Neurophysiological evidence of how quiet eye supports motor performance

Prolonged quiet eye (QE) duration is associated with greater performance in various types of targeting and interceptive tasks. However, the mechanism by which QE affects performance remains debatable. This study aimed to test the validity of the pre-programming and online control hypotheses using electromyography (EMG), electrooculography (EOG) and electroencephalography (EEG) during a golf putting task. Twenty-one college students were recruited for this study. Each participant performed 100 golf putting trials during which the putting performance, EMG, EOG, and EEG signals were recorded. The QE duration including the pre- and post-movement initiation components, and movement-related cortical potentials (MRCPs) were analyzed off-line. We found that successful putts were associated with longer QEtotal (the total QE duration from QE onset to QE offset), QEpre (QE occurring before movement initiation), and QEpost (QE occurring after movement initiation) durations than failed putts. Greater cortical activation in the MRCPs was observed within the prefrontal, premotor, and parietal cortices during successful putts compared with failed putts. These findings suggest that QE serves both pre-programming and online control roles in supporting golf putting performance.

     

Effects of concurrent arithmetical and syntactic complexity on self-paced reaction times and eye fixations

Two dual-task experiments (replications of Experiments 1 and 2 in Fedorenko, Gibson, & Rohde, Journal of Memory and Language, 56, 246–269 2007) were conducted to determine whether syntactic and arithmetical operations share working memory resources. Subjects read object- or subject-extracted relative clause sentences phrase by phrase in a self-paced task while simultaneously adding or subtracting numbers. Experiment 2 measured eye fixations as well as self-paced reaction times. In both experiments, there were main effects of syntax and of mathematical operation on self-paced reading times, but no interaction of the two. In the Experiment 2 eye-tracking results, there were main effects of syntax on first-pass reading time and total reading time and an interaction between syntax and math in total reading time on the noun phrase within the relative clause. The findings point to differences in the ways individuals process sentences under these dual-task conditions, as compared with viewing sentences during “normal” reading conditions, and do not support the view that arithmetical and syntactic integration operations share a working memory system.     

Quiet eye and the Bereitschaftspotential: visuomotor mechanisms of expert motor performance

Concurrent exploration of the Bereitschaftspotential (BP) and quiet eye period (QE) was implemented to assess potential mechanisms underlying psychomotor skills that differentiate expert and near-expert performers. Twenty golfers were classified by their USGA handicap rating as either a high handicap (HH; near-expert) or low handicap (LH; expert) to permit skill-based inferences. Participants completed 90 trials during which QE duration, BP activity, and putting performance were recorded. The application of single-subject analyses illustrated that LH golfers were more accurate and less variable in their performance than the HH group. Systematic differences in QE duration and BP were also observed, with experts exhibiting a prolonged quiet eye period and greater cortical activation in the right-central region compared with non-experts. A significant association between cortical activation and QE duration was also noted. The results of this investigation lend support to the motor programming/preparation function of the QE period. Practical and theoretical implications are presented and suggestions for future empirical work provided.     

Effects of eye color on frisbee toss

Light-eyed individuals generally perform better at self-paced activities while dark-eyed individuals perform better at reactive activities. Using multiple regression it was found that dark-eyed students hit a target with a frisbee more times than did light-eyed students.     

Effects of gender and competitive coaction on motor performance.

The purpose of this study was to assess the relations between competitive, cooperative, and noncompetitive coaction on the pursuit rotor performance of 108 male and female university students. Analysis indicated that men compared with women had the higher performance scores, regardless of the induced situation. In particular, the competitive men's performance indicated the greatest facilitation in a coaction situation.     

Effects of eye color and sex on accuracy in archery

126 subjects were 47 children in Grade 7, 49 students in Grade 8, and 30 adults, who shot arrows at bull's-eye targets from varying distances. Analysis of variance of accuracy scores indicated that there was no difference for eye color, but boys scored more points than did girls.     

Inferred goals in narratives: evidence from self-paced reading,recall, and eye movements

Three convergent methodologies were used to investigate the generation and reinstatement of goals not explicitly stated in a text. Readers read paragraphs adapted from J. S. Huitema, S. Dopkins, C. M. Klin, & J. L. Myers's (1993) study, which conveyed a character's goal early in the text. The goal was either stated explicitly or implied. An event was described later in the text that was either consistent or inconsistent with the goal. Line-by-line reading data, recall for the narratives, and eye-movement data were collected. Evidence is presented that readers infer a character's goal online at the time the information is presented, and the inferred goal functions like an explicitly stated goal in online comprehension processes and in the resulting memory representation.     

Use of verb information in syntactic parsing: evidence from eye movements and word-by-word self-paced reading

We investigated whether readers use verb information to aid in their initial parsing of temporarily ambiguous sentences. In the first experiment, subjects' eye movements were recorded. In the second and third experiments, subjects read sentences by using a noncumulative and cumulative word-by-word self-paced paradigm, respectively. The results of the first two experiments supported Frazier and Rayner's (1982) garden-path model of sentence comprehension: Verb information did not influence the initial operation of the parser. The third experiment indicated that the cumulative version of the self-paced paradigm is not appropriate for studying on-line parsing. We conclude that verb information is not used by the parser to modify its initial parsing strategies, although it may be used to guide subsequent reanalysis.     

Effect of caffeine on motor performance by caffeine-naive and -familiar subjects.

The purpose of this investigation was to assess the effect of caffeine on selected manipulation skills by caffeine-naive and caffeine-familiar subjects. The subjects were 20 caffeine-naive (less than 90 mg/d) and 20 caffeine-familiar (greater than 750 mg/d) college-age (21 +/- 1.7 yr.) women. Measurements included steadiness error time and frequency, duration of tracing, error time and frequency, and dexterity. Doses of 2.5, 5.0 mg.kg-1 body weight caffeine or a placebo (200 mg. methylcellulose) were administered randomly to all subjects on three separate occasions. A 2 x 3 repeated-measures analysis of variance yielded a significant group difference for steadiness error time between the 5 mg.kg-1 and 2.5 mg.kg-1 dose and between 5 mg.kg-1 and the placebo. For frequency of steadiness errors, the nonuser group posted significant gains for both 5.0 and 2.5 mg.kg-1 over the placebo control. On tracing error time and error frequency, 5.0 mg.kg-1 resulted in significant increases from both 2.5 mg.kg-1 and the placebo group. In the caffeine-naive group, both doses of caffeine led to significant increases in dexterity time from the placebo, and the 5.0 mg.kg-1 dose was significantly different from the 2.5 mg.kg-1 trial. It was concluded that caffeine had detrimental effects on selected performance skills of caffeine-naive women but not in caffeine-familiar women.     

Contextual strength does not modulate the subordinate bias effect: Evidence from eye fixations and self-paced reading

Eye movements were recorded in order to examine how different sources of information—namely, meaning dominance and strength of biasing context—influence the processing of biased ambiguous words. Gaze durations were longer on ambiguous target words when the preceding context instantiated the subordinate interpretation, even with strongly biasing contexts. Identical results were obtained with a self-paced reading study. Thus, contrary to recent findings (Kellas, Martin, Yehling, Herman, & Vu, 1995), the subordinate interpretation of a biased ambiguous word was not selectively accessed even when the preceding context strongly biased that interpretation. Discrepancies between the present experiments and the Kellas et al. experiment are discussed.     

Sensorimotor performance as a function of eye dominance and handedness.

Performance on a speeded target striking task was significantly associated with eye dominance and handedness for a sample of 30 subjects. They showed the expected higher performance with the dominant hand but also showed an effect of eye of input. Highest performance was obtained with binocular viewing, next best used the dominant eye, and poorest performance the nondominant eye. Effects were additive with no interaction between hand and eye dominance.     

Introspective duration estimation of reactive and proactive motor responses

The metajudgment of motor responses refers to our ability to evaluate the accuracy of our own actions. Can humans metajudge the duration of their Reaction Times (RTs) to a light-flash and the accuracy of their reproduction of a reference time interval bounded by two light flashes (Anticipatory Response Time, ART)? A series of four distinct experiments shows that RT_Meta and ART_Metajudgments are possible but with accuracies about ×2.4 and ×3 poorer than the corresponding RT and ART ones. In order to reveal the origin of this drop in performance, we ask whether a visual feedback synchronous with subjects’ key-presses could improve performance. We show that overall the presence of a visual feedback does not significantly improve metajudgment accuracy although such a trend is noticeable in ART_Meta. We then compare these performances with the passive perceptual estimation of the played back (Pb) RT and ART time intervals when bounded by two (RT_Pb) and three (ART_Pb) light flashes. We show that RT_Meta and RT_Pb accuracies are close to equal, but that ART_Meta is about ×2 less accurate than ART_Pb which in turn is ×1.5 less accurate than ART. The latter observation fails however to reach statistical significance hence not sustaining proposals that active time estimation is more reliable than passive one. The whole dataset is accounted for by a clock-type model where duration estimation performance is limited by four noise sources (visual, clock-count, motor and proprioceptive + efference copy) plus one proper to ART_Meta task. It is proposed that the latter reflects the impossibility for the time-counting system to use the same time origin more than once.     

Limb apraxia and motor performance

This study was desinged to determine if motor deficits in limb apraxia are task specific. Non-brain-damaged patients and apraxic and nonapraxic patients with left hemisphere damage performed language and limb apraxia tests and six motor tasks with the left hand. Contrary to previous data, no significant group differences occurred on a finger tapping task. Although task complexity or sequencing requirements affected group differences, greatest apraxic impairment was noted on a task of precise steadiness, but only when its response inhibition requirements were increased. This pattern of deficits appears to be associated with greater involvement of the premotor area in the apraxic group.     

Flow state in self-paced and externally-paced performance contexts: An examination of the flow model

ObjectivesKimiecik and Stein's (1992) flow model proposed that personal and situational factors affect the experience of flow. Singer, 1988, Singer, 2000 argued that different mental processes underlie self-initiated and reactive performances. The first purpose of this study was to examine main and interaction effects between imagery use and confidence on flow state in different performance contexts. The second purpose was to assess main and interaction effects between flow state, imagery, and confidence on self-paced service and externally-paced groundstroke performance in tennis.DesignThis field study used a repeated-measures design.MethodA pilot study was conducted to inform the set up of the two performance contexts. Flow states were assessed on two separate occasions, (a) for the service performance, and (b) for the groundstroke performance. A total of 60 junior tennis athletes completed imagery and confidence measures before the field test.ResultsA significant interaction between imagery and confidence was found for flow state in the groundstroke but not in the service task. No significant interaction effects were found for performance outcome. Flow state significantly predicted groundstroke performance, and imagery and confidence predicted service performance.ConclusionsThe examination of flow in different performance contexts is challenging. Imagery and confidence are central to the experience of flow. Flow state appeared to be more important for the externally-paced than self-paced task. The relationship between flow and performance is complex, which requires the conceptual expansion of Kimiecik and Stein's (1992) flow model.     

Psychometric schizotypy and motor performance

Motor abnormalities have long been a focus in discussions of schizophrenia. The present study used a newly developed line drawing task to examine fine motor performance and psychometrically assessed schizotypy in a large, randomly ascertained sample of young adults (N = 120) with no history of psychosis. Poor motor performance on the line drawing task, indexed by root-mean-square error (RMS), was significantly related to 4 separate psychometric measures of schizotypy in the overall sample. The psychometric schizotypy-RMS association remained significant for 2 of the schizotypy measures even when the effects of intellectual functioning, mental state factors, and sustained attention were statistically controlled in a regression analysis. The status of the line drawing index as a schizophrenia liability measure is discussed.     

Relationship of eye color to winning horseshoe pitching contests

Light-eyed individuals perform some self-paced activities better while dark-eyed individuals perform reactive activities better. In horseshoe pitching contests there were, however, no differences on winning or losing between 21 light- and 25 dark-eyed men at a county fair.     

Real and subjective contour Poggendorff illusions: no differences based on eye color

Measures of illusion magnitude for a real contour and two subjective contour Poggendorff figures were obtained from a large number of dark-eyed and light-eyed undergraduates. Illusion magnitude varied as a function of figure type. However, eye color neither had a significant overall effect on illusion magnitude, nor did it interact with the figure-type variable. These data indicate that the presence of intersecting lines is not the basis of the iris-pigmentation effect reported by Coren and Porac.     

Facilitatory and inhibitory effects of masked prime stimuli on motor activation and behavioural performance.

Three experiments investigated the impact of information provided by masked stimuli on motor activation. Masked primes were presented prior to target stimuli and these primes were identical to the target on compatible trials, identical to the target mapped to the opposite response on incompatible trials and task-irrelevant on neutral trials. A previous study [Eimer, M., & Schlaghecken, F. (1998). Effects of masked stimuli on motor activation: Behavioural and electrophysiological evidence. Journal of Experimental Psychology: Human Perception and Performance, 24, 1737-1747] found performance costs for compatible trials and benefits for incompatible trials. Experiment 1 showed that these effects are not due to 'perceptual repetition blindness'. Experiments 2 and 3 obtained evidence for an initial response facilitation triggered by the primes that was followed by inhibition. With short intervals between prime presentation and response execution, performance benefits were found for compatible trials and these turned into costs at longer intervals. It is argued that an early response facilitation mediated by direct perceptuo-motor links is subsequently inhibited by a central mechanism operating to prevent behaviour from being controlled by irrelevant information.