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.     

Priming arithmetic reasoning in an amnesic patient

The present study elucidates the role of implicit memory in problem solving by evaluating priming effects in a severely amnesic patient. An arithmetic series completion task was adopted to investigate the effects of lags, of items difficulty, as well as the influence of different distractor tasks on priming numerical reasoning. The results indicated that the priming effect was maximized in difficult trials and disappeared after long lags. On the other hand, the facilitation effect was not modulated by the nature of the distractor tasks. Critically, the experimental design controlled for peripheral facilitation of visual input and verbal output processes and a recognition task indicated that the effect may not be attributed to explicit memory. Thus, the facilitation must be located to a more central stage, possibly at the stage in which the abstract formula of the underlying algorithm are generated (Langdon & Warrington, 1997).     

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.     

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.     

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.     

Using SenseCam with an amnesic patient: accessing inaccessible everyday memories

Forgetting is a normal and everyday occurrence that may sometimes reflect a complete loss of the mnemonic record or a failure to encode it in the first place. However, on many occasions with the help of cues we can eventually or suddenly recall a memory that seemed to be lost, thus highlighting the probability that many instances of "forgetting" may in fact reflect inaccessibility rather than true loss. We report here on our amnesic patient CR who presents an extreme example of this normal everyday forgetting. For 4 weeks, CR recorded regular personal autobiographical events both on a SenseCam (henceforth SC) and in a written diary form. Subjective and objective aspects of recall were measured each weekend both without any cues and then with either a SC or diary cue. We show that the SC enabled CR to recall significantly more detailed episodic memories than reading the diary and importantly we observed that the qualitative nature of these memories was different. We comment on the considerable potential of SC for therapeutic purposes.     

Teaching an amnesic a complex cognitive skill

G.P., a Korsakoff's amnesic, was able to learn an algorithm for squaring two-digit numbers mentally over a 7-day period at a rate comparable to that of age-matched controls. He failed to show normal positive transfer to specific problems or to specific numbers used in components of the task. He also exhibited slight improvement in simple naming speed, forward digit span, simple multiplication speed, but no apparent improvement for the recall of repeated supraspan digit strings. He was unable to state the algorithm he had learned to square two-digit numbers, though he could implement it successfully. The results suggest that the compilation of a skill may involve two dissociable components: composition and proceduralization, with the former, but not the latter, occurring at normal rates for Korsakoff's amnesics.     

Medical expertise asa function of task difficulty

This paper is concerned with factors that disrupt the pattern of forward reasoning characteristic of experts with accurate performance. Two experiments are described. In the first, the performances of cardiologists, psychiatrists, and surgeons in diagnostic explanation of a clinical problem in cardiology were examined. In the second, the performances of cardiologists and endocrinologists in diagnostic explanation of clinical problems within and outside their domains of expertise were examined. The performances of researchers and practicing physicians are also compared. The results of Experiment 1 replicated earlier results regarding the relationship between forward reasoning and accurate diagnosis. There were no differences in recall as a function of expertise. Experts did not show any bias toward using specific knowledge from their own areas of expertise. The results of Experiment 2 showed that the breakdown of forward reasoning was related to the structure of the task. In particular, nonsalient cues induced some backward reasoning even in subjects with accurate diagnoses. Some differences were also found between the types of explanation used by researchers and practitioners. The practitioners referred more to clinical components in their explanations, whereas the researchers focused more on the biomedical components.     

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     

Musical expertise has minimal impact on dual task performance

Studies investigating effect of practice on dual task performance have yielded conflicting findings, thus supporting different theoretical accounts about the organisation of attentional resources when tasks are performed simultaneously. Because practice has been proven to reduce the demand of attention for the trained task, the impact of long-lasting training on one task is an ideal way to better understand the mechanisms underlying dual task decline in performance. Our study compared performance during dual task execution in expert musicians compared to controls with little if any musical experience. Participants performed a music recognition task and a visuo-spatial task separately (single task) or simultaneously (dual task). Both groups showed a significant but similar performance decline during dual tasks. In addition, the two groups showed a similar decline of dual task performance during encoding and retrieval of the musical information, mainly attributed to a decline in sensitivity. Our results suggest that attention during dual tasks is similarly distributed by expert and non-experts. These findings are in line with previous studies showing a lack of sensitivity to difficulty and lack of practice effect during dual tasks, supporting the idea that different tasks may rely on different and not-sharable attentional resources.     

The effect on a difficult co-ordination task of the frequency of signals

Subjects were required to direct, by moving hand and foot controls, a fugitive spot of light into one of four positions in accordance with changes in the source of signals, and simultaneously, to extinguish two lights using a left-hand response. Two groups of subjects have been tested on this complex co-ordination task. Increasing the frequency of the signals from four successively but irregularly functioning sources was found to increase significantly the “error” scores in controlling the fugitive spot. Variations in signal frequency did not affect the other part of the task requiring left hand responses to a different set of signals. The order of a sequence of 4-signal frequencies over four trials had no effect on the efficiency with which the task was performed.     

Recall of spatial location by the amnesic patient H.M

The amnesic patient H.M. was tested for immediate recall of the location of objects in an array. Three array-sizes were used: 16, 7, or 4 objects. With 16 objects, H.M.'s performance was at chance level; with the smaller arrays, his performance was above chance, but still well below the levels achieved by age-matched control subjects. The ability to recall location by H.M. did not differ under incidental and intentional learning conditions, thus failing to support the notion that automatic encoding skills may be selectively disrupted in amnesia.     

Acquisition of a same-different discrimination task by pigeons (Columba livia)

Four homing pigeons were trained to discriminate two figures simultaneously presented on an LCD screen. The figure was either a rectangle (A) or a square (B), and four combinations of the two figures, AA, AB, BA, BB, appeared in a pseudo-randomized order. The pigeons' task was to peck one of these figures based upon whether the two figures were identical or not. One pigeon successfully learned this discrimination, with proportions of correct responses above 90% in two consecutive sessions. Of the other birds, two performed above chance level but had difficulty meeting a learning criterion of above 80% in two consecutive sessions. All birds achieved this criterion when the combinations of figures presented were reduced to two. Results suggested that learning the present same-different discrimination is within the capacity of pigeons to a certain extent, although there exists considerable individual variation in the pigeons' skills to acquire complex discrimination.     

Acquisition of navigation by chimpanzees (Pan troglodytes) in an automated fingermaze task

These experiments investigated how chimpanzees learn to navigate visual fingermazes presented on a touch monitor. The aim was to determine whether training the subjects to solve several different mazes would establish a generalized map-reading skill such that they would solve new mazes correctly on the first presentation. In experiment 1, two captive adult female chimpanzees were trained to move a visual object (a ball) with a finger over the monitor surface toward a target through a grid of obstacles that formed a maze. The task was fully automated with storage of movement paths on individual trials. Training progressed from very simple mazes with one obstacle to complex mazes with several obstacles. The subjects learned to move the ball to the target in a curved path so as to avoid obstacles and blind alleys. After training on several mazes, both subjects developed a high level of efficiency in moving the ball to the target in a path that closely approached the ideal shortest path. New mazes were then presented to determine whether the subjects had acquired a more generalized maze-solving performance. The subjects solved 65–100% of the new mazes the first time they were presented by moving the ball around obstacles to the target without making detours into blind alleys. In experiment 2, one of the chimpanzees was trained using mazes with two routes to the target. One of the routes was blocked at one of many possible locations. After training to avoid the blind alley in different mazes, new mazes were presented that also had one route blocked. The subject correctly solved 90.7% of the novel mazes. When the mazes had one short and one long open route to the target the subject preferred the shorter route. When the short route was blocked, the subject solved only 53.3% of the mazes because of the preference for the shorter route even when blocked. The overall results suggest that with the training methods used the subjects learned to solve specific mazes with a trial-and-error method. Although both subjects were able to solve many of the novel mazes they did not fully develop a more general "map-reading" skill. Accepted after revision: 30 July 2001 Electronic Publication