Week 9 Flashcards
Adequate stimulus
Type of physical energy to which a sensory recept
Photons
Particles that transmit light
Wavelength
Distance from crest of one wave to crest of next (Colour)
Amplitude
The height of each wave. Intensity depends directly on amplitude (brightness)
Parts of the eye
Cornea
Pupil
Lens
Cornea
A clear layer that covers the front portion of the eye and contributed to our ability to focus our vision on an object
Pupil
The opening in the middle of the iris of the eye; the pupil changes its size to increase or decrease the amount of light let in the eye
Lens
The transparent structure located behind the pupil of the eye that changes its shape through the action of the muscles
Accomodation
Process of altering one’s existing scheme’s, or ideas, as a result of new information or new experiences
Photoreceptors
A receptive cell for vision in the retina, a rod or a cone
Ganglion cell
A neuron in the retina that receives information from photoreceptors by means of bipolar cells and from which axons proceed through the optic nerves to the thalamus
Bipolar cells
A neuron in the retina that receives information from photoreceptors and passes it on to the ganglion cells, from which axons proceed through the optic nerves to the brain
What do photoreceptors detect?
- Dark adaption
- Colour sensitivity
- Colour brightness
Photopigments
Complex molecules found in photoreceptors that generate electrical signals in the photoreceptors when they are exposed to light
3 Different kinds of cone receptors
Blue
Green
Red - responds to greeny/yellow
3 Different kinds of colour blind
Protanopia
Deuteranopia
Tritanopia
Protanopia
No red cones
Deuteranopia
No green cones
Tritanopia
No blue cones
Resolution
The size of the smallest difference can be identified. A increased resolution means that a smaller difference in location, colour, amplitude, or other attribute can be detected or distinguished
Monocular Depth Cues
Cues to distance that depend on input from only one eye
Bicular Depth Cues
Cues to distance that depend on input from both eyes
Motion Parallax
A monocular depth cue makes us perceive objects that are closer to us to be moving faster than objects that are further away from us
Retinal display
Images of objects at different distances will fall on different portions of the retina in each eye, causing disparity between the images of the object on the two retina and providing on indication of depth
Ventral stream
Involves areas at the bottom of the temporal love
Dorsal stream
Flow of information from the primary visual cortex through the parietal lobe; important for executing actions related to objects
Visual agnosia
The inability to recognize the identity of an object visually due to damage in the visual processing areas of the brain
Prosopagnosia
A form of visual agnosia in which face recognition is impaired due to damage to the visual processing areas
Akinetopsia/Motion blindness
Inability to see motion
Lateral inhibition
Reduction in activity that neighbouring neurons in the retina cause in each other
Receptive field
Portion of the visual field in which the presentation of visual stimuli will produce a change in the firing rate of a particular neuron
Neural convergence
Signals from different neurons come together and meet at a single neuron which can add up the signals or compare them
Orientation selective
Responses depend on proximity
Illusionary contours
Lines that are perceived do not exist
