PSYC 108 Midterm 1

How do you dualism and reductionism differ?

How do you dualism and reductionism differ?

Dualism believes the mind and body are separate, reductionism believes complex phenomena are derived from a single principal

What is the relationship between functional specialization and localizationism?

Functional specialization says cognitive functions are separated into different module set processed in different parts of the brain, localizationism says a single cognitive function is localized to single area of the brain

What is the human connectome and what is the goal of the human connectome project?

The human connectome is the wiring diagram of all the connections in the human brain, the goal of the human connectome project is to create a standard human connectome for cognitive neuroscientists (Detailed map)

What are the three steps of neurotransmission and why is it considered an electrochemical signal?

1. the action potential travels down the presynaptic neuron and signals the release of chemical messengers (Neurotransmitters)

2. Neurotransmitters are released from the presynaptic neuron and bind to the post synaptic neuron

3. Action potential begins from the axon hillock in the postsynaptic neuron

   • Electrical event = generating action potential

   • Chemical event = Neurotransmitters are released when the action potential reaches the end of a neuron

What are the different types of neurotransmitters and how do they influence the postsynaptic neuron?

• GABA glutamate dopamine serotonin

• Excitatory = Makes postsynaptic neuron more likely to fire (Glutamate)

• Inhibitory = Makes the postsynaptic neuron less likely to fire (GABA)

How do we use the terms of section in terms of reference to describe brain slices and brain regions?

1. Superior: towards the top

2. Anterior: towards the front

3. Posterior: towards the back

4. Inferior: towards the bottom

5. Medial: inner/innermost

6. Lateral: outward/outermost

Helps describe the relative location of brain regions to each other

Describe the three types of brain matter and how they are organized

• Gray matter: surface volume, where information is processed, cell bodies and dendrites

• White matter: interconnections where messages are relayed, axons and glia

• Cerebral spinal fluid composed of water, sugars, proteins, lipids, and electrolytes. protect protects from physical injury, Nutrition, waste removal

What are the categories of the general organization of the gray matter regions and what functions are they responsible for?

1. Gray matter regions = Cerebral cortex (Outer layer of the brain), Spinal cord gray matter, And subcortical nuclei

2. Sensory processing, motor control, and autonomic nervous system regulation

What are the types of glial cells and their functions?

Support cells in the central nervous system, which repair and nourish neurons, and form myelin. They undergo mitosis and divide into new cells, their dividing can lead to brain cancer. Found in the CNS. They release gliotransmitters, glutamate and ATP are most commonly released.

1. Schwan cells

2. Oligodendrocyte (produce myelin and provide electrical insulation)

3. Microglial cell (built in trash cans, defense and immune responses)

4. Ependymal cell (assist in production of movement of CSF)

5. Astrocyte (structural and metabolic)

How is grey matter organized in the brain?

thin outer layer on the cerebral hemispheres called the cerebral cortex, convoluted sheet with raised folds (gyri) and buried grooves (sulci). Groups of grey matter are functionally specialized.

1. Grouped by cytoarchitecture (cell type and location, single number)

2. By gyri and sulci

What are the categorical distinctions of the grey matter (locations/types)?

1. Hindbrain

2. Midbrain

3. Diencephalon

4. Basal ganglia

5. Limbic system

6. Cerebral cortex

Cerebral cortex

Mostly symmetrical two hemispheres made up of four lobes: frontal, parietal, temporal, and occipital

Sub-cortex

Limbic system, basal ganglia, diencephalon

Limbic system

Integrates information from present situation and previous experiences, implicated in memory, learning, and emotions

Cingulate gyrus

In Limbic system: emotion, reward, memory

Consists of anterior singulate, posterior cingulate, and retro spinal cortex

Hippocampus

In Limbic system: memory

Consists of subfields (CA1, CA2, CA3, denate gyrus, subiculum)

Olfactory bulb

In Limbic system: smell

Mammillary bodies

In Limbic system: memory

Basal ganglia

Motor activity, programming and terminating actions, learning of rewards, skills, and actions

Diencephalon

Consists of the thalamus, hypothalamus, subthalamic, and epithalamus (including pineal gland)

Thalamus

Relay sensory information between all sensory organs and the cortex (Except smell)

Hypothalamus

Regulates bodily functions and needs such as eating and drinking, temperature, sexual activity, and regulation of endocrine functions to maintain homeostasis

Midbrain

Inferior Colliculi (forms part of the subcortical pathway for audition), superior colliculi (Forms part of cortical pathway for orient gaze), Substantia nigra (Produces dopamine and regulates motor movements)

Hindbrain

Responsible for vital functions such as breathing and heart rate

Pons and medulla oblongata

Cerebellum is connected to hindbrain, integrates sensory motor information to enable smooth movement and dexterity

EEG—electroencephalography

• Measuring post synaptic electrical currents rather than potentials

• Summation of population of neurons that work synchronously

• Good temporal resolution

• poor spatial resolution

• 10-20 system electrodes on scalp

• Non-invasive

• Temporal coding—measuring synchrony and summed electrical potentials from millions of neurons (sensitive dendritic currents)

Single-neuron coding

• Very small electrode implanted into axon (intracellular) or outside axon membrane (extracellular)

• Records activity, doesn’t stimulate it

• Invasive

• Excellent spatial and temporal resolution

• Rate coding— measures number or action potentials per second for a single neuron

What is the difference between oscillation based analysis and event related potentials?

Both are done through EEG, oscillation has no specific stimulus or event (spontaneous action of neurons) and event related potential is averaged over the presentation of neural activity post-stimulation

What is structural imaging? What types are there?

Measures spatial configuration of different types of tissue in the brain

• static 3d imaging cut into viewable slices

  1. CT: computerized tomography measures x ray absorption. The amount of absorption is related to tissue density.

     • Bone = white (absorbs the most)

     • CSF: black (absorbs the least)

     • Brain matter: gray (intermediate)

  2. Magnetic resonance imaging: uses strong magnetic field and radiofrequency pulses to image the brain with better spatial resolution

What does MRI measure?

Energy released from protons of hydrogen molecules in water

What is MRI T1?

Most common structural images, gadolinium liquid contrast used for enhanced visualization of structures on T1

T1 weighted imaging gives 3d image of the brain with higher spatial resolution than CT, can discern gyri, helps with diagnosis of disease early on and link cognitive ability to specific brain structures

What is MRI: diffusion weighted?

DTI (diffusion tensor image) measures white matter organization by diffusion of water, helps with human connectome project to map white matter

What is Quantitative susceptibility mapping?

Measures amount of susceptibility a tissue has to the magnetic field

Common measurements in research: iron

What is Functional imaging? What does it measure?

Measures temporary changes and brain physiology associated with cognitive processing. It is used to produce dynamic mass of the moment to moment activity of the brain when engaged with cognitive. 4 dimension (except for EEG). Has poor temporal resolution measures BOLD signal (blood oxygen consumption), peaks at 6 seconds which is why the temporal resolution is poor

grey matter consumes O2 when a region is active, more blood is pumped to the region to compensate

Spatial resolution of MRI vs fMRI

Structural MRI = better resolution

fMRI = poorer resolution due to results being overlaid on structural MRI images

Spatial resolution

Scale of smallest unit of measurement

Temporal resolution

Amount of time needed to gather data in a location

Multivoxel pattern analysis

Helps us read the brain by analyzing patterns of neural responses in fMRI

We can read memories by inputting this data into computers

Why are lesion studies important to neuroscience?

lesions help us conduct “loss of function” studies, we study damaged brains to understand healthy ones

Organic lesions

Occur because of permanent brain damage to brain tissue

Simulated lesions

Temporary and reversible disruptions to neuron firing by magnetic or electrical stimulation

What are the structural prenatal and postnatal changes that occur in development?

Prenatal = creation of neurons and migration of neurons and folding of cortex

Postnatal = Increase in brain volume (450g to 1400g)

What are the functional changes that occur in development?

Myelination of axons, synaptic pruning, and change of cell morphology

What is the difference between nativism and Empiricism?

Empiricism = Experience is needed to acquire knowledge

Nativism = Some forms of knowledge are innate and do not need experience