Ch1-ch4: Study Questions

What do we mean by a "localization" study?

A study simply asking what brain area might be involved in a specific cognitive process or behavior.

What is a "syndrome? What is the "alien hand" syndrome and with what brain region is it associated?

Alien Hand syndrome: hand seems to take on a life of its own-impendent of patients intention. Sometimes patient have no control over their arm. Its associated with the SMA region of the brain or parietal. Syndrome: a group of symptoms that consistently occur together and are often associated with a particular disease or disorder.

What is the "dead-salmon" story supposed to teach us about the problem of multiple comparisons? What are "false positives"; "false negatives"?

Analysis of imaging data involves enormous numbers of statistical comparisons. The greater the number of comparisons the more likely we are to find significance by chance. Dead salmon story taught about the chance of error in data analysis. False positive - results show a condition exist when it actually does not, False negative - results show a condition does not exist, when it actually does exist.

Why is the fovea the area of greatest visual acuity. What do we mean by "retinotopic" mapping?

Because it contains almost exclusively cones which are the most sensitive visual receptors. Fovea - area of the retina that is densely packed with photoreceptors, and the higher the number of receptors, more cons, the greater the resolution or visual acuities. The fact that any location in the visual world has a specific relationship with a location on the retina. Retinotopic mapping refers to how the visual field is mapped onto the retina, and there exists a retinopic map of a stimuli in the visual filed, sort of like a topography map of sound frequency.

How does the brain scan from the subject with "alien hand syndrome" support a significant role for the parietal area in our taking "ownership" of our own movements?

Because it shows that damage in this area disrupts that control

Why might the rat be a good "model system" for the study of maze learning. What does this have to do with the study of spatial memory?

Because its life style suggests evolutionary pressure for that behavior, and maze learning involves the use of spatial memory

Why can't we code the quality of a stimulus in terms of the quality of the nerve impulses it generates?

Because nerve potentials do not differ in quality with the stimuli they code, -only in frequency.

How do we know that the motor cortex is not the source of the feeling of agency that accompanies a voluntary lifting of the arm?

Because of the many past studies/research done. When stimulating parts of the M1, movements of arm observed, but patient denies that he moved his arm. Brain stimulation -> hand raise (no free will)

In what sense may the receptive field of a neuron be thought of as the window through which the neuron views the world?

Because only information entering through that window will modulate the neurons activity

Why was the issue of "publicly observable data" such an important one for the Introspectionists?

Because the introspective method failed to provide any. Their theories were based on data that is not accessible to observers - data was collected from subjects and was biased to the subjects' own mind.

In what sense may psychophysics and mental chronometry be considered the study of cognitive processes?

Because they are measuring (the relation between stimuli and perception) the timing of events generated by stimuli. ex: Loudness (stimuli) vs intensity (perception)

Why were markers which could stain for different neurotransmitters so important?

Because they could identify connections between different parts of transmitter systems and help describe circuits involved. can see different types of cells and fibers.

Why were the experiments of researchers like Kohler and Tolman so important in challenging the behaviorist model?

Because they showed that formal reinforcement was not needed for learning; that animals could show insight, generate complex behaviors without reinforcement. ex: rats were able to acquire a "cognitive spatial map" and were able to use this knowledge to solve problems.

What do the initials BOLD stand for?

Blood Oxygen Level Dependent.

Where were the lesions in each case?

Both in the left hemisphere, but Broca had damage to the frontal area, while Wernicke's had a parietal lesion in the temporal lobe.

Distinguish between the nature of the language problems in Broca's and Wernicke's original patients?

Broca: left hemisphere CVA, Broca aphasia, had an issue where he lacked syntax, grammar, and connecting words. PROBLEMS OF EXPRESSION. Wernicke: acute left middle cerebral infarct with Wernicke's aphasia, had deficits in auditory comprehension, verbal expression, reading compression, and written expression. Had no problem with generating words but had issues with a clear lack of coherence in thoughts as reflected in language. PROBLEMS OF COMPREHENSION.

Can you explain how we generate an unlimited number of odor sensations from a limited number of receptor types. How is this similar to the way in which we generate an unlimited number of words from a limited number of letters?

By combining those types in a variety of different order. A set of 24 letters can be combined to form an almost infinite number of words.

How does the fish's lateral line organ provide two messages with a single receptor?

By using both inhibition and excitation to a stimulus. They have hair cells in the water that move.

How shall we define a code? What do we mean by a frequency code? How do we code the location of a stimulus to the skin?

Code is a system of words, letters, figures, or other symbols substituted for other words, letters, figures etc. Frequency code is the varying of action potentials which could be coded. For skin, there are corpuscles that generate sensations that signal. So we code the location of a stimulus to the skin by its location on a central structure-nucleus or cortex.

If vision is a sensory modality, give an example of a sub-modality?

Color, and movement.

In what sense did the development of computers make the idea of mental (cognitive) operation more respectable?

Computers did many of the same things that humans did, without consciousness or a mind. Were able to organize data more accurately and much faster.

What do we mean by "publicly observable data". Remember the discussion of Introspectionism and its problems. In what sense did the Romo experiment make the monkeys subjective experience "publicly observable"

Data available to all observers. The Romo monkeys made behavioral responses to the presentation of tactile strimuli just as would human observers. While we cannot know what went on in the head of either species, they used that stimuli to solve the problem.e., they operationalized the cognitive process using the same methods with monekys and humans.

How would an experimental anatomy differ from a descriptive anatomy?

Descriptive anatomy: is focused on staining brain parts, focusing on brain tissue with its histological techniques of preservation and microscopy. Tells you where each structure is and how cells are arranged. Experimental anatomy: focused on tracing techniques, doing specific experiments that target certain structures. allows you to trace connections between groups of cells.

Distinguish between "convergence" and "divergence" during the transmission of neural information.

Divergence: when two things are moving apart from each other, and the activity of one neuron modulates the activity of a number of neurons to which it is connected. Divergence allows one neuron to communicate with many other neurons in a network. Convergence: when two things/forces are moving together, and when the input of many neurons influences the firing of one neuron.

Can you distinguish between domain specific and domain general modules?

Doman specific: relatively specialized category like fruit, vegetables, wives, color. Restricted to processing one type of information. Domain general: memory, attention, emotion. Independent of the type of information they process

Historically, how has psychology dealt with the problem of mind?

Either by ignoring it or making it central. The first was to make cognitive processes or mental events central to the study of Psychology, and the second was to dismiss mental events completely and make the study of Psychology without the mind.

How can we tell an exogenous from an endogenous ERP?

Endogenous have short latency, which might reflect the sensory process, while exogenous occur later in the waveform, and might reflect the cognitive process, that's farther away than the sensory process requiring more travel through the more complex circuits.

What do we mean by "converging operations" as a guiding principle in cognitive neuroscience research

Exploring the same cognitive process with a wide variety of techniques and methods.

Where might we find clues as to the location of a brain region related to our recognition of faces?

From the clinical data relating the symptoms of prosopagnosia to damage to a specific area.

What was Penfield's major contribution to cognitive neuroscience? Why were the human stimulation experiments performed? How is it possible to do those kinds of things to a human being without their jumping off the table?

He discovered "motor strip' of brain tissue at the back of the frontal lobe, which was the first motor map evidence and he mapped the human cortical sensory and motor areas. To try and avoid functionally critical cortical areas that might be damaged during removal of the epileptic focus. Brain has no pain receptors, that's why people were not jumping off the table.

A thought experiment. If we rewired the brain of a human volunteer so that the auditory nerve went to the visual cortex and the optic nerve to the auditory cortex, how would he respond to thunder and lightning during a storm?

He would see thunder (sound) and hear lightning (visual)

What does the term hemodynamic mean and what is its relation to the BOLD response?

Hemodynamics is the dynamics of blood flow, part of the blood circulation process. While the BOLD response is a ratio that calculates how much oxygen there is, and since hemodynamics focuses on blood flow, oxygen is carried in the blood, and BOLD focuses on oxygen use. -Movement of mhemoglobin particles in the blood-and that is what is measured (relatively) in the BOLD response.

What is so striking about the timing data in the experiment in which subjects chose between making a "voluntary" movement of either the right or left hand?

How far in advance of the "intention" was the brain activity that preceded it - brain activity generated occurred before awareness of intention.

Define the terms independent and dependent variable. which one is manipulated by the experimenter; which one is observed. What is the role of a "control"?

IV: condition being manipulated by the experimenter. It's the variable believed to cause change. DV: outcome being measured and is observed to assess the effect. Control: ensures that the effect on the DV is a consequence of the IV and not of chance or other unrelated events.

Give an example of an invasive and a non-invasive recording technique

Invasive - Using a recording microelectrode or performing surgery to damage a part of the brain. You have to open the skull. Non-invasive technique: EEG, fMRI and EPR.

What role does the receptor potential play in the process of transduction?

It is a slow, decremental potential which provides the link between the onset of the stimulus and the generation of fast/spike potentials.

How does the ERP represent an advance over the EEG, since it is making use of very similar methods and information.?

It is linked to the presentation of a specific stimulus at a specific point in time.

Why is the monkey experiment relevant to the question of intention?

It showed that damaging a specific brain area prevented monkey from generating intention.

What is stereotaxic normalization and why do we need it?

It's an image realignment, correctness, and manipulation - aligns the image and changes the range of pixel intensity values. Adjusts for slight differences in the location of areas by putting them all into the same set of coordinates.

What do we mean by the action functions of vision?

Its role in controlling our movements. Such that visual information can help guide our actions, such as grabbing the cup - see what kind of cup it is, shape, and if there is liquid, material of the cup, which would all calculate into how we are going to grab it or look at it.

What is the relation between Kornhuber's work and the Libet experiment?

Kornhuber identified the regions to look at for activity preceding the movement - discovered the readiness potential.

Can you summarize briefly, the Behaviorist position on the role of mental events for the science of Psychology?

Mental events were were irrelevant to them and had no useful role for someone with a behaviorist position because it does not explain behavior. There needs to be an organized system of stimuli and reinforcement for a certain behavior to occur.

How do the sources of the electrical signals recorded by the microelectrode and the EEG electrode differ?

Microelectrode records only one (or a few) type of neuron and individual spike activity, and if passed at angle records the activity of two different modalities. While EEG is able to record more than one spike activity, recording thousands of neurons (thousands).

How does a dualist explain the relation between brain and mind in a voluntary act, like picking up a spoon?

Mind is first, and there is a free will. First intention, then brain activity, then action. intention: want to pick up spoon + awareness brain activity: neural event, signals sent action: you pick up the spoon.

Would you say that a BOLD signal is giving us a photograph of brain activity as it happens? Explain.

No—it always lags in time because it takes time for the hemoglobin to travel to the activated area

The author notes that we are pretty comfortable being dualists most of the time. What sort of things may make us a little more likely to at least consider the Astonishing Hypothesis?

Observing and dealing with people whose brain is not normal - those that lost control of their behavior or show cognitive pathologies such as Alzheimer's, stroke, severe depression.

What is the adequate stimulus for olfaction (smell), for taste?

Odor molecules, chemical substance dissolved in water/fluids.

In an optogenetic experiment, what is an optrode and what it is used for.

Optrodes: light emitting elements mounted over a small area of an exposed brain. Source of colored light. Great way to turn off and on individual neurons in a specific neural circuit. may be specifically tuned to activate a chemical which then opens or closes chemical channels and effects the firing of the neurons containing those channels.

What is the "cocktail party phenomenon" and why would anyone be interested in studying it?

Our ability to recognize information of interest in the midst of noise. It is an example of the attention process and may be used to study that process by looking at where its neural correlates are.

What is a voxel and how is it both similar to and different from a pixel?

Pixel: 2-dimension; Voxel: 3-dimensional, a cubic volume of brain tissue.

What does the abbreviation ROI mean? How might one find the ROI for a specific subject?

ROI - region of interest (in the brain). Present a stimulus related to some cognitive process; ex: movement, or a face, to a large group of subjects. Find the brain region which is activated in all or most of your subjects. This gives you a starting point for further analysis.

Distinguish between RA and SA neurons; Which of them is likely to help you swat the mosquito?

SA neurons: are slowly adaptive, and are more responsive to force than texture. SA continue to fire as long as the stimulus is present. RA neurons: are rapidly adaptive, and are more responsive to texture than force. RA stop responding very quickly. RA would be most likely to help us sway a mosquito since RA neurons are found in all cortical layers and because it responds rapidly to brief changes in the location of the mosquito.

Why is it necessary to "operationalize" any cognitive process we choose to study?

So that you can obtain publicly observable data on it.

Does our ability to identify the activation of specific layers of the motor cortex during a finger movement task (Fig 15) indicate an improvement in the spatial or temporal resolution of the imaging?

Spatial resolution

Why might it be important to measure the way in which specific neurons varied their firing rate as we changed the shape, movement, or color of a stimulus?

Such variation reflects a causal relation between the stimulus and the neuronal activity. Helps identify structures related to sensory processes.

What do we mean by "temporal resolution"? in imaging experiments.

Temporal resolution is the measure of the distance of time between the acquisitions of two images of the same area. Its used in fMRI's. Its how accurately we can measure the time at which the neural invents being measured occurred.

What do we mean by the concepts of cognitive "modularity"

That there are separate modules (mental or neural) for specific functions. Specific cognitive processes like memory seem to be processed in systems and subsystems dedicated to them.

What did Titchener mean when he said that a real Psychology "would begin where Behaviorism left off."

That there would be a new line in psychology, one that would put the mind back into psychology and focus on cognitive neuroscience. Behaviorism left out the most interesting aspects of human behavior—which would still need to be explained.

What kind of information did the Golgi method provide that made it so important to 19th century anatomists?

The ability to trace the structure of a complete single neuron

What, if anything, justifies studies like the one involving SMA stimulation in human?

The clinical need to map out areas for surgery and minimize damage to critical areas.

What does evolution have to do with the concept of a "model system"?

The concept depends on the assumption of a common ancestry (fruit fly, a rat, and a human share a common evolutionary ancestry) and therefore of commonality in structure and function since nature is conservating.

Define sensory adaptation and explain why it occurs.

The decline in sensation with continuous stimulation of a receptor. It reflects the absence of firing in the receptor. There is a reduction in sensitivity -> holding someone's hand for a long time.

In the cognitive subtraction design, what is being subtracted?

The event or stimulus from the baseline; when the subject is doing nothing vs when the stimulus is being presented.

What do we mean by the term modality? Give a couple of examples.

The quality of the stimulus, e.g. taste, touch, vibration, smell.

Why are X-rays of little use to the neurologist or cognitive neuroscientist?

The resolution is not fine enough to allow us to distinguish specific rotical or subcortical structures.

What do the terms macro-and micro refer to when we are talking about recording and stimulation?

The size (big or small) of the electrode.

What is Neuropsychology?

The study of the cognitive process of humans with brain damage

What do we mean by a "double dissociation"; Explain using the Broca and Wernicke cases.

The two cognitive processes (expression and comprehension) involve distinct mechanisms with little overlap. Broca had problems with expression but not comprehension, while Wernicke had problems with comprehension but not expression. You can separate the causes or origin of the symptom so that a lesion in one region affects Task A but not Task b and, in another region, Task b but not Task A.

What do we mean by "converging operations"? Give an example

The use of several different research techniques to study the same problem. Eg. Looking at clinical data for the site of a lesion in prosopagnosia; and seeing whether this same region is active in an fMRI when you look at faces

What are the somatosensory and motor areas and what are their functions? How do we know? What might you call the somatosensory representation of an elephant? of a monkey? How might the two differ?

These areas are were reception of information for body receptors / control of movement is located on the brain. We know by using recording from stimulation of the skin or joint movements for sensory and simulation of brain regions for motor. Somatosensory (S1) - sensations touch, vibrations. contains the sensory representation of the body. Its us where our body is and and what our body is doing. Motor areas (M1) - movements raising the arm, moving toes. It's a region that generating bodily movements. We know because these conclusions have been confirmed by observations made during stimulations of the brain in human patients undergoing neurosurgery to identify and remove tumors. In mice's, they tested their whiskers. For the elephant, the elephants truck, long tongue, and its snout account for its somatosensory part, and for monkeys they use their hands.

Why might the data of brain-damaged patients be useful?

They provide initial cues linking some cognitive process or behavior to a specific brain region or neural event.

In what sense is the role of the auditory hair cell rather similar to that of cilia in the lateral line organ?

They record movement of the liquid within which they are bathed. Cochlea of the ear also is in water, and there are low or high frequency sounds/waves.

If synapses are too small to be seen by the naked eye, can you describe the line of reasoning that led Ramon y Cajal to hypothesize that they existed. How did this hypothesis relate to Golgi's hypothesis of a "network"--who was right and how do we know?

They saw axons terminating in areas where another cell was known to be, and while the terminals were stained, the adjacent cell was not indicating an absence of structural continuity. They believed that neurons were individual units, with gaps between the terminals of one neuron and the processes of the next one. He inferred their existence form free terminals. Relates to Golgi's hypothesis of a network and how they work together. Cajal was right, and Golgi's studies and finds helped them later develop the correct hypothesis. - I If there was a network, the stained neuron would be seen to be continuous with another stained neuron-absence of connection implied absence of direct connectivity. Cajal was right and electron microscopy made it possible to visualize the gap.

What, if anything, do these findings suggest about a possible role for the parietal region in the sense of agency?

They suggest that it is critical for the existence of the sense of agency and our sense of will/awareness of intention.

What are the critical events being timed in the Libet experiment?

Timing of decision to move, timing of brain activity in relation to movement; timing of movement onset or muscle activity. Libet's experiment: used an EEG to record subjects pressing the button, focusing on the questions of which comes first, the decision to move or the brain activity generating the movement

What is the main goal of experimental tracing studies?

To define and generate neural circuits which are related to specific cognitive processes / function.

Why might you want to do brain scans during the Libet experiment?

To see what areas were activated and in what order

What is the relation between modality and topography in the somatosensory system. To which are columns linked?

Topography is how the body's surface and features are mapped onto the brain in a highly ordered fashion - it provides information about the location of a stimulus on the brain map. Modality is way of sensing a stimulus, providing information about the quality of that stimulus ex: touch vs vibration. To which are columns linked? --> Modality.

Can you distinguish between transduction, transmission, and coding?

Transduction: processes by which stimuli are turned into nerve impulses, neural coding is transduction. Transmission: how the information is processed and moved - involves conveying the message from its origin to other CNS regions. Coding: where information is processed and how impulses can be changed in size or number. involves using variation in that signal to convey information about some sensory property—e.g. intensity; frequency.

How might we obtain a double dissociation in normal subjects.

Use TMS to disable two different areas which generate complementary effects on cognitive processes.

What are we measuring when we use the term Teslas?

We are measuring the magnetic field applied to the brain tissue during MRI - The strength of the MRI magnet -which is related to the resolution of the MRI

How do we know when our electrode is recording impulses for only a single neuron?

When the size of the signal remains constant—two different sizes mean two different neurons—the larger the spike, the closer it is to the electrode.

What are the three questions we need to ask about the relation between the brain and any cognitive process?

Where? When? How?

Brodmann's areas are distinguished by differences in ____. How else might they differ?

With respect to chemistry (e.g. neurotransmitters) or their connections. Area 45 was involved in semantic (meaning) processing while Area 44 was involved in speech production. They might also differ in vision and other somatosensation properties.

What is the difference between the information provide by Fig 3-1, a and 3-1, b

a. Cell information; b: fiber connections.

Can you define the term receptive field? If you think of the visual world as a "sensory surface" and could record from neurons in a mouse retina, how would you go about defining the receptive field of a retinal neuron?

a. For any neuron, it is that feature of the sensory surface (e.g. location) which modulates (changes) the firing rate of the neuron. It can inhibit or excites the primary sensory neuron, and can either generate one or the either or generate both types of signals b. Locate a single neuron in the retina and present it with stimuli at different locations in the visual field. That location in which presentation of a visual stimulus will cause a change in the pattern of firing of thew neuron would be its RF.

Neural imaging has proven significant for both clinicians and researchers in cognitive neuroscience. Explain.

allows them to see the brain damage in a living patient. Makes it possible to do a localization of an area correlated with a disruption of a positive process in a living patient.

Given its obvious limitations, why does TMS remain in widespread use as an investigative tool?

because it is easy to use, it is reversible (unlike a lesion) and it provides evidence for the involvement of a specific brain area in a specific cognitive or behavioral function.

How do we infer the presence of mind in the cat? In one of our friends?

by the cat's behavior ; by our friends behavior.

What is the important difference between MRI and fMRI?

fMRI: is able to give information about the neural activity or brain function, unlike the MRI. fMRI generates functional information, while MRI provides a clear image of the brain structure. FMRI is a measure of the BOLD response - the flow of oxygenated blood to the region of interest. MRI: a very high resolution picture of the brain or other body part

Why does Crick call his hypothesis "Astonishing"?

he discovered evidence against dualism, found that free will is an illusion and that behaviors and decisions are part of the electrochemical interactions in the brain. Astonishing because it contradicted the way we normally view the causes of our actions.

What is the function of the stereotaxic instrument in tracing experiments?

in addition to fixing the animal in a standard plane with respect to landmarks, it allows you to place chemicals or lesions at or electrodes at various locations within the brain.

What about the action potential?

it is the medium by which the stimulus is coded

What do we mean by saying that the brain damaged patient may not only have lost something, but may also have added something.

patient is usually aware of his losses and often develops behaviors which will compensate for them but are not present in the same way in 'normal" people. May generate their own unique behaviors to cope, such as not speaking or using hand gestures.

What is the most important conclusion of the Libet experiment?

the brain activity that generated the movement happened before the awareness of the intention. There is no free will.

What is it about oxygen that makes it a possible marker for studies of brain function?

the brain requires oxygen for energy, and since neurons do not store oxygen, they obtain the oxygen from the hemoglobin in the local blood supply. Due to the local blood flow and the hemodynamic response, oxygen is a great possible marker for the studies of brain function.

What was Wittgenstein getting at when he asked his question

the fact that no real information is added by citing intention. he was trying to determine who is responsible for the free will of raising arm, asking if free will is involved in raising our arm.

What do we mean by dualism?

the hypothesis that the mind and body are two different and separate entities. ex: Mind (nonphysical) and body/brain (physical). also idea that there is free will.

What are the "events" in an "event-related" design?

the task or stimulus or condition of interest

What is a "tracer"? How do anterograde and retrograde tracing methods differ?

tracer: neural markers that can be identified in target areas. Tracers can be a radioactive substance, specific enzymes, viruses, fluorescent dyes, etc. A chemical that is taken up by and transported within the cell. Anterograde tracer: will label the axon leaving the injection site. from soma to terminals. retrograde tracer: will label neurons that send their axons to the injection site. from terminals back to soma.