perception Flashcards
attention
process of focusing on specific stimuli whilst ignoring others.
types of attention
sustained: focus on thing over a prolonged period of time without being distracted. deeply focuses, critical for assessing motion info, challenging.
divided: rapidly switching focus, perform multiple tasks, dependent on types of tasks, dont completely change from one to other, necessary for responding to daily events, tasks requiring high level of attention are harder to do divided vs automatic processes. similar tasks harder to do, responses to changing stimuli slower, may miss stimuli.
selective: choose focus on specific thing, ignore others, focus on important to help you survive. can be intentional or automatic, difficult to pay full attention to more than one thing at a time.
where is taste, sight, feel, smell and hear in the body
taste: primary gustatory cortex, frontal lobe
sight: primary visual cortex, occipital lobe
feel: primary somatosensory cortex, parietal lobe
smell: primary olfactory cortex, frontal lobe
hear: primary auditory cortex, temporal lobe
perception
Perception is the process by which we interpret and give meaning to sensory information.
top - down processing
In top-down processing, the perceptual process starts with higher level processing, and then works ‘down’ from the whole to the details.
bottom up processing
In bottom-up processing, the perceptual process starts with the raw sensory data, and then works ‘up’ to the brain for higher level processing.
Biopsychosocial Framework
Biological: Originate within the body. Physiological
psychological: Originate within the mind. Thoughts, cognitions, feelings.
social: Originate outside of the individual. Environmental
Depth Cues – Biological Factor
Depth perception is the ability to accurately estimate the distance of objects and therefore perceive the world in 3D.
monocular and binocular depth cues
monocular: Only need one eye to work. e.g Accommodation, Pictorial Cues. eye muscles bulging and flattening according to how far away an object is. In order to fit a large, close-up object in our visual field, our eye muscles need to cause a lens bulge. However, when focusing on an object in the distance, our eye muscles to flatten our lens.
binocular:Need both eyes to work together. Most useful for objects that are relatively close. EG: Convergence, Retinal Disparity.
pictorial depth cues
monocular
- Relative size: size of objects compared to other objects
- height in visual field: closer to horizon= further away
- Linear perspective: lines get closer as path goes further away
- interposition: partially blocked object is perceived as being further away than the object blocking it.
- texture gradient: The gradual reduction of detail that occurs as objects move further away.
binocular depth cues- convergence, retinal disparity
convergence: brain detects & interprets tension from the eye muscles when the two eyes turn inwards. happens when you focus on something very close to your face.
The greater the muscle tension, the closer the object.
The less the muscle tension, the further the object.
retinal disparity: difference between the images on the retina of the eye when we view something, as each eye sees everything from a different angle. The brain fuses these two images together.
The more different the images, the closer the object.
The more similar the images, the further the object.
Gestalt Principles
large subset of visual perception principles. Specifically, they refer to the principles that help us to make sense of visual stimuli by grouping together separate phenomena into meaningful wholes.
4 gestalt principles
figure ground: The figure (object) stands out against a less prominent ground (background). Reversible figures - figure and ground can be switched.
closure: we close up, fill in, or ignore gaps and see the object/s as complete.
similarity: We tend to see stimuli that are similar in size, shape, colour or form as forming a group. When similarity occurs, an object can be emphasised if it is dissimilar to the others. This is called anomaly
proximity: Stimuli that are positioned close together are seen as forming a group. The tendency to perceive parts of an image that are positioned close together as belonging to a group.
social factors- perceptual set
previous experience: ‘Sets’ predispose us to perceive information in a particular way.
context: The environment or setting in which a perception is made. not always accurate. not always accurate.
motivation: create behaviour designed towards achieving a particular goal. We see what we want to see rather than what was actually there.
emotional state: How we are feeling
cultural factors: Experience with a particular culture. Includes features that distinguish it from other communities such as the customs, traditions, beliefs, values and attitudes.
ambiguous figures: Visual stimuli that can be interpreted in more than one way. Our past experience determines what we see first
visual illusions
distortions of perceptions of visual images
misjudge the visual stimuli
the brain is tricked and not the eye.
powerful demonstrations of when visual perceptual principles fail to provide us with accurate interpretation of actual visual stimuli.
