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PSYCH306: Sensation and Perception

Unit 6: Smell, Taste, and Touch   In this unit, we will discuss the three remaining senses: smell, taste, and touch. Though we will only spend one unit on these three senses, each is complex and important; however, we use them less frequently than sight and sound. This unit will discuss the ways that taste, smell, and touch are anatomically related and explain why they are useful to us as humans. Pay special attention to the fact that both taste and smell are chemical senses, in that they give us information about the chemical composition of our surroundings.

Unit 6 Time Advisory
This unit should take you 10.5 hours to complete.

☐    Subunit 6.1: 3.5 hours

☐    Subunit 6.2: 3.5 hours

☐    Subunit 6.3: 3.5 hours

Unit6 Learning Outcomes
Upon successful completion of this unit, students will be able to:

  • explain the basic properties of olfactory, gustatory, and somatosensory stimuli;
  • explain the important sensory structures and their function(s) for each of these three sensory systems;
  • explain the fundamental aspects of the perception of taste;
  • explain the fundamental aspects of the perception of smell;
  • explain the fundamental aspects of the perception of touch; and
  • describe the basic auditory sensory pathways in the central nervous system.

6.1 Taste   - Reading: Stanford University: Professor Lera Boroditsky’s “Taste, Smell, and Touch: Lecture Notes” Link: Stanford University: Professor Lera Boroditsky’s “Taste, Smell, and Touch: Lecture Notes” (PDF)
 
Instructions: Click the link above to navigate to the web page and read “Section I: Taste.” Do not be concerned if some of the links to figures and illustrations do not work. NOTE: This reading applies to all subsections of section 6.1.
 
Terms of Use: This material has been hosted with the kind permission of Professor Lera Boroditsky.

6.1.1 The Importance of Taste: The Testing of Food   Note: The reading assigned beneath subunit 6.1 also covers this subunit.

  • Reading: BBC’s Science and Nature: Human Body and Mind: “Nervous System - Taste” Link: BBC’s Science and Nature: Human Body and Mind: “Nervous System - Taste” (HTML and Adobe Flash)
     
    Instructions: Click the link above to navigate to the web page. Read the main text. In addition, click the “Taste Animation” link and page through the animation using the yellow, right-pointing triangle.
     
    Terms of Use: Please respect the copyright and terms of use included on the above webpage.

6.1.2 The Four Types of Papillae: Filiform, Fungiform, Foliate, and Circumvallate Papillae   Note: The reading assigned beneath subunit 6.1 covers this subunit. As you read this section, consider why different areas of the tongue have different types of papillae.

6.1.3 Taste Buds, Taste Cells and Taste Pores   Note: The reading assigned beneath subunit 6.1 also covers this subunit.

  • Web Media: LearnersTV’s “The Sense of Taste” Link: LearnersTV’s “The Sense of Taste” (Shockwave)
     
    Instructions: Click the link above to navigate to the web page and watch the animation.
     
    Terms of Use: Please respect the copyright and terms of use included on the above document and webpage.

6.1.4 Taste Transduction   Note: The reading assigned beneath subunit 6.1 covers this subunit. As previously discussed, transduction in sensory systems is the morphing of an external stimulus into neural energy, or action potentials. Make sure you have a clear understanding of how chemicals in the mouth are transduced into electrochemical energy in neurons.

6.1.5 The Chorda Tympani Nerve   Note: The reading assigned beneath subunit 6.1 covers this subunit. As you read this section, consider why different neural pathways serve different parts of the tongue.

6.1.6 The Glosso-Pharyngeal Nerve   Note: The reading assigned beneath subunit 6.1 also covers this subunit.

  • Reading: West Virginia University: Mandy Hatfield’s (for Professor Kevin Daly) “The Gustatory Pathway” Link: West Virginia University: Mandy Hatfield’s (for Professor Kevin Daly) “The Gustatory Pathway” (Powerpoint)
     
    Instructions: Click the link above to open the web page, and find the text/link called “Taste” (third section from the top of the page). Open or download this PowerPoint document and view all the slides.
     
    Terms of Use: Please respect the copyright and terms of use included on the above document and webpage.

6.1.7 The Vagus Nerve   Note: The reading assigned beneath subunit 6.1 covers this subunit. As you read this section, consider why there are taste buds in areas other than the mouth.

6.1.8 Specificity vs. Distributed Encoding   Note: The reading assigned beneath subunit 6.1 covers this subunit. How is the issue of specificity vs. distributed coding similar to the coding of auditory information?

6.1.9 The Sensation of Taste: The Importance of Smell and Texture (Touch) on Taste   Note: The reading assigned beneath subunit 6.1 covers this subunit. Why do people sometimes hold their nose when having to eat or swallow something that tastes bad to them?

6.2 Smell   - Reading: Stanford University: Professor Lera Boroditsky’s “Taste, Smell, and Touch: Lecture Notes” Link: Stanford University: Professor Lera Boroditsky’s “Taste, Smell, and Touch: Lecture Notes” (HTML)
 
Instructions: Click the link above to navigate to the web page and read “Section II: Smell.” Do not be concerned if some of the links to figures and illustrations do not work. NOTE: This reading applies to all subsections of section 6.2.
 
Terms of Use: This material has been hosted with the kind permission of Professor Lera Boroditsky.

6.2.1 The Importance of Smell: Distinguishing Substances Before Contact   Note: The reading assigned beneath subunit 6.2 also covers this subunit.

  • Reading: BBC’s Science and Nature: Human Body and Mind: “Nervous system - Smell” Link: BBC’s Science and Nature: Human Body and Mind: “Nervous system - Smell” (HTML and Adobe Flash)
     
    Instructions: Click the link above to navigate to the web page. Read the main text. In addition, click the “Smell Animation” link and page through the animation using the yellow, right-pointing triangle.
     
    Terms of Use: Please respect the copyright and terms of use included on the above webpage.

6.2.2 Animal Use of Smell vs. Human Use of Smell   Note: The reading assigned beneath subunit 6.2 covers this subunit. What are pheromones? Why are they less important for humans than they are for many other animals?

6.2.3 Olfactory Mucosa   Note: The reading assigned beneath subunit 6.2 covers this subunit. As you read this section, consider how the olfactory mucosa is similar to the basilar membrane in the cochlea.

6.2.4 Olfactory Receptor Neurons   Note: The reading assigned beneath subunit 6.2 also covers this subunit.

  • Reading: West Virginia University: Faizan Kalwar’s (for Professor Kevin Daly) “The Olfactory Pathway” Link: West Virginia University: Faizan Kalwar’s (for Professor Kevin Daly) “The Olfactory Pathway” (Powerpoint)
     
    Instructions: Click the link above to open the web page, and find the text/link called “Olfactory” (third section from the top of the page). Open or download this PowerPoint document and view all the slides.
     
    Terms of Use: Please respect the copyright and terms of use included on the above document and webpage.

6.2.5 Cilia and Olfactory Receptor Proteins   Note: The reading assigned beneath subunit 6.2 covers this subunit. What visual receptor characteristic is similar in function to olfactory receptor proteins?

6.2.6 Olfactory Transduction   Note: The reading assigned beneath subunit 6.2 covers this subunit. Be certain that you have a good understanding about how chemical stimulation from odors is transformed into neural energy.

6.2.7 Glomeruli   Note: The reading assigned beneath subunit 6.2 covers this subunit. Where do the glomeruli sit in the neural pathway? From where do they receive their signals, and to where are their signals sent?

6.2.8 What is an Odotope?   Note: The reading assigned beneath subunit 6.2 covers this subunit. Be sure you understand the definition and significance of odotopes.

6.2.9 Pheromones and Odorless Molecules: Fear, Moods, and Attraction   Note: The reading assigned beneath subunit 6.2 covers this subunit. What are some of the possible roles of pheromones in human behavior and interaction?

6.3 Touch   - Reading: Hanover College: Professor John Krantz’s “Experiencing Sensation and Perception” Link: Hanover College: Professor John Krantz’s “Experiencing Sensation and Perception” (PDF)
 
Instructions: Read chapter 12. NOTE: This document is in a continuous state of updating. Ignore the internal notes, such as “[need illustration here],” for example. Most of the referenced figures are included at the end of the document; it is okay if not all the figures are available. ADDITIONAL NOTE: This reading applies to subsections 6.3.1-6.3.4.
 
Terms of Use: The linked material above has been reposted by the kind permission of John Krantz, and can be viewed in its original form here. Please note that this material is under copyright and cannot be reproduced in any capacity without explicit permission from the copyright holder.

6.3.1 Stimulus Properties: Pressure, Temperature, and Discrimination   Note: The reading assigned beneath subunit 6.3 also covers this subunit.

  • Web Media: Sumanas, Inc.’s “Receptors in the Skin” Link: Sumanas, Inc.’s “Receptors in the Skin” (Adobe Flash)
     
    Instructions: Click the link above to navigate to the web page. Choose the “Narrated” or “Step-Through” link to view the animation.
     
    Terms of Use: Please respect the copyright and terms of use included on the above document and webpage.

6.3.2 Adaptation   Note: The reading assigned beneath subunit 6.3 covers this subunit. Before reading this sentence, were you aware of the pressure of your buttocks on your chair? Were you aware of the feel of your clothes on your skin, especially things like underwear and socks? As you read this section, consider why you generally are not aware of such things.

6.3.3 Cortical Pathways   Note: The reading assigned beneath subunit 6.3 also covers this subunit.

  • Assignment: Hanover College: Professor John Krantz’s “Experiencing Sensation and Perception: Interactive Illustration 12.x, Somatosensory Pathways” Link: Hanover College: Professor John Krantz’s “Experiencing Sensation and Perception: Interactive Illustration 12.x, Somatosensory Pathways” (JAVA)
     
    Instructions: If you have installed the JAVA plug-in (see page #2 of this course), clicking the embedded link will open a page that illustrates cortical somatosensory pathways. Follow the directions on page #4 of the PDF document to manipulate the demonstration.
     
    Terms of Use: The linked material above has been reposted by the kind permission of John Krantz, and can be viewed in its original form here. Please note that this material is under copyright and cannot be reproduced in any capacity without explicit permission from the copyright holder.

6.3.4 Sensitivity of Receptors and Size in Cortex   Note: The reading assigned beneath subunit 6.3 covers this subunit. As you read this section, consider why it makes sense that more sensitive areas of the skin are served by larger portions of the cortex.

6.3.5 The Homunculi   - Web Media: Neuroscience for Kids’ “Your Really Weird Body Map.” Link: Neuroscience for Kids’ “Your Really Weird Body Map.” (Flash)
 
Instructions: Click the link above to navigate to the web page and watch the animation.
 
Terms of Use: Please respect the copyright and terms of use included on the above document and webpage.

6.3.6 Pain: Localized vs. Referred Pain   Note: The reading assigned beneath subunit 6.3 also covers this subunit.

  • Assignment: Hanover College: Professor John Krantz’s “Experiencing Sensation and Perception: Interactive Illustration 12.x, Melzack and Wall's Gate Control Theory Link: Hanover College: Professor John Krantz’s “Experiencing Sensation and Perception: Interactive Illustration 12.x, Melzack and Wall's Gate Control Theory” (JAVA)
     
    Instructions: If you have installed the JAVA plug-in (see page #2 of this course), clicking the embedded link will open a page that illustrates the gate control theory of pain. Follow the directions on pages #11 and #12 of the PDF document to manipulate the demonstration.
     
    Terms of Use: The linked material above has been reposted by the kind permission of John Krantz, and can be viewed in its original form here. Please note that this material is under copyright and cannot be reproduced in any capacity without explicit permission from the copyright holder.