Olfactory Physiology

I. Content: Olfaction is one of the two chemical senses. The other is taste (see Chapter 14). To be perceived as scent, a chemical must possess certain physical properties; however, even some molecules that possess these characteristics cannot be smelled. Compared to our other senses, olfaction has a number of unique physiological properties. Among the unique features is the fact that only approximately 35% of the genes that code for olfactory receptors in humans are functional. Another unusual feature is that most smells also stimulate the somatosensory system via the trigeminal nerve, and it is often impossible to distinguish the contribution of olfactory sensation from trigeminal stimulation.

II. Prerequisites: The students should have a firm understanding of middle vision.

III. Instructional Objectives: When requested, the students should be able demonstrate they know the difference between templates and structural definitions. Students should understand the brain structures associated with object recognition. Additionally, the student will be able to discuss the importance of face recognition.

IV. Instructional Procedures:

A. The instructor begins discussing different theories of object recognition. 
B. The instructor will discuss template versus structural theories of object recognition.
C. The instructor will discuss Beiderman's work.
D. The class will break up into groups and create objects using Geons
E. The instructor will discuss viewpoint dependence.
F. The instructor will discuss the extra striate cortex and where objects are processed.
G. The instructor will discuss the importance of face recognition.
H. The instructor will show a segment of a clip on face recognition.

V. Materials and Equipment:

A. Image of illusory contours
B. Figure 4.26
C. Figure 4.27
D. Figure 4.28
E. Inverted famous face powerpoint
F. Image similar to Figure 4.32
G. Video clip on face recognition

VI. Assessment:

Students will be given a multiple choice test to see if they understand the definitions and concepts presented in the lecture.

VII. Follow up Activities:


VIII. Self Assessment: I would review the multiple choice tests to determine how many answers the students correctly responded to. I would determine if there were particular terms or concepts that students had more difficulty with. I would then review this/these terms before the next lecture.

IX. Additional Resources:
Smell - Trademark infringement
Scented bowling ball
Smells of summer
Can sharks really smell blood?
Scientists explore the workings of taste
Using wasps to detect explosives

Rat learning simple 2-odor discrimination problem. The rat is in a training chamber. He has been trained to sample odors from a port in the wall and respond for fluid at a well below. On each trial, the rat samples an odor. One odor means he will get sucrose at the well; the other odor predicts quinine. The rat likes sucrose but wants to avoid quinine, so he must learn to use the predictive odor cues to guide his decision to respond at the well. At the beginning of this video, the rat does not know which odor means sucrose and which odor means quinine; by the end of the video the rat has learned the odor-outcome associations and is using them to guide his decisions.