Psychology Topic A Notes

What is Perception?

·         Perception is the way in which we make sense of a virtual or real image. Perception occurs in the brain and allows us to understand what we see.

Rods;they can detect movement when someone’s moving. Rods are sensitive to light and responds to movement.

Cones;they can detect colour, so we can see bright colours instead of a grayscale world. Cones are less sensitive to light but can detect colour.

What is the blind spot?

·         The blind spot is the area which there are no rods or cones going towards the optic nerve. This means that we don’t see things that appear on a sheet of paper (e.g.  – the blind spot test).

What is the role of the Optic Chiasma?

·         The Optic Chiasma is the brain in which some information from each eye crosses the opposite side of the brain, it then crosses over and creates an image in the brain.

Cornea – the clear, dome shaped tissue covering the front of the eye.

Iris – the coloured part of the eye - controls the amount of light that enters the eye by changing the size of the pupil.

Optic nerve – the nerve that transmits electrical impulses from the retina to the brain.

Pupil – the opening in the centre of the iris – it changes size as the amount of the light changes (the more light, the smaller the hole).

Retina– sensory tissue that lines the back of the eye. It contains millions of photoreceptors (rods and cones) that convert light rays into electrical impulses that relayed to the brain via the optic nerve.

Lens – a crystalline structure located just behind the iris - it focuses light onto the retina.

Monocular Depth cues:

Size Constancy; It is something that happens when you perceive depths (not a depth cue). When an object is far/near, it determines the depth of the object. The brain can help us to get a better perspective of the object in the eyes vision. {close – scaled down. Far – scaled up.}

Relative size; Objects making bigger images on the retina are perceived as being closer than ones making smaller images. They also indicate depth in photographs and drawings (we perceive bigger objects as being closer and small objects to be farther away).

Texture Gradient; Is when there’s more detail, and how we see the detail. The closer the object, the more detail you can see, and if the object is far away, the detail is vague, and not much detail.

Superimposition; Superimposition is when the position of one object puts it in front of another. The object blocking a focused object is closer, and the focused object will be further away, because it had been blocked.

Height in the Plane; This is when you have a scene, and the lowest parts is closer to you than the highest part of the scene…