yes / Background Unilateral trans-tibial amputees have bilaterally reduced toe clearance, and an increased risk of foot contact, while crossing obstacles compared to the able-bodied. While the able-bodied tend to lead with a ‘preferred’ limb it is equivocal whether amputees prefer to lead with the intact or prosthetic limb. This study determined the effects of laterality, compared to side of amputation, on amputees' obstacle crossing performance. To help understand why laterality could affect performance we also assessed knee proprioception for both limbs. Methods Foot placement and toe clearance parameters were recorded while nine amputees crossed obstacles of varying heights leading with both their intact and prosthetic limbs. Joint-position sense was also assessed. Participants self-reported which limb was their preferred (dominant) limb. Findings There were no significant differences in foot placements or toe clearance variability across lead-limb conditions. There were no significant differences in toe clearance between intact and prosthetic lead-limbs (p = 0.28) but toe clearance was significantly higher when amputees led with their preferred compared to non-preferred limb (p = 0.025). There was no difference in joint-position sense between the intact and residual knees (p = 0.34) but joint-position sense tended to be more accurate for the preferred, compared to non-preferred limb (p = 0.08). Interpretation Findings suggest that, despite the mechanical constraints imposed by use of a prosthesis, laterality may be as important in lower-limb amputees as it is in the able bodied. This suggests that amputees should be encouraged to cross obstacles leading with their preferred limb. / Engineering and Physical Sciences Research Council

Executive functions, potentially including the regulatory control of emotions and expressive fluency (verbal or design), have historically been associated with the frontal lobes. Moreover, research has demonstrated the importance of cerebral laterality with a prominent role of the right frontal regions in the regulation of negative affect (anger, hostility) and in the generation or fluent production of designs rather than verbal fluency (left frontal). In the present research, participants identified with high and with low levels of hostility were evaluated on a design fluency test twice in one experimental session. Before the second administration of the fluency test, each participant underwent the cold pressor stressor. EEG data collection took place before and after each experimental manipulation. It was hypothesized that diminished right frontal capacity in high hostiles would be evident through lowered performance on this cognitive stressor. Convergent validity of the "capacity model" was partially supported wherein high hostile men evidenced reduced delta magnitude over the right frontal region after exposure to a physiological stressor but failed to maintain consistent levels of right cerebral activation across conditions. The results suggest an inability for high hostile men to maintain stable levels of cerebral activation with stress after exposure to physiological and cognitive stress. Moreover, low hostiles showed enhanced cognitive performance on the design task with lower levels of arousal (heightened delta magnitude). In contrast, reduced arousal (heightened delta magnitude) yielded increased executive deficits in high hostiles as evidenced through increased perseverative errors on the design fluency task. / Ph. D.

Much of the research on differential hemispheric activation as a function of age or the presence of depression suggests that a relative decrease in left hemisphere activation is associated with depression, while a decrease of right hemisphere activation is associated with age. Recent research, however, has demonstrated the role of the right hemisphere in maintaining general behavioral arousal. Pilot data suggest that elderly people experience behavioral over-arousal when presented with stressful or novel environmental stimuli. Equally interesting is the finding in a single-case study that ambient light and noise have a differential effect on behavior presumed to be representative of the left and the right cerebral hemispheres. The left hemisphere appears to be more responsive to ambient light level, with the right hemisphere being more responsive to ambient noise level. The present study sought to provide further support of selective hemispheric activation to bright light, and to examine the relationships among hemi-activation, age and depression by using behavioral measures of lateral anterior (finger tapping rate) and posterior (dichotic listening) cortical functioning. Two identical experiments were employed to evaluate old and young, and depressed and non-depressed sUbjects. Direct evidence of right herni-aging effects on laterality was not significant in the first experiment, but data suggested the possibility of a ceiling effect for behavioral arousal in the older group which was not seen in younger subjects. The second experiment yielded no significant results between depressed and non-depressed groups. Hypotheses of under and over arousal in subjects are proposed to explain findings. Possible implications for treatment and recommendations for further research are proposed. / Ph. D.

The diploma thesis deals with the hygienic and working habits of left-handed pupils at the first level of elementary schools. The thesis is divided into two main parts, theoretical and research. The theoretical part of the thesis deals with basic information about laterality, brain hemispheres and school maturity. The main focus is on leftist and writing, where we focus on preparation for writing and individual hygiene and working habits of pupils. Problems of written speech and famous leftists are also mentioned. The research part is focused on the survey of the level of hygienic and working habits of primary school pupils. The research was conducted in the form of observations. The obtained results are graphically processed and interpreted. In conclusion, there is a recommendation for working with left-handers in practice.

Doctor Pharmaceuticae - Dpharm / The brain laterality of pharmacists may influence where the pharmacists are best suited to work. Brain laterality refers to the asymmetry of the hemispheres of the brain with regard to specific cognitive functions, such as objectivity and emotion. The left hemisphere functions objectively and rationally, whereas the right hemisphere is subjective and non-rational. Animal behaviour in the literature demonstrated an influence of brain laterality, thus selecting an ideal work environment may also be driven by brain laterality bias. Further support for the research included: amblyopia; hemiplegia; the WADA test. The research question investigated the matching of the brain laterality groups of pharmacists to their ideal work environments. The aims investigated: ear, eye, hand and foot dominance in determining brain laterality; influence of brain laterality and reductionistic variables on job choice; location of emotion generation and job choice. Five objectives investigated these aims: influence of brain laterality alone; influence of brain laterality and reductionistic variables; influence of a new brain laterality determining continuum; Propinquity Principle in achieving data; correctness of the Right Hemisphere Theory (RHT) or the Valence Theory (VT). The RHT suggests that the right hemisphere is dominant in processing all emotion. The VT argues that the left hemisphere is specialised in processing the positive emotions while the right hemisphere is specialised in processing the negative emotions. The resulting Null Hypothesis posits that there is no statistical difference between the different brain laterality groups enabling pharmacists to work competently in any placement. The Alternative Hypothesis was that there is a statistical difference between the brain laterality groups, thus brain laterality can be used to best place pharmacists into ideal placements.

This thesis presents an eclectic mix of studies which consider laterality in the context of previous findings of increased prevalence of Posttraumatic Stress Disorder (PTSD) in male combat veterans with non-consistent right hand preference. Two studies extend these findings not just to civilian populations and women, but to left handers and find that left, rather than mixed, handedness is associated with increased prevalence of PTSD in both general population and clinical samples, and to severity of symptoms in the former. To examine issues relevant to the fear response in healthy populations, a movie excerpt is shown to be theoretically likely to target the emotion of fear and to generate subjective and physiological (skin conductance) responses of fear. The film is used as a laboratory analogue of fear to examine possible differences in left and right handers in memory (for events of the film) and in an emotional Stroop paradigm known to produce a robust and large effect specifically in PTSD. According to predictions based on lateralisation of functions in the brain relevant to the fear response, left handers show a pattern of enhanced memory for visual items and poorer memory for verbal material compared to right handers. Immediately after viewing the film, left handers show an interference effect on the Stroop paradigm to general threat and film words and increased response latency compared to right handers, approaching performance of previously reported clinical samples with PTSD. A novel non-word Stroop task fails to show these effects, consistent both with accounts of interference as language processing effects and compromised verbal processing in PTSD. Unexpected inferior performance of females in memory for the film, contrary to previous literature, may also be amenable to explanations invoking compromised left hemisphere language functions in fear situations. In testing one theory of left handedness as due to increased levels of in utero testosterone, the 2D:4D (second to fourth digit ratio) provides mixed evidence in two samples. A possible association of more female-like digit ratios in males with PTSD is a tentative finding possibly relevant to sex differences in prevalence of PTSD. A critique of existing and inadequate theoretical accounts of handedness concludes the thesis and proposes a modification of the birth stress hypothesis to one specifically considering peri-natal trauma to account for the above findings. This hypothesis remains to be empirically tested.

Doctor Pharmaceuticae - Dpharm / The brain laterality of pharmacists may influence where the pharmacists are best suited to work. Brain laterality refers to the asymmetry of the hemispheres of the brain with regard to specific cognitive functions, such as objectivity and emotion. The left hemisphere functions objectively and rationally, whereas the right hemisphere is subjective and nonrational. Animal behaviour in the literature demonstrated an influence of brain laterality, thus selecting an ideal work environment may also be driven by brain laterality bias. Further support for the research included: amblyopia; hemiplegia; the WADA test. The research question investigated the matching of the brain laterality groups of pharmacists to their ideal work environments. The aims investigated: ear, eye, hand and foot dominance in determining brain laterality; influence of brain laterality and reductionistic variables on job choice; location of emotion generation and job choice. Five objectives investigated these aims: influence of brain laterality alone; influence of brain laterality and reductionistic variables; influence of a new brain laterality determining continuum; Propinquity Principle in achieving data; correctness of the Right Hemisphere Theory (RHT) or the Valence Theory (VT). The RHT suggests that the right hemisphere is dominant in processing all emotion. The VT argues that the left hemisphere is specialised in processing the positive emotions while the right hemisphere is specialised in processing the negative emotions. The resulting Null Hypothesis posits that there is no statistical difference between the different brain laterality groups enabling pharmacists to work competently in any placement. The Alternative Hypothesis was that there is a statistical difference between the brain laterality groups, thus brain laterality can be used to best place pharmacists into ideal placements. Global warming questions in the questionnaire determined positive and negative emotion as well as enthusiasm for global warming problems. In South Africa, probability cluster sampling was applied utilising postal and email methods. In the UK, non-probability purposive sampling was applied utilising four methods: snowballing, email, postal, and convenience sampling. Both countries produced similar results for the same sample size.

The aim of this study was to examine differences and associations concerning physical activity and cognitive functioning among children born preterm in comparison to those born full term. The sample consisted of 130 children at early school age (mean = 7.8 years), born at a gestational age (GA) of 23 - 42 weeks, and categorized into three groups; children born full term (GA 39 - 42), moderately preterm (GA 34 – 36) and very preterm (GA 23 - 33). Physical activities were perceived from parents’ ratings by use of the Child behaviour checklist (CBCL), and cognitive functioning by WISC-IV. Results showed that children born moderately preterm performed comparable to children born full term, both regarding physical activity ratings and cognitive performance. Children born very preterm were found to have significantly poorer full scale IQ, lower physical performance, fewer sport activities, and were less lateralized, in comparison to both children born full term and those born moderately preterm. Conclusion: a very preterm birth seems to generate long-term effects on physical activities, sport performance and cognitive functioning. Thus, more focus should be paid to children born at a very low GA to identify early deviations and to provide interventions to improve cognitive functioning and enhance physical performance; also in contexts other than sport activities. / Syftet med denna studie var att undersöka skillnader och samband mellan fysisk aktivitet och kognitivt fungerande inom gruppen för tidigt födda barn och i jämförelse med fullgångna barn. Urvalet bestod av 130 barn i tidig skolålder (medel = 7.8 år), födda i gestationsålder (GA) mellan 23 – 42 veckor kategoriserade i tre grupper; fullgångna barn (GA 39 – 42), moderat förtidigt födda (GA 34 – 36) och mycket förtidigt födda (GA 23 – 33). Fysisk aktivitet undersöktes utifrån föräldrars skattning genom användande av Child behaviour checklist (CBCL) och kognitivt fungerande utifrån WISC-IV. Resultaten visade att de moderat för tidigt födda barnen presterade jämförbart med de fullgångna barnen både vad beträffar fysisk aktivitet och kognitivt fungerande. De mycket för tidigt födda barnen visade sig ha signifikant sämre fullskale-IQ, lägre sportsliga prestationer, färre antal sporter och var mindre lateraliserade, jämfört med både de fullgångna barnen och de moderat förtidigt födda. Slutsats: en mycket förtidig födsel tycks generera långvariga effekter på fysiska aktiviteter, sportsliga prestationer och kognitivt fungerande. Således bör större fokus läggas på barn födda med en mycket låg GA för att identifiera tidiga avvikelser och tillhandahålla interventioner för att förbättra kognitivt fungerande och stimulera/förhöja fysiska prestationer; även i andra kontexter än sportsliga aktiviteter.

The purpose of this study was to examine the relationship between leg dominance and knee mechanics to provide further information about the etiology of ACL injury. Sixteen healthy females between the ages of 18 and 22 who were NCAA Division I varsity soccer players participated in this study. Subjects were instructed to perform a cutting maneuver; where they sprinted full speed and then performed an evasive maneuver (planting on one leg and pushing off to the other leg in a new direction) at a 45° angle with their dominate leg (DL) and non-dominate leg (NDL). Subjects were required to perform five successful cuts on each side given in a random order. Bilateral kinematic and kinetic data were collected during the cutting trials. After the cutting trials, subjects performed bilateral isometric and isokinetic testing using a Cybex Norm dynamometer at a speed of 60°/sec to evaluate knee muscle strength. During the braking phase the NDL showed greater (P=0.003) power absorption, greater (P=0.01) peak internal rotation angle and greater (P=0.005) peak flexion velocity. During the propulsive phase the DL showed greater (P=0.01) power production, greater (P=0.038) peak internal adductor moment and greater (P=0.02) peak extension velocity. In addition, no differences (P>0.05) in knee extensor and flexor isometric and isokinetic torques between the two limbs were shown. The results of this study show that a difference in knee mechanics during cutting does exist between the DL and NDL. The findings of this study will increase the knowledge base of ACL injury in females and aid in the design of more appropriate neuromuscular, plyometric and strength training protocols for injury prevention. / School of Physical Education, Sport, and Exercise Science

The database on hand preferences in non-human primates provides inconsistent and inconclusive findings, and is plagued by gaps and methodological issues. I studied hand preferences in the bonobo, which is a very interesting model for investigating evolutionary hypotheses on human handedness. There are few previous data on bonobos and they are from small samples and for relatively simple tasks. I studied a large sample of 94 bonobos in three zoos and one sanctuary, on a variety of actions. Five studies were performed to record: 1. hand use for spontaneous daily actions (non-social). 2. hand use for the tube task , a task that requires a manipulative bimanual coordinated precise action. 3. hand use for using a stick as a probe ( termite fishing ). 4. hand use for spontaneous social actions and gestures, recorded during their social interactions (intra-specific) and during interactions with humans (inter-specific). 5. hand use for induced begging gestures (begging for food from the observer). The results show significant manual laterality in almost all the behaviours studied. The hand preferences were present on an individual basis. The numbers of right-handed and left-handed individuals were similar, indicating no group-level bias, for any of the actions studied. There was no significant effect of the settings, rearing history, sex and age (except in study 2 where adults were more right-handed than younger subjects). I examined different factors that have been proposed as selective pressures for the emergence of handedness. Laterality was influenced by: postural demands (posture, activity of the other hand), precision, grip type, manipulation or bimanual coordination, tool-use, throwing, communication. Notably, the laterality was very marked for the tube task , the termite fishing task and the begging experiment, which suggests that the factors involved in these tasks could be important factors regarding laterality.