The effects of spatial representation on memory for verbal navigation instructions

Three experiments investigated effects of mental spatial representation on memory for verbal navigation instructions. The navigation instructions referred to a grid of stacked matrices displayed on a computer screen or on paper, with or without depth cues, and presented as two-dimensional diagrams or a three-dimensional physical model. Experimental instructions either did or did not promote a three-dimensional mental representation of the space. Subjects heard navigation instructions, immediately repeated them, and then followed them manually on the grid. In all display and experimental instruction conditions, memory for the navigation instructions was reduced when the task required mentally representing a three-dimensional space, with movements across multiple matrices, as compared with a two-dimensional space, with movements within a single matrix, even though the words in the navigation instructions were identical in all cases. The findings demonstrate that the mental representation of the space influences immediate verbatim memory for navigation instructions.     

Unitarian validation of a mathematical problem-solving exercise for sales occupations

A content-related test construction strategy was employed as a means of yielding a test with criterion-related evidence of validity. Utilizing a national sample of field sales job incumbents, a group-based job analysis method was developed to identify job requirements. A content validity and concurrent criterion-related study were then conducted. The results demonstrated both content and criterion-related evidence of validity. Differential validity by race or gender was not found. A comparison between minority and non-minority group regression lines found no statistically significant difference between slopes. However, a statistically significant difference between minority and non-minority intercept values was found. The results are discussed in respect to their consistency with other research findings. The significance of the study is addressed in light of the recent Unitarian approach towards the theoretical and practical nature of test validity. It is suggested that practitioners and researchers investigate further the elements of this research effort as guidance for satisfying professional and federal standards.     

Learning new problem-solving strategies leads to changes in problem representation

Children sometimes solve problems incorrectly because they fail to represent key features of the problems. One potential source of improvements in children's problem representations is learning new problem-solving strategies. Ninety-one 3rd- and 4th-grade students solved mathematical equivalence problems (e.g., 3 + 4 + 6 = 3 + __) and completed a representation assessment in which they briefly viewed similar problems and either reconstructed each problem or identified it in a set of alternatives. Experimental groups then received a lesson about one or both of two solution strategies, the equalize strategy and the add–subtract strategy. A control group received no instruction. All children completed posttest assessments of representation and problem solving. Children taught the equalize strategy improved their problem representations more than those not taught it. This pattern did not hold for the add–subtract strategy. These results indicate that learning new strategies is one source of changes in problem representation. However, some strategies are more effective than others at promoting accurate problem representation.     

Effects of attentional-focus instructions on movement kinematics

BackgroundRecent research has shown that internal (body-related) attention-focus instructions disrupt motor learning and performance, whereas paying attention to the environmental effects of movements (external focus) leads to better performance than an internal focus [see, for reviews, Wulf, G. (2007). Attentional focus and motor learning: a review of 10 years of research. E-Journal Bewegung und Training, 1, 4–14.; Wulf, G., &; Prinz, W. (2001). Directing attention to movement effects enhances learning: a review. Psychonomic Bulletin &; Review, 8, 648–660.]. However, Beilock's studies [Beilock, S. L., Bertenthal, B. I., McCoy, A. M., &; Carr, T. H. (2004). Haste does not always make waste: expertise, direction of attention, and speed versus accuracy in performing sensorimotor skills. Psychonomic Bulletin &; Review, 11, 373–379.] suggest that an internal focus is detrimental in experts but not in novices. Because detrimental effects of consciously attending to movements have generally been measured by performance scores such as accuracy scores or reaction times, it remains unclear how internal and external attentional-focus instructions influence movement kinematics when learning a new skill. To fill this gap, the present study investigated attentional-focus effects on a biomechanical level.MethodsA video of an expert juggler demonstrating a two-ball juggling task was presented to juggling novices. Experimental groups were given either body-related (internal group) or ball-related (external group) verbal instructions or no attention-guiding instructions (control group). In the retention phase without attention-guiding instructions, the body-movement and ball-flight aspects of performance focused on in the verbal instruction were subjected to biomechanical analyses.Results and ConclusionsJuggling performance improved equally in all three groups. However, internally vs. externally instructed acquisition phases had differential effects on the kinematics of the upper body as well as ball trajectories when performing the juggling task. Remarkably, ball trajectories in the control group who received no specific attentional cueing were similar to those in the externally instructed group. This suggests that task-relevant information is picked up independently of instructions, and that external instructions provide redundant information. Internal instructions for object-related tasks, however, may confront novice learners with the need to process additional information. As a result, task difficulty might be unnecessarily enhanced in an observational learning setting.     

Effects of instructions and format on reported visual imagery

156 subjects (students and working adults) completed Marks' Vividness of Visual Imagery Questionnaire in one of two formats reflecting item order (blocked, random) under one of three instructional conditions (easy, neutral, difficult) reflecting ease of image formation. Although the effect of instructions (but not format) was significant, scores were lower, i.e., more vivid imagery was reported, in the easy than in the neutral or difficult conditions, which did not differ. These results suggest that the validity of Marks' questionnaire is not seriously weakened by response leniency.     

On the mathematical representation of phenomena of emergence

This paper is a philosophical enquiry into the role that mathematics play in the articulation of science. It is conducted, in its essentials, in the spirit of Wittgenstein's views on the nature and function of philosophy, which are to lay bare, as it were, the manner in which we do whatever it is that we do, and then to examine the claims that we make for the deed. My conclusions should be easily accessible to those familiar with his thinking on the subject of science.

The case that has inspired the writing of this paper is not that of biology, nor is it the biological theory of evolution; rather, the case I have kept in mind while writing this paper is that of cognitive science, sometimes presented as a “science of mind” by its practitioners. It is primarily a computational theory characterized by two distinct approaches, one internal, the gist of which is that the brain/mind distinction is definitely passé; the other external, based on the view that the mark of human mentation is to be found in the ordinary use of old expressions to convey new meanings, i.e. in the Cartesian test for the existence of other minds, and its simpler computational version, the Turing test. Two intuitions underlie the paper: one, that language is obviously an adaptive characteristic of human organisms: one learns one's own mother's tongue, and feral children cannot conceptualize if first exposed to language after reaching puberty; two, empirical evidence supports the view that the “knowing brain” is different architecturally from the “untutored” one. These intuitions warrant regarding man's cognitive apparatus as an evolutionary system, and the “mind” as an emergent property.     

Children's cognitive representation of the mathematical number line

Learning of the mathematical number line has been hypothesized to be dependent on an inherent sense of approximate quantity. Children's number line placements are predicted to conform to the underlying properties of this system; specifically, placements are exaggerated for small numerals and compressed for larger ones. Alternative hypotheses are based on proportional reasoning; specifically, numerals are placed relative to set anchors such as end points on the line. Traditional testing of these alternatives involves fitting group medians to corresponding regression models which assumes homogenous residuals and thus does not capture useful information from between‐ and within‐child variation in placements across the number line. To more fully assess differential predictions, we developed a novel set of hierarchical statistical models that enable the simultaneous estimation of mean levels of and variation in performance, as well as developmental transitions. Using these techniques we fitted the number line placements of 224 children longitudinally assessed from first to fifth grade, inclusive. The compression pattern was evident in mean performance in first grade, but was the best fit for only 20% of first graders when the full range of variation in the data are modeled. Most first graders' placements suggested use of end points, consistent with proportional reasoning. Developmental transition involved incorporation of a mid‐point anchor, consistent with a modified proportional reasoning strategy. The methodology introduced here enables a more nuanced assessment of children's number line representation and learning than any previous approaches and indicates that developmental improvement largely results from midpoint segmentation of the line.     

Effects of subject-to-experimenter distance and instructions on lateral eye movement

Lateral eye movements and heart rate were recorded as 32 right-handed men answered verbal and spatial questions. Experimenter-to-subject distance (.8 and 1.5 m) and attention demand of instructions were manipulated in a 2 X 2 design. A significant main effect for distance and an interaction of distance by instructions appeared on the direction of eye movements independent of type of question. The greatest number of leftward eye movements occurred at the short distance with instructions demanding higher attention. These findings are consistent with evidence that emotional arousal produces greater right- than left-hemisphere activation.     

Effects of aging and encoding instructions on emotion-induced memory trade-offs

The effects of emotion on memory are often described in terms of trade-offs: People often remember central, emotional information at the expense of background details. The present experiment examined the effects of aging and encoding instructions on participants' ability to remember the details of central emotional objects and the backgrounds on which those objects were placed. When young and older adults passively viewed scenes, both age groups showed strong emotion-induced trade-offs. They were able to remember the visual details as well as the general theme of the emotional object, but they had difficulties remembering the visual specifics of the scene background. Age differences emerged, however, when participants were given encoding instructions that emphasized elaborative encoding of the entire scene. With these instructions, young adults overcame the trade-offs (i.e., they no longer showed impairing effects of emotion), whereas older adults continued to show good memory for the emotional object but poor memory for its background. These results suggest that aging impairs the ability to flexibly disengage attention from the negative arousing elements of scenes, preventing the successful encoding of nonemotional aspects of the environment.     

Effects of task instructions and oscillation frequency on bimanual coordination

Increases in the oscillation frequency of bimanual movements produce a switch from an anti-phase (180° relative phase) to an in-phase (0° relative phase) coordination pattern. This finding is observed when subjects are instructed not to intervene when they feel themselves slipping out of the anti-phase pattern. The question addressed in this study concerned how performance would be affected if subjects were instructed to try to maintain the pattern at all times. This issue was addressed using two separate groups of subjects: one group was given the do not intervene instructions, the other group was told to try to stay with the pattern at all times. Forearm rotations were tested in 15 s trials, paced by an auditory metronome set at 1.0, 1.5, 2.0, 2.5, and 3.0 Hz. Frequency distributions of the point estimates of relative phase were analyzed. The Do not Intervene group replicated previous findings, as indicated by the development of a bimodal histogram of relative phase distributions with increases in oscillation frequency. However, a very different pattern of findings emerged with increases in oscillation frequency for the group told to stay with the anti-phase pattern. Rather than a bimodal distribution being developed, the data maintained 180° as its central tendency — no secondary distribution developed around 0° relative phase. These data suggest that volitional control can over-ride the inherent dynamical tendencies of the motor system.