Visuo-haptic integration in perception and cognition

<p dir="ltr">Visuo-haptic perception is the integration of the visual and haptic perceptual modalities. These modalities are important to us in our everyday lives to navigate through and interact with, the world around us. Literature to date has attempted to investigate these two modalities independently and cross-modally to understand their weighting across different properties available for perception. There is a large body of evidence on visuo-haptic perception, however there are many methodological details that are inconsistent and have ultimately ‘muddied the waters’ in terms of understanding the application of their findings. To date, and to our knowledge, no body of research has investigated the unimodal and cross-modal transfer of visuo-haptic perception, across the three properties of surface, size and shape, using the same 3D stimuli presented haptically as it is visually. The current thesis aimed to do just that and to clear the waters around visuo-haptic perception of surface, size and shape. Furthermore, this thesis examined potential sex differences, and the role confidence plays in visuo-haptic perception, as well as how online visual research can compare to results obtained in laboratory (in-person) settings. Overall, there were little differences between the unimodal and cross-modal transfer of information in terms of surface and size perception, with both vision and haptics being accurate at each task. There were some noticeable differences in the shape study with vision having the better overall performance. The cross-modal transfer of information was surprisingly accurate across the difference property judgements, highlighting how well the separate information can be integrated to make accurate judgments. There were minimal sex differences to report, beyond that of a unimodal preference for women and cross-modal preference for men in terms of shape discrimination. There were no differences between confidence scores across the participants in each modality condition, however, overall, the confidence scores were low considering the performance on each task was relatively high. The online studies showed that performance on size and shape judgement was hindered by being online and using static images, putting into question how generalisable online studies are to real world visual perception.</p>