Laterality and directional preferences in a simple perceptual-motor task

The superiority of tensor or outward movements of hand and arm over flexor or inward movements has been described, but no evidence has been found relating to directional preferences in simple perceptual-motor tasks.

One hundred children, aged 9 to 13, 50 being right-handed writers and 50 left-handed writers, were tested on a stroke-making task, using both preferred and non-preferred hands. 75 per cent, of them exhibited a preference for outward movements of both hands, a finding which applied equally to both handedness groups. Thus an explanation based on writing habits is discounted.     

Redundancy in perceptual-motor testing: confirmation and generalization.

The Developmental Test of Visual-motor Integration was administered to 63 children in regular classrooms and 51 children in Special Education. Prediction based on total score (r = .68) was similar to a multiple R utilizing only five scores (.67). The over-all raw test score, based on all 24 designs, correctly classified 85% of the children while a combined abbreviated score utilizing only 5 designs achieved an 80% differentiation. Results were interpreted as confirming the hypothesis of redundancy in this perceptual-motor test.     

Force gradients in stimulus generalization

Pigeons were trained to peck with differing force requirements on a key specially designed to measure and control force of pecking without changes in the mechanical threshold. Following training on a key illuminated by a single wavelength, a generalization test was given. Force and rate gradients were obtained. Force gradients were shown to have a form similar to rate gradients. The slope of the force gradients was a direct function of the force of responding at the conclusion of training. Rate gradients were independent of the force of responding.     

Effects of practice and alcohol on performance of a perceptual-motor task

Practice may modify the effects of alcohol on perceptual-motor performance in at least three different ways: (1) alcohol may affect learning—that is, the rate at which performance of a skill improves with practice; (2) alcohol may have a greater effect on performance when the skill is unfamiliar than when it is practised; and (3) practice with alcohol may allow adaptation to its effects. These were investigated using a simple computer game in which subjects attempted to destroy a tank by pressing a key to release a bomb from a plane horizontally traversing the screen above it. The results demonstrated that (1) performance improved with practice; (2) with alcohol (0.8 mg/kg body weight), subjects were more variable and less accurate; (3) improvement with alcohol was greater than without alcohol, but as performance was impaired by alcohol, there was greater scope for improvement; (4) those who practised with alcohol still improved when switched to no alcohol late in practice; and (5) alcohol had the same effect early and late in practice. It is therefore concluded that there is no evidence to support any of the three suggestions outlined above.     

The drawing of squares and diamonds: a perceptual-motor task analysis

The aim of the present study was to establish the role of perceptual-motor factors in copying an equilateral four-sided figure. Children, 5 to 12 years, and adults, were asked to copy the figure presented in either "square" or "diamond" orientation under five conditions: control; large model presentation; neutral picture frame surround; partial visual information reduction; and total visual information loss. The model was present at all times. Scores were orientation and angular variability. Developmental trends were found for both figures; the diamond was less well performed than the square at all ages tested. Three perceptual-motor factors were found to be important: formulation of the movement plan; movement programming, and sensory feedback. The difficulty of the diamond is thought to be due to the high programming and hence planning demands in drawing oblique lines. Both kinaesthesis and sequential vision are important factors in drawing; and only from 12 years of age are environmental cues used efficiently to orient the figure.     

Contrast effects in maintained generalization gradients

In Experiment I, pigeons were given equal reinforcement (variable-interval 1-min) for responding during randomized presentations of eight line-orientation stimuli. Then, only responding in the vertical orientation was reinforced. Stable generalization gradients soon formed and persistent behavioral and local (transient) contrast effects appeared. Local contrast effects were not a function of relative reinforcement frequency or of any other variable known to produce contrast. Instead, they were related to average response rates associated with each stimulus. Experiment II showed that local contrast effects represent increases and decreases in response rates relative to baseline responding, and that these effects are relative; a given stimulus might enhance responding during a subsequent presentation of one stimulus, but depress responding when followed by another. These data indicate that discrimination learning is not adequately described as the acquisition of excitatory properties by some stimuli and inhibitory properties by others. A more adequate account implies that stimuli exert both excitatory and inhibitory effects related to their value.     

Acquisition of expertise on a difficult perceptual-motor task by an amnesic patient

While numerous studies have reported learning of perceptual-motor skills by amnesic patients, few if any have documented the eventual acquisition of expertise on a given task. This paper recounts the learning of the computer game Tetris by a hippocampal amnesic, whose acquisition of the task in a formal evaluation was somewhat slower than that of a comparison group, but who after many hours of self-paced practice achieved expert-level play.     

Generalization gradients in a navigation task with rats

In two experiments in a Morris pool, rats were trained to find a hidden platform which was located in a specific position in relation to two objects, B and F, which were presented together, one in front of the other. One object, B, was just above the platform (a beacon for the platform, the critical object) while the second object, F, was above the edge of the pool (the frame of reference). Then the rats received test trials, without the platform, in which B was presented in different positions in relation to F (i.e., in relation to its original position). In the two experiments the test results showed a generalization gradient as a function of the relative distance of the two objects: more time searching in the B segment, where the platform should have been, when B was in the original position (i.e., in front of F), which decreased symmetrically with distance of B from F. The present experiments show for the first time generalization gradients with rats across spatial locations when working with a navigation task.     

Frames of reference in perceptual-motor learning: Evidence from a blind manual positioning task

Participants moved a joystick to bring a computer-displayed cursor to each of six on-screen target locations arrayed around the center of the screen. At the start of each trial, the stick rested vertically, with a cursor occupying the center of the screen. A target appeared at another location and as soon as the stick was moved away from its rest position the cursor disappeared until the participant pressed a trigger on the stick to indicate when s/he thought the stick-controlled cursor was at the target site. With training, participants improved on the blind positioning task, but when conditions changed their performance suffered. Changing the hand used in the task or the location of the stick caused approximately equal disruptions, but changing both hand and location was significantly more disruptive than changing just one feature. The results support the hypothesis that perceptual-motor learning entails coding of extrinsic (spatial coordinates) as well as intrinsic (postural or body movement) information. Received: 14 October 1999 / Accepted: 6 November 2000     

The relationship between the EPI extraversion score and impulsiveness on a perceptual-motor task

This paper describes an investigation of the relationship between extraversion and impulsiveness. These two traits were measured respectively by the Eysenck Personality Inventory (EPI) and the IES Arrow-Dot test. The subjects were 50 males and 50 females matched for age. Arrow-Dot impulsiveness was found to correlate significantly with extraversion in both samples. In the female sample Arrow-Dot impulsiveness correlated only significantly with the ‘impulsiveness’ component of extraversion. In the male sample both the ‘impulsiveness’ and ‘sociability’ components of the extraversion factor contributed about equally to its variance.     

Transient effects of acquisition history on generalization in a matching-to-sample task

This study examined the role of learning history on the acquisition of a matching-to-sample task. Twelve preschool children learned four stimulus classes through instructions, shaping, or imitation. After reaching criterion, the subjects were exposed to changed discrimination contingencies to determine how each learning history affected the acquisition of responses appropriate to the new contingencies. All subjects reached criterion on the new relations, although the subjects with a shaping history adapted slightly more quickly than those subjects with a history of instructions or imitation. Given sufficient exposure to changed contingencies, rule-driven insensitivity to contingencies was overcome by experience with consequences. This result may be specific to younger subjects, but it suggests that instructions can be used in education without creating insensitivity to contingencies.