Eye movement and the Pulfrich effect

Thresholds for the identification of test lines were elevated when their orientation matched that of adapting lines. This proved to be true when the adapting field was moving or stationary. These results are discussed in relation to the conception of orientation-specific detectors postulated by Hubel and Wiesel.     

Movement prediction and movement production

The prediction of future positions of moving objects occurs in cases of actively produced and passively observed movement. Additionally, the moving object may or may not be tracked with the eyes. The authors studied the difference between active and passive movement prediction by asking observers to estimate displacements of an occluded moving target, where the movement was driven by the observer's manual action or was passively observed. In the absence of eye tracking, they found that in the active condition, estimates are more anticipatory than in the passive conditions. Decreasing the congruence between motor action and visual feedback diminished but did not eliminate the anticipatory effect of action. When the target was tracked with the eyes, the effect of manual action disappeared. Results indicate distinct contributions of hand and eye movement signals to the prediction of trajectories of moving objects.     

The influence of action video game playing on eye movement behaviour during visual search in abstract,in-game and natural scenes

Action game playing has been associated with several improvements in visual attention tasks. However, it is not clear how such changes might influence the way we overtly select information from our visual world (i.e. eye movements). We examined whether action-video-game training changed eye movement behaviour in a series of visual search tasks including conjunctive search (relatively abstracted from natural behaviour), game-related search, and more naturalistic scene search. Forty nongamers were trained in either an action first-person shooter game or a card game (control) for 10 hours. As a further control, we recorded eye movements of 20 experienced action gamers on the same tasks. The results did not show any change in duration of fixations or saccade amplitude either from before to after the training or between all nongamers (pretraining) and experienced action gamers. However, we observed a change in search strategy, reflected by a reduction in the vertical distribution of fixations for the game-related search task in the action-game-trained group. This might suggest learning the likely distribution of targets. In other words, game training only skilled participants to search game images for targets important to the game, with no indication of transfer to the more natural scene search. Taken together, these results suggest no modification in overt allocation of attention. Either the skills that can be trained with action gaming are not powerful enough to influence information selection through eye movements, or action-game-learned skills are not used when deciding where to move the eyes.     

Eye movement research on the propositional structure of short texts

The present paper describes the application of computer-based programs to the evaluation of eye movements during reading of short texts. These programs operate in background, that is, after an experimental session is completed and the raw data are collected on magnetic tape. The first program reduces the raw data into a sequence of fixation locations and durations, eye movements, and eye blinks. A second program utilizes calibration coordinates and line-of-text information to transform the reduced data into a standard grid format. Fixation order, locations, and durations for each line of text read are output with respect to the line of text. The final program summarizes fixation locations, frequencies, and durations with respect to analyses of the texts into levels within a hierarchy of propositions in the text base (Kintsch, 1974).     

Eye fixations in prediction of recognition and recall

Eye fixations were recorded at viewing of picture-label stimuli presented under either recall or recognition instructions; both retention tests were administered. Ss performed substantially better on the retention test of which they were informed, indicating differential encoding of the same stimuli in anticipation of test type. There was no correlation between recognition and recall of items, evidence that different information from the encoded stimuli was utilized in performing each test. Encoding strategies had no effect on how Ss regarded the stimuli, but viewing patterns were related to memory performance: More word fixations was associated with better verbal recall, while fewer picture fixations was associated with better recall and with better picture recognition.     

Information entropy and the variability of space-time movement error

The authors investigated the effects of movement time and movement distance on the information entropy and variability of spatial and temporal error in a discrete aiming movement. In Experiment 1, the authors held movement distance (100 mm) constant and manipulated 11 movement times (300-800 ms) of 8 participants. In Experiment 2, the authors tested 6 movement distances at 2 given movement times (15-60 mm at 300 ms; 40-240 mm at 800 ms) in 8 participants. The variability and entropy for spatial error increased with average movement velocity, whereas the variability and entropy for temporal error decreased as a function of average movement velocity. The common variance between variable error and entropy averaged about 84% and 72% for spatial and temporal errors, respectively, suggesting that the probabilistic approach of entropy reveals features that are not present in the standard deviation index of variability. The findings provide further evidence that information entropy may be a useful single-index representation of variability in the movement speed-accuracy relation.     

Eye movement Responses of Repressors and Sensitizers to a stressful film

Groups scoring high, intermediate or low on the Byrne R-S Scale viewed an industrial accident film while horizontal eye movements were assessed by means of infrared corneal reflection. Neutral and stressful film segments were scored in terms of deviations from the center of the perceptual field (point of looking scores), and the standard deviations of these scores were calculated as an index of perceptual scanning. A stressful segment was also dichotically scored as to whether the point of looking was on or off dominant elements of the scene. Results indicated that Repressors and Sensitizers had equivalent levels of perceptual scanning (and both significantly higher than Intermediates' level) independent of film segment content, but that they differed in on/off and average point of looking for the stressful segment such that Repressors were avoiding stressful content. These data suggest that relatively high perceptual scanning can be an avoidant defensive style of attending to dynamic stimulus displays. The issue of adaptiveness of responding is considered.     

Eye movement desensitization and reprocessing (EMDR): An overview

Eye movement desensitization and reprocessing (EMDR) is a recently developed psychotherapy procedure which has been reported to dramatically increase efficiency in the treatment of psychological disturbances rooted in traumatic memories. Following a review of the research on EMDR's efficacy, clinical considerations are addressed, including the client's experience and the potential for negative effects or treatment failure. Finally, the role of EMDR in clinical practice is discussed. Initial reports are encouraging, and further research is recommended. Clinicians who choose to use EMDR are urged to obtain formal training.     

The influence of proximal motor strategies on pianists' upper-limb movement variability

Repetitive movements are considered a risk factor for developing practice-related musculoskeletal disorders. Intra-participant kinematic variability might help musicians reduce the risk of injury during repetitive tasks. No research has studied the effects of proximal motion (i.e., trunk and shoulder movement) on upper-limb movement variability in pianists. The first objective was to determine the effect of proximal movement strategies and performance tempo on both intra-participant joint angle variability of upper-limb joints and endpoint variability. The second objective was to compare joint angle variability between pianist's upper-limb joints. As secondary objectives, we assessed the relationship between intra-participant joint angle variability and task range of motion (ROM) and documented inter-participant joint angle variability. The upper body kinematics of 9 expert pianists were recorded using an optoelectronic system. Participants continuously performed two right-hand chords (lateral leap motions) while changing movements based on trunk motion (with and without) and shoulder motion (counter-clockwise, back-and-forth, and clockwise) at two tempi (slow and fast). Trunk and shoulder movement strategies collectively influenced variability at the shoulder, elbow and, to a lesser extent, the wrist. Slow tempi led to greater variability at wrist and elbow flexion/extension compared to fast tempi. Endpoint variability was influenced only along the anteroposterior axis. When the trunk was static, the shoulder had the lowest joint angle variability. When trunk motion was used, elbow and shoulder variability increased, and became comparable to wrist variability. ROM was correlated with intra-participant joint angle variability, suggesting that increased task ROM might result in increased movement variability during practice. Inter-participant variability was approximately six times greater than intra-participant variability. Pianists should consider incorporating trunk motion and a variety of shoulder movements as performance strategies while performing leap motions at the piano, as they might reduce exposure to risks of injury.     

Eye movement correlates of younger and older adults' strategies for complex addition

This study examined performance measures and eye movements associated with complex arithmetic strategies in young and older adults. Participants added pairs of three-digit numbers using two different strategies, under choice and no-choice conditions. Older adults made more errors but were not significantly slower than young adults, and response times and errors showed no interaction between age and the number of carries. Older adults chose strategies less adaptively than young adults. Eye movements were consistent with use of required strategies on no-choice trials and reported strategies on choice trials. Eye movement data also suggested that young adults more successfully distinguished between strategies. Implications of these findings for understanding aging effects in complex arithmetic are discussed.     

Focus on variability: New tools to study intra-individual variability in developmental data

In accordance with dynamic systems theory, we assume that variability is an important developmental phenomenon. However, the standard methodological toolkit of the developmental psychologist offers few instruments for the study of variability. In this article we will present several new methods that are especially useful for visualizing and describing intra-individual variability in individual time-serial data of repeated observations. In order to illustrate these methods, we apply them to data of early language development. After reviewing the common techniques and measures, we present new methods that show variability in developmental time-series data: the moving min–max graph, and the progmax–regmin graph. In addition, we demonstrate a technique that is able to detect sudden increases of variability: the critical frequency method. Also, we propose a technique that is based on a central assumption of the measurement-error-hypothesis: namely the symmetric distribution of error. Finally, as traditional statistical techniques have little to offer in testing variability hypotheses, we examine the possibilities that are provided by random sampling techniques. Our aim with the present discussion of variability and the demonstration of some simple yet illustrative techniques is to help researchers focus on rich additional sources of information that will lead to more interesting hypotheses and more powerful testing procedures, adapted to the unique nature of developmental data.     

Eye movement control in reading and visual search: Effects of word frequency

Eye movements were recorded as subjects either read text or searched through texts for a target word. In the reading task, there was a robust word frequency effect wherein readers looked longer at low-frequency words than at high-frequency words. However, there was no frequency effect in the search task. The results suggest that decisions to move the eyes during reading are made on a different basis than they are during visual search. Implications for current models of eye movement control in reading are discussed.     

Eye movement control during reading: Effects of word frequency and orthographic familiarity

Word frequency and orthographic familiarity were independently manipulated as readers' eye movements were recorded. Word frequency influenced fixation durations and the probability of word skipping when orthographic familiarity was controlled. These results indicate that lexical processing of words can influence saccade programming (as shown by fixation durations and which words are fixated). Orthographic familiarity, but not word frequency, influenced the duration of prior fixations. These results provide evidence for orthographic, but not lexical, parafoveal-on-foveal effects. Overall, the findings have a crucial implication for models of eye movement control in reading: There must be sufficient time for lexical factors to influence saccade programming before saccade metrics and timing are finalized. The conclusions are critical for the fundamental architecture of models of eye movement control in reading -- namely, how to reconcile long saccade programming times and complex linguistic influences on saccades during reading.     

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.     

Eye gaze metrics reflect a shared motor representation for action observation and movement imagery

Action observation (AO) and movement imagery (MI) have been reported to share similar neural networks. This study investigated the congruency between AO and MI using the eye gaze metrics, dwell time and fixation number. A simple reach-grasp-place arm movement was observed and, in a second condition, imagined where the movement was presented from the first person perspective (1PP) and the third person perspective (3PP). Dwell time and number of fixations were calculated for whole scene and regions of interest (ROIs). For whole scene, no significant differences were found in the number of fixations for condition (AO, MI) or perspective. Dwell time, however, was significantly longer in AO than MI. For ROIs, the number of fixations was significantly greater in 1PP than 3PP. The data provide support for congruence between motor simulation states but also indicate some functional differences.     

Eye movements drive steering: reduced eye movement distribution impairs steering and driving performance

On a winding open road, a driver consistently looks to the inside of each bend before turning the steering wheel. When researchers disrupt this coordination by instructing drivers not to move their eyes, drivers' performance is impaired and their completion time during racing increases. The present authors examined whether changing internal states in a way that also restricts eye movements reduces coordination and affects performance. Participants (N = 24) completed a simulated rally stage under manipulation of their anxiety state through ego threat. Performance decreased under pressure, and the decrement was associated with a narrowing of the range of eye movements and a reduced correlation of eye movements with steering. The authors discuss the possibility that the deterioration in performance is a cost of maintaining steering when eye-movement driving input to the steering controller is reduced.     

Spatial and temporal variability of movement parameters in individuals with Down syndrome

This investigation compared spatial and temporal gait movement parameters of a sample of individuals with Down syndrome (n=12) and one of individuals without disabilities (n=12). All participants were evaluated on responses to a preferred pace and fast walk with the GAITRite Electronic Walkway. Spatial outcomes included step and stride length, step and stride width, toe-in/toe-out, and base of support. Temporal outcomes included step time, velocity, single and double leg support time, stance, and swing time. There were significant group differences for step length, step width, stride length, and velocity in the preferred walk condition. Significant group differences for step length, step width, and stride length were observed in the fast walk condition. Percentage differences also indicated lower scores for all spatial and temporal variables in relation to the control group. The ability to control gait movements appears to reflect earlier movement experiences, so it may be possible to use variable sensory feedback and specific training to modify and adjust movement responses and improve gait performance in Down syndrome.     

Eye movement desensitization and reprocessing for mental health problems: a systematic review and meta-analysis

ABSTRACT

There is no comprehensive meta-analysis of randomised trials examining the effects of Eye Movement Desensitization and Reprocessing (EMDR) on post-traumatic stress disorder (PTSD) and no systematic review at all of the effects of EMDR on other mental health problems. We conducted a systematic review and meta-analysis of 76 trials. Most trials examined the effects on PTSD (62%). The effect size of EMDR compared to control conditions was g = 0.93 (95% CI: 0.67–.18), with high heterogeneity (I²= 72%). Only four of 27 studies had low risk of bias, and there were indications for publication bias. EMDR was more effective than other therapies (g = 0.36; 95% CI: 0.14–0.57), but not in studies with low risk of bias. Significant results were also found for EMDR in phobias and test anxiety, but the number of studies was small and risk of bias was high. EMDR was examined in several other mental health problems, but for none of these problems, sufficient studies were available to pool outcomes. EMDR may be effective in the treatment of PTSD in the short term, but the quality of studies is too low to draw definite conclusions. There is not enough evidence to advise it for the use in other mental health problems.