Sensation & Perception Part 1 Flashcards
What is sensation?
Encoding environmental energy
What is perception?
Interpreting information received from the senses
What two parts of the eye bend light to create an image on the retina?
Cornea & lens
Which cells convert light energy into electrical signals?
Photoreceptors
What are the names of the two types of photoreceptors?
Cones and rods
How are the rods different from the cones?
Rods are larger, very sensitive to light, do not support color vision, used in low illumination
Cones are smaller, less sensitive to light, can be used to see colors, and are used in high illumination
Why does dark adaptation occur?
Photoreceptors are regenerating their photopigments
How many neurons are there in each optic nerve?
1 million
How many different types of cones are there?
Three - each one gives its greatest response to a different wavelength (colors)
Why is colorblindness more common in men than women?
The genes that code for the photopigments are on the X chromosome. If all of a person’s X chromosomes have colorblind genes, then they will be colorblind.
Men, XX
Women, XY
What is a monochromat?
Have only one cone type
See in black and white
What is a dichromat?
Have only two cone types
Can either be Red-Green or Blue-Yellow colorblind
What is an anomalous trichromat?
Have one cone type with an abnormal pigment
Have trouble distinguishing certain shades of color
What is a tetrachromat?
Have four cone types
Can see 100 times as many colors as a normal trichromat
Which cells in the retina send color information to the brain?
Ganglion cells
What are the three types of ganglion cells?
Red-Green
Blue-Yellow
Black-White
What produces color afterimages?
Fatigued ganglion cells
What are three pieces of evidence that face recognition differs from the process of recognizing other objects?
Different parts of the brain are responsible for each task
Faces are more difficult to recognize in photographic negatives than objects
Faces are more difficult to recognize when they are upside down than objects
What are the three variables that determine how attractive people will find a face?
Symmetry
Closer to the average face in a population
Exaggerated sex specific features of the face
What is change blindness?
Missing large changes in scenes because the form perception areas can only process a small part of the scene at any one time
In what lobe of the brain are the motion perception areas?
Parietal lobe
What is akinetopsia?
Motion blindness - caused by damage to motion perception areas of the brain
What depth cue is used to make 3D movies?
Binocular disparity
How does the Ames room manipulate depth cues?
Makes you think both corners of the room are at the same distance
How does the Muller-Lyer illusion work?
Manipulates vertices to make one line appear to be bulging toward you and the other away from you
< —- > this line appears shorter
>——< - this line appears longer
What is the Ponzo illusion?
Railroad tracks have depth cues that make the top bar look further away and thus bigger
What is responsible for the moon illusion?
Depth cues on the surface of the earth
An optical illusion in which the moon appears larger when it is closer to the horizon than when it is higher in the sky
