Sample Exam Questions The items listed below represent examples of what to expect should you need to take an essay make-up exam. Note that these cover the ENTIRE semester (and then some). I will NOT use any of the items below in your make-up exam. However, I thought you might find it useful to see the sorts of questions I've used in the past. Certainly some questions would be very similar to what are listed below. Mainly it is my expectation that seeing these will serve two purposes. (1) You might make an extra effort to attend the regular exam. (2) Should circumstances justify an essay make-up exam, you will have some idea of what types of questions I will ask. You can probably flip through the chapter and generate essay questions of your own so if you can answer these (and the ones you generate of similar style) you should do fine on the exam. General Background Questions Explain the difference between "sensation" and "perception." Be sure to include a discussion of where or how these concepts overlap (if they do overlap) as well as where or how they do not overlap (if they do not overlap). Perception is clearly a biological process (after all, we are biological entities, hence, everything we know can be traced either directly or indirectly to having been supplied to us through our senses). Take and defend the position that perception is a biological need. What is meant by sensory transduction? There are three complementary approaches to the study of perception (psychological, biological, & theoretical). Elaborate upon each of these. Vision & The Eye Questions The human eye is actually more unique to humans than most people typically are aware. Provide a lucid explanation (e.g., make clear how the advantages outweigh the disadvantages) of why our eyes make use of (sense) only the visible spectrum of light; why our eyes are placed where they are in our heads; and finally, why and how our eyes are capable of movement. Describe the structure of the human eye. Be sure to include a detailed description of the retina. Discuss the concept of receptive fields and how they are "distributed" across the retina. What types of retinal receptive fields are there? What is the Hermann Grid illusion and what are Mach bands? Choose one of these as an example in your discussion of why they are perceived. There is a potential problem that must be solved in order to have good vision. In order to have good resolution (clarity), one must have small receptive fields. However, good vision relies also on sensitivity (being able to detect weak signals) which comes from spatial summation (i.e., big receptive fields). How, if at all, is this solved in human vision? How is binocularity established from the perspective of cells in the visual cortex? As part of your answer, explain why/how those computer generated 3D pictures work. Name and describe the two traditional approaches to form perception. Be sure to point out their strengths as well as their weaknesses. Finally, include a discussion of a contemporary approach to form perception. What is Fourier Analysis? Of the statement, "Cats sometimes seem to behave as though they either have good imaginations or are capable of seeing and chasing 'ghosts' (things humans cannot see)," one of these possibilities is more likely to be true. Elaborate and explain why. Define and give two different examples of a metamer. What are two (and why are they) limitations of the Multichannel model of form perception? Why might an infant prefer to look at large rather than small finely detailed objects and also seem to have little to no preference for colored over black and white patterns/objects? If we perceive colors as a function of the particular combinations of wavelengths of light entering our eyes (e.g., blue = about 450 nm), then how does color constancy work? Consider; if I took a color photograph of a red plate and a blue cup in a brightly lit room, then took another picture of the same objects with only indirect lighting and then carefully cut them out of each photo and placed them side by side, they would probably appear to be different colors (i.e., different shades of blue and red). However, when we walk into the room and look at the plate and cup on the table, then reduce (or increase) the lighting, their colors seem the same. This is despite the fact that the wavelengths of light entering our eyes have changed!? It would not be to our perceptual advantage to have fewer than three different cone pigments, nor would it be to our advantage to have over 100 different cone pigments. Why? Would four different cone pigments be better than three? Defend your responses to these questions. Define each of the following: Strabismus, neon spreading, stereopsis, binocular-rivalry, convergence, accommodation, and amodal completion. Describe each of the seven different ways in which humans are capable of perceiving depth (i.e., accommodation, convergence, binocularity, interposition, size, perspective, and motion parallax). Describe "masking" and tell me something interesting about it. Why don't we experience "blurred vision" when we move our eyes from object-to-object? Perception of speed of movement is different for central relative to peripheral vision. Would we be better off or worse off (or neither) if it were reversed? Or, what's the "advantage" to having the current arrangement (central different from peripheral)? Is it true that bigger planes land (fly) at slower speeds than smaller ones? Why would one think that this is true? How does having a focal and ambient visual system potentially account for some nighttime automobile accidents? Hearing & The Ear Questions It is very unusual to encounter pure tones in the natural environment. Why would we be at a disadvantage if events and objects in nature were to broadcast their presence using only pure tones? What is the advantage (if any) of having an irregularly shaped pinna? What seems to be the purpose of the acoustic reflex? Explain why the middle ear serves as both an impedance matching device and, in some cases, a "surge protector." Why are blood vessels banned from the cochlea and how, then, are the cells inside nourished? What is the purpose/function of the oval window (attached to the outer wall of the vestibular canal) as well as the function/purpose of the round window (attached to the outer wall of the tympanic canal)? What are the two different cues that the auditory system uses for determining the location source of a sound, and how are they used to do so? Why is it that when you go to listen to a live band it seems like the drums and bass guitar seem to wash out the lyrics? Hint: This has to do with loudness contours and the "loudness" boost that manufacturers of audio equipment provide with their amplifiers. We are able to select portions of a complex sound stream to attend to (e.g., one voice amidst a background of other voices, sounds, etc.). What are (name and discuss) the four cues that most likely contribute to our ability to segregate single sound sources from a complex sound signal. In using interaural intensity differences to localize a sound source, would a creature that has a smaller head than ours be at a relative advantage or a relative disadvantage in localizing a range of high frequency sounds? Explain your answer. According to the duplex theory of sound localization, listeners use ITD (interaural time differences) to localize low-frequency sounds but IID (interaural intensity differences) to localize high-frequency sounds. Why does it make sense that this is so? In other words, why would it be strange if we used ITD to localize high-frequency sounds and IID to localize low-frequency sounds? Would our ability to localize sounds suffer, improve, or stay the same if for some reason we lost our outer ears? Please adequately defend your answer. Questions About Touch By rubbing a finger over the surfaces of various tactile gratings, each surface will vary in perceived roughness as a function of how closely together the peaks and troughs are to one another. Presumably, you can tell a higher frequency texture from a lower frequency texture by how quickly the surface "undulates" beneath your finger. Why is it that perceived frequency doesn't change if you rub your finger faster or slower? Why are embossed letters more difficult to read with fingers than Braille characters? Name and describe the four fiber groups that make up our experience of touch. Questions About Smell & Taste How does the example of uncovered butter in the refrigerator relate to our sense of smell? If smell is so important for taste (e.g., you can't discriminate reliably between a wedge of potato and a wedge of apple if your nose is blocked), then why is it that some things that smell great taste horrible, and some things that smell horrible can taste great? With the visual and auditory senses, different cells respond maximally to a specific range of stimuli, yet, with the olfactory senses, receptor cells do not respond in such a discriminating fashion. Instead, most of the olfactory receptor cells tend to respond to a whole throng of different odors which bear no similarity to one another. Hence, there is no evidence of the specialization observed for the visual and auditory systems. So, how is it that we are capable of discriminating smells from one another if the cells that receive such inputs don't seem to be able to make such discriminations? How do we know that olfactory adaptation occurs neurally rather than at the receptor cells? Describe Henning's Taste Tetrahedron. Is this the way taste works? Defend your answer. What is misleading about the "tongue maps" typically depicted in introductory level texts? What is the Bliss Point, and what does this have to do with food preference changes with age? Describe the possible link between sensory-specific satiety and some eating disorders.