Chapter 3

Question 1

Historically; what are the 3 main approaches to studying the brain from oldest to most recent?

Answer 1

Phrenology: assessed bumps on the head and attributed various personality and intellectual characteristics

Brain damage: study psychological functioning following damage to specific brain regions

Electrical stimulation and recording of NS activity: idea of brain cells sending information through electrical activity arose (send signals to and record electrical activity from the brain)

Question 2

What are some flaws of phrenology, brain damage, and electrical stimulation?

Answer 2

Phrenology
1. Patients with damage to specific brain areas didn’t experience the psychological deficits phrenologists had predicted
2. Shape of outer skull doesn’t match that of the underlying brain

Brain damage
1. Minority groups could differ from normative sample in social and economic determinants of brain health → available norms may not apply to their test performance

Electrical stimulation and recording
1. Show neural activity that reaches the surface of the scalp → tell us little, if anything about what is happening inside

Question 3

What is the difference between CT and MRI scan?

Answer 3

Computer tomography: 3D reconstruction of multiple X-rays taken through a part of the body

Magnetic resonance imaging; measures the release of energy from water in biological tissues following exposure to a magnetic field (superior by detecting soft tissues - tumors)
→ Limitations: show only brain structure, not activity

Question 4

What is the difference between a PET, fMRI, and MEG?

Answer 4

Positron Emission Tomogaphy (PET): measures changes in the brain’s activity in response to stimuli
→ Brain cells increase their intake of glucose when they are active
→ Injection of radioactive glucose-like molecules and the scanner measures where in the brain most of these glucose-like molecules are, allowing to determine which regions are most active

Functional MRI (fMRI): increase in oxygenated blood flowing to areas in response to the increased demand for O by the cells in a region
→ Measures the change in blood O2 level = indirect indicator of brain activity

Magnetoencephalography (MEG): detects electrical activity in the brain by measuring tiny magnetic fields in order to reveal patterns of magnetic fields on the skull’s surface → reveal which areas are becoming active in response to stimuli

Question 5

What is the difference between deep and transcranial brain stimulation?

Answer 5

Deep brain stimulation: neurosurgical procedure that implants battery-powered electrodes within the brain to provide electrical stimulation directly at specific areas

Transcranial magnetic stimulation: applies strong and quickly changing magnetic fields to the surface of the skull to create electric fields in the brain that can enhance/interrupt brain function

Question 6

Glutamate

Answer 6

• Most common excitatory neurotransmitter in CNS
• Associated with enhanced learning and memory (when abnormally high, may contribute to schizophrenia and other mental disorders → over stimulates receptors)

Question 7

GABA

Answer 7

• Most common inhibitory neurotransmitter in CNS
• Critical role in learning, memory, and sleep

Question 8

ACh

Answer 8

• Plays a role in arousal, selective attention, memory, and sleep
• NMJ releases ACh as well triggering movement

Question 9

MONOAMINES

Answer 9

NE, dopamine, and serotonin (contain 1 amino acid)
1. Dopamine
- Plays a critical role in motivation and rewarding experiences (reward system)
2. NE and serotonin
- Activate/deactivate various parts of the brain = influence consciousness, arousal, movement, and readiness to respond to stimuli (state of arousal)

Question 10

NEUROPEPTIDES

Answer 10

1. Endorphins
   - Play a role in pain reduction
   → Neuropeptides play a role in hunger and satiety and others can alter learning and memory

Question 11

What is a psychoactive drug? What are the 2 main types of psychoactive drugs that we can find?

Answer 11

Drugs that target the production or inhibition of neurotransmitters

Agonists (codeine and morphine): increase or mimic the effect of a neurotransmitter
Reduce emotional response to painful stimuli by binding to opioid receptors and mimic endorphins
Others block the reuptake of a neurotransmitter (antidepressants - serotonin)

Antagonist: block or decrease the effect of a neurotransmitter (pretend to be a neurotransmitter without exerting the effects of this)

Question 12

What does neural plasticity refer to?

Answer 12

Brain’s adaptability to almost any environment (brain is most adaptable during early development since our brains don’t mature fully until late adolescence/early childhood)

Question 13

What are the 4 ways in which a neuron network can change over development?

Answer 13

1. Growth of dendrites and axons
2. Synaptogenesis (formation of new synapses)
3. Pruning (death of certain neurons and the retraction of axons to remove connections that aren’t useful)
4. Myelination (insulation of axons with myelin sheath

Question 14

→ Brains change as we learn, such changes may arise from:

Answer 14

• New synapses
• Increased connections among neurons
• Strengthening of existing synaptic connections (neurotransmitters released into synapses produce stronger and more prolonged response) → “potentiation”
  → “Structural plasticity”: changes in the shape of neurons is critical for learning (axonal expansion or dendritic reshaping)

Question 15

Does PNS and CNS heal the same way following an injury?

Answer 15

→ CNS display limited regeneration following an injury or serious illness (still, certain brain regions can take over the functions previously performed by others)

Neurogenesis: creation of new neurons

Question 16

What are the 3 means of protection of the CNS?

Answer 16

1. Meninges: three protective layers (pia, arachnoid, and dura)
2. Ventricles: fluid-filled pockets that extend throughout the brain and SC that provide further protection
3. Cerebrospinal fluid: runs through the ventricles and bathes the CNS (provides nutrients and cushioning against injury)

Question 17

What is the corpus callosum and what is lateralization?

Answer 17

Bundle of neurons that connects the 2 hemispheres and allows for exchange of information

Lateralization: even though the hemispheres are connected and work together, each hemisphere serves different cognitive functions

Question 18

What are the functions performed by the frontal lobe?

Answer 18

• Assist in motor functions
• Language
• Decision making
• Certain types of memory
• “Executive functioning” (oversee and organize most other brain functions)

Question 19

What is the central sulcus and what are the 2 areas located in front and behind this and what are their functions?

Answer 19

Central sulcus: deep groove that separates the frontal lobe from the rest of the cortex

Motor cortex; part of the frontal lobe that lies just in front of the sulcus
- Each part of the cortex controls a specific body part (regions that require more precise control consume more cortical space)

Primary sensory cortex: part of parietal, next to the primary motor cortex, behind the central sulcus
- Sensitive to touch (pressure, pain, and temperature)
- Relays visual and touch information to the motor cortex (helps track objects’ locations, shapes, and orientations)
- Major role in spatial perception

Question 20

What is the prefrontal cortex and what is its function?

Answer 20

Located in front of the motor cortex
- Thinking
- Planning
- Language
Also contributes to mood, personality, and self-awareness (keeps impulses in check)

Question 21

What is the difference between Broca’s and Wernike’s area?

Answer 21

Broca’s area: key role in language production (profrontal cortex)
Wernike’s area: slightly above and behind the left ear; includes part of parietal lobe; main role in understanding language (parietal)

Question 22

Where is the parietal lobe and what are its functions?

Answer 22

Parietal: upper middle part of the cortex, behind the central sulcus
-Functions are mainly dictated by the primary sensory cortex

Question 23

What are the functions performed by the occipital lobe?

Answer 23

Occipital: back of the brain
Visual cortex: dedicated to seeing

Question 24

What are the functions performed by the temporal lobe?

Answer 24

Prime site of hearing, understanding language, and forming new conscious long-term memories

Question 25

What is the pathway to consciousness of the senses?

Answer 25

Sight, hearing, and touch → thalamus → primary sensory cortex → association cortex

Association cortex: spread throughout all 4 lobes
- Synthesizes sensory information to perform more complex functions (pull together size, shape, colour, and location info. to identify an object)

Smell → limbic system (involved in emotion, motivation, and memory)

Question 26

What are the basal ganglia?

Answer 26

Structures buried deep inside the cortex that help to control movements
→ After sensory information reaches primary and association areas, it’s transmitted to basal ganglia (these calculate a course of action and send blueprint of movement to motor cortex)
→ Help control emotions, language, decision making, learning, and memory
→ Enable us to learn new skills and develop habits that we value and find enjoyable and rewarding

Question 27

What is the limbic system and what is it composed of?

Answer 27

→ Interconnected set of structures that lies below the cortex, also known as the emotional center of the brain, closely tied to our ANS (regulates internal organs)
→ Play a role in emotion, motivation, learning, smell, and memory, which contribute and shape emotions; however,emotions shape our motivations and memories as well (reciprocal)
→ Thalamus, hypothalamus, amygdala, hippocampus

Question 28

What is the thalamus?

Answer 28

Consists of many nuclei, each connects to a specific region of the cerebral cortex → sensory relay station: sensory information passes through this, undergoes initial processing and then is relayed to the cortex

Question 29

What is the hypothalamus?

Answer 29

Located below the thalamus, regulates and maintains internal bodily states by influencing hormonal levels (helps regulate hunger, thirst, sexual motivation, and control body temperature)

Question 30

What is the amygdala?

Answer 30

Modulates memories based on how we feel; helps us pay attention to emotional impactful stimuli to remember what triggered our emotions

Question 31

What is the hippocampus?

Answer 31

Crucial role in memory (conscious memory for facts and events, and spatial memory
- Damage impacts the ability for learning new facts and remembering events
- It’s not essential for skill and habit learning (doesn’t require conscious access to the memory)

Question 32

What is the cerebellum?

Answer 32

Part of the hindbrain that plays a predominant role in our sense of balance and enables us to coordinate movement and learn motor skills (also contributes to executive, memory, spatial, and linguistic abilities)

Question 33

What is the brainstem composed of?

Answer 33

Midbrain: important role in movement; controls tracking of visual stimuli and reflexes triggered by sound (jumping when a balloon pops)
Pons: major role in triggering dreams, connects cortex to cerebellum
Medulla: regulates breathing, heartbeat, and other vital functions (nausea and vomiting)