Sensation & Perception Lectures 1-3 Flashcards
Sensation & Perception Lecture 1
What is the Turing test?
→The Turing test is a test of a machine’s ability to exhibit intelligent behaviour equivalent to, or indistinguishable from, that of a human.
→The test involves a human judge engaging in conversation with another human, as well as a machine designed to generate performance indistinguishable from a human. If the judge cannot reliably tell between the human and the machine, the machine has passed the test.
What is the difference between sensation and perception?
Sensation: is the process by which sense organs gather information and transmit it to the brain for initial processing.
→It is the raw and not meaningful
Perception: is the process in which the brain interprets those sensations and gives them meaning
→It is meaningful
What is the difference between bottom-up and top-down processing?
Bottom-up processing→the role of sensory data in shaping perception
Top-down processing→the influence of prior experience/knowledge in shaping perception
Bottom-up processing is the role of current sensations in shaping our perception, whereas top-down processing utilizes our prior knowledge and experience to shape perception. In other words, we typically interpret bottom-up information using top-down knowledge.
What is perception based on? How does perceptual interpretation work?
Perceiving is a construction based on prior knowledge. Sensations are interpreted based on your past experiences and knowledge. When seeing and perceiving, an individual interprets bottom-up information using top-down knowledge.
How are senses transmitted to the brain for processing and interpretation? How does it become a perception?
Energy or signal→ Sensor (transducer→converts signals into neural impulses)→Pathway→Sensation becomes perception
What is the difference between white and gray matter?
→Gray matter is gray because of the nucleus, thus an area with lots of cells is going to be darker and appear gray due to the nucleus. This is responsible for processing and thinking.
→White matter is white due to the myelin sheath. This is responsible for transportation or transmission.
What is the concept of spatial frequency?
Low spatial frequency: less detailed visual images→blurry images
High spatial frequency: high detailed visual images→sharp, crisp visual images
What are cones and rods? What is the purpose of cones and rods?
Cones:
→Cones are located in the center of the retina.
→Otopic-important in daylight vision
→Important for colour vision
Rods:
→Rods are only located in the periphery region of the retina and not in the fovea (the center of the retina).
→Scotopic→Rods are most useful during the night
→Rods are ‘colourblind’ →cannot differentiate colour
→There are no rods in the fovea since only cones exist in the fovea (center of retina). Thus we are technically blind in that area at night time.
What is the difference between colour blindness versus achromatopsia?
Colour blindness: means that the eye cannot differentiate between red/green or blue/yellow.
Achromatopsia: is when an individual cannot see any colours at all.
What is filling in?
The reason we do not see a hole in our vision due to our blind spot is due to filling in. The brain just fills in the ‘hole’ with what is supposed to be there.
What is brain plasticity?
Brain plasticity is the way the brain can re-organise itself and use different parts of the brain for different things.
How are visual fields represented on the brain (left-right/up-down)?
Left-visual field is represented in the right side of the brain
Right-visual field is represented in the left side of the brain
→Temporal stays on the same side, nasal part crosses over
→Upper and lower visual fields
What are hemianopia, quadrantanopia, and a scotoma?
Hemianopia: the complete right upper and lower visual field does not function thus the person is blind in the right eye (lesion is in the left-brain).
Scotoma: there is a blind spot in the upper right visual field (lesion is in the left brain).
Quadrantanopia: the complete upper right visual field does not function (lesion is in left brain).
What is the dorsal pathway?
Dorsal “Where” Pathway:
- Magno cells (large cells)
- Responsible for perception of spatial relations and motion
- Located in the parietal lobe
- If damages: patients will have trouble perceiving spatial relations, distance, and motion
What is the ventral pathways?
Ventral “What” Pathway:
- Parvo cells (small cells)
- Responsible for perception of objects and colour such as recognition of faces etc.
- Located in the temporal lobe
- If damaged, patients will have trouble perceiving faces and everyday items.
