Inspection Time (IT) is a speed measure that has been primarily investigated in the field of individual differences. However, Nettelbeck and Wilson (2004) proposed that IT could have promise as a biomarker for functional outcomes, particularly cognitive aging. The premise behind biomarker research is that chronological age is simply a proxy for the physiological and cognitive changes that occur in the body with advancing age. Biomarkers are measures that 'mark' the aging process and represent the biological age of an individual rather than the years since his/her birth. Speed of processing tasks offer promise as biomarkers because decline in speed of processing is one of the most robust findings in cognitive aging research. However, traditionally used tasks are problematic because they confound speed and accuracy and some are sensitive to cohort effects. Inspection time is a speed of processing measure that is free from these problems and is therefore a promising candidate for a biomarker. This dissertation presents the first empirical investigation of this proposition. One hundred and fifty elderly participants were assessed on IT, traditionally used biomarkers (e.g. grip strength, visual acuity), a battery of cognitive tasks (e.g. fluid ability and crystallised ability) and measures of everyday functioning (e.g. activities of daily living). These individuals were assessed on three separate occasions over a period of 18-months. For the biomarkers, initial scores, 6-month change scores and 18-month change scores were generated and used to predict final scores and 18-month change scores on the functional outcomes (cognition and everyday functioning). Results revealed that slow IT at the start of the study was associated with dependence in activities of daily living and poorer fluid ability at the end of the study. There was also evidence that slow IT at the start was associated with decline in fluid reasoning over the subsequent 18-months. Moreover, consistent with the major aims of this study, decline in IT over time was associated with more cognitive problems in daily life and poor fluid ability at the end of the study. Given that initial and change scores for IT were independent, due to the methodology used to estimate them, the two measures explained unique variance in the functional outcome measures.These findings are extremely encouraging, particularly given the relatively short time frame for this study. IT has predictive validity for everyday functioning and cognitive aging over an 18-month period, and therefore, it is concluded that IT has promise as a valid biomarker for functional age. Recommendations for further research include investigating the link between IT and mortality, examining the association between IT and a broader range of functional age measures, the replication of these findings in a different sample, and means for improving the sensitivity and specificity of the current IT estimation procedure. / Thesis (Ph.D.) -- University of Adelaide, School of Psychology, 2006.

Recent research has highlighted that information-movement couplings are unique to the constraints of the task, environment and performer. This recent research implies that skills should be developed in practice environments that are reflective of those found in competition. Representative environments should also allow the performer to attune to specifying information essential for success of a skill. However, in water polo, shooting practice is often conducted without the presence of a goalkeeper or defender. The aim of this study was to determine the effect of game-specific task constraints on the ball speed, accuracy and technique of the water polo shot. Ten male competitive level water polo players performed a total of forty shots comprising ten shots in each of four conditions from the 4m-penalty line. Conditions included all combinations of goalkeeper and defender (absent or present). Three Sony mini-digital cameras (50Hz) were placed perpendicular to the movement, giving rear, overhead and a right sagittal view. Ball speed was measured using a Radar-gun (Stalker Pro, USA). For each condition, means and standard deviations were determined for all outcome measures (shooting accuracy and ball speed) and technique variables. A repeated measures ANOVA was used to determine the effect (p<0.05) of the goalkeeper and defender individually as well as in combination on the dependent variables. Cohen's effect sizes were also used to determine the magnitude of the difference between conditions. The presence of a defender resulted in a significant increase in lateral trunk flexion at ball release, decreased the duration of the shot and selected swing sub-phases (i.e. pick-up to top of back swing time) and significantly altered the placement of the ball in the goal. When the goalkeeper only was present, this resulted in decreases in total shot time and pick-up to top of back swing time and significantly altered the placement of the ball in the goal. The presence of the defender and goalkeeper in combination brought about a moderate effect, decreasing the ball speed, significantly decreasing the success of the shots, scores achieved and significantly altering the placement of shots. Forward swing distance and selected swing sub-phases (i.e. total shot time, pick-up to top of back swing time, forward swing start to midway and forward swing start to release) were also significantly decreased in the presence of the defender and goalkeeper. These findings highlight the importance of maintaining appropriate task constraints during water polo shooting practice. In effect the removal of the defender and goalkeeper leads to the development of inappropriate information-movement couplings. Specifically, the presence of the defender and/or goalkeeper lead to reductions in the durations of selected swing sub phases, resulting in changes in the relative coordination and timing of the water polo shot. These findings indicate that in order to facilitate the development of this specific shooting skill, coaches should structure practice to replicate the perceptual information available during competition.

Optimising recovery post-game or post-training could provide a competitive advantage to an athlete, especially if more than one bout of exercise is performed in a day. Active recovery is one common method that is thought to enhance the recovery process. Another recovery method that is gaining popularity is water immersion. The objective of this thesis was to analyse whether these two recovery methods provided greater recovery from explosive exercise than passive recovery. A physiological rationale that may explain the possibility of enhanced recovery with water immersion was initially investigated. The literature surrounding active recovery, water immersion and passive recovery on strength, cycling, running and jumping was then examined. Following these reviews an experimental study was conducted investigating the effects of water immersion, active recovery and passive recovery conducted after repeated bouts of explosive exercise. The rationale for active recovery post-exercise is that during intense exercise, fluid from the blood is forced into the working muscles due to the increase in mean arterial pressure, which increases muscle volume and decreases blood plasma fraction. Active recovery reduces this exercise induced edema and, with an associated increase in blood flow throughout the body, may increase the metabolism of waste substrates produced during exercise. Researchers have observed this increased substrate metabolism with reductions in post-exercise blood lactate accumulation following active recovery. Water immersion would appear to cause a similar physiological response to active recovery without the need to expend extra energy. When a large portion of the body is immersed, hydrostatic pressure acts on the body's fluids within the immersed region. Fluids from the extravascular space move into the vascular system reducing exercise-induced increases in muscular volume and reducing soft tissue inflammation. Additionally, blood volume increases and is redistributed towards the central cavity, which in turn increases cardiac preload, stroke volume, cardiac output, and blood flow throughout the body. Cardiac output increases in relation to the depth of immersion and have been observed to increase by as much as 102% during head-out immersions. These cardiovascular responses occur without any increase in energy expenditure. If extra-intravascular fluid movement is enhanced, then the movement and metabolism of waste substrates could increase. Observations of increased post-exercise blood lactate clearance with water immersion would support this theory. Most methodologies studying the performance benefits of active recovery and water immersion suffer many limitations. These limitations often consist of the experimental time schedule not replicating what is likely to occur in a practical situation, no isolation of water temperature and hydrostatic pressure effects, and lack of a sport-like exercise consisting of repeated expressions of explosive power. Light-intensity active recovery and water immersion do not appear to be detrimental to performance, but neither does there appear to be enough evidence to claim they are beneficial. Effects of active recovery and water immersion would seem to be trivial to small, with any benefits more likely following multiple bouts of high-intensity exercise and recovery or following muscle damaging exercise. There may be a link between blood plasma fraction and performance, however, evidence is inconclusive. Given these issues and limitations the aim of this research was to investigate whether combinations of active recovery, water immersion and passive recovery could maintain peak power and work during subsequent bouts of explosive exercise. We also investigated whether there was any difference in subjects' blood plasma faction and perceived fatigue between the recovery modes. A cross-over experiment was conducted on seven subjects over four weeks. On the same day of each week subjects performed three sessions of maximal jumping, each two hours apart, followed by a different recovery method. Each jump session consisted of three sets of 20 maximal jumps repeated every three seconds, with a minute's rest in-between. Immediately following the jumping subjects performed 10 minutes of either (A) active recovery on a cycle ergometer followed by seated rest, (I) immersion to the gluteal fold in 19°C water followed by seated rest, (AI) active recovery followed by immersion, or (P) seated passive rest. Jumping was conducted on an instrumented supine squat machine that allowed the measurement of total peak power and total work. Pre-jump, post jump and post-recovery blood was taken and the percentage of blood plasma fraction calculated. Perceived leg fatigue was also measured at these times. Observed differences in total peak power and total work between the recovery modes were non-significant. No differences were observed in the change of blood plasma fraction between the recovery modes or perceived fatigue. One reason for any lack of difference between the recovery modes may have been the brevity of the recovery time. Research that has observed significant benefits of active recovery and water immersion compared to passive recovery have used recovery times greater of 15 minutes or more. Additionally, changes in blood plasma fraction between active recovery, water immersion and passive recovery have not been apparent until at least 10 minutes post-recovery in previous research. Alternatively, rather than brevity, it may be that active recovery or water immersion simply does not provide any benefit to performance recovery. Overall there is a meagre amount of research into active recovery, water immersion and passive recovery. Further research that incorporates a variety of exercise and recovery protocols is required.

Caffeine is now an unrestricted ergogenic aid for competitive athletes. Previous reviews of caffeine's effects on exercise performance have been limited to qualitative analysis. The purpose of this paper was therefore to quantitatively meta-analyze the effects of caffeine on exercise performance. We identified 90 estimates of performance effects of caffeine in 32 peer-reviewed studies. All estimates were converted to mean power in an equivalent time trial then subjected to a mixed-model meta-analysis. The fixed effects were gender, training status (elite athlete, non-elite athlete, non-athlete), dietary caffeine status (habitual consumer, non-consumer), caffeine abstention period, caffeine dose (mg/kg body mass), type of caffeine (pure or in coffee), delay between ingestion and performance test, duration of test, and presence or absence of fatiguing exercise before the test. The random effects accounted for within- and between-study variance. We found that caffeine enhanced mean power by 2.8% (90% confidence limits ± 1.1%) in male non-elite athletes who are habitual caffeine consumers abstaining from caffeine for 2 d before consuming 6 mg/kg of caffeine capsules 1 h before performing a 30-min time trial without intervening fatiguing exercise. The effects for other athletes and conditions were: females, 3.1% (± 2.7%); elite athletes, 2.9% (± 1.4%); non-athletes, 1.3% (± 1.2%); habitual non-consumers, 4.0% (± 1.4%); 7 d of abstention, 3.4% (± 2.6%); 0.3 mg/kg of caffeine, 1.6% (± 5.3%); caffeinated coffee, 1.0% (± 1.6%); 2-h delay before exercise, 2.9% (± 1.2%); 6-s exercise test, 1.6% (± 1.7%); prior fatiguing exercise, 3.0% (± 1.6%). Each of these effects of caffeine varied typically between studies by ± 1.4% (the between-study random effect; 90% confidence limits ± 0.9 to ± 3.5%). We conclude that caffeine has a greater effect on performance with athletes, with habitual non-consumers of dietary caffeine, when administered as pure caffeine, and in endurance exercise, but there is considerable uncertainty about the magnitude of the effects on individuals. More research is needed to reduce this uncertainty and to determine the performance effects of caffeine with females, following longer periods of dietary abstention, in low doses, and for brief exercise. There has also been no research on effects of caffeine on the repetitive fatiguing exercise typical of team sports.

[Truncated abstract] Exercise is generally recommended for individuals with type 1 diabetes mellitus since it is associated with numerous physiological and psychological benefits. However, participation in exercise can also increase the risk of experiencing severe hypoglycaemia both during exercise and recovery. Unfortunately, existing guidelines to minimise the risk of exercise-induced hypoglycaemia are often general and fail to take into account that different precautions are required for exercise of varying type, duration and intensity. Specifically, there are no evidence-based guidelines for safe participation in intermittent high-intensity exercise (IHE), which characterises the activity patterns of most team and field sports, manual labour occupations and spontaneous play in children. This is because the response of blood glucose levels to this type of exercise is not known. Consequently, the purpose of this thesis was to investigate the glucoregulatory responses to IHE that replicates the high-intensity work-to-recovery ratios observed in intermittent sports in individuals with type 1 diabetes, in order to assess the associated risk of hypoglycaemia. The first study of this thesis examined the effect of the repeated bouts of high-intensity exercise that characterise IHE compared to remaining inactive, on blood glucose and glucoregulatory hormone levels in individuals with type 1 diabetes. Eight healthy individuals with type 1 diabetes were tested on two separate occasions during which either a 20 minute rest (CON) or an IHE protocol designed to simulate the activity patterns of team sports was performed (repeated 4 second sprints every 2 minutes). ... During the second hour of recovery, Ra and Rd returned to baseline following MOD, but remained elevated after IHE. These changes in Ra and Rd were consistent with a lower glucose infusion rate (GIR) during early recovery from IHE and a higher GIR after 2 hours of recovery compared to MOD. In conclusion, the repeated bouts of high-intensity exercise associated with IHE stimulate a more rapid and greater increment in Ra during exercise and attenuate glucose Rd during early recovery. These findings assist in explaining, in part, the previous observation that the risk of hypoglycaemia might be lower during IHE and early recovery compared to MOD. Overall, the findings of this thesis have implications for current recommendations aimed at managing blood glucose levels during and after exercise to avoid hypoglycaemia.

This thesis contains three cross-sectional studies and an equipment development study, presented in the form of journal submissions, regarding the hydrodynamics experienced by swimmers during the various phases of the freestyle tumble turn.

Anxiety disorder is prevalent and costly. But its diagnosis is underdeveloped and treatment ad hoc. This could be corrected if the neural mechanisms of anxiety were known. All anxiolytic medications produce a decrease in rodent hippocampal theta rhythm - so hippocampal theta could underlie some types of anxiety. But, a review (Chapter 2) showed that ethanol and other anxiolytics increase FM-theta in the human scalp EEG and have other properties unlike hippocampal theta. The experiments in this thesis, therefore, tested for other potential homologues (Chapter 3) of hippocampal theta in the human EEG. The phase of hippocampal theta activity is reset in a working memory task and not an equivalent reference memory task in rats. Furthermore, low doses ethanol increases and high dose ethanol (and other anxiolytics) decrease theta activity. So, EEG was recorded from 15 scalp sites while participants performed non-verbal working memory and reference memory tasks before and after ethanol administration and assessed for the presence of phase-reset and ethanol-related changes in 5-7Hz and 8-11Hz spectral power (chapter 4 and 5). There was little general evidence for stimulus-induced phase-resetting of the ongoing EEG activity (Chapter 6). Increased post-stimulus synchronization in the theta frequency range was accompanied by increases in post-stimulus spectral power - suggesting that the synchronised activity was evoked rather than reset. Across 3 experiments (Chapter 7), low dose ethanol (54.5-146.6[mu]g/l) increased 5-7Hz theta, while the highest dose (307[mu]g/l) reduced task-related-increases in 5-7Hz activity. These effects were noted across electrode locations including frontal-midline sites and particularly at the beginning of the delay period. The suppression of 5-7Hz activity also coincided with an impairment in working memory performance. The dose-response curve for 5-7Hz theta was as predicted from rat hippocampal work. This particular component, linked to high working memory load or task difficulty, is a potential of homologue hippocampal theta. A clear decrease in theta with high dose ethanol, of this type, has not been reported previously. Activity in the 8-11Hz range typically increased with all doses of ethanol. It is clearly not a homologue of hippocampal theta. This is consistent with previous reports of increased alpha with high doses of ethanol - although these have been accompanied by increased, not decreased, theta. There is a potential homologue of hippocampal theta that can be detected in the human EEG (chapter 8); but the observed changes in 5-7Hz activity cannot be localised and may not be related to the hippocampus. It is clear there is more than one type of theta within the human EEG - with opposing sensitivities to ethanol. Critically, these types were detected at a single site and apparently in phase with one another. The current data, together with the previous literature, suggest that theta can be generated concurrently in distinct networks that, under specific task demands, can become coherent and so produce synchonised activity. Future studies need to test higher doses of ethanol and other anxiolytics and use different experimental paradigms to further differentiate the theta systems in the human EEG. Human EEG could be useful for differentiating sub-types of anxiety, and the choice and effectiveness of interventions delivered.

Background: Very few studies have examined the demands of prolonged batting on physical, psychophysical and performance responses. Objective: The purpose of this study was therefore to determine the physiological and perceptual responses of batsmen scoring a simulated One Day International century. Furthermore, the impact that these responses had on batting performance were also measured. Methods: Seventeen male cricketers currently playing for Rhodes University or the country districts side, performed a simulated bating innings (BATEX©), typical of scoring a One Day international century. The BATEX© protocol consisted of six, five over stages (21 minutes each), with each stage matched to a specific phase of play where batsmen were encouraged to bat with the mindset of that phase. During stages one, three and five players ran at a “self-selected cruise pace” whereas during stages two, four and six players were required to run at maximum speed. At set intervals, selected physiological, perceptual and performance measures were recorded. Results: Most physiological responses increased and decreased accordingly with the low and high intensity stages with the exception of respiratory exchange ratio and core temperature responses. Mean physiological responses however, showed a progressive rise over time. Central ratings of perceived exertion increased as a function of intensity and duration. Sprint times got slower as the protocol progressed, while accuracy (impact accuracy) improved significantly (p<0.05) after stage one and then stabilised for the remainder of the protocol. Conclusion: The simulated batting protocol significantly impacted the physiological and perceptual responses over time. This was due to both the intensity and the duration of the work-bout. Furthermore, the increased physiological load placed on the batsmen significantly impacted the physical performance of the batsmen. An increase in sprint times (players getting slower) towards the end of the protocol may indicate the presence of physical fatigue. This physical fatigue did not however seem to impact the batsmen cognitively as accuracy improved after the first stage and then remained constant over time.

The objective of the present study was to investigate and compare the human responses to two load carriage tasks performed with three different load masses and on three different gradients. The task of carrying hydrogel in one hand was observed in a silviculture industry and crude physiological and perceptual responses were measured. This task was simulated in a laboratory setting together with a suggested intervention of backpack carriage. Eighteen conditions were established which consisted of the two modes of carriage and a combination of three load masses (9kg, 12kg and 15kg) and three gradients (5%, 10% and 15%). Twenty eight Rhodes University female students comprised the sample and the experimental procedures were conducted on a Quinton treadmill. Each participant was required to complete nine of the eighteen conditions which were each four minutes in duration. Postural changes were assessed using lateral and posterior digital images taken at the second and fourth minute and compression and shearing forces were estimated with the ErgolmagerTM Physiological responses (heart rate, ventilation and metabolic responses) were measured continuously with the Quark b² and perceptual responses ('central' and 'local' RPE) were measured every minute during the experimentation and body discomfort was rated at the completion of each condition. Overall responses revealed that hand carriage (146 bt.min⁻¹ , 25.09 mIO₂. kg-l.min⁻¹) was generally found to be more physiologically stressful than backpack carriage (130 bt.min⁻¹, 22.15 mIO₂.kg⁻¹ .min⁻¹) independent of load mass and gradient. Physiological responses were higher (113 bt.min-1 to 174 bt.min⁻¹ ) in responses to increasing gradient as opposed to increasing load mass (104 bt.min-1 to 153 bt.min⁻¹ ) for both backpack and hand carriage. Categorisation using the guidelines of Sanders and McCormick (1993) allowed for classification of conditions, with respect to physiological responses, into 'moderate', 'heavy' and 'very heavy' stress. For almost all of the physiological responses the majority of conditions which were classified as 'moderate' were backpack carriage conditions and the conditions classified as 'very heavy' were mostly hand carriage conditions. In terms of postural responses hand carriage resulted in more strain and greater compression and shearing forces on the spine. In terms of the compression forces increasing gradient had a greater affect on backpack carriage (681 N to 935 N) compared to hand carriage (570N to 793N). In contrast, increasing load mass had a larger affect on hand carriage postures and compression forces (751 N to 935N) in comparison to backpack carriage (723N to 780N). Shearing forces were found to be worse in hand carriage conditions overall. Although participants generally underrated perceived exertion in relation to cardiorespiratory responses, these perceptions revealed that backpack carriage, with a mean 'central' RPE of 12 compared to 11 for hand carriage, was somewhat preferred to hand carriage and that increasing gradient was perceived to be marginally more straining than increasing load mass.

This dissertation explores Wittgenstein’s views on the mind-body problem. It is possible to provide an examination of Wittgenstein’s approach by tracing the evolution of the theory of mind and the mind-body problem, by considering the current ways of dealing with the mind-body problem, and Wittgenstein’s critique of the notion of the mind. Wittgenstein’s views on the nature of philosophy and the relationship between philosophy and psychology make it possible to understand and as this dissertation argues – see beyond – the conceptual confusion that has since arisen out of philosophic tradition that perpetuates a ‘myth of the mind’. Schools of thought such as the Cartesians and cognitivists have attempted, through the construction of various elaborate theories, to solve the ‘riddle’ of the mind and to address the so-called ‘mind-body problem’. Cognitive science, in particular, has used the tradition and the myth of the mind as a basis for its research. Wittgenstein shows that such thinking is particularly muddled. By examining Wittgenstein’s approach to the mind-body problem, it is argued here that theories based on the tradition of the ‘myth of the mind’ are inherently flawed. Wittgenstein uses his methods, consisting of his notions of ‘grammar’, ‘language games’ and the re-arrangement of concepts, to extrapolate meaning and to see through the conceptual confusions that the use of language causes and that give rise to the mind-body problem . / Psychology / M.A. (Psychology)