Lecture 5 – Visual Perception: Context and TheoriesLast Class: Sensation versus PerceptionSensation – oOccurs in the sensory organs.oEnergy from a physical stimulus in the environment that is picked up by sense organs.Light, sound, smell, etc. Translates this into some sort of neural impulse or signal. Perception – oFollows sensation. oWhen the brain organizes sensed information (organizes those impulses), and translates it/interprets it as something meaningful.Perception – understanding what is around us. McGurk Effect and the Brain We talked about how different senses might interact…People perceive speech as what they see…Compared brain activity for people who experienced the McGurk effect and those people who did not experience this effect.The left superior temporal sulcus is important for audiovisual integration during speech perception. oMore active for people who experienced the McGurk effect. Region is important for integrating senses – so if it is activated more, coupling audiovisual information more tightly that someone who is less susceptible – more influenced by the McGurk effect. Underlying neuromechanisms for this effect. oIndividual differences are seen in the brain!How we take in information is represented in the brain. From the Eyes…Early visual system – oStep 1 – Light waves enter the eye and are focused on the retina, a thin layer of tissue at the back of the eye. oStep 2 – Photoreceptors in the retina (rods and cones) convert light to electrical activity. Rods – dim light visions. Cones – colour and detail. oStep 3 – This electrical signal is sent to bipolar cells then onto ganglion cells.