Unit 0

Question 1

What does Morpheus suggest defines what is real in “The Matrix”?

Answer 1

Real is simply electrical signals interpreted by your brain.

Question 2

What is sensation?

Answer 2

The process of capturing physical energy, which is then transduced into neural signals.

Question 3

What is perception?

Answer 3

The process that involves the cortical processing of neural signals, which allows us to learn about the real world.

Question 4

What is the order of events in perception?

Answer 4

1. Capturing physical energy
2. Physical stimulation (physical energy needs to stimulate some nerve cells)
3. Transduction of physical energy into neural signal: Sensation
4. Transmission of neural signals to the brain
5. Cortical processing: Perception (awareness of stimulus)
6. Active feedback

Question 5

What is the meaning behind the allegory of the cave?

Answer 5

Plato’s “Allegory of the Cave” illustrates the limitations of human perception, suggesting that humans only see the shadows of reality rather than reality itself

Question 6

Who was Gustav Fechner?

Answer 6

• Invented psychophysics
• Considered to be the true founder of experimental psychology
• Believed in panpsychism: all matter has consciousness

Question 7

What is psychophysics?

Answer 7

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

Question 8

Who was Ernst Weber?

Answer 8

Discovered that the smallest change in a stimulus (weight of an object) that can be detected is a constant proportion of the stimulus level (Weber’s Law)

Question 9

What is Weber’s Law?

Answer 9

The principle stating that the smallest change in a stimulus is a constant proportion of the stimulus level.

Question 10

Who is Wilhelm Wundt?

Answer 10

• Father of experimental psychology
• The first person to call himself a psychologist
• Founded the first formal lab for psychology (Leipzig, Germany)

Question 11

Who is James J. Gibson?

Answer 11

• Postulated an active “information pick-up” of perceptual units from the environment
• Coined the term “affordance”

Question 12

What is affordance?

Answer 12

the opportunities for action provided by a particular object or environment

Question 13

Who is Johannes Muller?

Answer 13

Formulated a doctrine stating that the nature of a sensation depends on which sensory fibers are stimulated, not on how the fibers are stimulated

Question 14

Who is Hermann von Helmholtz?

Answer 14

• The first person to measure the speed of neural impulse
• Invented the ophthalmoscope
• Wrote On the Sensations of Tone (1863), one of the first studies of auditory perception

Question 15

Who is Santiago Ramon y Cajal?

Answer 15

• Created incredibly detailed drawings of neurons and neural structure
• Father of neuroscience

Question 16

What are the main philosophical approaches to perception?

Answer 16

• Nativism: the mind produces ideas that are not derived from external sources, and that we have abilities that are innate and not learned. (born with it)
• Empiricism: all knowledge comes through the senses

Question 17

What is dualism?

Answer 17

the mind has an existence separate from the material of the body

Question 18

What is materialism?

Answer 18

the only thing that exists is matter, and all things, including mind and consciousness, are the result of interactions between bits of matter. (Believed now)

Question 19

What is panpsychism?

Answer 19

the mind exists as a property of all matter–that is, that all matter has consciousness

Question 20

How are perceptual processes measured?

Answer 20

Psychophysics: the behavioral response of organisms to stimulation
Neurophysiology, brain imaging: the specific neural energies in response to stimulation

Question 21

What can be measured for psychophysics?

Answer 21

Absolute threshold, two-point threshold, JND (just noticeable difference)

Question 22

What is the absolute threshold?

Answer 22

The minimum amount of stimulation necessary for a person to detect a stimulus 50% of the time

Question 23

What is the two-point threshold?

Answer 23

The minimum distance at which two stimuli can be distinguished

Question 24

What is the JND (just noticeable difference)?

Answer 24

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 (also known as difference threshold)

Question 25

How can psychophysics be measured?

Answer 25

Signal detection theory

Question 26

What is the signal detection theory?

Answer 26

Makes the distinction between an observer’s ability to perceive a signal and their willingness to report it

Question 27

What is sensitivity?

Answer 27

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 28

What is a criterion?

Answer 28

an internal threshold that is set by the observer. If the internal response is above criterion, the observer gives one response (eg. yes, I hear that). Below criterion, the observer gives another response (eg. no, I hear nothing)

Question 29

What are the possible outcomes for the signal detection theory?

Answer 29

Correct rejection (phone wasn’t ringing, didn’t check phone)
Hit (Check phone, phone was ringing)
False alarm (Check phone, phone wasn’t ringing)
Miss (didn’t check phone, phone was ringing)

Question 30

What is d’?

Answer 30

a measure of signal separability. Tells us by how many standard deviations the two signals are separated

Question 31

What is the equation for d’?

Answer 31

d’=Z(hit rate) - Z(false alarm rate)

Question 32

What happens if d’ is fixed?

Answer 32

change the pattern of error by shifting the decision criterion

Question 33

What are some electrophysiological techniques?

Answer 33

• Patch clamps: study individual ion channels
  -Single unit recordings: study firing of individual neurons
• Multi-unit recordings: study small ensembles of neurons

Question 34

What is electroencephalography?

Answer 34

EEG: measures electrical activity from populations of many neurons using many electrodes on the scalp

Question 35

What is event-related potential?

Answer 35

ERP: a measure of electrical activity from a subpopulation of neurons in response to particular stimuli that requires many EEG recordings
Upward hill: negative voltage
Downward hill: positive voltage

Question 36

What is electrocorticography/ Intracranial EEG

Answer 36

• EEG recorded inside the skull on top of the dura mater
• Performed by neurosurgeons to localize epileptic focus in pharmacologically intractable epilepsy

Question 37

What is magnetoencephalography?

Answer 37

MEG: Measures changed in magnetic activity across populations of many neurons in the brain
- Better localization than EEG, but more expensive

Question 38

What is magnetic resonance imaging?

Answer 38

MRI: Uses the responses of atoms to strong magnetic fields and radio waves to form images of structures like the brain.

Question 39

What is functional magnet resonance imaging?

Answer 39

fMRI: Measures localized patterns of activity in the brain
- Activated neurons provoke increased blood flow, which can be quantified by measuring changes in oxygenated and deoxygenated blood to strong magnetic fields

Question 40

What is a blood oxygen level-dependent signal?

Answer 40

he ratio of oxygenated to deoxygenated hemoglobin that permits the localization of brain tissue that is most involved in a task

Question 41

What is positron emission tomography?

Answer 41

Define the location in the brain where neurons are especially active, by measuring the metabolism of brain cells using safe radioactive isotopes
- Water labeled with radioactive oxygen 15O is injected
- Positrons break off and generate pairs of gamma rays that flow in opposite directions, which can be detected
- The more active regions demand more oxygen