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Predators impose a strong selective pressure on the behavioural traits of prey species. Group living, or sociability, allows individuals to reduce their own risk of predation through avoidance, dilution, and confusion effects. Another potentially beneficial mechanism is behavioural lateralisation, or "handedness", the asymmetrical expression of cognitive brain functions through a directional bias in visual or motor tasks. In my thesis, I explore the interaction between behavioural lateralisation, sociability, and predation in both natural and captive populations of Trinidadian guppies (Poecilia reticulata). In Chapter Two, I examine the consistency between current behavioural lateralisation methodologies and assess the assumptions behind these methods, including the number of incorporated turn choices and the impact of random chance. In Chapter Three, I present the use of environmental DNA in assessing natural piscine guppy predator communities at six sites across the Northern Range of Trinidad. Using this measure of predation, I assess its viability in predicting differentiation of adaptive anti-predatory behaviours in natural guppies, including sociability, activity, and both visual and motor lateralisation. In Chapter Four, I assess the visual lateralisation of guppies tested either solitarily or in groups in the presence or absence of a live predator, the blue acara (Andinoacara pulcher). Using a repeated measures design, I investigate the repeatability of guppies' visual lateralisation in terms of personality variation across the investigated contexts. In Chapter Five, I assess the visual lateralisation of natural guppies when viewing a social stimulus and their sociability across a gradient of predation risk using nineteen sites in the Northern Range of Trinidad. Overall, my research demonstrates relatively low levels of lateralisation throughout contexts and populations. However, subtle trends in the lateralisation of eye-use when viewing a predatory or social stimulus appear to exist in relation to predation risk, with an apparent social conformity in lateralisation when assessed in groups.

The vast majority of multicellular eukaryotes show some form of symmetry, whether this be radial or bilateral. In vertebrates, bilateral symmetry is apparent at the whole organism level, however internal organs have a defined left and right sidedness in placement and internal symmetry. In mammals, the left/right body axis is defined early in development in an organ called the Embryonic Node. The analogous laterality organ is the Kupffer's Vesicle in teleost fish. In this project I characterise two zebrafish mutants which exhibit defects in laterality establishment; one which contains a premature stop codon in the spliceosomal gene prpf8 and another which contains null mutations in pierce1 and pierce2, two genes with currently unknown function. Preliminary investigations into these prpf8 and pierce1/2 mutants observed a high percentage of unlooped hearts, indicative of problems in left/right axis formation. I investigated Kupffer's Vesicle to determine whether the cilia in this structure are present and functional. Subsequently, I examined key laterality marker genes to elucidate the downstream effects on cardiac laterality caused by the KV cilia perturbation. Additionally, for the prpf8 mutant fish I investigated why mutation of a protein involved in the key processes of splicing would have such detrimental effects on cilia morphology and function by examining Prpf8 protein localisation in both prpf8 mutant and Prpf8 knockdown fish models. My findings indicate that Prpf8 plays a significant role in ciliogenesis, with mutants and knockdowns exhibiting global cilia defects. The reason for this, as of yet, is still unclear. However, I present strong preliminary data that show prpf8 localises to cilia axonemes, suggesting a direct mechanism for Prpf8-cilia protein interaction. In contrast, I also present data showing an increase in mis-splicing of arl13b, a critical cilia gene, in multiple Prpf8 mutant models, suggesting a more indirect, spliceosomal role for Prpf8 in causing cilia dysfunction. With regard to the pierce1/pierce2 double mutant, I show that loss of both these proteins is critical for cilia motility in the KV, and that rescue of either one of the genes rescues cilia motility and restores correct heart looping directionality. This project has wide reaching implications on the understanding and possible diagnosis of a range of conditions including heterotaxy related congenital heart disease as well as primary cilia dyskinesia and Retinitis Pigmentosa.

This thesis presents a series of studies investigating laterality in chimpanzees and its links with personality examined as behavioural style and social networks. The studies presented in this work were conducted by observing a group of 19 chimpanzees in captivity and present new findings in this species. However, this thesis has a broad evolutionary perspective, addressing important questions regarding personality and laterality that could prove helpful to the understanding of the evolution of laterality in vertebrates. Chapter 1 offers a general review of the three main areas of knowledge investigated: laterality, animal personality and primate social networks. Then, the first study of this project, presented in Chapter 2, began by exploring hand preference in the chimpanzee group, investigating spontaneous actions and unimanual tasks and expanding previous research by studying posture, between-task consistency and temporal stability. Chapter 3 investigated additional measures of motor laterality and proposed a novel way of measuring laterality in primates. Together, Chapters 2 and 3 directly examine laterality in chimpanzees and serve as the base from which to explore the links between laterality, personality and social networks in the subsequent studies. If lateralization is rooted in emotional processing and hemispheric lateralization, then individual differences in behaviour (particularly those that reflect emotional expression) would show a relationship with individual laterality. In order to address this question, Chapter 4 studies behavioural style in chimpanzees and its possible link with laterality. Simultaneously, if intraspecific coordination plays a role in the development of population level laterality, similarly lateralised individuals would likely have strong bonds to coordinate with each other. Chapter 5 introduces the approach and techniques of social network analysis and uses them to explore and describe the social structure of the group while describing the integration of a new adult chimpanzee. Chapter 6 applies social network analysis to explore if laterality plays a role in the way the group is structured. Lastly, Chapter 7 integrates all empirical chapters and presents the final discussion and conclusions of the thesis.

Polycystins are a family of transmembrane proteins found in metazoan species that play a plethora of roles, at multiple stages, throughout the lifespan of the animal organism. In human, two loci encoding polycystins, PKD1 and PKD2, were found to be causative of autosomal dominant polycystic kidney disease. Later studies identified these two genes in other organisms, such as mouse and zebrafish, which served as models for investigating the function and regulation of the two proteins. PKD1 and PKD2 behave as interacting partners and form cation-permeable channels, which are thought to control cellular proliferation. The interaction of the two proteins was shown to involve the respective coiled-coil (CC) domains of each protein, a typical protein-protein interaction domain. Later studies then determined that PKD2 is also able to interact with other PKD2 molecules through the CC domain, as well as other domains distributed throughout the protein. PKD2 has also been shown to play a role in left-right (L-R) asymmetry determination, in partnership with a PKD1 paralog, PKD1L1 (PKD1-like-1). The two have also been suggested to interact, presumably through their respective CC domains. The aim of the work described in this thesis is to test the differences and similarities between the interaction mechanisms of PKD1-PKD2 and PKD1L1-PKD2, in order to better understand how these molecules perform their function. I first investigated the molecular mechanisms involved in the PKD1L1-PKD2 interaction, through the use of biochemical techniques, by comparing the interaction of PKD2 WT or mutant proteins fragments with destabilized or truncated CCs. The results obtained suggest that the molecular mechanisms of interaction are likely different between the PKD1-PKD2 and PKD1L1-PKD2 complexes, in that the PKD1L1-PKD2 interaction does not appear to require the CC domain for interaction. I performed phenotypic analysis on embryos carrying truncation or insertion mutations in the region of Pkd2 encoding the CC region. The phenotypic data indicates, for the first time, a separation between the role played by PKD2 in L-R and kidney development. Furthermore, the results described in this thesis also indicate that the PKD2 CC performs distinct functions, at the molecular level, in different contexts.

Conceptual knowledge (or semantic knowledge) refers to our shared knowledge for words, objects, people and emotions. The anterior temporal lobes (ATLs) have been identified as a critical region for the representation of conceptual knowledge through convergent evidence from fMRI in healthy participants, cortical electrode implantation and damage-deficit correlations. With the involvement of the ATLs established, recent research has begun to focus on the functions of subregions of the ATLs - with particular interest surrounding the functions of the left and right ATLs. This thesis investigated three main research questions: (1) What are the functions of the left and right ATLs in semantic representation? (2) How does unilateral damage affect the semantic system and what mechanisms underlie the robustness of the system? (3) Do functional gradations exist within the ATLs? These questions were addressed using convergent methodologies including functional neuroimaging and transcranial magnetic stimulation (TMS) in healthy participants and behavioural and neuroimaging investigations in patients who have undergone unilateral ATL resection. To address the question of left vs. right ATL function, this thesis began by directly comparing the predictions of the different accounts of ATL function in a large-scale meta-analysis of the existing neuroimaging literature (Chapter 2) and in a large sample of patients who had undergone unilateral left or right ATL resection (Chapter 3). The overarching finding was that conceptual knowledge is underpinned by a primarily bilateral ATL system, whereby both the left and right ATLs are critical for normal semantic processing. Secondary to this bilateral representation, relative functional gradations were observed both between and within the ATLs. To address the second research question, Chapter 4 investigated the robustness of the semantic system to unilateral damage, specifically regions involved in the maintenance of conceptual knowledge were localised. Results showed that upregulation occurred within regions previously associated with semantic knowledge. The upregulation of activation after unilateral resection also mimicked the upregulation in control participants during more challenging semantic processing. Chapter 5 examined the behavioural relevance of upregulation in the contralateral ATL after unilateral perturbation using a novel TMS protocol in healthy participants. The findings observed here suggest that the bilateral ATL system is resistant to a degree of unilateral damage/perturbation because semantic representations are distributed between the hemispheres. Therefore, unilateral damage/disruption only results in a mild semantic impairment, as the undamaged/unperturbed hemisphere is available to compensate. Finally, Chapter 6 explored functional gradations within the ATLs by comparing responses in the ventral ATL to different conceptual categories, presented as visual and auditory inputs. The functional gradations observed here are proposed to emerge via differential structural and functional connectivity between the ATLs and sensory-motor and limbic cortices.

Substantial evidence shows that attentional bias towards threat plays a fundamental role in anxiety and that deficits in frontal brain functioning might explain this. However, a paucity of research on anger related attentional bias leaves unanswered questions about whether similar mechanisms underpin aggression. This has led to a lack of theoretical explanations for anger related attentional bias and effective interventions to reduce anger. Electroencephalographic (EEG) evidence suggests that the hemispheric specialisation of the frontal brain predicts differential responding to emotional stimuli in anger and anxiety. Manipulating motivational direction, via unilateral hand contractions (UHCs), provides a means to explore the causal relationship between anger and attentional bias to threat. Previously, this method has only been used to change experiential and expressional aspects of emotion and its effectiveness in modulating attentional components of emotion regulation are unknown. Therefore, this Thesis aims to explore whether UHCs effectively modulate attentional bias to threat in relation to, and independent of trait anger. It also aims to discover the underlying neural effects of the UHC method to examine whether threat-related attentional changes reflect modulations in cognitive control and/or approach motivation. Finally, this Thesis aims to bridge the gap between the attentional bias and frontal brain asymmetry literature. These aims will be addressed by employing Emotional Stroop and Dot Probe paradigms as well as event related potentials measures. The findings provide evidence that UHCs provides an effective technique to modulate attentional bias to threat. Specifically, RHCs reduce attentional bias to threat independent of trait anger and in individuals with low trait anger but they do not modify attentional bias to threat in high anger individuals. In contrast, LHCs increase attentional bias to threat and this reduced task relevant processing, independent of trait anger. The implications of these novel findings and future directions of research are discussed.

The study of lateralisation has taken several forms ranging from investigating morphological asymmetries to research on lateralised motor and perceptual functions with many studies successfully evidencing lateralisation in a variety of species. This study, featuring three species (olive baboons, rhesus macaques, and spotted hyaenas) investigated visual field biases with the aim of determining whether emotional valence underpins these biases whilst also considering the influence of a number of other factors such as emotional intensity, age, sex, rank, and, for the first time, oestrus cycles (olive baboons only). This study aimed to establish whether Campbell’s (1982) Right Hemisphere Hypothesis or Silberman & Weingartner’s (1986) Valence Hypothesis offered the more valid theory for the lateralisation of emotion by considering interactions across the full spectrum of emotion – a question the almost exclusive investigation of negatively affective scenarios by previous studies has been unable to answer. Furthermore, this study provided a new methodology for investigating behavioural lateralisation by suggesting that separating the visual spectrum into five fields (extreme left, mid left, centre, mid right and extreme right) allows a more accurate insight into the lateralisation of visual perception than the traditional hemifield model. Finally, a more conservative method is proposed for analysing behavioural data in future studies from this field and suggests that these methods provide a more accurate representation of the lateralisation of emotion than those previously employed. A population-level left side bias was found for the spotted hyaenas, thus providing the first evidence of significantly lateralised behaviour in a large carnivore and, for this species at least, lending some support to Campbell’s (1982) Right Hemisphere hypothesis but as population-level biases were not found for either of the other species it may be premature to suggest this support is unequivocal. Significant age effects were found in two species as adult olive baboons and spotted hyaenas were both found to express significant left side biases. Spotted hyaenas were also found to express significant left side biases for females, dominant individuals, high intensity interactions, and sexual valence interactions whilst olive baboons expressed a significant left side bias during negative valence behaviours but no significant lateral biases were found in any context for rhesus macaques. In olive baboons behaviours performed by males and those of a low intensity were found to occur more frequently in the mid and central visual fields and neutral valence behaviours were less occurrent in the extreme visual fields whilst in spotted hyaenas sexual, positive and negative valence behaviours were significantly less centralised than neutral valence behaviours. Non-oestrus adult female olive baboons were significantly more strongly lateralised than in-oestrus females, thus suggesting an influence of sex hormones upon lateralisation that may also have been apparent from the hyaena data, particularly regarding the significant lateral biases observed for females and dominant individuals. Finally, this thesis discusses a number of methodological issues that were encountered during this study and provides recommendations for future research in this field. Namely, this thesis provides an updated method for calculating laterality bias that is much more suitable for species with binocular vision and details a novel method of assessing visual field preferences by considering central and peripheral visual fields as separate entities. Furthermore, this thesis suggests that the weighted method designed and implemented for this study provides a much more accurate methodological foundation for analyses which avoids the caveats that may have affected previous research and thus provides a considerably more robust template that should be encouraged for any similar subsequent studies.

Several studies have reported a strong bias in both human and non-human species for cradling their infants to the left side of the body. Most studies suggest that the main reason this phenomenon is the predominance of the right hemisphere of the brain for the processing of emotions and its transference, through brain laterality, to the left side of the body. Many other variables, including handedness, footedness, stress and depression have also been found to have some effect on cradling side. However, no study has been published for an Arab population. Given the strong religious and cultural belief of most Arabs that only the right hand should be used for most daily tasks, this study investigated the affect on cradling side of this habit, in addition to the factors named above. 369 Saudi citizens took part in this study. 234 lived in Saudi Arabia and 135 had lived in the UK for five or more years. 267 were women and 102 were men. Each answered a questionnaire which asked about their ‘preferred’ cradling side and then the 102 men were videotaped spontaneously cradling a real infant and an infant-like doll. Unfortunately, only the male sample could be videotaped due to restrictions on filming females in Saudi Arabia. The results confirmed those of previous studies by showing a very strong bias to leftside cradling. No difference was found between males and females in cradling a doll, or between the Saudi-based sample and the UK-based sample but the bias was significantly reduced in men. Apart from the influence of gender, the factors that reduced the cradling bias for a real infant were found to be lack of experience of parenthood, depression, stress and greater age of the infant. In cradling a doll, the most influential variables were handedness, footedness and depression. Further work is required on Arab samples, especially in examining spontaneous cradling by women and its relation to depression and stress. A mother’s mental state is known to affect the health of the infant and cradling side could be a useful filter for neonatal women who might require psychiatric treatment. Further research could also shed light on gender differences in the processing of emotion.

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.

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.

Objective: The purpose of this thesis was to determine the degree of difference between anthropometric and heel pad tissue characteristics of the lower extremities of PMHS compared to living populations as well as to establish a wholistic procedure for extensive measurements of the foot using methodology previously used in lower limb anthropometry, x-ray imaging, and ultrasound imaging studies.Methods: Thirty-seven PMHS were included in the anthropometry analysis, 21 PMHS were included in the x-ray analysis, and 32 PMHS were included in the ultrasound analysis. For the anthropometry, measurements were taken in seated and standing positions and included bimalleolar breadth, heel breadth, navicular height (medial prominence), navicular height (inferior medial border), talar head height, plantar curvature height, lateral malleolar height, medial malleolar height, acropodion foot length, hallux foot length, horizontal foot breadth, ball of foot length, and dorsum height. Comparisons were then made between left and right feet, seated and standing positions, males and females, and PMHS and living populations. For the x-ray analysis, two of the anthropometry measurements, navicular height (inferior medial border) and talar head height, had values for anthropometry compared against measurements determined through x-ray imaging. For the ultrasound analysis, ultrasound images were taken of the plantar foot at the calcaneus at loadings of 0, 5, 10, 15, 20, and 30 Newtons. Thicknesses, stiffnesses, and compressibility indexes were determined using the images, and these values were then compared against values seen in living populations. Results: Left and right feet were found to have no significant differences in anthropometry. Seated and standing positions were found to be significantly different in 12 of the 13 measurements. Male values were found to be significantly different from female values in both seated and standing positions for all measurements except for plantar curvature height. By determining percent difference values between seated and standing positions for both males and females, no significant difference was found between sexes in their respective measurement changes from seated to standing positions except in plantar curvature height and lateral malleolus height. Eleven of the 13 measurements showed agreement between PMHS and living populations, with talar head height and plantar curvature height showing greater than 10% difference. In the x-ray analysis, navicular height was significantly different between anthropometry and x-ray values, and talar height was not significantly different. In the ultrasound analysis PMHS were found to have thinner and stiffer heel pads with lower compressibility than living populations.Conclusions: A wholistic procedure for foot measurements and analysis was developed which incorporates methodology from previous literature. For foot measurement, x-ray imaging was shown to be necessary for certain landmarks but not for others. Results from this study have provided quantification of posture and sex differences as well as quantification for differences between PMHS and living populations for foot anthropometry. Differences were also quantified for the thickness, stiffness, and compressibility of PMHS compared to living populations. The results show that PMHS anthropometry sufficiently represents that of living people’s anthropometry when sex and postural differences are accounted for, but PMHS is not representative of living populations regarding heel pad thickness, stiffness, or compressibility, and these differences must be considered in lower extremity testing.

Laterality of eye use has been increasingly studied in cetaceans. Research supports that many cetacean species keep prey on the right side while feeding and preferentially view unfamiliar objects with the right eye. In contrast, the left eye has been used more by calves while in close proximity to their mothers. Despite some discrepancies across and within species, laterality of eye use generally indicates functional specialization of brain hemispheres in cetaceans. The present study aimed to examine laterality of eye use in bottlenose dolphins (Tursiops truncatus) and rough-toothed dolphins (Steno bredanensis) under managed care. Subjects were video-recorded through an underwater window while viewing two different stimuli, one predictable and static and the other unpredictable and moving. Bottlenose dolphins displayed an overall right-eye preference, especially while viewing the unpredictable, moving stimulus. Rough-toothed dolphins did not display eye preference while viewing stimuli. No significant correlations between degree of laterality and behavioral interest in the stimuli were found. Only for bottlenose dolphins were the degree of laterality and curiosity ratings correlated. This study extends research on cetacean lateralization to a species not extensively examined and to stimuli that varied in movement and degree of predictability. Further research is needed to make conclusions regarding lateralization in cetaceans.

In an effort to further the understanding of fine motor control in the lips, this study measured isometric ramp-and-hold force dynamics at the oral angles in neurotypical young adults (24 females/22 males) examining the independent variables of oral angle side (L/R), handedness, age, and sex. Force dynamics were measured with a wireless data acquisition system and force sensors (ForceWIN10). During the visuomotor task, participants completed randomized blocks of isometric ramp-and-hold trials at 4 target levels (0.25, 0.5, 1, and 2 Newtons) presented via a 15-inch computer monitor. Patients were encouraged to meet and hold the line “as rapidly and accurately as possible”. A maximum voluntary contraction force task was also completed. Significant interactions between force target and muscle group were found in the dependent variables of peak force, mean force, criterion hold percentage, and maximum voluntary contraction force. A significant relationship was indicated between biological sex and maximum voluntary contraction force (means: F = 3.99 N, M = 5.53 N). A slight statistically significant advantage for the L-oral angle during T2 of the criterion hold percentage was identified for left-handed individuals, though the number of those participants (n = 5) limits the reliability of the measure. Target force level was significant for dF/dtmax and reaction time. In addition, 35% of the participants were identified to have a dominant side of their face, though it did not correlate with handedness. Advisor: Steven M. Barlow

Females in sport are under-represented in data and analysis when compared to their male counterparts. This disparity also applies to women’s softball in comparison to men’s baseball. To help fill this gap, this study evaluated the extent and impact of laterality in women’s college softball’s Power Five and Group of Five conferences from 2015-2017. This study focused on the extent of a left-sided lateral preference in women’s college softball, possible interactions between throwing hand and batting preference, to what extent the platoon effect exists in the sport, and the extent of positional bias in the sport. As one of the largest studies on the laterality of women in sport, with a sample size of over 3,000 women’s college softball players, this study contributes to the understanding of the manual act of throwing and the bimanual act of batting by females. The results from this study indicated that a left-sided lateral preference occurred more often in women’s softball than in the public, with slap hitters a possible cause. However, without a method to identify which batters in softball are slap hitters, it was difficult to draw as rich of conclusions about laterality in women’s softball as those drawn for men’s professional baseball. The study also provided an assessment of performance variables that could impact the way the game is played and how coaches make recruiting decisions.

Skin cancer is the most commonly diagnosed cancer in the United States and melanoma is considered the deadliest form of skin cancer. Although the environmental causes of melanomas are known, the molecular mechanisms involved are still being researched. Melanomas present more often on the left side of the body, but explanations for this laterality are conflicting and largely focused on epidemiological factors. In this thesis, both epidemiological and genetic factors affecting melanoma laterality are analyzed to explore how tumor laterality and patterning may arise in general. The Surveillance, Epidemiology, and End Results (SEER) and The Cancer Genome Atlas (TCGA) databases were used to analyze clinical cases of melanoma. Data analysis was conducted by calculating a laterality ratio of asymmetric melanomas and comparing how these ratios differ in epidemiological and genetic variables. A machine learning algorithm was also applied to predict which variables or groups of variables may determine laterality. Results showed that, as established, melanomas tend to exhibit left-sided laterality, but epidemiological factors alone are not good indicators of where tumors present. Genomics analysis revealed several genes and targets of interest. Genes involved in cell adhesion were consistently significant, but there was no conclusive evidence that a specific gene or set of genes causes left-sided patterning. Although results did not reveal specific genetic targets as determinants of melanoma laterality, they prove that the methods used can be tools for analyzing tumor laterality in general and can help in predicting what variables are important in molecular mechanisms indicating laterality.

Lateralization is specialization of the brain hemispheres in certain tasks, such as language, mathematics, cognition and motor skills. It is one of the most queried topics related to the human brain. After the invention of modern medical imaging techniques including functional magnetic resonance imaging (fMRI), scientific research about the human brain, including lateralization, gained huge momentum. There have been a remarkable numbers of studies about lateralization and most of these studies focused on investigating which part of the brain dominates in which tasks. However, there have been very few lateralization studies on brain intrinsic activity, i.e., resting state activity where subjects are asked to stay awake while resting without performing any specific tasks. Independent component analysis (ICA), a data-driven blind source separation method, has become one of the conventional data analysis tools for brain imaging data. ICA can separate the brain imaging data into functional regions that are temporally coherent, and functional network connectivity (FNC) of these regions can be computed. FNC is a measure that captures the temporal covariance of the brain networks. In this dissertation, we focus on the lateralization during the resting state and assess hemispheric differences during the resting state. The lateralization of the resting state networks and their association with age and gender is presented using a large resting state fMRI dataset. A novel approach for generating hemisphere specific time-courses and computing FNC inside the hemispheres and between hemispheres is proposed and the relationship of these FNC values with age, gender and mental illness, schizophrenia is reported. Finally, a new framework to estimate power spectral density of 4D brain imaging data and a dimension reduction method to reduce dimensionality from 4D frequency domain to 2D frequency domain has been proposed. This framework helps us to reveal spatiotemporal organization differences between hemispheres. In summary, our work has made several contributions to advance lateralization analysis and has improved our understanding of various aspects of hemispheric differences during the resting state

Abstract: Personality has been documented in diverse taxa and growing attention is being directed towards the ecological implications of consistent variation in individual behaviour. These implications include the rise in habituation behaviour by wildlife living in human-disturbed areas, which has resulted in trophic disruptions, risks to human safety, and environmental damage. For ungulates, habituation behaviour may also contribute to global declines in migratory behaviour. The purpose of this thesis was to explore the sources of variation in the behaviour of elk (Cervus canadensis) and determine their relevance to changing migratory patterns. I had three specific objectives to: 1) quantify personality (also known as behavioural syndromes) in both wild and captive elk and determine whether personality can predict variations in migratory choices; 2) determine whether aversive conditioning designed to increase the wariness of elk was affected by personality type and the nature of the aversive stimulus; and 3) quantify cerebral lateralization as a potential measure of behavioural plasticity and determine its relationship to personality. I conducted research on wild elk in each of Banff and Jasper National Parks, Alberta, Canada, and on captive elk near Leduc, Alberta, from 2010 to 2013. I demonstrated the presence of behavioural syndromes in elk by identifying seven covarying behavioural traits that together delineated a gradient of shy to bold personality types. Aversive conditioning was more effective at increasing wariness in bolder elk, but extinction of this learned wariness behaviour (or recidivism) was also greater in these individuals when the aversive stimulus was removed. These patterns of responsiveness were similar whether targeted elk were subjected to conditioning chases as part of a group or when conditioning also included isolation of the target from all conspecifics. However, the isolation method significantly reduced recidivistic behaviour during the extinction period, particularly for bolder elk. Measures of laterality, determined by observing the front limb biases of elk foraging in snow, revealed that less lateralized individuals were also more plastic in their responses to both aversive and benign stimuli by people. The combination of laterality and personality best predicted the migratory choices of individual elk. Together, my results suggest that personality and laterality contribute to the responses of individuals to changing environments in diverse contexts, both natural and anthropogenic. Better methods for measuring these attributes in wild animals will make it possible for wildlife managers, conservationists, and planners to foster greater rates of coexistence between people and wildlife in an increasingly urbanized world.

More breast cancers are diagnosed in the left breast than the right. The ratio (l/r) is called the laterality ratio. We analyzed 1.2 million cases of breast cancer diagnosed in the US between 1973 and 2010 and recorded by the Surveillance, Epidemiology, and End Results (SEER) program. We found that the laterality ratio depends upon the country of birth, but not race of the patient. We identified five countries of birth that had p-values larger than 0.995, while we expected to see less than 1. Those born in Japan (l/r=1.14, p=0.997), the Ryukyu Islands (l/r= 2.6, p=0.998), Laos (l/r=1.62, p=0.9999) and Algeria (l/r=2.1 p=0.9959) had significantly larger laterality ratios compared to the overall SEER population (l/r=1.04). Those born in Poland (l/r=0.92, p=0.997) had a laterality ratio significantly less than expected. We compared the laterality ratio calculated for tumors occurring in each quadrant of the breast for two immigrant populations: those born in Japan and those born in Poland. We found the only significant difference was in the laterality ratio of the upper outer quadrant. Thus, the birthplace effect appears to only occur in the upper outer quadrant of the breast. Finally, we found a small, but statistically significant, increase in the breast cancer laterality ratio with age, and decrease with birth year and year of diagnosis.

For centuries regeneration was thought to be unattainable in the spinal cord, but recent tools and advancements imbue optimism. This dissertation serves to guide the field in using a genetically-labeled mouse for studying CST regeneration, and to assess wiring of CST regeneration that results from PTEN deletion.Mice designed to have yellow-fluorescent protein (YFP) expressed by the CST (CST-YFP mice) were proposed to be useful for studying CST regeneration. We show by anterograde labeling, anterograde degeneration, and retrograde labeling that some YFP-labeled axons in the spinal cord are not of the CST. We further demonstrate that dense YFP-labeled arbors impede tracing individual YFP-labeled axons such as could be used to confirm CST origins. We also found that YFP fluorescence in these mice is faint for clearing-based 3D imaging as could be used for screening regenerative responses. These results overall limit the utility of CST-YFP mice for studying CST regeneration.Deletion of PTEN has been demonstrated to enhance CST regeneration after spinal cord injury. For regeneration to be functionally meaningful, it is critical that the axons form synapses. We assessed whether CST axons that regenerated due to PTEN deletion form synapses at the level of electron microscopy. In PTEN-floxed mice that were injected with AAV-Cre near birth to delete PTEN and as adults given a complete thoracic crush lesion, we identified synaptic structures of regenerated CST axons caudal to the lesion. This result indicates that manipulation of the PTEN pathway can produce a regenerative response that may contribute to caudal circuitry.Toward understanding regeneration that may contribute to circuitry of motor function, the laterality of CST regenerative growth that results from PTEN deletion was assessed. PTEN-floxed mice were injected with AAV-Cre near birth and as adults given a dorsal hemisection lesion in the low thoracic spinal cord. By anterograde tracing, CST laterality in control mice was found to be predominantly contralateral to the injected cortex. Laterality of regenerative growth caudal to the lesion was found to be variable and sometimes predominantly on the ipsilateral side. These results indicate that regenerative growth does not follow the contralateral rule of the non-injured CST.

Lateralization is a part of virtually every function we think makes us human, yet there is no integrated neurophysiological explanation of the development of lateralization and interhemispheric integration. In this thesis I propose how development, lateralization in visual processing, and interhemispheric connectivity are all intertwined. I begin with evidence from neurocomputational modeling that lateralization in visual processing can be accounted for by a difference in the length of long-range lateral connections brought on by typical human developmental processes. The model can explain processing asymmetries for low vs. high spatial frequencies, local vs. global stimuli, as well as the right hemisphere lateralization of faces. Next, I show modeling evidence against the prevailing hypothesis that lateralization and interhemispheric communication are both functions of brain size. Previous papers have argued that lateralization is related to hemispheric independence which increases with brain size, due to both longer latency and proportionally fewer interhemispheric connections in larger brains. I examine interhemispheric connectivity across species using a new allometric analysis of existing data and examine latency effects through a re-analysis of neural network modeling data. Both results suggest that inter- hemispheric communication is robust across brain sizes. Along the way, I examine the neurophysiological development of long-range connections. I use neural network modeling to show that developmental changes in the physiology of axons may bias learning towards more local intrahemispheric circuits early in development, with long distance interhemispheric circuits becoming more prominent as connections mature. These modeling results are broadly consistent with the develop- mental trajectory of both interhemispheric communication and lateralization. I conclude by attempting to integrate these results into existing theories of developmental and adult visual lateralization. In many domains, communication is the key to the development of specialization. I hope this work can refocus our efforts to understand how interhemispheric communication affects the development of each lateralized function in the brain and treat any relationships between hemispheric independence and lateralization as an unexpected special case worth investigating further

Previous research suggests that those who use their non-dominant hand for at least some tasks (“mixed handers”) have better episodic memory than people who use their dominant hand nearly all the time (“strong handers”). Evidence suggests that this is because mixed handers have greater access to the right hemisphere, which is active during the retrieval of episodic memories. Most of this previous research has focused on list learning. The present study extends these findings to memory for prose. Furthermore, this study investigated whether mixed or strong handers would be more susceptible to previously studied effects demonstrating that taking a specific perspective may affect what someone remembers from a story. One hundred fifty UT students were split into three groups of 50. All 150 were given a short story about two boys skipping school. However 1/3 were told to imagine they were burglars, 1/3 were told to imagine they were potential homebuyers, and 1/3 were given no such instructions. After a five minute lag time, during which participants completed a handedness questionnaire, everyone was given five minutes to recall as much as possible from the story. While perspective did affect what was recalled, perspective and handedness did not interact. More importantly, there was a main effect of handedness. As predicted, mixed handers remembered more from the story than strong handers. The findings suggest that degree of handedness may be a variable of interest to cognitive and educational psychologists who studying reading the processing of prose material.

In today's world there is a need for products and services that are accessible to all individuals. Universal Design is the concept that products and environments should be usable by all people, to the greatest extent possible, without the need for adaptation or specialization. There is a growing need for such products. However, many products are not accessible to all potential customers, arguably due to a lack of experience, design tools, and engineering methods for creating universally designed products. This research compares paired products to determine the differences between "Universal Design (UD)" and "Standard" Products. For each pair of products, a functional model and activity diagram were developed and analyzed. For each product pair, the identified differences in the products were recorded in a Universal Design differences database. Through systematic analysis of the Universal Design differences database and other research in Universal Design, a set of three Handheld Universal Design Tools was created. The toolset consists of the Handheld Universal Design Checklist, The Handheld Universal Design Guidelines, and the Handheld Universal Design Matrix. These three tools are designed to be used in the concept generation phase of product design or redesign. The Handheld Universal Design Tools were evaluated using a human subjects experiment. Control and test groups were asked to generate concepts for redesigning a product. The metrics of quality, universality, laterality, senior usability and inclusivity were used to evaluate the design concepts. The results of the study suggest that Handheld Universal Design Tools assist engineers in generating design concepts appropriate for Universally Designed products. As a part of the research, Universal Design was presented to first year mechanical engineering students with pre- and post- surveys on the students' perceptions of engineering. Subsequent analysis of the surveys indicated that exposure to Universal Design affects students' perceptions of engineers' overall role in society and their capacity to help others. The Handheld Universal Design Checklist, Guidelines and Matrix represent an initial step to provide engineers with tools to create Universally Designed products.

There is clear evidence that the autonomic nervous system (ANS) is lateralized at both the peripheral as well as the central levels of the nervous system. Both the vagus and the sympathetic ganglia asymmetrically innervate the sino-atrial node and the myocardium of the heart. This lateralization has also been observed in afferent as well as efferent projections to nuclei in the brainstem, hypothalamus, and amygdala. Where laterality has not been as clear is in regions of the frontal lobe dedicated to the regulation of autonomic nervous system responses. This study addressed that issue via the implementation of lateralized autonomic response-evoking tasks. With the use of cardiovascular and electrodermal measures, the present study indexed autonomic responses to lateralized stimuli. This study also explored the role of lateralization within sex as well as in relation to reported gender identity. The findings lend support to the right hemisphere as serving a dominant role in regulating sympathetic nervous system activity, while lending less conclusive support for lateralization of parasympathetic nervous system regulation. Men demonstrated greater lateralization for sympathetic nervous system responses across several different metrics of autonomic indices. The exploration of gender variables in relation to lateralization of autonomic responses was generally not supported.

This dissertation presents a novel behavioral task of lateralized attention: the speeded Lateralized Attention Network Task (sLANT) and establishes behavior and ERP features of single and multiple test administration. In addition, EEG Biofeedback was implemented in a double-blind, randomized, placebo controlled experiment contrasting the effects of EEG training protocols on hemispheric attention as measured by the sLANT. EEG Biofeedback mechanisms were also investigated. Protocols were selected to contrast training hemisphere (C3 vs C4) and reward frequency (SMR: 12-15 Hz, Beta: 15-18 Hz) with active placebo training. Significant protocol by session effects on performance Accuracy and ERP features demonstrate EEG Biofeedback has an effect beyond "Sham", has specific protocol effects by training hemisphere and frequency, and can be successfully blinded in a research context.

Language research has moved from the left hemisphere (LH) processing all language, to a differential processing across hemispheres. Davidson (1995) suggests the right hemisphere (RH) is specialized for experiencing negative emotions, while the LH is specialized for experiencing positive emotions. However, when readers' perceive emotion, the RH processes emotion regardless of valence. Examining laterality of perception versus experience of emotions has not been thoroughly tested using cognitive paradigms. Experience was examined using positive, negative, and neutral moods induced via pictures from the International Affective Picture Inventory. We predicted a LH advantage for positive or neutral mood induction and a RH advantage when negative mood was induced. Perception of emotions was tested using valence judgments. Predictions were a RH advantage for natural and man-made target words preceded by positive and negative central words and a LH advantage for targets preceded by neutral central words. An overall LH advantage for the semantic decision task was found. The valence of the central word did have an effect on accuracy and reaction time of the subsequent semantic decision words. Although there was no effect of visual field for the negative mood induction condition, there was a trend toward a significant interaction between mood and visual field. A LH advantage was found for accuracy of the semantic decision task for the positive mood induction, which partially supports experimental predictions. This experiment examined the effect of valence on hemispheric asymmetry. Arousal level was controlled for in order to have a non-confounded measure of valence. Given experimental findings, arousal level may be an important variable when examining valence.

In the majority of the depression literature, there has been little attention paid to the mechanisms underlying the differences that occur among individuals with this label. In a theoretical paper by Shenal, Harrison, and Demaree (2003), they proposed that the differences in depression symptomology may be due to differences in the function (and dysfunction) of the right and left frontal lobes. They go on to explain that each frontal lobe may have a direct influence on patterns of depression symptomology. In the current experiment there was an effort to look at performance differences among depressed and non-depressed males on a tests of affective memory (AAVLT) and functioning for the left (COWAT) and right (RFFT) frontal lobes. Results were non-significant for group based differences but other significant effects were found. Reliable findings included a primacy effect for the recall of words from the negative word list from the AAVLT, whereas t a "normal" primacy and recency effects were found for the recall of positive and neutral word lists. There were also significant differences (across trials) for both groups suggesting a "normal" learning curve. It is thought that the non-significant comparisons among the groups are likely due to the qualitatively mild depression scores among participants, which is likely not adequate to capture the level of dysfunction discussed in the original hypothesis.

Congenital heart disease (CHD) is the major cause of death in the first year of life, the estimated incidence being 0.5-5% of live births; therefore it is important to understand the genetic causes underlying the complex process of heart formation to help prophylaxis, diagnosis and treatment of affected patients. CHD is the commonest phenotype associated with left-right (LR) disorders. LR asymmetry is determined during embryonic development. The three major body axes ? antero-posterior, dorso-ventral and left-right ? are patterned at gastrulation. LR asymmetry is established shortly after the two other major axes are patterned. The process of LR determination can be sub-divided into four integrated steps: 1. breaking of molecular symmetry in the gastrulation organizer; 2. transfer or relay of this asymmetric information to the lateral plate mesoderm (LPM), from which most internal organs will be formed; 3. reinforcement and propagation of asymmetric cues throughout the LPM and 4. conversion of asymmetric molecular information into proper organ morphogenesis. The goal of this work is to investigate mechanisms involved at two specific points in the laterality pathway: the initial generation/maintenance of asymmetric gene expression in the LPM and the morphogenetic translation of these early events into correct heart formation in the mouse. My emphasis has been on the characterization of laterality targeted cells via careful analysis of Pitx2c expression using a Pitx2c-lacZ reporter transgene, the role of BMP signalling, via Smad1, in generation/maintenance of early asymmetric signalling in the LPM, and the later involvement of both Smad1 and Pitx2 in cardiac morphogenesis through analyses of knockout mice.

DOES A CONTINUOUS MEASURE OF HANDEDNESS PREDICT READING RELATED PROCESSES AND READING SKILLS ACROSS THE LIFESPAN? by Michele Harrison Brenneman The purpose of this research was to investigate the relationship between handedness, reading skills, and reading related cognitive processes. The research results with regard to handedness, specific reading skills, and reading related cognitive processes are ambiguous at best. The method in which handedness is measured contributes to these diverse research findings, therefore the present investigation addressed these methodological limitations. A large normative sample of up to 1383 participants that ranged in age from 4 to 80 completed the Woodcock Johnson Psycho-Educational Battery-Revised (Woodcock & Johnson, 1989a; Woodcock & Johnson, 1989b) or the Woodcock Johnson Psycho-Educational Battery-Third Edition (Woodcock, McGrew, & Mather, 2001) in combination with the Dean Woodcock Sensory Motor Battery (Dean & Woodcock, 2003) lateral preference scale, a continuous measure of handedness. Polynomial multiple regression analyses indicated curvilinear relationships between handedness and reading comprehension and basic reading skills, along with handedness and auditory working memory. Individuals towards the extremes of the handedness continuum performed lower on the reading related tasks. Therefore, just knowing a general classification of right, left or mixed handed will not provide significant knowledge regarding lateralization or potential cognitive and academic costs and benefits. One overarching implication of these findings is that laterality is an important predictor variable of reading skills and related reading processes, hence knowledge of an individual’s hand preference on a continuum may well be useful for evaluative purposes.

While the preferred arm of right handed individuals has traditionally been viewed as being dominant with respect to motor output, non-preferred arm advantages have recently been described by this laboratory for the matching of target arm positions in the absence of vision. The aim of this dissertation, therefore, was to determine the extent to which this asymmetry reflects arm differences in the utilization of movement-related feedback. To accomplish this, three matching experiments were conducted using servomotor-driven manipulanda devices that recorded elbow position in the horizontal plane. In study 1, a comparison was made between the static position matching abilities of the two arms during visually versus proprioceptively-guided tasks. In this case, non-preferred arm accuracy was found to be enhanced during the proprioceptive task, whereas the preferred arm made smaller errors when targets were visual in nature. In study 2, arm differences in the ability to match proprioceptively-determined target movement speeds were assessed. This study showed that, unlike the sense of arm position, the acuity of dynamic proprioception sense was relatively similar for the two arms, except in the case of average acceleration matching where a non-preferred arm accuracy advantage was seen. Lastly, in the third study, the ability to coordinate both arm position and movement speed proprioceptive information was tested. In this case, absolute matching errors were again smaller for the non-preferred versus preferred arm. Overall, the results of this dissertation lend support to the notion that the two arms rely to different degrees on visual versus proprioceptive feedback. This asymmetry may reflect the roles played by the two arms during the performance of many bimanual activities of daily living where vision guides movements of the preferred arm, while the non-preferred arm plays a more assistive role utilizing primarily proprioceptive feedback.

Recent research on the neuropsychology of emotion and pain has indicated that emotion and pain are complex processes that may substantially influence each other. Disorders of negative emotion and pain are known to co-occur (Delgado, 2004); however, it is not clear whether negative emotional conditions lead to pain or whether increased pain experiences lead to negative emotion. Further, certain negative emotions, such as hostility or anger, may produce differential effects on the experience of pain, such that they may lead to an increase in pain or a decrease in pain. An increase or decrease in pain perception may lead to altered behavioral, cognitive, and neuropsychological effects in high hostility. In order to more clearly examine the aforementioned relationships, the current experiment examined auditory emotion perception before and after cold pressor pain in high and low hostile men. Additionally, quantitative electroencephalography (QEEG) was used to measure changes in cerebral activation as a result of auditory emotion perception and cold pressor pain. Results indicated that identification of emotion post-cold pressor differed as a function of hostility level and ear. The high hostile group increased identification of stimuli at the right ear after cold pressor exposure, while the low hostile group increased identification of stimuli at the left ear after cold pressor exposure. Primary QEEG findings indicated increased left temporal activation after cold pressor exposure and increased reactivity to cold pressor pain in the high hostile group. Low hostile men had a bilateral increase in high beta magnitude at the temporal lobes and a bilateral increase in delta magnitude at the frontal lobes after the cold pressor. Results suggest decreased cerebral laterality and left hemisphere activation for emotional and pain processing in high hostile men.

From a neuropsychological perspective, hostile men have displayed dysregulation of right cerebral systems as evidenced through an exaggerated sympathetic stress response, with cardiovascular reactivity for blood pressure and heart rate. Altered right cerebral functioning, with hostility and anger, has been demonstrated within functional cerebral systems to include auditory (Demaree & Harrison, 1997), visual (Harrison & Gorelczenko, 1990; Herridge, Harrison, Mollet, & Shenal, 2003), somatosensory (Herridge, Harrison, & Demaree, 1997; Rhodes, Harrison, & Demaree, 2002), motor (Demaree, Higgins, Williamson, & Harrison, 2002) and premotor systems (Williamson & Harrison, 2003). Each of these studies has demonstrated cardiovascular reactivity (blood pressure and heart rates measures) concurrently with altered sensory or motor functional correlates of the right hemisphere. However, the neuropsychological mechanisms and functional regulation for the mobilization of glucose have not been examined.

One hundred twenty-six right-handed undergraduate men and women underwent physiological measurements of SBP, DBP, and HR before and after verbal and figural fluency tasks, used as stressors. Dynamic and functional cerebral regulation of cardiovascular reactivity was assessed, specifically, the role that the frontal lobes have in regulating SBP, DBP, and HR in men and women. Sex differences in the functional cerebral regulation of these cardiovascular factors were predicted. Hostility was assessed in these participants, using the Cook-Medley Hostility Inventory (6 total groups of 21 participants each: high-, mid-, and low-hostile participants were identified). Sex and group (hostility) differences were predicted, as well as task (fluency type) differences. Comparisons were also made from a time estimation task (30 and 180 seconds), and the effect that women's menstrual cycle had on fluency. The MCSDS and the STAI were administered. The principal findings of the current investigation were that the verbal fluency task raised SBP across sex and group, that both stressors raised SBP or DBP in different patterns (no sex differences were found), while stressors interacted with both sex and group. High-hostile men performed better on the first trial of the verbal fluency test compared to low-hostile men, while high-hostile women performed worse on the first trial of the verbal fluency test, compared to low-hostile women. Men perseverated more on each trial of the verbal fluency test, while women perseverated less across trials. High-hostile men's time perception seems to be more rapid than low-hostile men, while for women it is the opposite. Women reported significantly more stress from the figural fluency task than men. Women in the luteal phase of menstruation did better on the verbal fluency test than women in the follicular phase of menstruation, and hostility and menstrual phase interact with verbal fluency. This study encourages the consideration of neuropsychological sex differences in order to better understand cardiovascular regulation mechanisms and disease, leading to the development of improved prevention and behavioral management programs. Findings supporting this idea may bring about a new research focus, as some forms of cardiovascular disease may be more appropriately investigated as arising from neuropsychological problems.

Stankov's work on attention and intelligence suggests that the dual task paradigm, requiring the division of attention, is a better measure of general intellectual ability than the single task paradigm which does not make this demand. Sixty right handed undergraduates remembered digit and visual-spatial sequences alone and in two dual task conditions involving lateralized key tapping as the primary task. R gher intercorrelations were found under dual task conditions in which the tasks competed for the same hemisphere's resources. Better memory performance resulted when both tasks were lateralized to the same hemisphere. Hierarchical models combining general attention resources with ,lateralized hemispheric resources best account for these resutsi

Reflective eye movementa as a function of cognitive nodes were studied in English speaking and Spanish bilingual populations (N=20). A total of 40 questions were asked with the initial, lateral eye movement recorded. Questions consisted of 20 verbal-mathematical type intended to elicit right-eye movement and 20 spatial questions intended to elicit left-eye movement. A significant difference in responses was found dependent on the type of questions asked (F=114.3421,p