Perception of movement patterns: tracking of movement

The tracking of complex two-dimensional movement patterns was studied. Subjects were blindfolded, and their right hand moved around stencil patterns in the midsagittal plane, while the left hand concurrently reproduced the right-hand movement. The accuracy with which the left hand shadowed the criterion movements of the right hand was measured in shape and size. Right-hand movements were active or passive. Present tracking performance was contrasted with errors in recall reported by Bairstow and Laszlo (1978). Results showed that tracking performance was accurate. Active and passive criterion movements were tracked differently. Tracking was clearly superior to recall performance.     

Structural complexity of motor patterns: A study on reaction times and movement times of handwritten letters

This study investigates the effects of psychomotor complexity on latencies for beginning to write single letters and numerals, and on times taken to complete the first strokes of letters and numerals. An experiment measured simple and choice reaction times for writing homogeneous graphemes (i.e., letters or numerals made up of similar strokes) and for writing heterogeneous graphemes (i.e., characters made up of dissimilar strokes). It was assumed that the motor programme for writing a letter is retrieved from long-term memory and briefly held, until it is used, in a short-term buffer store. The experiment examined the hypothesis that it is more difficult to read out homogeneous than heterogeneous stroke-structures from this store. For three out of four allographic grapheme pairs, homogeneous graphemes required longer initiation times or longer movement times for completion of the first stroke than did heterogeneous graphemes. These results are discussed in relation to recent findings on motor programming based on the use of reaction-time paradigms.     

Voluntary head movement and allocentric perception of space

Although visual input is egocentric, at least some visual perceptions and representations are allocentric, that is, independent of the observer's vantage point or motion. Three experiments investigated the visual perception of three-dimensional object motion during voluntary and involuntary motion in human subjects. The results show that the motor command contributes to the objective perception of space: Observers are more likely to apply, consciously and unconsciously, spatial criteria relative to an allocentric frame of reference when they are executing voluntary head movements than while they are undergoing similar involuntary displacements (which lead to a more egocentric bias). Furthermore, details of the motor command are crucial to spatial vision, as allocentric bias decreases or disappears when self-motion and motor command do not match.     

Children's use of gaze and limb movement cues to infer deception

A sample of 96 children from kindergarten, 2nd, 4th, and 6th grades judged the truthfulness of peers who varied in gaze and limb movement while providing verbal communications. Results indicated that children attributed greater lying to the peers who displayed indirect rather than direct gaze and active rather than nonactive limb movement. The use of these cues was more evident in 4th- and 6th-grade children than it was in kindergarten and 2nd-grade children. Pilot studies indicated that adults and children as young as 5-6 years of age associated indirect gaze and active limb movement with anxiety. The findings are discussed with respect to children's theory of mind, concepts of lying, understanding of display rules, and learning of physiological cues associated with deception.     

Complex movement patterns: Learning retention and sources of error in recall

In this study of kinaesthesis, the learning, retention, and recall of complex patterns was examined. Subjects were blindfolded, held a stylus in the right hand, and moved around stencil patterns, either actively or passively. The patterns were recalled with a free active movement of the right hand, after various amounts of practice, immediately or after a 60-s interval, once or twice in succession, with and without visual guidance. The shape and size of the drawings was compared with the criterion patterns. The effect of practice varied depending on whether the criterion movement was active or passive, and on the measure of recall performance. Even when the criterion patterns were freely practised, the recall traces showed large errors in shape and systematic shrinkage in size, and there were large individual differences. Regardless of these errors, recall performance was reliable. The effect of an unfilled retention interval varied as a function of practice. When the patterns were recalled under visual guidance, there was no shrinkage in the size of the drawings.     

The community alcohol use scale: A scale for use in prevention programs

The Community Alcohol Use Scale (CAUS) was developed as a continuous, reliable, valid, and acceptable measure for primary prevention studies. Items were written following a comprehensive review of the literature on alcohol dependence and alcoholism. Based upon the responses of 315 respondents to the 100-item initial version of the scale, the 45-item CAUS was developed. The CAUS was then cross-validated on a local sample (n = 274) and a provincial sample (n = 745). Estimates of internal consistency were .91, .96, and .94, respectively, for the initial and cross-validation samples. Correlations of .48 and .69 were obtained between the CAUS and the Michigan Alcohol Screening Test for the initial and local cross-validation samples. In the provincial cross-validation sample a correlation of .62 was obtained between the CAUS and the Usual Weekly Alcohol Index. Preliminary cutting scores were developed to identify those at risk for alcoholism, and alcoholics. The CAUS has potential use as an evaluative and predictive instrument in a variety of primary prevention programs.     

The adaptation to sensory information in the production of bimanual movement patterns

Bimanual in-phase and anti-phase patterns were performed in the transverse plane under optimal and degraded proprioceptive conditions, i.e., without and with tendon vibration. Moreover, proprioceptive information was changed midway into each trial to examine on-line reorganization. In addition to the proprioceptive perturbation, the availability of visual information was manipulated to study to which degree sensory information from different modalities interact. Movement patterns performed under identical sensory conditions were compared, i.e., the first 15 s (control) and the 15 s following a change in afferent input (transfer). In the control and transfer conditions, movements with vibrations were less accurate than those without vibrations indicating the influence of optimal proprioceptive information in the calibration and recalibration of intrinsic bimanual movement patterns. Furthermore, pattern stability was affected by the nature of the transfer condition. This indicated that the degree of fluctuations in a sensory transfer situation depended upon the quality of the proprioceptive information experienced in the initial conditions. The influence of visual information was not without importance, although the nature of the coordination mode must be taken into account. In the control conditions, in-phase movements were less stable when vision was absent, whereas anti-phase movements were more stable when vision was not present. This observation was made independent of the available proprioceptive information revealing differences in visual guidance between both coordination modes. In the transfer conditions, pattern stability was similar during the vision and no-vision conditions suggesting a limited influence of visual information in the recalibration process.     

Chronometric comparison of actual and imaged complex movement patterns

The authors' aim in this study was to consider the functional equivalence of internal imagery, external imagery, and action execution. Sixteen elite gymnasts imaged and performed a complex gymnastic vault. Ten performers imaged from an internal perspective, and 6 used an external perspective. Although the results revealed that the time to image the entire motor task did not significantly differ from the time required to physically perform it, irrespective of the imagery perspective used, the temporal organization of the action was different within the imagery conditions than it was in the physical condition. The results do not provide support for the principle of temporal functional equivalence. The authors discuss the results in light of recent findings from the cognitive neuroscience and psychology literatures.     

Multi-segmental movement patterns reflect juggling complexity and skill level

The juggling action of six experts and six intermediates jugglers was recorded with a motion capture system and decomposed into its fundamental components through Principal Component Analysis. The aim was to quantify trends in movement dimensionality, multi-segmental patterns and rhythmicity as a function of proficiency level and task complexity. Dimensionality was quantified in terms of Residual Variance, while the Relative Amplitude was introduced to account for individual differences in movement components. We observed that: experience-related modifications in multi-segmental actions exist, such as the progressive reduction of error-correction movements, especially in complex task condition. The systematic identification of motor patterns sensitive to the acquisition of specific experience could accelerate the learning process.     

Development and phonetic differentiation of speech movement patterns.

It is often hypothesized that speech production units are less distinctive in young children and that generalized movement primitives, or templates, serve as a base on which distinctive, mature templates are later elaborated. This hypothesis was examined by analyzing the shape and stability of single close-open speech movements of the lower lip recorded in 4-year-old, 7-year-old, and adult speakers during production of utterances that varied in only a single phoneme. To assess the presence of a generalized template, lower lip movement sequences were time and amplitude normalized, and a pattern recognition procedure was implemented. The findings indicate that speech movements of children already converged on phonetically distinctive patterns by 4 years of age. In contrast, an index of spatiotemporal stability demonstrated that the stability of underlying patterning of the movement sequence improves with maturation.     

Character movement and the representation of space during narrative comprehension

Traditional research on situation models has examined the accessibility of locations and objects during narrative experiences. These studies have described a ubiquitous gradient effect: Spatial locations and objects in reader focus are more accessible than locations farther from this focus, with accessibility decreasing as a function of distance. How might readers’ expectations about character movement, beyond information about spatial locations, additionally affect this accessibility gradient? In two experiments, we investigated whether reader expectations for character movement impact the accessibility of spatial information from memory. In Experiment 1, participants read stories that described characters moving in either a unidirectional or a random pattern through a learned environment. In Experiment 2, characters moved forward in a unidirectional way or backtracked through previously explored rooms. The results suggest that reader expectations for character movement can influence the accessibility of spatial information. Such expectations play a critical role in processes of narrative comprehension.     

Eye movement guidance in reading: the role of parafoveal letter and space information

The relation between parafoveal letter and space information in eye movement guidance during reading was investigated in 2 experiments. Contingent upon the reader's fixation, the type of parafoveal information available to the right of fixation was varied by (a) space information only, (b) space information with letter information added at some delay, or (c) letter and space information simultaneously. In addition, the onset of the relevant parafoveal information was delayed between 0 and 250 ms into the fixation. The time course of processing the 2 types of information (letters or spaces) differed, as did the nature of their impact on the eye movement record. Although both letter and space information influenced saccade length and initial landing positions within words, only letter information had an effect on fixation duration. In addition, fixation duration was affected only by information entering within the first 50 ms of the fixation, whereas saccade length was affected by information arriving at any time during the fixation. The results are consistent with a model of eye movement control in which 2 independent processes are operating in tandem to determine when and where to move the eyes during reading.     

Linguistic focus and memory: An eye movement study

We report an eyetracking study investigating the effects of linguistic focus on eye movements and memory during two readings of a text. Across two presentations of the text, a critical word either changed to a semantically related word or remained unchanged. Focus on the critical word was manipulated using context. Eye movements were monitored during reading, and there was a secondary task of detecting the word change. Results indicated that when a word changed, participants were more successful at detecting it when it was in focus. In the second display, there were more fixations and longer viewing times on a changed than on an unchanged word, but only when the critical word was in focus; eye movement data for changed and unchanged words did not differ when the word was not in focus. We suggest that linguistic focus leads to more detailed lexical semantic representations but not more effortful initial encoding of information.