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.

Many architects report about mentally visualizing 3D aspects of their design ideas while simply working with 2D sketches of them. Indeed, in architecture, the general practice of conveying 3D building information by means of 2D drawings bears on the assumptions that every architect can mentally visualize a building in 3D by looking at its 2D drawings or sketches and that architects, as many report, can capture the 3D aspects of a building design during such 3D mental visualization practices. Additionally, many intuitively believe that the levels at which architects perform such 3D mental visualization practices is highly correlated to their spatial visualization abilities as defined by existing measures of spatial visualization ability. This thesis presents the outcomes of protocol studies and analyses that were conducted with the aim of developing an in-depth understanding about such 3D mental visualization practices and capabilities of architects on the basis of four research questions. First, what might be the nature of the 3D mental visualization phenomena that architects claim to experience: what are the features of these 3D mental visualizations as evidenced in specific tasks; and what might be the nature of the mental representations created during these visualization processes? Second, can every architect carry out these 3D mental visualization practices; might there be individual differences among architects' performances? Third, might 3D mental visualization of buildings be only an architectural skill; can non-architects, who can read 2D architectural drawings, visualize a building in 3D based on its 2D drawings and can they do so to the same levels of performance of those of architects? Fourth, might performance in 3D mental visualization tasks be related to/predicted by spatial visualization ability? The major conclusions of this thesis with regard to the first research question include that (1) architects can be visualizing the buildings in one of the two major forms or by alternatively switching between them: by imagining themselves situated within (almost) the actual size 3D building environment or by imagining a 3D small scale model of the building; (2) the mental representations they create during these visualization processes capture the various visual and spatial aspects of the buildings with a structure similar to that of an actual size or small scale model of the visualized space/form, yet the way they capture these aspects is not like the way these aspects would be captured from a certain viewpoint in reality; and (3) what they experience during these visualization processes is not like the continuous holistic visuospatial experience that one would have when looking at a building or walking inside/around a building. With regard to the second, third and fourth research questions this thesis concludes that (question 2) architects differ in their 3D mental visualization skills; (question 3) 3D mental visualization is an architectural skill in that it relies on certain abilities that become heightened in architects, possibly during education; and (question 4) 3D mental visualization skills are not related to spatial visualization ability as defined by the standard paper-folding test of spatial visualization ability.

This thesis explores neural activity associated with processing of rotated alphanumeric characters, focusing particularly on linear and quadratic trend components of orientation-dependent activity. Choice of these components was driven by results of reaction-time (RT) studies; judging whether characters are normal or backward (parity task) typically elicit RTs that are linearly related to character disorientation, implying mental rotation of the characters to the upright, while judging whether they are letters or digits (categorisation task) elicits RTs related nonlinearly to disorientation, combining both linear and quadratic component, but not indicative of mental rotation. In Experiment 1 neural activity was monitored using fMRI while participants performed these tasks. In the next two experiments, neural processing was monitored with high-density EEG. In Experiment 2 participants performed the same two tasks, while in Experiment 3 they performed the category task and red-blue colour judgements. In Experiment 1, linear increases in fMRI activation were elicited only by the parity task and were observed in the posterior portion of the dorsal intraparietal sulcus and lateral and medial pre-supplementary motor areas, suggesting a fronto-parietal network underlying mental rotation. Experiment 2 showed that linear increases in parietal negativity between 350 and 710 ms only evident in the parity task, again indicating that mental rotation is only elicited by that task. Contrary to previous evidence, Experiment 2 indicated that both hemispheres may be involved in mental rotation, but rotation is faster in the right hemisphere than in the left hemisphere. Experiment 1 also showed that effects of orientation common to both tasks were best characterised by a quadratic trend, and were restricted to the supramarginal gyrus. This activation was interpreted as representing orientation-dependent shape recognition. Experiments 2 and 3 also revealed orientation-dependent neural activity at three distinct stages prior to mental rotation. First, on the P1 component, there was a difference between oblique and vertical orientations, suggesting the extraction of orientation based on axis of elongation. Next, orientation affected the N1 component, with longer latencies and larger amplitudes with misorientation, and smaller effects for inversion than for intermediate angular rotations. Finally, changes in orientation affected the P2 component differently for the parity and category tasks, probably signalling the perception of orientation relative to a parity-defined memory representation, and serving as a preparation for mental rotation. These experiments identify both the orientation-specific neural processing that occurs prior to the onset of mental rotation, and the subsequent neural correlates of mental rotation itself. / Top Achiever Doctoral Scholarship, University of Auckland Doctoral Scholarship, The New Zealand Neurological Foundation, University of Auckland Research Fund (Project numbers: 3607199, 3605876 3604420)

This thesis explores neural activity associated with processing of rotated alphanumeric characters, focusing particularly on linear and quadratic trend components of orientation-dependent activity. Choice of these components was driven by results of reaction-time (RT) studies; judging whether characters are normal or backward (parity task) typically elicit RTs that are linearly related to character disorientation, implying mental rotation of the characters to the upright, while judging whether they are letters or digits (categorisation task) elicits RTs related nonlinearly to disorientation, combining both linear and quadratic component, but not indicative of mental rotation. In Experiment 1 neural activity was monitored using fMRI while participants performed these tasks. In the next two experiments, neural processing was monitored with high-density EEG. In Experiment 2 participants performed the same two tasks, while in Experiment 3 they performed the category task and red-blue colour judgements. In Experiment 1, linear increases in fMRI activation were elicited only by the parity task and were observed in the posterior portion of the dorsal intraparietal sulcus and lateral and medial pre-supplementary motor areas, suggesting a fronto-parietal network underlying mental rotation. Experiment 2 showed that linear increases in parietal negativity between 350 and 710 ms only evident in the parity task, again indicating that mental rotation is only elicited by that task. Contrary to previous evidence, Experiment 2 indicated that both hemispheres may be involved in mental rotation, but rotation is faster in the right hemisphere than in the left hemisphere. Experiment 1 also showed that effects of orientation common to both tasks were best characterised by a quadratic trend, and were restricted to the supramarginal gyrus. This activation was interpreted as representing orientation-dependent shape recognition. Experiments 2 and 3 also revealed orientation-dependent neural activity at three distinct stages prior to mental rotation. First, on the P1 component, there was a difference between oblique and vertical orientations, suggesting the extraction of orientation based on axis of elongation. Next, orientation affected the N1 component, with longer latencies and larger amplitudes with misorientation, and smaller effects for inversion than for intermediate angular rotations. Finally, changes in orientation affected the P2 component differently for the parity and category tasks, probably signalling the perception of orientation relative to a parity-defined memory representation, and serving as a preparation for mental rotation. These experiments identify both the orientation-specific neural processing that occurs prior to the onset of mental rotation, and the subsequent neural correlates of mental rotation itself. / Top Achiever Doctoral Scholarship, University of Auckland Doctoral Scholarship, The New Zealand Neurological Foundation, University of Auckland Research Fund (Project numbers: 3607199, 3605876 3604420)

This thesis explores neural activity associated with processing of rotated alphanumeric characters, focusing particularly on linear and quadratic trend components of orientation-dependent activity. Choice of these components was driven by results of reaction-time (RT) studies; judging whether characters are normal or backward (parity task) typically elicit RTs that are linearly related to character disorientation, implying mental rotation of the characters to the upright, while judging whether they are letters or digits (categorisation task) elicits RTs related nonlinearly to disorientation, combining both linear and quadratic component, but not indicative of mental rotation. In Experiment 1 neural activity was monitored using fMRI while participants performed these tasks. In the next two experiments, neural processing was monitored with high-density EEG. In Experiment 2 participants performed the same two tasks, while in Experiment 3 they performed the category task and red-blue colour judgements. In Experiment 1, linear increases in fMRI activation were elicited only by the parity task and were observed in the posterior portion of the dorsal intraparietal sulcus and lateral and medial pre-supplementary motor areas, suggesting a fronto-parietal network underlying mental rotation. Experiment 2 showed that linear increases in parietal negativity between 350 and 710 ms only evident in the parity task, again indicating that mental rotation is only elicited by that task. Contrary to previous evidence, Experiment 2 indicated that both hemispheres may be involved in mental rotation, but rotation is faster in the right hemisphere than in the left hemisphere. Experiment 1 also showed that effects of orientation common to both tasks were best characterised by a quadratic trend, and were restricted to the supramarginal gyrus. This activation was interpreted as representing orientation-dependent shape recognition. Experiments 2 and 3 also revealed orientation-dependent neural activity at three distinct stages prior to mental rotation. First, on the P1 component, there was a difference between oblique and vertical orientations, suggesting the extraction of orientation based on axis of elongation. Next, orientation affected the N1 component, with longer latencies and larger amplitudes with misorientation, and smaller effects for inversion than for intermediate angular rotations. Finally, changes in orientation affected the P2 component differently for the parity and category tasks, probably signalling the perception of orientation relative to a parity-defined memory representation, and serving as a preparation for mental rotation. These experiments identify both the orientation-specific neural processing that occurs prior to the onset of mental rotation, and the subsequent neural correlates of mental rotation itself. / Top Achiever Doctoral Scholarship, University of Auckland Doctoral Scholarship, The New Zealand Neurological Foundation, University of Auckland Research Fund (Project numbers: 3607199, 3605876 3604420)

This thesis explores neural activity associated with processing of rotated alphanumeric characters, focusing particularly on linear and quadratic trend components of orientation-dependent activity. Choice of these components was driven by results of reaction-time (RT) studies; judging whether characters are normal or backward (parity task) typically elicit RTs that are linearly related to character disorientation, implying mental rotation of the characters to the upright, while judging whether they are letters or digits (categorisation task) elicits RTs related nonlinearly to disorientation, combining both linear and quadratic component, but not indicative of mental rotation. In Experiment 1 neural activity was monitored using fMRI while participants performed these tasks. In the next two experiments, neural processing was monitored with high-density EEG. In Experiment 2 participants performed the same two tasks, while in Experiment 3 they performed the category task and red-blue colour judgements. In Experiment 1, linear increases in fMRI activation were elicited only by the parity task and were observed in the posterior portion of the dorsal intraparietal sulcus and lateral and medial pre-supplementary motor areas, suggesting a fronto-parietal network underlying mental rotation. Experiment 2 showed that linear increases in parietal negativity between 350 and 710 ms only evident in the parity task, again indicating that mental rotation is only elicited by that task. Contrary to previous evidence, Experiment 2 indicated that both hemispheres may be involved in mental rotation, but rotation is faster in the right hemisphere than in the left hemisphere. Experiment 1 also showed that effects of orientation common to both tasks were best characterised by a quadratic trend, and were restricted to the supramarginal gyrus. This activation was interpreted as representing orientation-dependent shape recognition. Experiments 2 and 3 also revealed orientation-dependent neural activity at three distinct stages prior to mental rotation. First, on the P1 component, there was a difference between oblique and vertical orientations, suggesting the extraction of orientation based on axis of elongation. Next, orientation affected the N1 component, with longer latencies and larger amplitudes with misorientation, and smaller effects for inversion than for intermediate angular rotations. Finally, changes in orientation affected the P2 component differently for the parity and category tasks, probably signalling the perception of orientation relative to a parity-defined memory representation, and serving as a preparation for mental rotation. These experiments identify both the orientation-specific neural processing that occurs prior to the onset of mental rotation, and the subsequent neural correlates of mental rotation itself. / Top Achiever Doctoral Scholarship, University of Auckland Doctoral Scholarship, The New Zealand Neurological Foundation, University of Auckland Research Fund (Project numbers: 3607199, 3605876 3604420)

La rotation mentale (RM) est la capacité à faire tourner mentalement l’image d’un objet en 2 ou en 3 dimensions. C’est une forme d’imagerie mentale qui nécessite des transformations visuo-spatiales. Au regard de sa nature dynamique, la RM se trouve à l’interface entre imagerie mentale et imagerie motrice. Le transfert de RM, ainsi que ses liens avec les processus moteurs, restent à ce jour controversés. Les résultats de ce travail montrent qu’un entraînement spécifique à la RM améliore la performance aux tests de RM, tel que celui de Vandenberg et Kuse (VMRT). Suite à cet entraînement, les différences de genre sont atténuées. Un transfert vers l’apprentissage de l’anatomie a également été observé, attestant de l’existence de micro-compétences, ou micro-expertises, communes entre RM et apprentissage de l’anatomie. Les résultats montrent que ce transfert s’opère aussi dans l’autre sens, de l’apprentissage de l’anatomie vers la perception spatiale d’un mouvement sportif. Dans le même ordre d’idée, chez les enfants, la RM partagerait des micro-expertises avec la motricité lorsque celle-ci intègre des roulades, des changements de directions ou des sauts. L’ensemble des résultats expérimentaux met en évidence qu’un programme d’entraînement spécifique visant l’amélioration de la capacité de RM peut donc se transférer vers l’acquisition de connaissances en anatomie, la motricité, ainsi que le développement moteur de l’enfant. L’émergence de la différence de genre en RM et en imagerie motrice, quant à elle, varie selon les tests utilisés. Pour le VMRT, elle serait effective à partir de l’âge de 9 ans. De nouvelles recherches sur la chronométrie mentale permettront sans doute de déterminer l’émergence de cette différence de genre au regard de la précision de l’imagerie motrice / Mental rotation (MR) is the ability to rotate the mental image of a 2D or 3D object. The relationship between MR and motor processes, as well as the transfer of MR, is still debated in the literature. The present results provided evidence that a specific MR training might contribute to enhance the MR ability, and the performance on the MR tests such as the Vandenberg and Kuse MR test (VMRT). Interestingly, gender differences were attenuated following training. A transfer was further observed on human anatomy learning. MR training and human anatomy learning are therefore hypothesized to share similar micro-competences. Our results also showed a transfer from anatomy learning to the spatial perception of a motor skill. Finally, MR has been found to share some micro-competences with motor performance requiring performing a forward roll, changing of directions and jumping. Hence, MR would be useful for the motor performance itself. Altogether, our results provided evidence that a specific MR training can be transferred to the human anatomy learning process, motor performance, as well as to child motor development. While the emergence of gender differences in MR might depend on the test used, such difference would be effective at 9 years of age for the VMRT. So far, future research remains necessary to determine in greater details the emergence of motor imagery accuracy in regards to its temporal aspects

Research on mental rotation has consistently found sex differences, with males outperforming females on mental rotation tasks like the Vandenberg and Kuse (1978) mental rotation test (MRT; D. Voyer, Voyer, & Bryden, 1995). Mental rotation ability has been found to be enhanced with experience (Nazareth, Herrera & Pruden, 2013) and training (Wright, Thompson, Ganis, Newcombe, & Kosslyn, 2008) and the effects of training have been found to be transferable to other spatial tasks (Wright et al., 2008) and sustainable for months (Terlecki, Newcombe, & Little, 2008). Although, we now are fairly certain about the malleability of spatial tasks and the role of spatial activity experience, we seem to have undervalued an important piece of the puzzle. What is the mechanism by which experiential factors enhance mental rotation performance? In other words, what is it that develops in an individual as a consequence of experience? The current dissertation sought to address this gap in the literature by examining cognitive strategy selection as a possible mechanism by which experiential factors like early spatial activity experience enhance mental rotation performance. A total of 387 adult university students were randomly assigned to one of three experimental conditions. The three experimental conditions differed in the amount and type of non-spatial information present in the task stimuli. Participant eye movement was recorded using a Tobii X60 eye tracker. Study I investigated the different types of cognitive strategies selected during mental rotation, where eye movement patterns were used as indicators of the underlying cognitive strategies. A latent profile analysis revealed two distinct eye movement patterns significantly predicting mental rotation performance. Study II examined the role of early spatial activity experience in mental rotation performance. Male sex-typed spatial activities were found to significantly mediate the relation between participant sex and mental rotation performance. Finally, Study III examined the developmental role of early spatial activity experience in cognitive strategy selection and strategy flexibility to enhance mental rotation performance. Strategy flexibility was found to be significantly associated with mental rotation performance. Male sex-typed spatial activity experiences were found to be significantly associated with cognitive strategy selection but not strategy flexibility. Implications for spatial training and educational pedagogy in the STEM fields are discussed.

Observing others performing actions is a common way to learn new motor skills. Such ability appears to be linked with one’s ability to imagine actions (motor imagery) (Wang et al. 2014). While motor imagery has been widely used in the context of athletic performance, the same approach has also been advocated in rehabilitation settings, where they often target populations with chronic pain using mobile health applications (de la Vega and Miro 2014). However, we still have very limited information as to how the ability to perform motor imagery addresses this rehabilitation application (Johnson et al. 2012). In the present study, we examined this question by looking at modulation in corticospinal excitability in the context of a motor imagery task. The imagery task itself consisted of judging whether images depicting hands in different postures represented either right or left hands. Based on prior neuroimaging and chronometric studies, such laterality judgments about hand postures are thought to involve mental rotations of one’s own hand (i.e., a form of implicit motor imagery) and thus provided an ideal context to evaluate if advocating such strategy is a valid approach to elicit motor activation in rehabilitation patients (Butson et al. 2014; Goble and Brown 2008; Parsons 1987). To this end, we used non-invasive transcranial magnetic stimulation (TMS) to probe the excitability of the motor system while young healthy participants performed mental rotations in the hand judgment task. Corticospinal excitability was tested in both hemispheres separately (target muscle: first dorsal interosseous) with participants (n=18) seated in front of a computer screen while they performed hand laterality judgments using a commercial set of pictures depicting bare hands in different postures. Excitability was tested also under two other conditions to contrast with variations measured during the hand laterality task, i.e. a mental counting task and a control task (looking at the image of a static foot). In all conditions, TMS (110% resting motor threshold) was set to trigger at ~half of the mean response time in the hand laterality task measured prior to testing with TMS. Comparison of task-related variations in MEP amplitude revealed no significant hemispheric main effect or interaction, although MEPs tended to be larger in general in response to left TMS. A “task condition” effect was observed owing to the large MEP facilitation elicited during the mental counting task, which was significantly different (p<0.001) from either the control “Foot” task or the hand rotation task. In fact, the latter task tended to be associated with MEP depression. A secondary experiment involving a subset of participants (n=6) to examine the influence of image contents (i.e. hand performing actions instead of bare hands) and probing more proximal muscles produced similar results as the main experiment. These results indicate that the general assumption that laterality tasks involving body parts will lead to internal mental rotation and motor activation and enhanced excitability is not necessarily true. In fact, our observations suggest that participants may rely on non-motor strategies based on visual cues when making laterality judgments about body parts. As well, no evidence for hemispheric asymmetry was found with the hand laterality task which is in line with other recent reports. Collectively, these results highlight the need to exert caution when using laterality tasks for rehabilitation purposes. One cannot simply assume that such tasks will translate into motor simulation and facilitation of the motor system. More research should be undertaken before recommending the hand mental rotation task as a viable rehabilitation option for chronic pain.

This dissertation investigated the effects of complex backgrounds on mental rotation. Stimulus familiarity and background familiarity were manipulated. It systematically explored how familiarizing participants to objects and complex backgrounds affects their performance on a mental rotation task involving complex backgrounds. This study had 113 participants recruited through the UCF Psychology SONA system. Participants were familiarized with a stimulus in a task where they were told to distinguish the stimulus from 3 other stimuli. A similar procedure was used to familiarize the backgrounds. The research design was a 2 stimulus familiarity (Familiarized with the Target Stimulus, not familiarized with the Target Stimulus) by 2 background familiarity (Familiarized with Target Background, not familiarized with Target Background 1) by 2 stimulus response condition (Target Stimulus, Non-Target Stimulus) by 3 background response condition (Target Background, Non-Target Background, Blank Background) by 12 degree of rotation (0, 30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330) mixed design. The study utilized target stimulus and target background familiarity conditions as the between-subjects variables. Background, stimulus, and degree of rotation were within-subjects variables. The participants' performance was measured using reaction time and percent of errors. Reaction time was computed using only the correct responses. After the familiarization task, participants engaged in a mental rotation task featuring stimuli and backgrounds that were present or not present in the familiarization task. A 2 (stimulus familiarization condition) by 2 (background familiarization condition) by 2 (stimulus response condition) by 3 (background response condition) by 12 (degree of rotation) mixed ANOVA was computed utilizing reaction time and percent of errors. Results suggest that familiarity with the Target Background had the largest effect on improving performance across response conditions. The results also suggest that familiarity with both the Target Stimulus and Target Background promoted inefficient mental rotation strategies which resulted in no significant differences between participants familiarized with neither the Target Stimulus nor the Target Background. Theoretical conclusions are drawn about stimulus familiarity and background familiarity. Future studies should investigate the effects of long term familiarity practice on mental rotation and complex backgrounds.