These lectures consider why the world seems like it does to us. We will explore the field of perception, focusing mainly on vision, from the low-level firing of sensory receptors, through the perception of complex forms in 3D space, to visual attention and the use of vision to guide action. Throughout, there will be an emphasis on key concepts with wide applicability in psychology, for instance: that the brain has evolved to reconstruct reality in a way that is useful to us; that we are wired to detect sudden changes, as this is where the important new information is likely to be; that the brain employs special mechanisms to separate (interesting) changes in the world from (irrelevant) variations in the pattern of stimulation; that the brain continuously makes predictions about the world and tests these against sensory evidence; that speed is vital, so it uses short cuts and heuristics, which often involve assumptions about the world; that the brain solves complex problems by breaking them down into simpler sub-problems; and that we can often learn most about how a complex system is organised by studying situations where it makes mistakes. For this last reason, we will look at many examples of visual illusions, which help to illustrate many of the main tricks and short-cuts that our perceptual systems use.
Learning outcomes: by the end of this section, students should be able to:
- Understand the concept of perception as a function adapted for gathering relevant information from the environment
- Understand how perceptual experience can be measured and related to the physical properties of stimuli.
- Understand ways in which perceptual experience can be explained by low-level physiological processes
- Appreciate the distinction between bottom-up and top-down processes, and the roles they play in perception
Schacter , Gilbert & Wegner. Psychology Second European Edition (2016), Chapter 4: Sensation & Perception.
Snowden, R., Thompson, P. & Troscianko, T. (2012) Basic vision: An introduction to visual perception. Oxford UP, 2nd edn.
Wolfe, J.M., Kluender, K.R. & Levi, D. M. (2015) Sensation and perception. Sinauer, 4th edn.
NB – earlier editions of all three books can be used.