Perception Flashcards
What is perception?
The psychological process by which stimulation of the senses is translated into meaningful experience.
What is sensation?
The physical process that precedes the organisation and interpretation of the external stimuli by the brain.
What are the 3 stages of the perceptual process?
- Stimulus.
- Electrical signal.
- Experience and action.
What is bottom-up processing?
The processing of incoming sensory input as it travels up from the sensory structures to the brain.
What is top-down processing?
The brain uses knowledge, beliefs, and expectations to interpret sensory information.
What is perceptual organisation?
The bits of incoming sensory data must be organised into meaningful wholes in order to be interpreted.
What is the figure and ground principle?
The brain organises the sensory input into:
- Figure (the centre of attention).
- Ground (the less distinct background).
What is occlusion?
When one object hides or partially hides another from view.
- Provides information about an objects relative distance.
What is relative size?
When two objects are of equal size, the one that is further away will take up less of your field of view than the closer one.
What is relative height?
Objects higher in the field of view are usually seen as more distant.
What are examples of monocular cues?
- Occlusion.
- Relative size.
- Relative height.
- Perspective convergence.
- Texture gradient.
- Shadow.
- Motion parallax.
What is an example of a binocular cue?
Retinal disparity
What is retinal disparity?
The slight difference in what each eye sees when looking at the same object.
Why are neurons in V1 orientation and edge detectors?
They respond to bars of light oriented in a particular direction.
What is functional specialisation?
Different cortical areas are specialised for different visual functions.
What is the vision for perception (or ‘what’) system?
It processes shape, size, objects, orientation, and text information.
- Object recognition.
What is the vision for action (or ‘how’) system?
Processes location, distance, position, and motion.
- Visually guided action.
What is visual form agnosia?
A condition involving severe problems with object recognition even though visual information reaches the visual cortex.
What is optic ataxia?
A condition involving severe problems with the use of vision to guide movements.
Symptoms of optic ataxia.
- Poor at making precise visually guided movements.
- Can recognise objects or line drawings.
Explain the process that leads to the correct categorisation of a source.
- The sound wave reaching the ear includes the superimposed effects of multiple sound events.
- Components from the independent sound events need to be segregated and components that belong to the same event integrated.
What are binaural cues in sound localisation?
Cues are based on a comparison of the signals reaching the left and right ear.
What are examples of binaural cues?
Interaural time difference:
- The difference in when a sound reaches the left and right ears.
Interaural level difference:
- The difference in the sound pressure level of sound reaching the two ears.
- Occurs because of the barrier created by the head.
What are monoaural cues in sound localisation?
Cues based on the spectrum of frequencies that reach the ear.
What is an example of a monoaural cue?
Spectral cue:
- The difference in the spectrum of frequencies that reach the ear.
- Caused by the reflections of the sounds from the head and within the folds of the pinna.
What are auditory areas characterised by?
- Hierarchial processing.
- Tonotopy.
What are “what” streams responsible for?
Recognising the identity and content of a sound source.
What are “where” streams responsible for?
Indicating location and direction of sound sources.
What is somatosensation?
The ability to sense and perceive:
- Touch.
- Proprioception.
- Temperature.
- Pain.
- Itch.
What is the homunculus?
Parts of the body with the highest tactile acuity are represented by larger cortical areas.
What is proprioception?
The sense of body position and movement.
- It is a subconscious process that allows you to know where your body is in space without relying on sight.
What do chemical senses do?
- Identify things that the body needs for survival - should be consumed.
- Detects things that would be harmful for the body - should be rejected.
Why do chemical senses undergo neurogenesis?
Their receptors are exposed to potentially harmful chemicals (e.g., bacteria).
- Neurogenesis is unique to these senses.
