Virtual environment (VE) systems have been touted as exciting new technologies with many varied applications. Today VEs are used in telerobotics, training, simulation, medicine, architecture, and entertainment. The future use of VEs seems limited only by the creativity of its designers. However, as with any developing technology, some difficulties need to be overcome. Certain users of VEs experience negative side effects from being immersed into the graphically rendered virtual worlds. Some side effects that have been observed include: disorientation, headaches, and difficulties with vision. These negative side effects threaten the safety and effectiveness of VE systems. Negative side effects have been found to develop in a variety of environments. The research focus on VE side effects thus far has been on the symptoms and not the causes. The main goals of this research is fourfold: 1) to compare a new measure for side effects with established ones; 2) begin analyzing the causes of side effects with an analysis of head-tracking; 3) to examine any adaptation that may occur within a session and between days of a session; and, 4) to examine possible predictors for users who may experience side effects. An experiment was conducted using two different VEs with either head-tracking on or head-tracking off over four days. A questionnaire, a balance test, a vision test, and magnitude estimations of side effects were used to assess the incidence and severity of sickness experienced in the VEs. Other assessments, including a mental rotation test, perceptual style, and a questionnaire on pre-existing susceptibility to motion sickness were administered. All factors were analyzed to determine what their relationships were with the incidence and severity of negative side effects that result from immersion into the VEs. Results showed that head-tracking induces more negative side effects than no head-tracking. The maze task environment induces more negative side effects than the office task environment. Adaptation did not occur from day to day throughout the four testing sessions. The incidence and severity of negative side effects increased at a constant rate throughout the 30 minute immersive VE sessions, but did not show any significant changes from day to day. No evidence was found for a predictor that would foretell who might be susceptible to motion sickness in VEs. / Master of Science

Mental rotation skills predict later achievement in STEM (Wai, Lubinski, & Benbow, 2009). Prior research shows that children’s mental rotation skills improve after training (Hawes, Gilligan-Lee, & Mix, 2022; Uttal et al., 2013). However, most studies have used dynamic stimuli where children see objects rotating. We hypothesized that reading books that practice mental rotation with only static images could improve children’ mental rotation skills. We preregistered a pretest-training-posttest design with 4- and 5-year-olds (N = 80). Children completed a mental rotation assessment at pretest, four to six reading days with an experimenter over two weeks in one of two randomly-assigned conditions (Mental Rotation Book Condition versus Control Book Condition), and a mental rotation assessment at posttest. The Mental Rotation Books involved mental rotation practice while the Control Books did not. Consistent with our hypothesis, condition was a significant predictor of posttest mental rotation accuracy, controlling for age, verbal ability, and pretest mental rotation accuracy. Children in the Mental Rotation Book condition significantly improved from pretest (M = .59, SD = .24) to posttest (M = .75, SD = .21), while the control group did not. However, condition was not a significant predictor of posttest mental transformation skills, math achievement, or spatial vocabulary, controlling for age, verbal ability, and respective pretest scores. Book-reading may be a scalable method for improving mental rotation skills in early childhood and warrants further intervention studies using book-reading at home or in schools to improve spatial skills. / Psychology

The present study investigated whether spatial ability is correlated with the ability to accurately recognize faces. A samp~e pf 36 undergraduates were recruited for this study. Participants completed two measures of spatial ability: The Purdue Visualization of Rotations Test as a measure of mental rotation and the Object Location Memory Test as a measure of memory for the location of objects in relation to one another. Facial recognition was measured usipg the Cambridge Face Metnory Test, which measures the recognition of faces in both upright and inverted positions. As predicted, a significant relationship was found between mental rotation and inverted facial recognition, r = .33,p < .05. There was not a significant relationship between object location memory and upright facial recognition, r=.07,p > .05. Interestingly, upright facial recognition was more closely associated with mental rotation, though the relationship did not reach statistical significance r = .24,p > .05. There was not a significant relationship between overall spatial ability and overall facial recognition, r = .17,p > .05. The traditional gender differences were found oh spatial ability such that males outperformed females on mental rotation (Males: M= 12.73, SD= 3.93; Females: M= 9.32, SD= 4.11) and females outperformed males on object location memory (Females: M= 18.80, SD= 5.53; Males: M= 14.09,_ SD= 8.19). A significant gender difference on facial recognition such that females outperform males was not found, which contradicts findings from past J research (McBain, Norton, & Chen, 2009). These results suggest that mental rotation is an important factor in human facial recognition.

In this work, we present a set of methods aimed at improving the discriminative power of time-varying features of signals that contain noise. These methods use properties of noise signals as well as information theoretic techniques to factor types of noise and support signal inference for electroencephalographic (EEG) based brain-machine interfaces (BMI). EEG data were collected over two studies aimed at addressing Psychophysiological issues involving symmetry and mental rotation processing. The Psychophysiological data gathered in the mental rotation study also tested the feasibility of using dissociations of mental rotation tasks correlated with rotation angle in a BMI. We show the feasibility of mental rotation for BMI by showing comparable bitrates and recognition accuracy to state-of-the-art BMIs. The conclusion is that by using the feature selection methods introduced in this work to dissociate mental rotation tasks, we produce bitrates and recognition rates comparable to current BMIs.

This dissertation employed a mixed-methods approach to examine the relationship between spatial reasoning ability and understanding of chemistry content for both middle school students and their science teachers. Spatial reasoning has been linked to success in learning STEM subjects (Wai, Lubinski, & Benbow, 2009). Previous studies have shown a correlation between understanding of chemistry content and spatial reasoning ability (e.g., Pribyl & Bodner, 1987; Wu & Shah, 2003: Stieff, 2013), raising the importance of developing the spatial reasoning ability of both teachers and students. Few studies examine middle school students’ or in-service middle school teachers’ understanding of chemistry concepts or its relation to spatial reasoning ability. The first paper in this dissertation addresses the quantitative relationship between mental rotation, a type of spatial reasoning ability, and understanding a fundamental concept in chemistry, the particulate nature of matter. The data showed a significant, positive correlation between scores on the Purdue Spatial Visualization Test of Rotations (PSVT; Bodner & Guay, 1997) and the Particulate Nature of Matter Assessment (ParNoMA; Yezierski, 2003) for middle school students prior to and after chemistry instruction. A significant difference in spatial ability among students choosing different answer choices on ParNoMA questions was also found. The second paper examined the ways in which students of different spatial abilities talked about matter and chemicals differently. Students with higher spatial ability tended to provide more of an explanation, though not necessarily in an articulate matter. In contrast, lower spatial ability students tended to use any keywords that seemed relevant, but provided little or no explanation. The third paper examined the relationship between mental reasoning and understanding chemistry for middle school science teachers. Similar to their students, a significant, positive correlation between scores on the PSVT and the ParNoMA was observed. Teachers who used consistent reasoning in providing definitions and examples for matter and chemistry tended to have higher spatial abilities than those teachers who used inconsistent reasoning on the same questions. This is the first study to explore the relationship between spatial reasoning and understanding of chemistry concepts at the middle school level. Though we are unable to infer cause and effect relationship from correlational data, these results illustrate a need to further investigate this relationship as well as identify the relationship between different spatial abilities (not just mental rotation) and other chemistry concepts.

This study aimed to better understand visuomotor tracking and spatial visual imagery. 101 Participants performed four tasks: A Manual Tracking Task (MTT), in which participants mouse-tracked the path of a circle, sometimes with occlusion. A Multi-Object Tracking task (MOT), in which participants tracked several objects simultaneously. The Sussex Cognitive Styles Questionnaire (SCSQ), in which participants self-reported their experience with imagery. A Mental Rotation Task (MRT) in which participants mentally rotate Tetris-like objects. The results demonstrated a significant correlation between the technical/spatial subscale of the SCSQ and the occluded MTT, the MRT, the MOT but not the visible MTT. A multiple regression showed that occluded MTT and the MRT together significantly predicted the spatial/technical subscale of the SCSQ above visible MTT and MOT. These findings support the claim that the cognitive resources behind mental imagery may also be recruited during other tasks that arguably draw on the need for internal visualization.

The different spatial experiences in the lives of young boys and girls may partly explain sex differences in spatial skills (Baenninger & Newcombe, 1995; Nazareth et al., 2013; Newcombe, Bandura & Taylor, 1983). While several studies have examined the influence of spatial activities on the development of spatial skills (e.g., Nazareth et al., 2013) there currently exists no widely used comprehensive measure to assess children’s concurrent participation in spatial activities and engagement with spatial toys. Study 1 of the current dissertation filled this gap in the field of spatial research through the creation of the Spatial Activity Questionnaire, a comprehensive survey designed to assess children’s involvement in spatial activities and engagement with spatial toys of diverse gender-typed content. The toys and activities 295 children were reported to have access to and engage with were explored to assess patterns of play with spatial and gender-stereotyped toys and activities. A sample of 76 children between 4 and 6 years of age and their primary caregivers participated in studies 2, 3, and 4 to explore the toys and activities young children have access to and play with (study 2), the link between play and mental rotation (study 3), and the relation between play, gender stereotypes, and mental rotation skills (study 4). Findings reveal great variability in the toys and activities children have access to and play with, with sex difference suggesting girls play with low-spatial and stereotypically feminine toys and activities more than boys while boys play with highly-spatial and stereotypically masculine toys and activities more than girls. Adding to the exiting literature suggesting the inconsistency of sex differences in early mental rotation skills, our results suggest no sex differences in children’s mental rotation ability. Furthermore, no relations were discovered between children’s play, gender stereotypes, and mental rotation ability. These findings point to the need to further explore the influence of play on when and how sex differences in mental rotation ability develop in order to promote fun and easy ways to support spatial learning in young boys and girls.

Previous research has shown a link between the spatial words children use and their performance on spatial reasoning tasks. There is a dearth of measures of spatial language, especially those that focus on a specific type of word. This dissertation introduces three studies, using two measures of dimensional adjective comprehension, one in English and one in Spanish. Study one found that bilingual children’s knowledge of dimensional adjectives in one language is not predictive of their performance on dimensional adjectives in the other language, but that general vocabulary within a language predicts performance in that language. This study also showed that within a pair of polar opposite terms (e.g., long and short) children are more likely to know the term describing the big dimension and not the small dimension than vice versa. The second study found that the number of dimensional concepts children comprehend predicts how well they perform on a spatial scaling test, controlling for age and general vocabulary. The final study failed to find a link between dimensional adjective knowledge and performance on the children’s mental transformation task. These findings might have important implications for early education, showing that supporting children’s understanding of language might have an impact on their spatial reasoning.

An important aspect of cognitive neuroscience is to localise specific brain regions involved in cognitive tasks, and to determine the mediating brain processes. There are several investigative approaches towards this, but amongst them, only transcranial magnetic stimulation (TMS) is able to interfere with the brain in such a way as to show the critical involvement of a brain region in a particular behaviour. TMS can be applied in normal subjects during the performance of a cognitive task and the resulting disruption of activity in the targeted brain region leads to an alteration in, or suspension of, behaviour consequent upon that brain activity. More recently, another brain stimulation technique has emerged that may also be able to contribute to the investigation of human cognition. Transcranial direct current stimulation (tDCS) applies a weak direct current to a targeted brain region, modulating cortical excitability and thereby altering the behavioural output. tDCS may be able to provide information that complements TMS and other investigative techniques by modulating behaviour in a way that depends on the role the brain region is carrying out in the task. This thesis describes a series of experiments in which TMS and tDCS were applied to two well-studied cognitive behaviours, working memory (WM) and mental rotation (MR). WM is the temporary retention of information that can be manipulated in order to guide behaviour. The most popular psychological model of WM proposes a multi-modal central executive (CE) that acts upon information stored in dedicated buffers (Baddeley, 1986). The dorsolateral prefrontal cortex (DLPFC) is a strong candidate as a key CE node (D'Esposito & Postle, 2000; Petrides, 2000b; Smith & Jonides, 1997; Stuss & Knight, 2002). MR is a visuo-cognitive process by which an image can be mentally modified into an orientation other than the one in which it is displayed (Corballis & McLaren, 1984). The area centred around the intraparietal sulcus is a brain key region for MR (Alivisatos & Petrides, 1996; Harris et al., 2000; Jordan et al., 2001). The work presented in this thesis examines the roles of the DLPFC and posterior parietal cortex (PPC) in WM and MR, respectively, and also highlights some of the methodological issues that are necessary to consider in order to produce reliable virtual lesions. The studies were carried out in young healthy volunteers, and were approved by the institutional ethics committee. In one study, repetitive TMS (rTMS) was shown to disrupt the manipulation of verbal information held in WM when administered over the right DLPFC, a result which supports a process-based segregation of the human prefrontal cortex for WM. Low- and high-frequency rTMS did not disrupt performance on another popular test of executive processing, n-back, a result which suggests that specific stimulation and task conditions must be met in order to produce virtual lesions, but also questions the critical importance of recruitment of the DLPFC for a running span task. rTMS applied to the right PPC replicated results from a previous TMS investigation, supporting the critical role this region in the rotation of images (Harris & Miniussi, 2003). When the left PPC was stimulated, impairment was produced only for the rotation of inverted stimuli. A role for the left PPC in the rotation of objects-as-a-whole is proposed based on these findings. The use of tDCS in the investigation of WM and MR is amongst the first to be described. Stimulation of the left DLPFC led to decreased performance accuracy on a verbal WM task in a polarity-specific manner. The pattern of results produced supports the role of the DLPFC as a node of a CE. tDCS over the left DLPFC did not modulate n-back task performance, a result which supports the TMS results that the involvement of the left DLPFC is not critical to the successful performance of the n-back task, although methodological issues remain of concern in relation to this conclusion. MR was not affected by tDCS applied to the right PPC and this result is most likely a direct demonstration of the importance of electrode montage. In conclusion, these studies show that rTMS and tDCS can be usefully applied to create virtual cortical lesions or modulate cortical excitability during the performance of cognitive tasks in humans, and can play an important role in investigating cognitive neuropsychological models. More widespread use of these techniques to complement lesion studies and functional neuroimaging is recommended.

<p>Children’s ability to manipulate objects is the end-point of several important developments. To imagine objects in different positions greatly improves children’s action capabilities. They can relate objects to each other successfully, and plan actions involving more than one object. We know that one-year-olds can insert an object into an aperture. Earlier research has focused on the start and goal of such actions, but ignored the way in between. This thesis shows that children are unable to fit an object into an aperture unless they can imagine the different projections of the object and rotate it in advance. The problem of how to proceed with an object-aperture matching was studied in 14- to 40-month-old children with a box, different holes and a set of fitting wooden blocks. Study I focused on how to orient a single object to make it fit. Studies II and III added a second object or aperture, introducing choice. In Study I there was a huge difference between 18 and 22 months in solving the fitting problem. Successful insertion was related to appropriate pre-adjustments. The older children pre-adjusted the object orientation before arriving at the aperture(s). The younger used a feedback strategy and that did not work for this task. To choose was more difficult than expected; one must not only choose one alternative, but also inhibit the other. Fifteen-month-olds were unable to choose between sizes and shapes, 20-month-olds could choose between sizes, 30-month-olds could choose between sizes and shapes, but not even 40-month-olds could choose between objects with different triangular cross-sections. Finally, the relationships between an object and an aperture, supporting surface or form were investigated. When comparing tasks requiring relationships between an object’s positive and an aperture’s negative form, between a 3D and a 2D, and between two 3D-forms, we found that the main difficulties is relating positive and negative form.</p>