Psychology 224 Neuroscience Lecture Preview PDF

Psychology 224: Neuroscience Sensory Systems: Vision and Audition Reading: Carlson, Chapters 6 &7  Announcement Exam #3 Exam 3 will be on 11/7, not 11/4. The Visual System  LIGHT *Depolarized in darkness* INFORMATION FLOW ...

Psychology 224: Neuroscience Sensory Systems: Vision and Audition Reading: Carlson, Chapters 6 &7  Announcement Exam #3 Exam 3 will be on 11/7, not 11/4. The Visual System  LIGHT *Depolarized in darkness* INFORMATION FLOW The retinal ganglion cells encode how much light falls on the center and surround of their receptive fields and they carry information about the wavelength of that light (color). What does the cortex do?  Primary Visual Cortex The primary visual cortex is often called the “striate cortex”, because it contains dark staining layer The primary visual cortex is Striate cortex of a rhesus also referred to macaque monkey  Primary Visual Cortex Approximately 25% of V1 is devoted to processing information from the fovea, which represents a small part of the visual field. Cells in V1 respond to specific features of the visual world – each individual cell in V1 collects information from several different retinal ganglion cells Orientation & Movement Mostneurons in V1 are sensitive to orientation Stimulus ON This cell is maximally responsive to the vertical line! Visual Association Cortex V1 cannot “see” a whole object, only features Output of V1 is sent to the adjacent extrastriate cortex, or V2 – V2 cells receive input from several V1 cells – here, information begins to be reassembled to “rebuild” visual scene From V2, the visual information then takes one of 2 paths: – The Ventral Stream – Projects to the inferior temporal lobe  Processes “what” an object is – The Dorsal Stream – Projects to the posterior parietal lobe  Processes “where” an object is “Where?” “What?” The Auditory System  Sound as a Stimulus Sounds are produced by objects that vibrate A vibrating object causes the molecules of air to alternately condense together and pull apart, creating a sound wave Structure of the Human Ear  The Outer Ear Sound is first collected from the environment by the pinnae Sound waves are funneled by the pinnae into the ear canal The length and shape of the ear canal enhances certain sound frequencies  The Tympanic Membrane The tympanic membrane is the ear drum It is a thin membrane at the end of the outer ear canal Vibrates in response to sound Border between outer and middle ear  Middle Ear The ossicles are three tiny bones that amplify and transmit sounds to the inner ear They are the smallest bones in the body Vibrations from the tympanic membrane first reach the malleus (hammer)  Middle Ear The malleus (hammer) connects with the incus (anvil). The incus connects to the stapes The stapes is attached to the oval window of the cochlea The stapes is the smallest bone in the body Anatomy of the Ear 3. 4. 1. 2.