Perception

• Cornea

  The cornea is a curved transparent covering of the eye, it begins to bend light rays inwards to assist focussing.
• Aqueous Humour

  A watery fluid which helps to maintain the shape of the eyeball and provides nutrients and oxygen to the eye, as well as carrying away waste products
• Iris

  A circular, coloured muscle that expands and contracts to control the amount of light entering the eye (contracts in bright light and for close up vision and expands/dilates during arousal and in dim light).
• Pupil

  An adjustable opening within the iris through which light enters the eye; appears as black. (not a structure but a space!)
• lens

  a transparent, flexible convex structure that changes shape to focus the light onto the retina
• ciliary muscle

  muscles attached to each end of the lens and enables the process of accomodation
• retina

  light sensitive neural tissue/membrane that is made up of several layers of specialised neurons at the back of the eye known as photoreceptors.
• photoreceptors

  receptor cells (either rods or cones) found at the back of the retina, that are specialised to detect and respond to light.
• rod receptors

  rod receptors are located mainly around the outer edge of the retina, have low visual acuity and specialise in night vision. They detect movement and stimuli in the peripheral vision. there are approximately 100 million in each eye. they have a shorter wavelength of light detection.
• cone receptors

  cone receptors are mainly in the centre of the retina and detect fine detail. they have a longer wavelength of light detection. they have 'day vision' and detect colour.
• fovea

  a small cup shaped area near the centre of the retina which has only cones within it and it provides high visual activity.
• blind spot

  contains no photoreceptor cells as it is a small central region of the retina where the optic nerve leaves the eye.
• vitreous humour

  nourishes and supports the retina and helps support the shape of the eyeball.
• optic nerve

  the nerve that connects the eye to the brain.
• occipital lobe

  The occipital lobe sits at the back of the head and is responsible for receiving and processing visual stimuli
• sensory receptors

  receptors in different parts of the body that detect sensory stimuli
• sensation

  a physiological process that involves our initial detection and transmission of a stimulus energy. It is the same process for everyone with regular vision.
• perception

  an active process where the brain responds to the information by selecting, organising and interpreting it in a meaningful way. This is psychologically based and is influenced by a number of factors that are unique to the individual.
• reception

  taking it in! - the process of sensory receptors detecting a stimulus (or changes to a stimulus). EX: as we chew, saliva dissolves chemicals.
• transduction

  turning light into sight! - the process of sensory receptors converting the stimulus into impulses of electrochemical energy for neural activity. EX: tastebuds (chemoreceptors) convert the chemical energy into electrochemical neural impulses.
• electrochemical energy

  refers to energy stored or produced during chemical reactions. electrochemical energy is involved in the process of functioning neurone in the visual system.
• transmission

  from site to brain! - the process where the nerve impulses leave the sensory receptor site and are transmitted to the primary sensory cortex to respond. EX: tastebuds in the mouth send the neural impulses through the thalamus to the primary
• selection

  paying attention!! - filter through the neural impulses by selecting some features for further processing and ignore others (which will receive no further processing). past experiences or context can come into play. it leaves details out simply due to a lack of time to process everything.
• organisation

  finding form!! - the process of reassembling the features of sensory stimuli into meaningful information. once broken down into important parts, the brain then needs to put everything back together and make sense of it. the brain uses 'visual perception principles' to automatically organise info in a meaningful way.
• interpretation

  creating meaning! - involves assigning meaning to sensory stimuli so we understand what it represents in the external world. often relies on past experiences, motives and values.

  
  

  - temporal lobe identifies the object from memory

  - parietal lobe judges where the object is in the space

  - the brain interprets the taste as either pleasant or potentially dangerous.
• visual illusion

  Visual illusions are consistent perceptual errors in

  interpreting a real external stimulus.
• ponzo illusion

  An illusion where 2 horizontal lines of equal length are drawn inside two converging lines but the line in the narrow section of the converging lines is perceived as longer.
• zollner illusion

  Involves a series of parallel lines intersected by short diagonal lines. The parallel lines are truly parallel but despite this because the addition of diagonal lines the illusion is perceived as converging or diverging lines.
• ames room illusion

  caused by an internally distorted room, viewed through a peephole, disrupting perceptual constancies.
• muller-lyer illusion

  the illusion of differing lengths is created by the different figures at the end of each line. it's due to our past experiences of living in a 3D world.
• spinning dancer illusion

  a GIF image of a dancer pirouetting on one foot on a vertical axis. the illusory effect is that the viewer can alternate between perceiving a clockwise/anticlockwise spin. Both directions are possible for the same silhouette.
• agnosia (including causes)

  Agnosia is a rare condition that is usually caused by

  neurological disorder or damage to parts of the brain. It is

  a perceptual disorder, which occurs when a person's

  perceptual processing is impaired, so they have limited

  ability to make sense of sensory information.
• visual agnosia (including characteristics)

  a neurological condition that involves inability to interpret or recognise visual stimuli despite vision completely functioning.
• prosopagnosia

  being unable to recognise faces but able to recognise other objects