Summary Class notes - Perceptual Processes

Course
- Perceptual Processes
- N/A
- 2015 - 2016
- DU
- Psychology
438 Flashcards & Notes
0 Students
  • This summary

  • +380.000 other summaries

  • A unique study tool

  • A rehearsal system for this summary

  • Studycoaching with videos

Remember faster, study better. Scientifically proven.

Summary - Class notes - Perceptual Processes

  • 1453071600 Lecture 1: How sensation turns into perception

  • Look at lecture notes as most of it is revision from Year 1
  • What is the Mach Band illusion?
    ---> bright and dark stripes (Mach bands) are illusions formed by the visual system

    The apparent enhanced contrast that is typically seen at the edges (between bright and dark patterns). Most people can see a brighter strip opposing the dark side and a darker strip opposing the bright side. (see slide 1, p. 4 lecture notes)

    (p. 46-47 perceptual textbook)
  • How many rods and cones do the ganglion cells receive input from?
    120 rods
    6 cones
  • Edges are powerful cues for the perceptual system (see slide 1, p. 7 lecture notes)
  • What does lesions to MT(V5) result in?
    An inability to detect moving objects
  • What do neurons in the inferior temporal lobe (ventral stream) respond selectively to?
    Complex objects including faces
  • What can lesions to the infero-temporal cortex lead to?
    Deficits in object recognition (agnosia) + prosopagnosia
  • What are neurons in the parietal lobe (dorsal stream) involved in?
    Visually guided behaviour (action)
  • What does lesions to the parietal lobe (dorsal stream) lead to?
    Optic ataxia - a deficit in the visual control of reaching and other movements
  • What are patients with lesions to the ventral stream unable and able to do?
    Unable - to perceive the correct orientation 
    Able - to produce the correct action when instructed
  • What are feature detectors?
    Neurons that are specialised to detect particular stimuli in their receptive field
  • Fovea = only cones
    Peripheral retina (all of the retina outside the fovea) = contains both rods and cones
    (there are many more rods than cones in the peripheral area)
  • Signals generated in the receptors travel to the bipolar cells and then to the ganglion cells. The axons of the ganglion cells transmit signals out of the retina into the optic nerve.
  • What are two reasons why rod vision is more sensitive than cone vision?
    1. It takes less light to generate a response from an individual rod receptor than from an individual cone receptor.

    2. The rods have greater convergence than the cones.
  • What did Kuffler find out about the spatial layout of the ganglion cell's receptive field?
    It is essentially concentric ---> a small circular area in the centre responds to an increase in illumination, and a surrounding ring responds to a decrease in illumination. 
    ---> the ganglion cell fires fastest when the spot matches the size of the excitatory centre, and it reduces its firing rate when the spot begins encroach on its inhibitory surround.  

    (p. 46 perceptual textbook)
  • 1453158000 Lecture 1 Quiz

  • A stimulus is: 

    a) the physical energy that begins the perceptual process
    b) the psychological correlate of physical energy
    c) the manner in which sensory nerve fibers communicate with one anotherd) another word for a perception
     a) the physical energy that begins the perceptual process
  • An eyeball that is too long for it's optics is
    a) hyperopic
    b) myopic
    c) emmetropic
    d) astigmatic
    b) myopic
  • Most of the ________ cones are found in the ___________ of the retina
    a) 5 million; periphery
    b) 5 million; fovea
    c) 5 thousand; periphery
    d) 5 thousand; fovea
    b) 5 million; fovea
  • The axons of the ________ cells make up the optic nerve
    a) rod and cone
    b) ganglion
    c) bipolar
    d) complex cells
    b) ganglion
  • Receptive fields are defined as the
    a) spatial range over which an individual can see at a given time
    b) spatial range over which light increases the response of a cell
    c) spatial range over which light has an influence on a cell's response
    d) concentric center/surround layout of retinal ganglion cells
    c) spatial range over which light has an influence on a cell's response
  • At a given retinal eccentricity, the size of P ganglion cell receptive fields tends to be
    a) larger than M cell receptive fields
    b) smaller than M cell receptive fields
    c) the same size as M cell receptive fields
    d) unrelated
    b) smaller than M cell receptive fields
  • An object whose image falls on the nasal portion of the eye is sent to the ________ side of the brain
    a) left
    b) right
    c) ipsilateral
    d) contralateral
    d) contralateral
  • The lateral geniculate nucleus consists of
    a) 4 parvocellular layers and 2 magnocellular layers
    b) 3 parvocellular layers and 3 magnocellular layers
    c) 2 parvocellular layers and 4 magnocellular layers
    d) 1 parvocellular layers and 5 magnocellular layers
    a) 4 parvocellular layers and 2 magnocellular layers
  • Which of these statements is true about P cells in the LGN?
    a) They respond more quickly and transiently than M cells
    b) They are rarely sensitive to the color of the light on their receptive fields
    c) They are orientation selective
    d) They analyze spatial information at a finer level of detail than M cells
    d) They analyze spatial information at a finer level of detail than M cells
  • Visual cortex is located in the _______ lobe of the brain
    a) occipital
    b) temporal
    c) parietal
    d) all of the above
    d) all of the above

    - the occipital cortex is the main region for vision; however, each of these areas have a role to play in vision.
  • The extrastriate cortex is ________
    a) the temporal lobe
    b) all parts of visual cortex not including V1
    c) the parietal lobe
    d) all of the cortex that is not striate cortex
    b) all parts of visual cortex not including V1
  • Milner and Goodale proposed that the "where" pathway should be called the "how" pathway because ________
    a) it describes how something moves
    b) it provides information needed for taking action on objects
    c) it is able to discriminate between two or more object forms
    d) its function is too poorly understood
    b) it provides information needed for taking action on objects
  • Lesioning a monkey's area MT ________
    a) makes it easier for the monkey to detect small changes in the direction of movement
    b) increases the monkey's threshold for detecting the direction of movement
    c) decreases the monkey's ability to see forms
    d) decreases the monkey's ability to see color
    b) increases the monkey's threshold for detecting the direction of movement
Read the full summary
This summary. +380.000 other summaries. A unique study tool. A rehearsal system for this summary. Studycoaching with videos.

Latest added flashcards

Who explained how differences in neural activity translate into changes in neural circuity?
Hebb
---> proposed that cells at presynaptic terminals that have the same activity as the postsynaptic cell are more likely to form stable synapses. In contrast, those synapses that do not correlate with the postsynaptic cell are weakened
What causes retinal displacement?
Saccades 
---> There is no coherent motion pattern in images, so we perceive the retinal displacement as movement
How do artists convey movement in their art?
Artists have used cues that are associated with movement, such as blur, to convey a dynamic aspect to their painting
---> Early pictures convey movement by showing animals frozen in a moving state
What is one possible reason why modern art has an aesthetic appeal?
They are particularly affective stimuli in stimulating neurons in the visual cortex

E.g. Mondrian’s paintings are particularly effective in activating neurons in V4 that are selective for form and colour.
What is a criticism of Egyptian art?
Human figures are shown as anatomical impossibilities. Head, feet and breasts are all shown from the side, but the shoulders are shown in the front view.

• In addition, the size of images of people were determined not by their relative size to other objects, but by their relative importance
What was Plato's criticisms of painting?
Painting only portrayed one aspect of an object, whereas in reality one object can produce many different representations
Why did Michaelangelo leave many of his paintings and sculptures unfinished?
He believed that the brain's imagination would provide for a more vivd deception of the scene
What is top down knowledge?
Our perceptions are influenced by pervious experience of the visual world
The ability of the brain to produce images in the absence of sensory images in apparent during what?
Dreaming, visual imagery and during hallucinations
What is the El Greco fallacy?
People with astigmatism are not usually aware of the elongated nature of the image in the eye, because their brains take account of it (constancy of perception).