Chapter 1 (M. Wolfe)

Question 1

What is the difference between sensation and perception?

Answer 1

Sensation is the ability to detect a stimulus and, perhaps, to turn that detection into a private experience. Perception is the act of giving meaning to a detected sensation

Question 2

What is the difference between dualism and materialism?

Answer 2

Dualism is the idea that the mind and body are separate, that the mind has a non-material existence. Materialism is the idea that the only thing that exists in the universe is matter, and that both the mind and body are made of matter—the mind is what the brain does.

Question 3

What is the “just noticeable difference” (JND)?

Answer 3

The JND is the smallest detectable difference between two stimuli, or the minimum change in a stimulus that can be correctly judged as different from a reference stimulus. It is also known as the “difference threshold.”

Question 4

What is psychophysics?

Answer 4

Psychophysics is the science of defining quantitative relationships between physical and psychological (subjective) events.

Question 5

Explain Weber’s law.

Answer 5

Weber’s law is the principle describing the relationship between stimulus and resulting sensation that says the just noticeable difference (JND) is a constant fraction of the comparison stimulus. In other words, the JND is proportional to the stimulus magnitude.

Question 6

Explain Fechner’s law.

Answer 6

Fechner’s law is a principle describing the relationship between stimulus magnitude and resulting sensation magnitude such that the magnitude of subjective sensation increases proportionally to the logarithm of the stimulus intensity. As the stimulus grows larger, larger changes are required for the changes to be detected by a perceiver.

Question 7

Describe the method of constant stimuli.

Answer 7

The method of constant stimuli involves the presentation of many stimuli, ranging from rarely to almost always perceivable. They are presented one at a time and participants respond to each presentation: “yes/no,” “same/different,” and so on.

Question 8

What is the method of limits?

Answer 8

The method of limits involves presenting stimuli that vary incrementally in one dimension until the participant responds differently.

Question 9

What is the method of adjustment?

Answer 9

The method of adjustment is a psychophysical method, which uses the method of limits idea, but in which the participant controls the change in the stimulus.

Question 10

What is magnitude estimation?

Answer 10

Magnitude estimation is a psychophysical method in which the participant assigns values according to perceived magnitudes of stimuli

Question 11

What is Stevens’ power law?

Answer 11

It is a principle describing the relationship between stimulus and resulting sensation that says the magnitude of subjective sensation is proportional to the stimulus magnitude raised to an exponent. Exponent values less than one yield curves that get flatter as stimulus values increase, whereas exponent values more than one yield curves that continuously increase as stimulus values increase. An exponent value of one yields a straight line.

Question 12

How does cross-modality matching work?

Answer 12

In cross-modality matching, the observer adjusts the intensity of one kind of stimulus until it matches the perceived intensity of another kind of stimulus. For instance, adjusting the brightness of a light to match the spiciness of some food.

Question 13

What are the signal and noise in signal detection theory?

Answer 13

Signal detection theory is a psychophysical theory that quantifies the response of an observer to the presentation of a signal in the presence of noise. The signal is the target stimulus and the noise is the interference that occurs, and is sometimes confused with the signal.

Question 14

What is the difference between sensitivity and criterion in signal detection theory?

Answer 14

Sensitivity is the ease with which an observer can distinguish a signal from noise, regardless of any bias they may have in responding. The criterion represents your willingness to say “yes” or “no” to whether you perceived a potential signal and thus is a measure of your bias in responding.

Question 15

What can be inferred by doing a Fourier analysis?

Answer 15

A Fourier analysis is a mathematical theorem by which any signal can be divided into a set of sine waves. Combining these sine waves will reproduce the original signal. Fourier analysis can be performed on sound waves and on images.

Question 16

Define spatial frequency.

Answer 16

Spatial frequency is the number of repetitions of a sine wave per unit area. In audition, it is the number of cycles per second; in vision, it is the number of cycles per degree.

Question 17

What is the central idea of Müller’s doctrine of specific nerve energies?

Answer 17

The central idea of Müller’s doctrine of specific nerve energies is that we are aware only of the activity in our nerves, and we cannot be aware of the world itself. In addition, what is most important is which nerves are stimulated, and not how they are stimulated.

Question 18

What are cranial nerves?

Answer 18

Cranial nerves are twelve pairs of nerves that originate in the brain stem and reach the periphery through openings in the skull. They are dedicated mainly to sensory and motor systems.

Question 19

Explain how neurons communicate with one another

Answer 19

Neurons have axon terminals (presynaptic) as well as dendrites (postsynaptic). The axon terminal of the presynaptic neuron releases neurotransmitters that bind to receptors on the dendrite of the postsynaptic neuron, thus communicating from the axon of the first neuron to the dendrite of the second neuron.

Question 20

What are neurotransmitters?

Answer 20

Neurotransmitters are chemical substances used in neuronal communication at synapses.

Question 21

When is an action potential created?

Answer 21

An action potential, or firing of a neuron, is created when the membrane of the neuron permits sodium ions to rush into the cell, thus increasing the voltage. Very quickly afterward, potassium flows out of the cell, bringing the voltage back to resting voltage.

Question 22

Which forms of non-invasive brain imaging have the highest temporal resolution?

Answer 22

Electroencephalography (EEG) and magnetoencephalography (MEG) both have very high temporal resolution but low spatial resolution. They are the best techniques for making fine observations of an observer’s neural responses to a stimulus over time.

Question 23

Which forms of non-invasive brain imaging have the highest spatial resolution?

Answer 23

Computerized tomography (CT) and magnetic resonance imaging (MRI) both have extremely high spatial resolution. They are the best options for creating non-invasive structural images of the brain.

Question 24

Which forms of non-invasive brain imaging are good for investigating how the brain functions?

Answer 24

Functional magnetic resonance imaging (fMRI) and positron emission tomography (PET) are both capable of visualizing the brain’s metabolic activity over time. fMRI tracks the flow of oxygenated blood in the brain, while PET tracks the metabolism of safe radioactive isotopes

Question 25

A variant of magnetic resonance imaging that makes it possible to measure localized patterns of activity in the brain.

Answer 25

functional magnetic resonance imaging (fMRI)

Question 26

magnetoencephalography (MEG)

Answer 26

A technique, similar to electroencephalography, that measures changes in magnetic activity across populations of many neurons in the brain.

Question 27

Neuro-imaging

Answer 27

A set of methods that generate images of the structure and/or function of the brain. In many cases, these methods allow us to examine the brain in living, behaving humans.

Question 28

panpsychism

Answer 28

The idea that the mind exists as a property of all matter—that is, that all matter has consciousness.

Question 29

qualia (sing. quale)

Answer 29

In philosophy, private conscious experiences of sensation or perception

Question 30

sensitivity

Answer 30

The ability to respond to transmitted signals. 2. In signal detection theory, a value that defines the ease with which an observer can tell the difference between the presence and absence of a stimulus or the difference between stimulus 1 and stimulus 2.

Question 31

What is two-point touch threshold?

Answer 31

The minimum distance at which two stimuli (e.g., two simultaneous touches) are just perceptible as separate.