Week 6 Readings Flashcards
1
Q
What two main metabolites does the brain use, delivered via the blood?
A
Oxygen and glucose.
2
Q
Despite being only 2% of our total body weight, what percentage of the oxygen and calories we consume does the brain use?
A
20%
3
Q
Can a lack of “brain fuel” explain our limited cognitive capacity?
A
No, as long as we are not oxygen-deprived or malnourished, we have more than enough oxygen and glucose to fuel the brain.
4
Q
Is it true that humans use only 10% of their brain?
A
No, this is a myth. Modern neuroimaging shows that we use all parts of the brain at different times and certainly more than 10% at any given time.
5
Q
If we have enough brain fuel and neurons, what most likely explains our limited cognitive abilities?
A
The way neurons are wired up, especially the competitive behavior among neurons.
6
Q
What is an example of competitive behavior among neurons in the brain?
A
In the visual cortex, neurons are wired to inhibit each other, meaning when one neuron fires, it suppresses the firing of nearby neurons.
When two neurons that are wired in an inhibitory way both fire, neither neuron can fire as vigorously as it would on its own, limiting the brain’s response to visual information.
7
Q
What is the most likely cause of our limited capacity for cognitive tasks?
A
The complex way in which neurons communicate and inhibit each other, rather than the depletion of resources like oxygen or glucose.
8
Q
What are the three parts that we divide the brain into (for simplicity in this course)?
A
The brain stem, cerebellum and cerebral hemispheres
9
Q
Which part is referred to as the “trunk” of the brain?
A
The brainstem
10
Q
What essential functions does the brain stem regulate?
A
Respiration (breathing), heart rate, and digestion.
11
Q
What happens if a patient sustains severe damage to the brain stem?
A
The patient will require life support to stay alive.
12
Q
In many countries, what condition defines a person as “brain dead”?
How do other countries define “brain death”?
A
Loss of brain stem function.
Other countries require significant tissue loss in the cortex, which is responsible for conscious experience.
13
Q
What regions make up the brain stem?
A
The medulla, pons, midbrain, and diencephalon (which includes the thalamus and hypothalamus).
14
Q
What additional functions (other than respiration, heart rate and digestion) are the brain stem regions involved in?
A
The sleep–wake cycle, some sensory and motor functions, growth, and other hormonal behaviors.
15
Q
What is the cerebellum, and where is it located?
A
The cerebellum is the distinctive structure at the back of the brain, often referred to as the “small brain.”
16
Q
Who referred to the cerebellum as the “small brain,” and why?
A
The Greek philosopher Aristotle referred to it as the “small brain” to distinguish it from the “large brain,” or cerebrum.
17
Q
What are the primary functions of the cerebellum?
A
The cerebellum is critical for coordinated movement and posture.
18
Q
In addition to movement and posture, what other abilities has neuroimaging implicated the cerebellum in?
A
Neuroimaging studies have implicated the cerebellum in a range of cognitive abilities, including language.
19
Q
Why is it not surprising that the cerebellum influences more than just movement and posture?
A
Because the cerebellum contains the greatest number of neurons of any structure in the brain.
20
Q
What are the cerebral hemispheres responsible for?
A
They are responsible for our cognitive abilities and conscious experience.
21
Q
What structures make up the cerebral hemispheres?
A
The cerebral cortex, white matter, and subcortical structures (including the basal ganglia, amygdala, and hippocampal formation).
22
Q
What is the cerebral cortex?
A
The largest and most visible part of the brain, consisting of two hemispheres and giving the brain its characteristic gray, convoluted appearance.
“The outermost gray matter of the cerebrum; the distinctive convolutions characteristic of the mammalian brain.”
23
Q
What term did Aristotle coin for the cerebral cortex, and why?
A
He coined the term “cerebrum” (Latin for “large brain”) to distinguish it from the “small brain” (cerebellum).
24
Q
What are the folds and grooves of the cerebral cortex called?
A
The folds are called gyri (singular: gyrus) and the grooves are called sulci (singular: sulcus).
25
How many hemispheres does the cerebral cortex consist of?
Two hemispheres.
26
What does subcortical mean?
Structures that lie beneath the cerebral cortex, but above the brain stem.
27
What are gyri and sulci?
Gyri: (plural) Folds between sulci in the cortex.
Gyrus: (plural form, gyri) A bulge that is raised between or among fissures of the convoluted brain.
Sulci: (plural) Grooves separating folds of the cortex.
Sulcus: (plural form, sulci) The crevices or fissures formed by convolutions in the brain.
28
What are the four lobes of the cerebral hemispheres?
The occipital, temporal, parietal, and frontal lobes.
29
What is the primary function of the occipital lobe?
Vision.
30
Which lobe is involved in vision, auditory processing, memory, and multisensory integration?
The temporal lobe.
31
Besides vision, what else is the temporal lobe responsible for?
Auditory processing, memory, and the convergence of multisensory information (e.g., vision and audition).
32
What is the parietal lobe responsible for?
It houses the somatosensory cortex (body sensations), is involved in visual attention, and contains multisensory convergence zones.
33
Where is the motor cortex located, and what other functions are associated with this lobe?
The motor cortex is located in the frontal lobe, which is also involved in motor planning, language, judgment, and decision-making.
34
Which lobe is proportionally larger in humans compared to other animals, and why?
The frontal lobe, because it is involved in higher cognitive functions like judgment, decision-making, and motor planning.
35
An area of the cerebrum that lies below the lateral sulcus; it contains auditory and olfactory (smell) projection regions.
Temporal lobe
36
An area of the cerebrum just behind the central sulcus that is engaged with somatosensory and gustatory sensation.
Parietal lobe
37
Define the somatosensory cortex
The region of the parietal lobe responsible for bodily sensations; the somatosensory cortex has a contralateral representation of the human body.
38
Define the motor cortex
Region of the frontal lobe responsible for voluntary movement; the motor cortex has a contralateral representation of the human body.
39
Why are subcortical structures so named?
Because they reside beneath the cortex.
40
What are the basal ganglia?
Subcortical structures of the cerebral hemispheres involved in voluntary movement.
41
What is the limbic system?
A loosely defined network of nuclei in the brain involved with learning and emotion.
42
What is the primary function of the basal ganglia?
The basal ganglia are critical to voluntary movement.
43
Which structures do the basal ganglia make contact with?
The cortex, the thalamus, and the brain stem.
44
Which subcortical structures are part of the limbic system?
The amygdala and hippocampal formation.
45
What is the limbic system involved in?
It plays an important role in emotion, particularly in aversion and gratification.
46
Does the limbic system include only subcortical structures?
No, it also includes some cortical structures.
47
What does contralateral mean/signify?
Literally “opposite side”; used to refer to the fact that the two hemispheres of the brain process sensory information and motor commands for the opposite side of the body (e.g., the left hemisphere controls the right side of the body).
48
What does it mean to say "functions are lateralized"?
To the side; used to refer to the fact that specific functions may reside primarily in one hemisphere or the other (e.g., for the majority individuals, the left hemisphere is most responsible for language).
49
What is a callosotomy?
Surgical procedure in which the corpus callosum is severed (used to control severe epilepsy).
50
What is a split-brain patient?
A patient who has had most or all of his or her corpus callosum severed.
51
What is the visual hemifield?
The half of visual space (what we see) on one side of fixation (where we are looking); the left hemisphere is responsible for the right visual hemifield, and the right hemisphere is responsible for the left visual hemifield.
52
What connects the two cerebral hemispheres?
A dense bundle of white matter tracts called the corpus callosum.
53
How is sensory and motor function represented in the two hemispheres?
They have a contralateral representation; the left hemisphere controls the right side of the body and vice versa.
54
What is meant by lateralized functions in the brain?
Some functions reside primarily in one hemisphere or the other.
55
In most right-handed and many left-handed individuals, which hemisphere is most responsible for language?
The left hemisphere.
56
What happens when the corpus callosum is severed or not fully developed?
It leads to split-brain patients, who can help us understand the functioning of the two hemispheres.
57
How does contralateral representation affect a split-brain patient’s perception of objects in their visual field?
If an object is placed in only the left or right visual hemifield, only the respective hemisphere will see it.
58
Why might a split-brain patient deny seeing a picture presented to the right hemisphere?
Because language is often localized in the left hemisphere, which did not see the picture.
59
How can a split-brain patient demonstrate that the right hemisphere perceives an image?
If asked to press a button when seeing an image, the left hand (controlled by the right hemisphere) will respond.
60
What advantages do split-brain patients have compared to those with a fully functional corpus callosum?
They can search simultaneously in both visual fields and perform tasks that require coordination of both hemispheres, exhibiting less competition between them.
61
What is gray matter?
Composes the bark or the cortex of the cerebrum and consists of the cell bodies of the neurons.
62
What is white matter?
Regions of the nervous system that represent the axons of the nerve cells; whitish in color because of myelination of the nerve cells.
63
What is myelin?
Fatty tissue, produced by glial cells that insulates the axons of the neurons; myelin is necessary for normal conduction of electrical impulses among neurons.
64
What is gray matter primarily composed of?
Neuronal cell bodies (soma).
65
What are the main functions of the cell body in gray matter?
The cell body contains the genes of the cell, is responsible for metabolism (keeping the cell alive), and synthesizes proteins.
66
What is the primary composition of white matter?
The axons of neurons, particularly those covered with a sheath of myelin.
67
What is the function of axons in white matter?
Axons conduct electrical signals from the cell and are critical for cell communication.
68
What does the expression “use your gray matter” refer to?
It encourages a person to think harder, likely referencing the cerebral hemispheres more generally and the gray cortical sheet.
69
Why are both gray and white matter important?
Both are critical to the proper functioning of the mind; losses in either can result in deficits in language, memory, reasoning, and other mental functions.
70
Which is on the "outside", grey or white matter?
Outer grey matter, inner white matter
71
What provides the strongest evidence for a specific role or function of a particular brain area?
Converging evidence—similar findings reported from multiple studies using different methods.
72
What was phrenology, and when was it popular? What assumption did phrenologists make about the brain and the skull? What has been proven wrong about phrenology?
Phrenology was an organized attempt to study brain functions in the first half of the 19th century.
They assumed that features of the brain, such as its uneven surface, are reflected on the skull.
The assumption that the skull reflects the underlying brain structure.
73
How did phrenologists attempt to correlate brain functions?
They correlated bumps and indentations of the skull with specific functions of the brain, claiming, for example, that artistic people have different skull ridges compared to those good at spatial reasoning.
74
Despite its inaccuracies, how did phrenology impact modern neuroscience?
It influenced the understanding that different parts of the brain are devoted to specific functions that can be identified through scientific inquiry.
75
What advancements have improved the method of brain dissection?
The discovery of various staining techniques that can highlight particular cells
76
Why is brain dissection especially useful for studying specific groups of neurons?
Because the brain can be sliced very thinly, examined under a microscope, and particular cells can be highlighted, allowing for high spatial resolution.
77
What changes can dissections help scientists study?
Changes in the brain that occur due to various diseases or experiences, such as exposure to drugs or brain injuries.
78
What is virtual dissection, and how is it conducted?
Virtual dissection studies with living humans use imaging techniques like computerized axial tomography (CAT) or MRI scanners to visualize brain structures.
79
What do CAT and MRI scans reveal about the brain?
They reveal various brain structures with very high precision and can help detect changes in gray or white matter.
80
How can changes in the brain detected by imaging correlate with behavior?
Changes in the brain can be correlated with behaviors such as performance on memory tests, implicating specific brain areas in certain cognitive functions.
81
What is spatial resolution?
A term that refers to how small the elements of an image are; high spatial resolution means the device or technique can resolve very small elements; in neuroscience it describes how small of a structure in the brain can be imaged.
82
What are lesions?
A region in the brain that suffered damage through injury, disease, or medical intervention.
83
What does the term to ablate mean?
Surgical removal of brain tissue.
84
What is transcranial magnetic stimulation (TMS)?
A neuroscience technique whereby a brief magnetic pulse is applied to the head that temporarily induces a weak electrical current that interferes with ongoing activity.
85
What is temporal resolution?
A term that refers to how small a unit of time can be measured; high temporal resolution means capable of resolving very small units of time; in neuroscience it describes how precisely in time a process can be measured in the brain.
86
What is transcranial direct current stimulation (tDCS)?
A neuroscience technique that passes mild electrical current directly through a brain area by placing small electrodes on the skull.
87
What is the purpose of inducing lesions or ablating parts of the brain in animal research?
To infer that the removed structure is important for specific behaviors if the animal’s behavior changes after the lesion.
88
In human studies, what types of patients are examined for brain lesions?
Patients who have lost a brain region due to a stroke or injury, or who have had surgical removal of a structure to treat a disease (e.g., callosotomy for epilepsy).
89
How can brain function be inferred from patient case studies?
By measuring changes in the behavior of patients before and after the lesion
90
What does transcranial magnetic stimulation (TMS) involve?
Applying a brief magnetic pulse to the head to temporarily induce a weak electrical current in the brain.
91
How are the effects of TMS described, and what is its primary function?
They are referred to as temporary virtual lesions, but it's more accurate to describe them as interference with normal neuronal communication.
92
What is the temporal resolution of TMS, and what are its limitations?
TMS allows precise study of when events in the brain happen, but its application is limited to the surface of the cortex and cannot reach deep areas of the brain.
93
How does transcranial direct current stimulation (tDCS) differ from TMS?
tDCS uses electrical current directly applied via electrodes on the skull, while TMS induces current with magnetic pulses.
94
What effects has tDCS shown when combined with cognitive training?
It has been shown to improve performance in various cognitive functions such as mathematical ability, memory, attention, and coordination.
95
What is positron emission tomography (PET)?
A neuroimaging technique that measures brain activity by detecting the presence of a radioactive substance in the brain that is initially injected into the bloodstream and then pulled in by active brain tissue.
96
What is the purpose of neuroimaging tools?
To study the brain in action while it is engaged in specific tasks.
97
What does positron emission tomography (PET) measure?
PET records blood flow in the brain by detecting a radioactive substance injected into the bloodstream.
98
How does a PET scanner determine which brain areas are active during a task?
More blood and radioactive substance flow into active neuron populations, allowing researchers to infer activity in specific brain regions.
99
What is functional magnetic resonance imaging (fMRI) used for?
To measure changes in oxygen levels in the blood without requiring any substance to be injected.
100
How do PET and fMRI compare in terms of spatial resolution?
Both tools have good spatial resolution, although not as precise as dissection studies.
101
What is a limitation of PET and fMRI regarding temporal resolution?
They have poorer temporal resolution (compared to dissection studies) because it takes several seconds for blood to arrive in active areas of the brain, so they do not provide precise timing of when activity occurred.
102
How does a PET scanner measure brain activity during a task?
The PET scanner detects a radioactive substance injected into the bloodstream of the participant before or while performing a task (e.g., adding numbers). Active neuron populations require metabolites, leading to increased blood flow and more radioactive substance in those regions. By detecting this substance in specific brain areas, researchers can infer that those areas were active during the task.
103
What does electroencephalography (EEG) measure?
EEG measures the electrical activity of the brain.
104
How does the temporal resolution of EEG compare to that of PET or fMRI?
EEG has much greater temporal resolution, providing millisecond precision, whereas PET and fMRI have a temporal resolution of seconds.
105
What is used to measure electrical activity through EEG during a task?
Electrodes are placed on the participant's head to measure electrical activity while they perform a task.
106
Why does EEG have poor spatial resolution?
EEG has poor spatial resolution because the electrical activity detected at any electrode can originate from anywhere in the brain, giving only a rough idea of the activity's source.
107
What is electroencephalography (EEG)?
A neuroimaging technique that measures electrical brain activity via multiple electrodes on the scalp.
108
What does diffuse optical imaging (DOI) measure to provide information about brain activity?
DOI measures the infrared light that is shined into the brain and reflects back out, analyzing how the light properties change when it interacts with oxygenated blood or active neurons.
109
How does DOI provide high spatial and temporal resolution?
When DOI is configured to directly detect active neurons, it achieves both high spatial and temporal resolution.
110
What happens to DOI's temporal resolution when it is set up to detect changes in blood oxygen levels?
The temporal resolution becomes low and is comparable to that of PET or fMRI.
111
What can researchers infer from the properties of the collected light in DOI?
Researchers can infer which regions of the brain were engaged by the task based on the changes in light properties.
112
What is diffuse optical imaging (DOI)?
A neuroimaging technique that infers brain activity by measuring changes in light as it is passed through the skull and surface of the brain.
113
Why is converging evidence crucial in understanding brain functions, and what does it suggest about the complexity of the brain?
Converging evidence from multiple studies using various tasks and neuroimaging tools strengthens our belief in the role of specific brain areas, such as the hippocampal formation in memory. This complexity indicates that only ongoing advances in brain research will reveal whether the brain can truly understand itself.
114
Describe the key factors of the parietal lobe (what it is, where it is, what its involved with, etc)
The parietal lobe is located between the frontal and occipital lobes.
- It is involved in bodily sensations, visual attention, and integrating the senses.
- The parietal lobe is home to the somatosensory (body sensations) cortex and structures involved in visual attention and multisensory convergence zones.
115
Describe the key factors of the temporal lobe (what it is, where it is, what its involved with, etc)
The temporal lobes are located laterally (right behind your ears).
- The temporal lobe is responsible for vision, along with the occipital lobe.
- It is also involved in auditory processing, memory, and multisensory integration (e.g., the convergence of vision and audition).
116
Describe the key factors of the frontal lobe (what it is, where it is, what its involved with, etc)
The frontal lobe is the forward-most region in the cerebrum (closest to the forehead).
- As the motor cortex is located within the frontal lobe, it is responsible for motor output, planning, language, judgment, and decision-making.
- The frontal lobe is proportionally larger in humans than in any other animal.
117
Describe the key factors of the occipital lobe (what it is, where it is, what its involved with, etc)
The occipital lobe is the back most (posterior) part of the cerebellum.
It is involved in vision, as is much of the temporal lobe.
118
Describe the key factors of the cerebellum (what it is, where it is, what its involved with, etc)
The cerebellum is the distinctive structure at the back of the brain.
- It contains the greatest number of neurons of any structure in the brain.
- The cerebellum is critical for coordinated movement and posture.
- Recent research findings have implicated the cerebellum in a range of cognitive abilities, including language.
119
Describe the key factors of the brain stem (what it is, where it is, what its involved with, etc)
The brain stem is sometimes referred to as the “trunk” of the brain.
- It is responsible for many of the neural functions that keep us alive, including regulating our respiration (breathing), heart rate, and digestion.
- It includes the medulla, pons, midbrain, and diencephalon (which consists of thalamus and hypothalamus). Collectively, these regions are involved in our sleep–wake cycle, some sensory and motor function, as well as growth and other hormonal behaviors.
120
The single most basic part of the human brain – a part that is seen in other, less-evolved animals - is the ______. This essential area helps to regulate such critical functions as breathing, digestion, and the beating of your heart.
brainstem
121
Which of the following would NOT be considered a structure that is part of the limbic system?
the pituitary gland.
the hypothalamus.
the thalamus.
the amygdala.
the medulla.
the medulla
122
The thick bundle of neurons that connects the left and right cerebral hemispheres is called the ______. This structure allows those hemispheres to communicate with each other.
corpus callosum
123
What is psychophysiology?
Psychophysiology is defined as research where the dependent variable is a physiological measure and the independent variable is behavioral or mental, often conducted noninvasively with awake human participants.
124
What are psychophysiological methods?
Any research method in which the dependent variable is a physiological measure and the independent variable is behavioral or mental (such as memory).
125
What is structural magnetic resonance imaging (sMRI), how does it work, and how is it used in psychophysiology research?
sMRI is a noninvasive technique that visualizes anatomical structures within the human body by placing a participant in a magnetic field (66,000 times stronger than Earth's) to align atoms.
Low-energy radio frequencies are then pulsed, causing the atoms to emit energy as they return to alignment, which the machine converts into a three-dimensional image.
In psychophysiology research, sMRI is used to compare the size of brain structures in different groups (e.g., pleasure-related areas in depressed individuals) and improve spatial accuracy in functional magnetic resonance imaging (fMRI).
126
What is functional magnetic resonance imaging (fMRI) and how does it measure changes in neural activity?
fMRI is a method used to assess changes in brain activity during thought by measuring neural activity in different areas. It builds on sMRI principles, leveraging the fact that firing neurons consume energy, requiring replenishment from glucose and oxygen transported by hemoglobin in the blood.
As neurons activate, oxygenated hemoglobin decreases due to oxygen consumption, prompting the body to supply more oxygenated hemoglobin to the active area. This replenishment occurs over several seconds as neural activity declines.
127
What is functional magnetic resonance imaging (fMRI) and how does it assess changes in brain activity?
Functional magnetic resonance imaging (fMRI) is a noninvasive imaging technique used to measure brain activity by detecting changes in blood flow and oxygenation. It operates on the principle that active neurons consume energy, which is replenished by glucose and oxygen from the bloodstream. When a group of neurons fires during a specific task, they require more oxygen, leading to a decrease in the amount of oxygenated hemoglobin in the surrounding blood.
As the neurons continue to fire, the body compensates by increasing blood flow to that area, supplying more oxygenated hemoglobin. This results in a higher concentration of oxygenated blood in the active region compared to deoxygenated blood. fMRI captures these changes in blood flow and oxygen levels, allowing researchers to infer which areas of the brain are engaged during specific cognitive tasks. The entire process takes several seconds, reflecting the dynamic nature of brain activity.
128
Does fMRI measure neural activity?
fMRI measures blood volume and blood flow, from which researchers infer neural activity; it does not measure neural activity directly.
129
What is the typical temporal/spatial resolution of fMRI?
fMRI typically has poor temporal resolution but provides excellent spatial resolution when combined with structural MRI (sMRI).
130
What is the relationship between temporal and spatial resolution in fMRI?
There is generally an inverse relationship between temporal and spatial resolution; increasing temporal resolution typically decreases spatial resolution and vice versa.
131
What is the blood-oxygen-level-dependent (BOLD) signal?
The signal typically measured in fMRI that results from changes in the ratio of oxygenated hemoglobin to deoxygenated hemoglobin in the blood.
132
What is one clinical application of fMRI?
fMRI is used prior to neurosurgery to identify areas associated with language, allowing surgeons to avoid those areas during the operation.
133
How does fMRI contribute to research in psychology?
fMRI helps researchers identify differential or convergent patterns of activation associated with tasks, such as determining if the same brain areas are recruited for tasks involving emotionally charged words compared to neutral words.
134
Can fMRI reveal changes in brain activation patterns in psychological disorders?
Yes, fMRI can show how relationships in brain activation change in psychological disorders such as anxiety or depression, even in the absence of overt performance differences.
135
What is Electroencephalography (EEG) used for?
EEG is used to study brain activation by measuring the electrical activity in the brain.
136
How does EEG measure brain activity?
EEG uses at least two electrodes, often up to 256, to measure the difference in electrical charge (voltage) between pairs of points on the head.
The electrodes are fastened to a flexible cap (similar to a swimming cap) that is placed on the participant's head.
137
Does EEG introduce new electrical activity to the brain?
No, EEG measures the electrical activity that is naturally occurring within the brain without introducing any new electrical activity.
138
How does EEG differ from fMRI in terms of what it measures?
EEG measures neural activity directly, whereas fMRI measures a correlate of that activity, such as changes in blood flow.
139
What is electrocorticography (ECoG) and how does it differ from traditional EEG?
ECoG involves placing electrodes directly on the brain's surface (invasive), allowing for more precise localization of neural activity, typically used before medical procedures to localize activity, such as the origin of epileptic seizures. In contrast, traditional EEG places electrodes on the scalp (noninvasive) to measure neural activity.
140
Why is the localization of neural activity less precise when using EEG compared to ECoG?
Localization is less precise in EEG because the electrical activity must travel through the skull and scalp before reaching the electrodes, which can cause some distortion. However, it can still localize activity within several millimeters when it is near the scalp.
141
What is a major advantage of EEG in terms of temporal resolution?
EEG has excellent temporal resolution, allowing data to be recorded thousands of times per second, which enables researchers to document events that occur in less than a millisecond.
142
How do EEG analyses typically evaluate the recorded data?
EEG analyses typically investigate changes in amplitude or frequency components of the recorded EEG on an ongoing basis or averaged over dozens of trials.
143
What does Magnetoencephalography (MEG) measure, and how is it different from EEG?
MEG measures neural activity by detecting the weak magnetic fields produced by the flow of electrical charge (current) associated with neural activity, whereas EEG measures the electrical activity directly.
144
Why are special rooms needed for MEG recordings?
Special rooms are needed because the magnetic fields of interest are very weak, and these rooms are shielded from external magnetic fields to avoid contamination of the signal being measured.
145
How does the spatial resolution of MEG compare to that of EEG?
MEG provides better spatial resolution than EEG because magnetic fields can pass through the skull and soft tissue with minimal distortion, while EEG is more susceptible to such distortions.
146
What are the advantages of MEG over EEG in terms of temporal resolution and susceptibility to distortion?
MEG has the same excellent temporal resolution as EEG and is less susceptible to distortions from the skull and scalp, resulting in better spatial resolution.
147
Why is MEG less widely available compared to EEG?
MEG is much less widely available because its recording apparatus is significantly more expensive than that of EEG.
148
What are EEG and MEG particularly good at measuring?
EEG and MEG are excellent for elucidating the temporal dynamics of neural processes, such as how quickly a person recognizes an unexpected word in a sentence.
149
How do EEG and MEG contribute to our understanding of brain networks?
They allow researchers to understand the roles of different brain networks in various tasks and how these networks may function abnormally in psychopathology.
150
What is a positron?
A particle having the same mass and numerically equal but positive charge as an electron.
151
How does Positron Emission Tomography (PET) work?
PET relies on a positron-emitting tracer atom introduced into the bloodstream in a biologically active molecule, such as glucose or fludeoxyglucose, which concentrates in areas with higher metabolic needs.
152
What does fludeoxyglucose do in a PET scan?
Fludeoxyglucose acts similarly to glucose in the body, concentrating in areas where glucose is needed, indicating higher metabolic activity.
153
How are the spatial locations of tracer molecules determined in PET?
The spatial location of the tracer is determined by detecting positrons emitted from the tracer molecule, allowing for the construction of a three-dimensional image of active brain areas.
154
What is the temporal resolution of PET images, and what does this mean?
PET images represent neural activity over tens of minutes, which is considered poor temporal resolution for certain applications.
155
Why are PET images often combined with computed tomography (CT) images?
PET images are combined with CT images to improve spatial resolution, often down to several millimeters.
156
What unique questions can PET help researchers answer regarding neurotransmitters?
PET can use tracers that bind to neurotransmitter receptors, allowing researchers to study the action of neurotransmitters in the brain.
157
What is a limitation of PET in research settings?
Very few research centers have the equipment needed to obtain PET images or to create the positron-emitting tracer molecules, which typically must be produced on-site.
158
What is depolarization?
A change in a cell’s membrane potential, making the inside of the cell more positive and increasing the chance of an action potential.
159
What is hyperpolarization?
A change in a cell’s membrane potential, making the inside of the cell more negative and decreasing the chance of an action potential.
160
What is neural plasticity?
The ability of synapses and neural pathways to change over time and adapt to changes in neural process, behavior, or environment.
161
What is Transcranial Magnetic Stimulation (TMS)?
TMS is a noninvasive method that causes depolarization or hyperpolarization in neurons near the scalp by using a magnetic field.
162
Is TMS considered a psychophysiological method?
No, TMS is not considered psychophysiological because the independent variable is physiological rather than the dependent variable.
However, it does qualify as a neuroscience method because it deals with the function of the nervous system, and it can readily be combined with conventional psychophysiological methods.
163
How does TMS work?
A coil of wire is placed just above the participant's scalp. When electricity flows through the coil, it produces a magnetic field that travels through the skull and affects nearby neurons, inducing a current that leads to depolarization or hyperpolarization.
164
What effects can TMS produce when applied to the primary motor cortex?
TMS can produce or block muscle activity, such as inducing a finger twitch or preventing someone from pressing a button.
165
What sensations can TMS evoke when used over the primary visual cortex?
TMS can produce sensations of flashes of light or impair visual processes.
166
What is the difference between single-pulse TMS and repetitive TMS?
Single-pulse TMS depolarizes site-specific neurons causing them to fire, while repetitive TMS produces lasting effects on neural activity that can either be attenuated or amplified, depending on various factors.
167
What is the significance of using repetitive TMS in research?
Repetitive TMS can explore neural plasticity, which is the ability of connections between neurons to change, and has implications for treating psychological disorders and understanding long-term changes in neuronal excitability.
168
Can TMS be combined with other methods?
Yes, TMS can be readily combined with conventional psychophysiological methods to study the function of the nervous system.
169
What psychophysiological methods focus on the peripheral nervous system, and how do they function?
Methods include skin conductance, cardiovascular responses, muscle activity, pupil diameter, eye blinks, and eye movements.
Skin conductance measures the electrical conductance between two points on the skin, which varies with moisture levels controlled by sweat glands and the sympathetic nervous system (SNS).
170
What psychological activities can skin conductance investigate, and what is its limitation?
Skin conductance can assess reactions to psychological stimuli, such as fearful images in psychopaths. However, it has poor temporal resolution, typically taking several seconds for the response to emerge and resolve.
It provides a straightforward way to measure the sympathetic nervous system's response to various stimuli, despite its temporal limitations.
171
What is the parasympathetic nervous system?
One of the two major divisions of the autonomic nervous system, responsible for stimulation of “rest and digest” activities.
172
What is the sympathetic nervous system?
One of the two major divisions of the autonomic nervous system, responsible for stimulation of “fight or flight” activities.
173
What are some common cardiovascular measures used in psychophysiological research?
Common cardiovascular measures include heart rate, heart rate variability, and blood pressure.
174
How do the parasympathetic nervous system (PNS) and sympathetic nervous system (SNS) influence heart activity?
The PNS decreases heart rate and contractile strength, while the SNS increases heart rate and contractile strength.
175
How is heart rate monitored, and what makes it a sensitive measure of cognitive activity?
Heart rate is monitored using a minimum of two electrodes by counting heartbeats over a specific time period or assessing the time between successive heartbeats. It is sensitive to cognitive activity as it can respond to psychological changes in less than a second.
176
What does heart rate variability measure, and what conditions is it associated with?
Heart rate variability measures the consistency in the time interval between heartbeats.
Changes in heart rate variability are associated with stress and psychiatric conditions.
177
How can cardiovascular measures help researchers in studying responses to stimuli?
These measures allow researchers to monitor SNS and PNS reactivity to various stimuli or situations, such as comparing heart rate responses between individuals with arachnophobia and those without when viewing pictures of spiders.
178
What does electromyography (EMG) measure? How does it function similarly to EEG?
EMG measures the electrical activity produced by skeletal muscles.
Like EEG, EMG measures the voltage between two points to assess activity.
179
What are some applications of EMG in research?
EMG can determine when a participant initiates muscle activity for a motor response, detect incorrect responses, and identify activity in muscles responsible for facial expressions like smiles and frowns.
180
What is one advantage of using EMG in emotion research?
EMG can detect very small facial movements that are not observable from simply looking at the face.
181
What is the temporal resolution of EMG, and how does it compare to other techniques?
The temporal resolution of EMG is similar to that of EEG and MEG, allowing for precise timing in measuring muscle activity.
182
What physiological measures can provide valuable information in research regarding eye activity?
Eye blinks, eye movements, and pupil diameter.
183
How are eye blinks typically assessed in research?
Eye blinks are assessed using EMG electrodes placed just below the eyelid or near the eyes to measure the electrical activity associated with the blinks.
184
What is one alternative method for measuring eye movements?
A camera can be used to record video of the eye, allowing researchers to determine the absolute direction of gaze.
185
How is eye position extracted from video recordings during a task?
Researchers conduct a calibration period where the participant looks at known targets, then compare the recorded eye position during the main task with data from the calibration phase.
186
What does research on eye movements reveal when participants view pleasant or unpleasant images?
People spend different amounts of time looking at the most arousing parts of the images, which can vary based on psychopathology.
187
How is pupil diameter measured and what does it indicate?
Pupil diameter can be recorded over time from video, and it is commonly used as an index of mental effort when performing a task, influenced by competing inputs from the SNS and PNS.
188
What method would be most appropriate for studying brain structures associated with cognitive control?
Techniques such as fMRI or PET would be appropriate.
189
Which methods are best for investigating how cognitive control unfolds over time?
EEG or MEG would be good choices for this purpose.
190
If you're interested in studying the bodily response to fear in different groups of people, which measures would be most suitable?
Peripheral nervous system measures would be most appropriate.
191
Which of the following brain imaging techniques provides the highest level of temporal resolution?
a) electroencephalography (EEG).
b) magnetic resonance imaging (MRI).
c) functional magnetic resonance imaging (fMRI).
d) computer tomography (CT).
e) positron emission tomography (PET).
a) EEG
192
Irene has been having migraines lately and she goes to visit her doctor. Her doctor sends her to have a brain imaging test that will measure changes in the naturally occurring oxygen in the blood in her brain. Which type of procedure is Irene going to have?
a) bilateral electroconvulsive viewing (BEV).
b) electromyography (EMG).
c) functional magnetic resonance imaging (fMRI).
d) positron emission tomography (PET).
e) diffuse optical imaging (DOI)
c) functional magnetic resonance imaging (fMRI).
193
What are the two components of the peripheral nervous system?
The somatic nervous system (volitional control) and the autonomic nervous system (nonvolitional control).
194
Which nerves does the peripheral nervous system use to control behaviors?
Cranial and spinal nerves.
195
How is the central nervous system divided?
The central nervous system is divided into the forebrain, midbrain, and hindbrain.
196
What is the function of the cerebral cortex in the forebrain?
It houses sensory, motor, and associative areas that gather sensory information, process information for perception and memory, and produce responses.
197
What tasks are performed by the central nervous system?
The CNS performs a variety of tasks, including processing sensory information, perception, memory, and response production.
198
How do simple brain-based behaviors in invertebrates compare to those in humans?
Basic behaviors, such as physiological responses made by individual neurons, appear very similar in both invertebrates and humans.
It suggests that these basic behaviors have been conserved across species and form the foundation for more complex behaviors in animals that evolved later.
199
Define homo habilis
A human ancestor, handy man, that lived two million years ago.
200
Define homo sapien
Modern man, the only surviving form of the genus Homo.
201
What has led to the complexity of the brain and nervous system through evolution?
The complexity has evolved through natural selection and sexual selection, which drive behavioral and cognitive refinement.
Charles Darwin (1859, 1871) proposed these forces as the engines of evolutionary change.
202
What is the ectoderm?
The outermost layer of a developing fetus.
203
What is the process of neural induction?
A process that causes the formation of the neural tube.
204
What is the rostrocaudal plane?
A front-back plane used to identify anatomical structures in the body and the brain.
205
What is spina bifida?
Spina bifida is a pathological condition where the caudal (tail-end) part of the neural tube does not close, affecting the spinal cord’s lumbar and sacral regions.
206
What is ontogeny in the context of the nervous system?
Ontogeny refers to the development of the nervous system in an individual.
207
From which embryonic layer does nervous tissue emerge during development?
Nervous tissue emerges from the ectoderm, one of the three layers of the mammalian embryo.
208
What structure forms as a result of neural induction?
The neural tube forms and extends in a rostrocaudal (head-to-tail) direction.
209
What happens if the neural tube does not close properly in the caudal region?
It results in a condition called spina bifida, where the lumbar and sacral segments of the spinal cord are disrupted.
210
What is the forebrain?
A part of the nervous system that contains the cerebral hemispheres, thalamus, and hypothalamus.
211
What is cephalization in the context of neural development?
Cephalization is the process where the rostral (head) end of the neural tube balloons up during development.
212
At what point during gestation can the forebrain, midbrain, hindbrain, and spinal cord be visually delineated?
Around day 40 of gestation.
213
What occurs at approximately 50 days into gestation in terms of brain development?
Six cephalic (head-related) areas can be anatomically discerned by about 50 days into gestation.
214
What does the development of the neural tube eventually give rise to in the rostral end?
It gives rise to the forebrain, midbrain, hindbrain, and spinal cord.
215
What are the progenitor cells that form the lining of the neural tube called?
They are called neuroblasts.
216
What do neuroblasts generate in the central nervous system?
Neuroblasts generate all the neurons and glial cells of the central nervous system.
217
How do neuroblasts behave during early development?
Neuroblasts rapidly divide and specialize into many varieties of neurons and glial cells.
218
What are neuroblasts?
Brain progenitor cells that asymmetrically divide into other neuroblasts or nerve cells.
219
What is the neuroepithelium?
The lining of the neural tube.
220
What is the neural crest?
A set of primordial neurons that migrate outside the neural tube and give rise to sensory and autonomic neurons in the peripheral nervous system.
221
Why do the forebrain and hindbrain expand into larger cephalic tissues than the midbrain?
The proliferation of neuroblasts is not uniform along the neural tube, causing the forebrain and hindbrain to expand more than the midbrain.
222
What does the neuroepithelium generate besides neurons and glial cells?
It generates a group of specialized cells that migrate outside the neural tube to form the neural crest.
223
What does the neural crest give rise to?
The neural crest gives rise to sensory and autonomic neurons in the peripheral nervous system.
224
What is the two divisions of the peripheral nervous system?
The autonomic and the somatic nervous system
225
What is the autonomic nervous system?
A part of the peripheral nervous system that connects to glands and smooth muscles. Consists of sympathetic and parasympathetic divisions.
226
What is the somatic nervous system?
A part of the peripheral nervous system that uses cranial and spinal nerves in volitional actions.
227
How many pairs of cranial and spinal nerves make up the somatic nervous system?
The somatic nervous system consists of 12 pairs of cranial nerves and 31 pairs of spinal nerves.
228
What is the function of the somatic nervous system?
It controls voluntary movements of the body's muscles.
229
What does the autonomic nervous system control?
It controls involuntary actions involving muscles and glands, such as those in visceral structures.
230
What is the telencephalon, and why is it significant in mammalian evolution?
he telencephalon, or cerebrum, is a newer development in mammalian evolution, responsible for higher cognitive functions.
231
What are the furrows in the brain's surface called?
The furrows are called sulci (singular: sulcus).
232
What are the bulges between the sulci called?
The bulges between sulci are called gyri (singular: gyrus).
233
How is the cerebral cortex divided?
The cortex is divided into two hemispheres, and each hemisphere is further divided into four lobes.
234
What sulci divide the brain into its main lobes?
The central sulcus divides the hemisphere into frontal and parietal-occipital lobes, and the lateral sulcus marks the temporal lobe.
235
Where is the temporal lobe located?
The temporal lobe is located below the lateral sulcus.
236
What is the area just in front of the central sulcus called?
It is called the primary motor cortex, also known as the precentral gyrus.
237
What is the function of the primary motor cortex?
It connects to the muscles of the body and moves them under volitional control.
238
What types of body movements are controlled by the primary motor cortex?
It controls a wide range of movements, from mastication (chewing) to movements in the genitalia.
239
What is the primary motor cortex (briefly)?
A strip of cortex just in front of the central sulcus that is involved with motor control.
240
Which body parts have a greater representation on the primary motor cortex?
Fingers, thumbs, and lips occupy a greater representation compared to other body parts like the trunk.
241
What is the term for the disproportionate representation of body parts on the primary motor cortex?
The magnification factor.
242
Where is Broca's area located?
Broca's area is located at the lower end of the central sulcus, close to the lateral sulcus, in the left frontal lobe.
243
What is the primary function of Broca's area?
Broca's area is involved in language production.
244
Who documented various forms of aphasia related to damage in Broca's area?
Pierre Paul Broca, a French neuroscientist, documented these cases in 1861.
245
What are some effects of damage to Broca's area?
Damage can lead to loss of the ability to speak or result in partial speech that is impoverished in syntax and grammar.
246
What cognitive processes related to working memory have been found in the frontal lobe?
Subvocal rehearsal and central executive processes.
247
What is the magnification factor?
Cortical space projected by an area of sensory input (e.g., mm of cortex per degree of visual field).
248
What is Broca's area?
An area in the frontal lobe of the left hemisphere. Implicated in language production.
249
What are aphasias?
Due to damage of the Broca’s area. An inability to produce or understand words.
250
Where is the primary somatosensory cortex located?
The primary somatosensory cortex is located in the parietal lobe on the postcentral gyrus.
251
What does the primary somatosensory cortex represent?
It represents the whole body and receives inputs from the skin and muscles.
252
How does the primary somatosensory cortex relate to the primary motor cortex?
The primary somatosensory cortex parallels, abuts, and connects heavily to the primary motor cortex and resembles it in terms of areas devoted to bodily representation.
253
Which nerves send sensory signals to the primary somatosensory cortex?
All spinal nerves and some cranial nerves, such as the facial nerve, send sensory signals from the skin and muscles.
254
What types of sensory inputs are received by the primary somatosensory cortex?
The primary somatosensory cortex receives inputs related to touch and other sensory signals from the skin and muscles.
255
What is located close to the lower (ventral) end of the primary somatosensory cortex?
The taste area (secondary somatosensory cortex), which is involved with taste experiences.
256
Which structures provide taste experiences to the taste area?
The taste area receives inputs from the tongue, pharynx, epiglottis, and other structures involved in taste.
257
Where is Wernicke's area located?
Wernicke's area is located in the temporal lobe, just below the parietal lobe and under the caudal end of the lateral fissure.
258
What is the primary function of Wernicke's area?
Wernicke's area is involved with language comprehension.
259
How is Wernicke's area connected to Broca's area?
They are connected through the arcuate fasciculus, a bundle of nerve fibers.
260
What happens if Wernicke's area is damaged?
Damage to Wernicke's area can result in various forms of agnosia, which is an inability to know or understand language and speech-related behaviors.
261
What are some types of agnosias associated with Wernicke's area damage?
Individuals may experience word deafness (inability to recognize spoken language) or word blindness (inability to recognize written or printed language).
262
What area is located close to Wernicke's area and what is its function?
The primary auditory cortex is located close to Wernicke's area and is involved with auditory processing.
263
Where is the brain region devoted to smell (olfaction) located?
The brain region devoted to smell is located inside the primary olfactory cortex (prepyriform cortex).
264
What is the arcuate fasciculus?
A fiber tract that connects Wernicke’s and Broca’s speech areas.
265
What is Wernicke's area?
A language area in the temporal lobe where linguistic information is comprehended
266
What is the thalamus?
A part of the diencephalon that works as a gateway for incoming and outgoing information.
267
Where is the primary visual cortex located?
The primary visual cortex is located in the occipital lobe at the very back of the cerebral cortex.
268
How do optic nerves relay visual information to the brain?
Optic nerves travel to the thalamus (specifically the lateral geniculate nucleus, LGN) and then to the visual cortex, where retinal images are projected.
269
What is the process called when images on the retina are transformed into neural signals?
This process is called transduction.
270
What happens to the attributes of an image in the visual cortex?
The attributes (features) of the image, such as color, texture, and orientation, are decomposed and processed by different visual cortical modules.
271
How are visual attributes recombined in the visual cortex?
They are recombined to create a singular perception of the image in question.
272
What functions are associated with the limbic system?
The limbic system processes memory (hippocampus and fornix), attention, and emotions (cingulate gyrus).
273
What role does the globus pallidus play in the brain?
The globus pallidus is involved with motor movements and their coordination.
274
How do the hypothalamus and thalamus contribute to bodily functions?
They are involved with drives, motivations, and the trafficking of sensory and motor inputs.
275
What key role does the hypothalamus play in the endocrine system?
The hypothalamus regulates endocrine hormones in conjunction with the pituitary gland, which extends from it through a stalk (infundibulum).
276
What is the limbic system?
A loosely defined network of nuclei in the brain involved with learning and emotion.
277
What is the hippocampus?
(plural form, hippocampi) A nucleus inside (medial) the temporal lobe implicated in learning and memory.
278
What is the fornix?
(plural form, fornices) A nerve fiber tract that connects the hippocampus to mammillary bodies.
279
What is the cingulate gyrus?
A medial cortical portion of the nervous tissue that is a part of the limbic system.
280
What is the globus pallidus?
A nucleus of the basal ganglia. Involved with motor movements and thier coordination.
281
What structures are visible as we descend down from the thalamus?
The midbrain, including the superior and inferior colliculi, and the substantia nigra.
282
What functions do the superior and inferior colliculi serve?
They process visual and auditory information.
283
What is the role of the substantia nigra?
The substantia nigra is involved in the regulation of movement and is notably associated with Parkinson's disease.
284
What does the reticular formation regulate?
The reticular formation regulates arousal, sleep, and temperature.
285
What functions does the pons serve in the hindbrain?
The pons processes sensory and motor information, connects the cerebral cortex with the medulla, and transfers information between the brain and spinal cord.
286
What is the primary function of the medulla oblongata?
The medulla oblongata processes vital functions such as breathing, digestion, heart and blood vessel function, swallowing, and sneezing.
287
What does the cerebellum control?
The cerebellum controls motor movement coordination, balance, equilibrium, and muscle tone.
288
What is the pons?
A bridge that connects the cerebral cortex with the medulla, and reciprocally transfers information back and forth between the brain and the spinal cord.
289
What is the cerebellum?
A nervous system structure behind and below the cerebrum. Controls motor movement coordination, balance, equilibrium, and muscle tone.
290
What two parts make up the brain stem?
The midbrain and the hindbrain make up the brain stem.
291
How is the arrangement of gray and white matter different in the spinal cord compared to the cerebral cortex?
In the cerebral cortex, gray matter (neuronal cell bodies) lies outside and white matter (myelinated axons) lies inside.
In the spinal cord, this arrangement is reversed: gray matter resides inside and white matter outside.
292
What are the paired nerves that exit the spinal cord called?
The paired nerves are referred to as ganglia.
293
What is the direction of the dorsal nerves and what is their function?
Dorsal nerves (afferent) exit towards the back (dorsal side) and receive sensory information from the skin and muscles.
294
What is the direction of the ventral nerves and what is their function?
Ventral nerves (efferent) exit towards the front (ventral side) and send signals to muscles and organs to elicit a response.
295
What is immunocytochemistry?
A method of staining tissue including the brain, using antibodies.
296
What technique allows researchers to visualize selected neurons of specific types?
Modern staining procedures, known as immunocytochemistry, allow visualization of selected neurons.
297
What advancements have electron microscopes provided in the study of nerve cells?
Electron microscopes offer better resolution for studying fine structures, such as the synaptic cleft between pre- and post-synaptic neurons.
298
What is the significance of the synaptic cleft in neuron communication?
The synaptic cleft is the gap between pre- and post-synaptic neurons where neurotransmission occurs, playing a critical role in neuron communication.
299
What early methods were used to study the function of the nervous system?
Lesion studies in animals and studies of neurological damage in humans provided insights by ablating or destroying parts of the nervous system and documenting effects on behavior.
300
What advancement followed lesion studies for investigating neuronal functions?
Sophisticated microelectrode techniques allowed recording from single neurons in animal brains, leading to theories about sensory and motor information processing.
301
What technique is used to study the activity of many neurons simultaneously?
Electroencephalographic (EEG) techniques are used to study the function of large ensembles of neurons, both with and without stimulation.
302
How does computerized axial tomography (CAT) visualize the brain?
CAT uses X-rays to capture multiple images of the brain and compiles them into 3-D models, although it has inferior resolution compared to MRI.
303
What is the advantage of magnetic resonance imaging (MRI) over CAT scans?
MRI provides much better resolution of brain images but does not offer functional information about the brain.
304
How does Positron Emission Tomography (PET) acquire functional images of the brain?
PET uses radio-labeled isotopes of certain chemicals (like fluorodeoxyglucose) that enter active nerve cells, emitting positrons that are captured and mapped into scans.
305
What are the disadvantages of PET scans?
PET scans are invasive and have poor spatial resolution, which is why they are often coupled with CAT scanners for better resolution.
306
What is the principle behind functional MRI (fMRI) techniques?
fMRI visualizes brain function by detecting changes in blood flow over time, providing functional information about the brain during tasks.
307
Why are fMRI and PET techniques popular among cognitive neuroscientists?
They provide valuable functional information about brain activity as individuals engage in tasks, helping to understand cognitive processes.
