1. Chapter Seven Nonvisual Sensation and Perception

2. CHAPTER 7 NONVISUAL SENSATION AND PERCEPTION

3. Audition Sound as a Physical Stimulus – Intensity Amplitude of sound wave Sound waves vary from quiet whisper to rock band Logarithmic scale of sound intensity – Frequency Number of cycles per unit of time, wavelength of a sound stimulus Pitch determined by the wave having the lowest frequency (fundamental frequency) Timbre, or quality, determined by additional waves Ultrasound: Frequencies above 20,000 Hz Infrasound: Frequencies less than 20 Hz

4. Figure 7.2 The Auditory World Differs Across Species

5. Table 7.1 Sounds Vary Along the Dimensions of Amplitude, Frequency, and Complexity

6. Table 7.2 Intensity Levels of Common Sounds

7. Audition The Structure and Function of the Auditory System – The Outer Ear – pinna and auditory canal – The Middle Ear – eardrum, ossicles (malleus, incus, stapes), tympanic membrane, oval window – The Inner Ear – semicircular canal, cochlea

8. Figure 7.4 The Anatomy of the Ear

9. Figure 7.5 The Cochlea

10. Figure 7.6 Sound Frequencies Are Translated by the Basilar Membrane

11. Figure 7.7 The Movement of the Cilia Regulates Neurotransmitter Release by Hair Cells

12. Audition The Structure and Function of the Auditory System – Central Auditory Pathways Dorsal and ventral cochlear nucleus of the medulla Superior olive Inferior colliculus Medial geniculate nucleus (MGN) of the thalamus – The Auditory Cortex Primary auditory cortex – columns respond to single frequencies Secondary auditory cortex – activated by complex stimuli

13. Figure 7.8 Auditory Pathways from the Cochlea to the Cortex

14. Figure 7.9 Tonotopic Organization is Maintained by the Auditory Cortex

15. Audition Auditory Perception – Pitch Perception Due to frequency, intensity and context of stimulus Tonotopic organization – Loudness Perception Decibel level describes physical qualities of sound stimulus Loudness is human perception of that stimulus Equal loudness contours – Localization of Sound Comparison of arrival times of sounds at each ear and differences in intensities important for horizontal plane Pinna important for localizing sound in vertical plane

16. Figure 7.10 Equal Loudness Contours

17. Figure 7.11 We Localize Sound by Comparing Arrival Times at Both Ears

18. Hearing Disorders Age-related hearing loss – Poor circulation to the inner ear – Effects of exposure to loud noise Conduction loss Loss due to damage to inner ear, auditory pathways, or auditory cortex

19. The Body Senses Vestibular System – Movement Receptors of the inner ear Semicircular canals Otolith organs: Utricle and Saccule – Central Pathways Axons originating in otolith organs and semicircular canals Ventral posterior (VP) nucleus of the thalamus Primary somatosensory cortex and primary motor cortex

20. Figure 7.13 The Vestibular Structures of the Inner Ear

21. The Body Senses Touch – Hairy skin and glabrous skin (hairless) – Layers Epidermis Dermis Subcutaneous tissue – Touch Receptors – mechanoreceptors – Touch Pathways

22. Figure 7.14 Mechanoreceptors of the Skin

23. Table 7.3 Major Features of the Mechanoreceptors

24. Figure 7.15 Two-Point Discrimination Thresholds

25. Figure 7.16 The Four Classes of Sensory Axons Differ in Size and Speed

26. Figure 7.17 Dermatomes Are Areas of Skin Served by the Dorsal Roots of One Spinal Segment

27. Figure 7.19 Somatosensory Information Is Sent to the Ventral Posterior and Intralaminar Nuclei of the Thalamus

28. The Body Senses Touch – Somatosensory Cortex Primary somatosensory cortex found in postcentral gyrus of parietal lobe Secondary somatosensory cortex found in posterior parietal lobe – Plasticity of Touch Somatosensory cortex rearranges itself in response to changes in the amount of input it receives – Somatosensory Disorders

29. Figure 7.20 Somatosensory Cortex

33. Figure 7.21 Drawings of a Patient with Neglect Syndrome

34. The Body Senses Temperature – Thermoreceptors Cold fibers Warm fibers – Share pathways with sense of pain

35. Figure 7.22 Responses by Cold and Warm Fibers

36. The Body Senses Pain – A Purpose for Pain – Receptors for Pain Nociceptors Chemicals that activate nociceptors – Pain Pathways to the Brain Ascending pain fibers (A and C) Substance P Substantia gelatinosa, spinothalamic pathway, ventral posterior (VP) nucleus of the thalamus, anterior cingulate cortex, somatosensory cortex – Managing Pain

37. Figure 7.23 Ascending Pain Pathways

38. Figure 7.24 Descending Messages Influence Pain

39. Figure 7.26 Olfactory Information Travels from the Epithelium to the Brain

40. The Chemical Senses Taste – Taste Receptors Found on tongue and other areas of the mouth Papilla contain taste buds Taste buds have 50-150 receptor cells – Taste Pathways Taste fibers in tongue form parts of cranial nerves VII, IX, and X Gustatory nucleus of the medulla Ventral posterior medial (VPM) nucleus of the thalamus Gustatory cortex in the parietal lobe Orbitofrontal cortex in the frontal lobe

41. Figure 7.27 The Taste Receptors

42. Figure 7.28 Taste Pathways to the Brain