Terry McMorris

University of Chichester, Chichester, England, United Kingdom

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Publications (38)71.52 Total impact

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    ABSTRACT: The aim of the present study was to develop a measure that determines the reasons for losing possession in professional soccer. Fifty five national soccer teams that took part in 2006 and 2010 World Cup games were selected for this study. The Losing Possession Observational Checklist for Soccer was developed and applied to games in these tournaments. The results of inter-rater and intra-rater reliabilities showed that the new checklist had good stability (Қ= .75) and objectivity (Қ= .75). In addition, the results of exploratory factor analyses showed that losing possession in soccer included skill execution and parameterization, skill under stress, and speed and timing problems that accounted for 77% of common variance. In conclusion, current findings demonstrated that losing possession in soccer is multidimensional in nature and consists of motor and cognitive factors on the basis of specialist and statistical confirmation.
  • Terry McMorris, Beverley J Hale
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    ABSTRACT: The primary purpose of this study was to examine, using meta-analytical techniques, the differential effects of differing intensities of acute exercise on speed and accuracy of cognition. Overall, exercise demonstrated a small, significant mean effect size (g=0.14, p<0.01) on cognition. Examination of the comparison between speed and accuracy dependent variables showed that speed accounted for most of the effect. For speed, moderate intensity exercise demonstrated a significantly larger mean effect size than those for low and high intensities. For speed of processing during moderate intensity exercise, central executive tasks showed a larger effect size than recall and alertness/attention tasks; and mean effect size for counterbalanced or randomized studies was significantly greater than for studies in which a pre-exercise followed by during or post-exercise protocol was used. There was no significant difference between mean effect sizes when testing took place post-exercise compared to during exercise for speed but accuracy studies demonstrated a significantly larger mean effect size post-exercise. It was concluded that increased arousal during moderate intensity exercise resulted in faster speed of processing. The very limited effect on accuracy may be due to the failure to choose tests which are complex enough to measure exercise-induced changes in accuracy of performance.
    Brain and Cognition 10/2012; 80(3):338-351. · 2.82 Impact Factor
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    ABSTRACT: The aim of the present study was to develop a measure that determines the reasons for losing possession in professional soccer. Fifty five national soccer teams that took part in 2006 and 2010 World Cup games were selected for this study. The Losing Possession Observational Checklist for Soccer was developed and applied to games in these tournaments. The results of inter-rater and intra-rater reliabilities showed that the new checklist had good stability (Қ= .75) and objectivity (Қ= .75). In addition, the results of exploratory factor analyses showed that losing possession in soccer included skill execution and parameterization, skill under stress, and speed and timing problems that accounted for 77% of common variance. In conclusion, current findings demonstrated that losing possession in soccer is multidimensional in nature and consists of motor and cognitive factors on the basis of specialist and statistical confirmation.
    · 0.54 Impact Factor
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    Mohsen Shafizadeh, Terry McMorris, John Sproule
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    ABSTRACT: The effect of different sources of external attentional focus on learning a motor skill was assessed in the present study. 30 students (12 men, 18 women) participated voluntarily and were divided, according to type of external focus, into target, club swing, and target-club swing groups. The task was a golf putting skill. The target focus group attended to the target (hole), the club swing focus group attended to the execution of the club's swing, and the target-club swing focus group attended to both. All participants performed 50 trials of the putting skill in the acquisition phase and 10 trials in the 24-hr. delayed retention phase. The dependent variable was the error in the putting skill measured as the distance from the hole to the ball after each strike. Results showed the target-club swing focus group had better scores in the acquisition and retention phases than the other groups. It was concluded that external focus instruction helped the learners to integrate target cue with action cue and is more effective in skill learning than other external-focus instructions. These results support the claims of ecological psychology theorists concerning the effects of external focus of attention.
    Perceptual and Motor Skills 10/2011; 113(2):662-70. · 0.49 Impact Factor
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    ABSTRACT: The purpose of this study was to compare, using meta-analytic techniques, the effect of acute, intermediate intensity exercise on the speed and accuracy of performance of working memory tasks. It was hypothesized that acute, intermediate intensity exercise would have a significant beneficial effect on response time and that effect sizes for response time and accuracy data would differ significantly. Random-effects meta-analysis showed a significant, beneficial effect size for response time, g=-1.41 (p<0.001) but a significant detrimental effect size, g=0.40 (p<0.01), for accuracy. There was a significant difference between effect sizes (Z(diff)=3.85, p<0.001). It was concluded that acute, intermediate intensity exercise has a strong beneficial effect on speed of response in working memory tasks but a low to moderate, detrimental one on accuracy. There was no support for a speed-accuracy trade-off. It was argued that exercise-induced increases in brain concentrations of catecholamines result in faster processing but increases in neural noise may negatively affect accuracy.
    Physiology & Behavior 03/2011; 102(3-4):421-8. · 3.16 Impact Factor
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    Terry Mcmorris, Turner, J Beverley, Ed D Hale, Sproule
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    ABSTRACT: The purpose of this review was to examine the evidence for an acute exercise-neuroendocrines-cognition interaction. Theoretically, exercise at the catecholamines thresholds initiates increased brain concentrations of catecholamines via activation of the vagus nerve. This should facilitate cognition. Exercise at the thresholds for > 30 mins and heavy exercise induce further catecholamines concentrations and increased brain concentrations of the hypothalamic-pituitary-adrenal axis (HPAA) hormones. This will induce neural noise and inhibition of cognition. Increased concentrations of brain derived neurotrophic factor (BDNF) may have a positive effect on cognition. Human and animal studies support increased brain turnover of catecholamines, HPAA hormones and BDNF following exercise. Empirical evidence shows increased peripheral concentrations of catecholamines and their metabolites in an exercise plus cognition condition: facilitation of cognition during moderate duration exercise at the thresholds: inhibition of cognition during long duration exercise at the thresholds: and equivocal results during heavy exercise. It was concluded that there is some evidence for an acute exercise-neuroendocrines-cognition interaction but more research is required particularly during heavy exercise.
    Physiology & Behavior 01/2011; · 3.16 Impact Factor
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    ABSTRACT: Expert performers in sports that include a high proportion of closed skills have often been found to score relatively high in field independence tests; a field-independent cognitive style may be advantageous for learning and performance of closed skills. The relationship between field dependence-independence (measured on a Portable Rod and Frame Test) and the acquisition of a kayak skill was examined. Undergraduates (6 men, 11 women; M age=21.6 yr., SD=3.2) who had no previous kayaking experience participated. Participants completed a structured teaching session (2 hr.) designed to develop three key subskills necessary for the kayak roll. Number of trials taken to consistently perform the underwater orientation and paddle movement subskills and duration of practice taken to develop the upper/lower body separation subskill as well as participants' ability to complete the roll were assessed. Field independence was associated with better performance of subskills and skill acquisition tests. Learners with greater field independence may have an advantage when acquiring sport skills that require cognitive restructuring and a strong reliance on kinesthetic and proprioceptive feedback.
    Perceptual and Motor Skills 04/2010; 110(2):479-87. · 0.49 Impact Factor
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    ABSTRACT: It was recently observed that dehydration causes shrinkage of brain tissue and an associated increase in ventricular volume. Negative effects of dehydration on cognitive performance have been shown in some but not all studies, and it has also been reported that an increased perceived effort may be required following dehydration. However, the effects of dehydration on brain function are unknown. We investigated this question using functional magnetic resonance imaging (fMRI) in 10 healthy adolescents (mean age = 16.8, five females). Each subject completed a thermal exercise protocol and nonthermal exercise control condition in a cross-over repeated measures design. Subjects lost more weight via perspiration in the thermal exercise versus the control condition (P < 0.0001), and lateral ventricle enlargement correlated with the reduction in body mass (r = 0.77, P = 0.01). Dehydration following the thermal exercise protocol led to a significantly stronger increase in fronto-parietal blood-oxygen-level-dependent (BOLD) response during an executive function task (Tower of London) than the control condition, whereas cerebral perfusion during rest was not affected. The increase in BOLD response after dehydration was not paralleled by a change in cognitive performance, suggesting an inefficient use of brain metabolic activity following dehydration. This pattern indicates that participants exerted a higher level of neuronal activity in order to achieve the same performance level. Given the limited availability of brain metabolic resources, these findings suggest that prolonged states of reduced water intake may adversely impact executive functions such as planning and visuo-spatial processing.
    Human Brain Mapping 03/2010; 32(1):71-9. · 6.88 Impact Factor
  • Stephen Draper, Terry McMorris, John K. Parker
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    ABSTRACT: Objective The purpose of the present study was to examine the effect of acute, short-duration exercise on the performance of simple and choice visual reaction and movement times.Method Following an incremental test to exhaustion to determine exercise intensities, 12 male participants completed simple and choice reaction tests on a cycle ergometer where both reaction time and movement time were measured, with each test being performed on a separate day. Tests were performed at rest, moderate, heavy and severe intensities.ResultFor reaction time, a 2-way (reaction time complexity × exercise intensity) repeated measures Analysis of Variance demonstrated a significant interaction effect (p = 0.02) and polynomial contrasts demonstrated a linear effect for choice reaction time (p < 0.05) (where choice reaction time decreased with increasing exercise intensity), but no significant effect for simple reaction time. For movement time, polynomial contrasts for exercise intensity showed a significant quadratic effect (p = 0.01) (with movement time fastest in the moderate to heavy domains). There was a significant main effect for complexity in both reaction (p < 0.001) and movement (p = 0.002) time.Conclusion The results of this study showed that simple and choice reaction times were affected differently by acute, short-duration exercise of differing intensities. The movement time data differ from previous research and show a quadratic effect rather than a linear one.
    Psychology of Sport and Exercise. 01/2010; 11(6):536-541.
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    Karen Davranche, Ben Hall, Terry McMorris
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    ABSTRACT: This study aimed to determine how cognitive control, engaged in a task requiring selective inhibition, is affected by acute steady-state exercise. An adapted version of the Eriksen flanker task, involving three types of trials that varied according to their level of congruency (congruent trials, stimulus-incongruent trials, and response-incongruent trials) was performed during 2 periods of 20-min cycling at a carefully controlled intensity (50% of maximal aerobic power). The results indicated that moderate exercise improves reaction time (RT) performance on the Eriksen flanker task. This facilitating effect appeared to be neither dependent on the nature of the interference (stimulus level conflict vs. response level conflict) nor on the amount of cognitive control engaged in the task (congruent vs. incongruent trials). Distributional RT analyses did not highlight any sign of impairment in the efficiency of cognitive control.
    Journal of sport & exercise psychology 10/2009; 31(5):628-39. · 2.45 Impact Factor
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    ABSTRACT: The purposes of this study were to examine the effect of acute incremental exercise on the performance of a central executive task; the responses of the sympathoadrenal system (SAS) and hypothalamic-pituitary-adrenal axis (HPAA) during exercise, while simultaneously carrying out the central executive task; and the ability of Delta plasma concentrations of epinephrine, norepinephrine, adrenocorticotropin hormone (ACTH) and cortisol to predict Delta performance on the central executive task. Subjects undertook a flanker task at rest and during exercise at 50% and 80% maximum aerobic power (MAP). SAS and HPAA activity were measured pre- and post-treatment by plasma concentrations of catecholamines, and cortisol and ACTH, respectively. Reaction time (RT) and number of errors for congruent and incongruent trials on the flanker task showed significant main effects with performance at 80% MAP higher than in the other conditions. RT post-correct responses were significantly faster than RT post-error at rest and 50% MAP but not at 80%. Pre- and post-treatment catecholamines showed a main effect of exercise with a linear increase. Post-treatment ACTH concentrations at 80% MAP were significantly greater than in the other conditions. Delta epinephrine and ACTH combined were significant predictors of Delta RT and Delta norepinephrine was a significant predictor of Delta number of errors. It was concluded that exercise must be at a high intensity to affect performance on the flanker task. Both the SAS and HPAA appear to play a role in the exercise-cognition interaction.
    International journal of psychophysiology: official journal of the International Organization of Psychophysiology 06/2009; 73(3):334-40. · 3.05 Impact Factor
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    ABSTRACT: Transit in high-speed marine craft subjects occupants to a rough ride as the boat impacts the waves. This induces high levels of physical stress, which may inhibit cognitive performance during military operations and life-saving activities. Land-based research suggests that suspension seats reduce vibration and, therefore, stress. We hypothesized that subjects using suspension seats would demonstrate better cognitive performance, lower perceptions of exertion, fatigue, and sleepiness, and lower salivary concentrations of cortisol than those using fixed seats. Subjects, naval personnel, were divided into fixed (N = 6) and suspension seat (N = 6) groups. Subjects undertook forward and backward number recall and random number generation tests pre- and post-transit (3 h in sea states 2-3). Salivary cortisol concentrations were sampled pre- (1100 h) and post-transit (1700 h) and at the same times on a control day. Post-transit perceptions of exertion, fatigue, and sleepiness were measured subjectively. The suspension seat group demonstrated better performance post-transit than the fixed seat group for forward number recall and showed a significant pre- to post-transit improvement in backward number recall. The suspension seat group reported less fatigue and sleepiness. The suspension seat group had significantly higher salivary cortisol concentrations than the fixed seat group post-transit. Regression analyses found a quadratic correlation between delta cortisol concentrations and delta random number generation scores (R2 = 0.68). Results show that the use of suspension seats during transit in high-speed marine craft may be advantageous with regard to cognitive performance.
    Aviation Space and Environmental Medicine 02/2009; 80(1):24-8. · 0.78 Impact Factor
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    Karen Davranche, Terry McMorris
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    ABSTRACT: The main issue of this study was to determine whether cognitive control is affected by acute moderate exercise. Twelve participants [4 females (VO(2 max)=42 ml/kg/min) and 8 males (VO(2 max) = 48 ml/kg/min)] performed a Simon task while cycling at a carefully controlled workload intensity corresponding to their individual ventilatory threshold. The distribution-analytical technique and the delta plot analysis [Ridderinkhof, K. R. (2002). Activation and suppression in conflict tasks: Empirical clarification through distributional analyses. In W. Prinz & B. Hommel (Eds.), Common mechanisms in perception and action. Attention and performance (Vol. 19, pp. 494-519). Oxford: Oxford University Press.] were used to assess the role of selective response inhibition in resolving response conflict. Results showed that cognitive processes appeared to be differently affected by acute moderate exercise. Reaction time results confirmed that performance is better (faster without change in accuracy) when the cognitive task is performed simultaneously with exercise. Between-trial adjustments (post-conflict and post-error) highlighted that cognitive control adjustments are also fully efficient during exercise. However, the effect of congruency (Simon effect) appeared to be more pronounced during exercise compared to rest which suggests that the response inhibition is deteriorated during exercise. The present findings suggest that acute moderate exercise differently affects some specific aspects of cognitive functions.
    Brain and Cognition 01/2009; 69(3):565-70. · 2.82 Impact Factor
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    ABSTRACT: This research aimed to investigate the time course effect of a moderate steady-state exercise session on response execution and response inhibition using a stop-task paradigm. Ten participants performed a stop-signal task whilst cycling at a carefully controlled workload intensity (40% of maximal aerobic power), immediately following exercise and 30 min after exercise cessation. Results showed that moderate exercise enhances a subjects’ ability to execute responses under time pressure (shorter Go reaction time, RT without a change in accuracy) but also enhances a subjects’ ability to withhold ongoing motor responses (shorter stop-signal RT). The present outcomes reveal that the beneficial effect of exercise is neither limited to motor response tasks, nor to cognitive tasks performed during exercise. Beneficial effects of exercise remain present on both response execution and response inhibition performance for up to 52 min after exercise cessation.
    Brain and Cognition 01/2009; · 2.82 Impact Factor
  • The British journal of Sports Medicine. 01/2009; 43(7):531-535.
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    ABSTRACT: To examine how different safety rope protocols impact on subjective anxiety and self-confidence levels and plasma cortisol concentrations and the relationship between subjective states and cortisol during rock climbing. Participants (n = 12) were tested in three climbing conditions that were designed to invoke low, moderate and high physical and mental stress. Plasma cortisol concentrations were collected before and after climbing and participants reported subjective anxiety and self-confidence states for each climb. Repeated measures analysis of variance showed significant differences between conditions for somatic anxiety (F(2, 22) = 7.74, p = 0.009), self-confidence (F(2, 22) = 9.52, p = 0.001) and change in plasma cortisol concentration (F(2, 22) = 3.71, p = 0.041). Preplanned polynomial comparisons showed that these were linear effects; somatic anxiety was higher in the higher stress conditions whilst self-confidence was lower. Plasma cortisol concentration change was also linear. Regression analyses showed cubic relationships between plasma cortisol concentration and cognitive anxiety (R(2) = 0.452), self-confidence (R(2) = 0.281) and somatic anxiety (R(2) = 0.268). There is a relationship between plasma cortisol concentration and subjective anxiety and self-confidence states during rock climbing. Changes in the way the safety rope is organised can impact on anxiety, cortisol concentration and self-confidence during rock climbing.
    British journal of sports medicine 05/2008; 43(7):531-5. · 3.67 Impact Factor
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    ABSTRACT: The purpose of the study was to examine the usage of norepinephrine (NE) and dopamine (DA) in the brain when exercising while simultaneously undertaking cognitive tests. Plasma concentrations of the NE metabolite 3-methoxy 4-hydroxyphenylglycol (MHPG) and the DA metabolite homovanillic acid (HVA) showed a linear increase from rest to exercising at 40% and 80% maximum power output (W.max) while simultaneously undertaking cognitive tasks (random number generation (RNG) and response time). Delta plasma concentrations of MHPG and HVA at each exercise intensity while undertaking cognitive tasks and while exercising without cognitive tasks did not differ. Taking blood samples at 0, 1, 3, and 5 min following cessation of exercise did not affect results. Regression correlations showed that delta MHPG and HVA plasma concentrations at the 1 and 3 min sampling times were strong predictors of delta RNG, response time and movement time. Reaction time at 80% W.max significantly increased, while movement time at 80% W.max significantly decreased. It was concluded that these results provide no support for a direct effect of increased catecholamines concentrations on cognitive performance during exercise. The regression data suggest that there is some relationship between exercise, catecholamines concentrations and cognition.
    Pharmacology Biochemistry and Behavior 04/2008; 89(1):106-15. · 2.61 Impact Factor
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    ABSTRACT: Dehydration can affect brain structure which has important implications for human health. In this study, we measured regional changes in brain structure following acute dehydration. Healthy volunteers received a structural MRI scan before and after an intensive 90-min thermal-exercise dehydration protocol. We used two techniques to determine changes in brain structure: a manual point counting technique using MEASURE, and a fully automated voxelwise analysis using SIENA. After the exercise regime, participants lost (2.2% +/- 0.5%) of their body mass. Using SIENA, we detected expansion of the ventricular system with the largest change occurring in the left lateral ventricle (P = 0.001 corrected for multiple comparisons) but no change in total brain volume (P = 0.13). Using manual point counting, we could not detect any change in ventricular or brain volume, but there was a significant correlation between loss in body mass and third ventricular volume increase (r = 0.79, P = 0.03). These results show ventricular expansion occurs following acute dehydration, and suggest that automated longitudinal voxelwise analysis methods such as SIENA are more sensitive to regional changes in brain volume over time compared with a manual point counting technique.
    Human Brain Mapping 01/2008; 30(1):291-8. · 6.88 Impact Factor
  • Terry McMorris, Tom Rayment
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    ABSTRACT: The purpose of this study was to examine the effect of one bout and three intermittent bouts of short-duration, high-intensity running on the performance of a sports-specific psychomotor skill. Participants (N=13) were male soccer players (M age 20.5 yr., SD=2.0) who had been playing semi-professionally for M=2.1 years, SD=1.11 and trained twice a week. They undertook a soccer-passing test in three conditions: following rest, following a 100-m sprint and following 3 x 100-m sprints, with 30-sec. rest intervals between sprints. Passing accuracy showed a significant linear deterioration, while number of passes showed a significant quadratic effect. Low to moderate linear regression correlations were found between posttest heart rate and absolute and variable errors on the test. It was concluded that short-duration, high-intensity exercise has a negative effect on accuracy in a sports-specific task that requires both perceptual judgment and motor control.
    Perceptual and Motor Skills 11/2007; 105(2):523-30. · 0.49 Impact Factor
  • 47th Annual Meeting of Society for Psychophysiological Research (SPR), Savannah, GA, USA; 10/2007

Publication Stats

429 Citations
71.52 Total Impact Points

Institutions

  • 2000–2012
    • University of Chichester
      Chichester, England, United Kingdom
  • 2007–2011
    • The University of Edinburgh
      • Institute for Sport, Physical Education and Health Sciences
      Edinburgh, SCT, United Kingdom
  • 1996–1999
    • Markfield Institute of Higher Education
      Markfield, England, United Kingdom