natural

In recent years, it has become common to defend science against charges of bias against the supernatural by explaining that science must remain methodologically natural but does not assume metaphysical naturalism. While such a response is correct, some details about the distinction between methodological naturalism and ontological or metaphysical naturalism have been lacking, as has a clear understanding of the distinction between the methodological restriction of science to natural explanations and naturalistic claims about the scope of those methods. We still require an account of the natural that explains well why science is restricted to giving naturalistic methods, and why the pursuit of natural explanations is not tantamount to the assumption that only natural causes exist. I suggest that the distinguishing characteristics of the natural are not metaphysical at all but broadly epistemological, concerning goals of intersubjectivity and predictability. I argue that by focusing on naturalistic goals we can better explain why the pursuit of natural explanations need not presume any purely natural metaphysics. But I also suggest that the adoption of natural methods is not entirely metaphysically neutral, as it is associated with values that may be more closely associated with some metaphysical views than others.     

Consistent reproduction of movement sequences during acquisition of a pursuit tracking task

A pursuit tracking task is used as a vehicle to investigate the manner in which response consistency is affected by practice. Detailed examination of movement patterns shows that subjects can reproduce the mid-phase of a movement relatively consistently while the accelerative and decelerative phases of the movement remain highly variable. The findings are discussed with reference to Sparrow's 1983 concept of efficiency in conjunction with Norman and Shallice's 1980 model of automated action.     

Perceptual control models of pursuit manual tracking demonstrate individual specificity and parameter consistency

Attention, Perception, & Psychophysics - Computational models that simulate individuals’ movements in pursuit-tracking tasks have been used to elucidate mechanisms of human motor control....