cognitive neuroscience

As a result of a brain injury to the medial temporal lobes and neighboring subcortical structures, a patient exhibits a number of cognitive and behavioral changes. Of the options here, which is the LEAST likely to be affected?

Somatosensation

Which term is used to describe an idiosyncratic union between or within sensory modalities, such as experiencing the color red whenever seeing the letter A?

Synesthesia

The nodes of Ranvier are

points along axons that are not surrounded by myelin.

Which of the following imaging techniques would be best for visualizing a skull fracture?

CT (computed tomography)

Compare and contrast EEG and MEG. Highlight their similarities and differences in your answer.

EEG: cheap, large signal, signal distorted by skull/scalp, spatial localization, sensitive mostly to radial dipoles (neurons on gyri), allows subjects to move, sensors attached to head, can be done anywhere. MEG: expensive, tiny signal, signal unaffected by skull/scalp, spatial localization, sensitive mostly to tangential dipoles (neurons in sulci), subjects must remain still, sensors in helmet, requires special laboratory with magnetic shielding. SIMILARITIES: Good temporal resolution, problematic spatial resolution, no structural or anatomical information.

How do two neurons communicate with each other? Describe the process of synaptic transmission, including both chemical and electrical synapses.

EDIT THIS!! Synapses can be thought of as converting an electrical signal (the action potential) into a chemical signal in the form of neurotransmitter release, and then, upon binding of the transmitter to the postsynaptic receptor, switching the signal back again into an electrical form, as charged ions flow into or out of the postsynaptic neuron.

The brainstem includes all of the following components EXCEPT the

Hypothalmus

The term saltatory conduction refers to the fact that

action potentials occur only at the nodes of ranvier in axons

Which of the following neuroimaging techniques involves manipulating the orientation of hydrogen atoms?

fMRI

With regard to the two main output pathways from the occipital lobe, ________ is to ________ as dorsal is to ventral.

"where" ; "what"

Which area of the body has the greatest amount of representation in the human primary somatosensory cortex?

hands

The primary visual pathway is best described as

retina-->optic nerve-->optic chiasma-->thalamus-->occipital lobe

When a picture of a hammer is placed in front of Patient H, she is unable to identify it. How can you determine if her difficulty is in recognizing the object or in simply remembering its name?

Ask her to demonstrate its use rather than identifying it

The effect of a particular neurotransmitter on postsynaptic neurons

B: depends on the properties of the postsynaptic neuron. C: may be modulated by the presence or absence of another neurotransmitter. Both b and c are true.

The structure of a prototypical neuron. In your answer, provide definitions for the following terms: soma, axon, dendrite, myelin, and synapse.

Dendrites: the area where neurons receive most of their information. the signals picked up by the dendrites cause electrical changes in a neuron that are interpreted by an area called the soma (cell body). The soma takes all the information from the dendrites and puts it in an area called the axon hillock, which is then put in the axon. This is when the signal is called an action potential. The axon is covered in myelin which helps to prevent the signal from degrading. Synapse will communicate the signal to the next neuron? The nucleus contains the DNA. INFORMATION: A neuron's outer surface is made up of a semipermeable membrane. This membrane allows smaller molecules and molecules without an electrical charge to pass through it, while stopping larger or highly charged molecules. The nucleus of the neuron is located in the soma, or cell body. The soma has branching extensions known as dendrites. The neuron is a small information processor, and dendrites serve as input sites where signals are received from other neurons These signals are transmitted electrically across the soma and down a major extension from the soma known as the axon, which ends at multiple terminal buttons. The terminal buttons contain synaptic vesicles that house neurotransmitters, the chemical messengers of the nervous system. The synapse is a very small space between two neurons and is an important site where communication between neurons occurs. Once neurotransmitters are released into the synapse, they travel across the small space and bind with corresponding receptors on the dendrite of an adjacent neuron. Receptors, proteins on the cell surface where neurotransmitters attach, vary in shape, with different shapes "matching" different neurotransmitters.

Marie-Jean-Pierre Flourens, an early neuroscientist, is believed to have been the first to make what claims about the brain?

Flourens proposed that the semicircular canals were involved in the maintenance of posture and balance. He hypothesised that a lesion in the semicircular canals was responsible for the previously described vestibular symptomatology. According to this theory, the brain acts only as a functional entity although specific functions are controlled by specifics parts of the brain. Flourens reached this theory using ablation and stimulation methods and many experimental investigations on mammalian species, especially rabbits and pigeons.

Describe the structure, and explain the function, of three types of glial cells.

Microglia cells act as the immune defense of central nervous system. They travel throughout the brain and spinal cord to remove things like damaged neurons, and pathogens. Macroglia cells include astrocytes, these are star shaped glial cells that provide nutrient support to neurons, helping repair damage to nervous system tissue, regulating communication between neurons and maintaining the blood-brain-barrier. Schwann cells are responsible for covering neurons with an insulatory material called myelin in the peripheral nervous system.

Information about which of the following senses does NOT pass through the thalamus on the way to the cortex?

Olfaction

A patient who has difficulty matching pictures of the same object taken from different vantage points may be showing which dysfunction?

apperceptive agnosia

In myelinated axons, action potentials are generated

at the nodes of Ranvier only

Paul Broca and Carl Wernicke discovered two different forms of aphasia. Compare and contrast them.

Paul Broca's first patient was a man known as 'Tan' because that was the only syllable he was able to utter. Broca found that the patient appeared to have normal language comprehension and could indeed use hand gestures to communicate. Since the patient didn't show serious cognitive impairment it suggested that damage to a specific brain region could be causing these problems. At autopsy Broca discovered there to be a large lesion in an area of the left frontal lobe, this area is now known "Broca's area". appeared to show that the center for speech production is localised in Broca's area in the left prefrontal cortex. The language deficit caused by damage to Broca's area is now called Broca's aphasia. Broca's aphasic's speech is slow, laboured, halting, and lacking many function words. Carl Wernicke was able to determine the area of the brain responsible for language comprehension (1874). He found that many patients with intact left frontal lobe still had language problems, however they were different to those involved in Broca's studies. Wernicke's patients demonstrated other types of language problems, their speech is rapid, fairly well formed, but empty of meaning, neologisms are very common and comprehension is severely impaired. Wernicke found that the area of the brain damaged was located in the left parietal cortex. Wernicke's area is therefore located in the temporal lobe (rather than the frontal lobe), between the primary auditory cortex and the angular gyrus. The semi-nonsensical babbled stream of Wernicke's aphasia is also known as "fluent aphasia". Wernicke's area is responsible for connecting symbols to their referents and for the access and manipulation of words, as it is located behind the auditory projection zone.

The technique known as ________ can be used to induce virtual lesions in humans

TMS (transcranial magnetic stimulation)

Communication between the two hemispheres of the brain occurs mainly through the

corpus callosum

Describe how and why the term cognitive neuroscience was chose

The field of cognitive neuroscience concerns the scientific study of the neural mechanisms underlying cognition and is a branch of neuroscience. Cognitive neuroscience overlaps with cognitive psychology, and focuses on the neural substrates of mental processes and their behavioral manifestations.

Which of the following statements best describes the "neuron doctrine"?

The nervous system consists of physically distinct cells that are functionally interactive.

Which of the following is the best example of cortical plasticity?

The processing of tactile information by blind people in cortical regions that process visual information in sighted people

You would like to understand at what point in time an event took place in the brain. What neuroimaging method would you choose? Explain why you would choose this method and what information you would be missing.

The recorded EEG signals usually reflect two types of brain activities, spontaneous and event-related activities. The major techniques to detect event-related potentials can be divided into two categories, time-locked averaging techniques and spectral analysis techniques. Time-locked averaging techniques are usually used to detect evoked activities, which are time-locked to the presentation of stimuli. Because most noise occurs randomly, time-locked averaging techniques can greatly reduce the noise while preserving the event-related signals in the EEG. EDIT

Give several reasons why the following statement is incorrect: "The right visual field is processed by the left hemisphere of the brain, while the left visual field is processed by the right."

The visual field of each eye has the left and right hemifields. Through the optic chiasm, the visual signals from the left hemifields of both eyes are sent to the right hemisphere of the brain, while the signals from the right hemifields of both eyes are sent to the left hemisphere of the brain. So each hemisphere of the brain is responsible for processing the visual information in the opposite visual field from both eyes.

What is a mental representation? How are mental representations transformed? Give an example to support each of your two answers.

a mental representation is a hypothetical internal cognitive symbol that represents external reality. It facilitates understanding of information received and perceived from our environment. The storage and retrieval of knowledge would be impossible without mental representations. Mental representations are the way in which we create 'copies' of the real things around us, which we perceive. An example of a mental representation would be

Resecting or removing regions of cortex and cutting the corpus callosum are techniques that are usually used to

alleviate severe chronic epilepsy.

The ________, which is comprised of astrocytes, protects the brain from chemical compounds circulating in the body that might otherwise interfere with neuronal activity.

blood-brain barrier

The two main divisions of the central nervous system are the

brain and spinal cord.

2. How do we know that somatosensory cortex is plastic? Describe the method and results of at least one experiment to support your answer.

brain plasticity, refers to the brain's ability to CHANGE throughout life. The human brain has the amazing ability to reorganize itself by forming new connections between brain cells. Somatosensory cortex is plastic in the sense that it can change in internal organization so that the response properties of neurons in the cortex are altered. NEED Describe the method and results of at least one experiment to support your answer.

A central issue of modern cognitive neuroscience is whether specific human cognitive abilities

can be localized to particular parts of the brain.

Demyelinating diseases such as multiple sclerosis disrupt normal neural communication by

causing deterioration of the fatty substance that normally coats and insulates axons.

The highest density of ________, or color-sensitive photoreceptors, can be found in the ________ of the retina.

cones / fovea

Within a neuron, the transmission of information is usually ________. Between neurons, the transmission of information is usually ________.

electrical ; chemical

Choose two of the following methods and briefly describe how they work. For each of your choices, describe a research question (real or hypothetical) for which this method would be an appropriate choice, and explain why.

fMRI (functional magnetic resonance imaging): measures brain activity by detecting changes associated with blood flow. This technique relies on the fact that cerebral blood flow and neuronal activation are coupled. When an area of the brain is in use, blood flow to that region also increases. the brightness of each part on the image tells us how much neural activity is going on in that part of your brain. If you wanted to see if someone had a stroke, you could use this by looking at the effects of the stroke on the brain. MORE INFO: In one experiment, UCLA researchers performed fMRI scans on women who had recently lost a close relative to breast cancer, and found significant differences in brain activity when the women looked at pictures of their deceased relative, based on the type of grief the women were experiencing. Whereas those with "ordinary grief" had activity in areas of the brain that process emotional pain, women with more long-term or "complicated grief" also had greater activity in areas of the brain associated with pleasure, addiction and rewards, suggesting that memories of their lost loved ones were triggering feelings of both pain and pleasure [source: UCLA]. CT (computed tomography): A computed tomography (CT or CAT) scan allows doctors to see inside your body. It uses a combination of X-rays and a computer to create pictures of your organs, bones, and other tissues. It shows more detail than a regular X-ray. The computer stacks these scans one on top of the other to create a detailed image of your organs, bones, or blood vessels. For example, a surgeon may use this type of scan to look at all sides of a tumor to prepare for an operation. Doctors use CT scans (or CAT scans) to look for broken bones, cancers, blood clots, and more

Which of the following methods measures the BOLD signal?

functional Magnetic resonance imaging

How do receptive fields of cells in the ventral and dorsal streams differ? How do these characteristics support the functions of the ventral and dorsal streams?

he ventral stream (or "vision-for-perception" pathway) is believed to mainly subserve recognition and discrimination of visual shapes and objects, whereas the dorsal stream (or "vision-for-action" pathway) has been primarily associated with visually guided reaching and grasping based on the moment-to-moment analysis of the spatial location, shape, and orientation of objects. It has been proposed, however, that the dorsal stream also processes tools as a category, so that manipulable objects would be processed by those brain regions that are important for the execution of actions. The ventral stream (also known as the "what pathway") is involved with object and visual identification and recognition. The dorsal stream (or, "where pathway") is involved with processing the object's spatial location relative to the viewer and with speech repetition.

A patient like G.S. who had visual object agnosia would have difficulty in identifying an object unless

he was permitted to touch the object before making a response.

Information about the left hand is processed

in the right hemisphere for the primary somatosensory cortex and bilaterally for the secondary somatosensory cortex.

Ebbinghaus, who is considered the father of modern memory research, was among the first to demonstrate that

internal mental processes can be measured in rigorous and reproducible ways.

The part of the thalamus that is most important in relaying information to the primary visual cortex is the

lateral geniculate nucleus

The two main classes of cell in the nervous system are

neurons and glial cells

You decide that you want to measure blood flow of the brain. Which of the following methods could you use?

none of the above

According to ensemble theories of object recognition, it is possible to confuse similar-looking objects because

objects that appear similar activate overlapping networks of cells

A magnetic resonance imaging (MRI) image is constructed from signals that are generated by:

protons rebounding to the MRI's magnetic field

Functional magnetic resonance imaging (fMRI) is based on a measurement of

ratios of oxygenated to deoxygenated hemoglobin in the brain.

Which of the following things would have been the most difficult for the famous individual studied by Paul Broca, compared to before his stroke?

reading a book aloud

The case of Anne Green was remarkable in that after being falsely convicted of murdering her newborn child

she survived an attempted hanging.

You have isolated a neuron in the occipital lobes that you believe is responsible for processing information about color. What type of neurophysiological technique would allow you to assess this hypothesis in a living animal?

single cell-recording

Phrenologists believed that the contour of the skull could provide valuable information about an individual's cognitive capacities and personality traits. This approach was based on the assumption that

skull protrusions are caused by disproportionate development of the brain areas beneath them, which are responsible for different specific functions.

The primary auditory cortex is located in the

superior temporal lobe.

What is an event-related potential (ERP)? What benefits do ERPs bring to a researcher's toolkit?

the measured brain response that is the direct result of a specific sensory, cognitive, or motor event. More formally, it is any stereotyped electrophysiological response to a stimulus. The study of the brain in this way provides a noninvasive means of evaluating brain functioning in patients with cognitive diseases. Event related potentials (ERPs). Precise picture of neural activity over time (ms resolution). Direct (measure neuronal activity). Non invasive. Relatively inexpensive, Not many limitations in the possible experimental paradigms.

Of the following choices, the strongest evidence for a link between the sense of smell and the triggering of memories is the observation that

the olfactory cortex has direct connectivity to the limbic cortex.

The value of the membrane potential to which an axon must be depolarized to initiate an action potential is called the ________ potential for that neuron.

threshold

The term synapse, coined by Sherrington, refers to the junction between

two adjacent neurons.

Which of the following things would have been the most difficult for the famous individual described by Carl Wernicke, compared to before his stroke?

understanding a speech

Wernicke is to ________ as Broca is to ________.

understanding speech ; speaking

The Stroop effect demonstrates that when viewing

words, we cannot help but activate word representations even when they are irrelevant to the task.

Computer axial tomography is to MRI as ________ is to ________.

x-ray ; radio frequencies