Gibson's (1979) ecological approach to vision and perception suggested that objects hold motoric information that is automatically perceived upon first sight. This is the theory of affordances. Subsequent research has extensively suggested that the simple viewing of an object can automatically elicit motor response codes for relevant actions. In the present PhD thesis this affordance effect hypothesis was examined under experimental conditions that allowed the properties of this effect to be identified, particularly how it is modulated under different types of vision and attention. The methodological approaches applied included measurements of response times to simple motor tasks, as well as measurements of corticospinal excitability by applying transcranial magnetic stimulation (TMS) techniques. Participants viewed real objects (or depictions of these) associated with specific limb actions (i.e. pinching and grasping), thus allowing associations to be drawn between the physical properties of the stimuli and the recorded reaction times or TMS-induced reactions. First and foremost, behavioural and neurophysiological evidence was provided that visual objects can automatically activate motor programmes for congruent actions, even in cases where there is no need to implement these actions. Furthermore, the temporal evolution of the affordance effect was investigated under various experimental conditions. It was found that object affordances are generated soon after first viewing an object (- 300 ms), but dissipate quite rapidly after that (- 600 ms). Finally, the present studies and findings provided strong evidence that vision and attention serve a pivotal role in the generation of the affordance effect, and that variations in how an object is perceived can greatly affect the way affordances are generated. Overall, the present PhD provided experimental evidence on a highly topical field within Psychology and Neuroscience that concerns the relationship between visual perception and motor planning.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:580657 |
| Date | January 2012 |
| Creators | Makris, Stergios |
| Publisher | City University London |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
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