1. Stimuli are detected through the process called:

c. sensation.

2. You’re listening to music on your iPod. The sound waves transmitted through the earbuds lead to vibrations in the fluid in your cochlea. This activity causes the hair cells to bend, which causes nearby nerve cells to fire. This process of transforming stimuli into electrical and chemical signals of neurons is:

a. transduction.

3. According to signal detection theory, our ability to detect weak stimuli in the environment is based on many factors, including which of the following?

b. fatigue and motivation

4. While rollerblading outside, you get something in your eye. As the day goes on, your eye still feels irritated. It is possible you’ve scratched your ____________, which is the transparent outer layer, the function of which is to protect the eye and bend light to help focus light waves.

d. cornea

5. The blind spot of the retina lacks ____________ because it is the location where the optic nerve exits the retina.

b. rods and cones

6. In color vision, the opponent-process theory was developed to explain the ____________, which could not be explained by the ____________ theory.

a. afterimage effect; trichromatic

7. A developmental psychologist is interested in studying children’s ____________, which is the term we use for the sense of hearing.

d. audition

8. Frequency theory of pitch perception suggests it is the number of ____________ that allows us to perceive differences in pitch.

c. neural impulses firing

9. One large study conducted in the United States by Shargorodsky and colleagues (2012) found hearing loss in what percentage of teenagers?

b. 20%

10. The wiring of the olfactory system is unique, because other sensory systems relay data through the ____________ before information is passed along to higher brain centers, but this is not the case for olfactory information.

a. thalamus

11. ____________ specialize in recognizing specific characteristics of your visual experience, such as angles, lines, and movements.

a. Feature detectors

12. We are aware of where the parts of our bodies are in space because of specialized nerve endings called ____________, which are primarily located in the joints and muscles.

a. proprioceptors

13. Hector is staring at the small print on the back of a credit card. Which of the following would be a binocular cue to indicate how close the credit card is to his face?

a. tension of the muscles focusing the eyes

14. One of the gestalt organizational principles suggests that objects close to each other are perceived as a group. This is known as:

d. proximity.

15. When two objects are similar in actual size and one of these objects is farther away than the other, the object at a distance appears to be smaller than the closer object. This is a monocular cue called:

c. relative size.

16. Use the evolutionary perspective of psychology to explain the importance of any two aspects of human taste.

Answers may vary. Humans gravitate toward sweet, calorie-rich foods for their life-sustaining energy, which was adaptive for primitive humans foraging in trees and bushes. We tend to avoid bitter and sour tastes as this gives us an evolutionary edge because poisonous plants or rancid foods are often bitter or sour.

17. How is extrasensory perception different from the perception of subliminal stimuli?

Extrasensory perception is the purported ability to obtain information about the world without any sensory stimuli. Subliminal stimuli are sights, sounds, smells, tastes, and feelings occurring below absolute threshold. Another difference is that there is research evidence for the influence of subliminal stimuli, but there is no reliable data to back up claims about ESP.

18. The transformation of a sound wave into the experience of something heard follows a complicated path. To better understand the process, draw a diagram starting with a sound in the environment and ending with the sound heard by an individual.

Diagrams will vary; see Infographic 3.3. The pinna funnels sound waves into the auditory canal, focusing them toward the eardrum. Vibrations in the eardrum cause the hammer to push the anvil, moving the stirrup, which presses on the oval window, amplifying waves. Pressure on the oval window causes fluid in the cochlea to vibrate and bend the hair cells on the basilar membrane. If vibration is strong enough in the cochlear fluid, the bending of hair cells causes nearby nerve cells to fire. The auditory nerve carries signals to the auditory cortex in the brain, where sounds are given meaning.

19. Why does placing ice on a sore shoulder stop the pain?

The gate-control theory of pain suggests that the perception of pain can either increase or decrease through the interaction of biopsychosocial factors. Signals are sent to open or close the “gates” that control the neurological pathways for pain. When large myelinated fibers are active, the gates are more likely to close, which then inhibits pain messages from being sent on. With a sore shoulder, applying ice to the injured area can stimulate the temperature and pressure receptors of the large fibers. This activity closes the gates, temporarily interfering with the pain message that would have been sent to the brain.

20. Describe the difference between absolute threshold and difference threshold.

An absolute threshold is the weakest stimuli that can be detected 50% of the time. A difference threshold is the minimum difference between two stimuli that can be noticed 50% of the time.