1 / 50

Psychology 210

Psychology 210. Lecture 5 Kevin R Smith. Today. The Auditory system The Somatosensory system The chemical systems. Properties of sounds. Sounds are waves Amplitude: loudness Frequency: pitch. Audible Sound. The ear. The ear. Outer ear Pinna Auditory canal. Anatomy of the ear.

phuc
Télécharger la présentation

Psychology 210

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Psychology 210 Lecture 5 Kevin R Smith

  2. Today • The Auditory system • The Somatosensory system • The chemical systems

  3. Properties of sounds • Sounds are waves • Amplitude: loudness • Frequency: pitch

  4. Audible Sound

  5. The ear

  6. The ear • Outer ear • Pinna • Auditory canal

  7. Anatomy of the ear • Middle ear • Tympanic membrane: Ear drum • Oscicles • Malleus (Hammer) • Incus (Anvil) • Stapes (Stirrup) • Oval Window

  8. Anatomy of the ear • Inner ear • Semicircular canals • Cochlea • Basilar membrane • Hair cells

  9. The basilar membrane • Hair cells translate vibrations from the sound waves into frequencies • Higher pitches are processed closer to the base • Lower pitches are processed closer to the apex • Tonotopic organization

  10. The hair cells move Opens Ca channels Leads to the perception of a signal Different hair cells move depending on the frequency of the incoming sound Transduction

  11. Hair cells • Hair cell damage • Noise, infections, genetic diseases, aging • Higher frequencies are harder to hear as you age • Regeneration • Can occur in birds and some invertebrates • Generally does not occur in humans

  12. The Pathway to the brain • The auditory nerve • Cochlear nucleus • Superior olivary nucleus • The inferior colliculus • Thalamus (medial geniculate nucleus) • Primary auditory cortex

  13. In the superior olivary nucleus • Information from the ears is first combined here • May have some role in localization of sounds • Tonotopically organized

  14. Organization of the MGN • Similar to the LGN for vision • Different layers have different inputs • Tuning curves become more specific • Tonotopically organized

  15. Organization of A1 • Tonotopically organized • Just like the cochlea, superior olivary nucleus, and MGN, different tones are processed in different locations

  16. After A1 • Like vision: A2, A3, A4… • Two pathways • Dorsal “where” pathway • Ventral “what” pathway • Researchers try and relate auditory systems to visual systems • Some similarities have been found, but nothing is certain

  17. Is the auditory system contralaterally organized? • Somewhat • 80% of incoming information into each auditory cortex is from the contralateral ear and 20% is from the ipsilateral ear • Why the combining of the incoming information from the two ears?

  18. Spatial cues • We need information from both ears to locate where a sound is in space • Two main cues • Interaural intensity (level) difference (IID or ILD) • Interaural time difference (ITD) • Also our pinna provides information about how vertical a sound is

  19. Interaural Intensity Differences • The ear that is closer to the sound hears a louder sound than the ear that is farther from the sound • The difference in loudness here is a difference in intensity • Our head provides a shadow effect over the far ear • Based upon the difference in intensity, our brain can calculate where the sound was

  20. Interaural Time Differences • The ear that is closer to the sound hears the sound earlier than the ear that is farther from the sound • Based upon the difference in time, our brain can calculate where in space the sound was

  21. IIDs and ITDs

  22. IIDs and ITDs • Only provide information about where a sound is along the horizontal • We use our pinnas to locate where a sound is vertically • Head related transfer functions

  23. Changing the shape of the pinna change localization abilities Eventually subjects learn to localize sounds properly Interesting Note

  24. The somatosensory system • The Vestibular System • Touch • Temperature • Pain

  25. The Vestibular System • Fluid filled cavaties • Semicircular canals • Otoliths • Saccule • Utricle • Found near the ear and auditory structures

  26. How the vestibular system works • Fluid filled cavities • Contain hair cells • Sensitive to direction of movement • Either hyperpolarize or depolarize • Provide information about the location in space of the head • Semicircular canals • Provide more information about the rotation of the head

  27. How the vestibular system works

  28. Pathway to the brain • Auditory nerve • Pons, medulla, cerebellum • Vestibular nuclei • Ventral posterior thalamus • Primary somatosensory cortex and primary motor cortex

  29. The vestibular system • Information is highly integrated with information from the visual cortex • Also, projects to the spinal cord for feedback regarding posture

  30. Touch • The Sensory inputs • Meissner’s corpuscles • Pacinian corpuscles • Merkel’s disks • Ruffini’s endings • Free nerve distributions • Hair follicle receptors

  31. Differences between receptors • Size of receptive field • Small • Meissner’s corpuscles • Merkel’s disks • Large • Pacinian corpuscles • Ruffini’s endings

  32. Differences between receptors • Rate of adaptation • Fast • Meissner’s corpuscles • Pacinian corpuscles • Slow • Merkel’s disks • Ruffini’s endings

  33. Differences between receptors • Location • Shallow in the skin • Meissner’s corpuscles • Merkel’s disks • Deep in the skin (digestive tracts, joints) • Pacinian corpuscles • Ruffini’s endings

  34. Differences between receptors • Type of information processed • Pressure • Meissner’s corpuscles • Merkel’s disks • Pressure and vibrations • Pacinian corpuscles • Stretch • Ruffini’s endings • Pain and temperature • Free nerve endings

  35. Meissner’s Corpuscles

  36. Pacinian corpuscles

  37. Pathway to the brain • Spinal cord • Medial lemniscus • Ventral posterior nucleus of the thalamus • S1

  38. Organization of S1 • Somatotopically organized • Cortical magnification • The amount of cortex devoted to your hand is more than the amount of cortex devoted to your torso, even though your torso is larger • Why?

  39. Somatotopy • Your hand is much more sensitive to touch than your back • Same with face, mouth, eyes, etc…

  40. Homunculus

  41. Other types of receptors • Free Nerve Ending Receptors • Thermoreceptors • Respond to warmth or cold • Nociceptors • Respond to mechanical pain, extreme heat, or both

  42. The chemical senses • Senses that use chemical receptors • Olfaction: Smell • Olfactory epithelium detects molecules in the air • Taste • Saliva dissolves food into molecules

  43. Smelling….. • 1000 different smell receptors • Each receptor detects a broad range of smells • Based upon the combination of activity from the receptors, our brain constructs the smell

  44. The olfactory system • The nose • Olfactory epithelium • Olfactory receptor cells synapse onto olfactory nerves within the olfactory bulb

  45. The olfactory system • Pathway to the brain • Olfactory bulb axons form the olfactory tract • Olfactory cortex • Thalamus: Medial dorsal nucleus • Projects to all over the brain • Various frontal areas

  46. Taste • The tongue • Four different taste buds • Sweet, sour, salty, bitter • Umami: savory • Possibly a fifth type of taste bud • Papilla • Bumps on the tongue • Each contains up to 100 taste buds

  47. The Tongue

  48. Pathway to the brain • Tongue: taste fibers – cranial nerves –Thalamus: ventral posterior medial nucleus – parietal lobe

More Related