Lecture 16- Behaviour, Language and Learning

Question 1

What is behaviour?

Answer 1

• A complex collection of actions, conscious/unconscious, voluntary/involuntary
• Often involving interaction with others and in response to an internal or external stimulus

Question 2

What systems are largely in control of behaviour?

Answer 2

-Mostly under control of nervous and endocrine systems

Question 3

What is the role of prefrontal cortex?

Answer 3

• Organizes thoughts and actions
• Intimately invovled in “executive function” : cognitive function, social behaviour, recall past information/ that not currently in the environment in order to help plan future events.

Question 4

Where is the prefrontal cortex?

Answer 4

Prefrontal is (roughly) the part of the frontal lobes anterior to motor areas (pre-central gyrus and SMA)

Question 5

How does the prefrontal cortex control behaviour?

Answer 5

Emotional & cognitive processes in prefrontal cortex exert control over behaviour by activity that originates in the ventromedial area and which passes to premotor & motor cortex

Question 6

In general what does damage to the prefrontal cortex cause?

Answer 6

Patients with damaged prefrontal cortex typically experience an abnormal emotional state with unusual behaviour due to lack of concentration and ability to plan. Also changes to emotional capacity/ personality.

Question 7

What is a lobotomy?

Answer 7

• Common neurosurgical procedure used in 1940’s & 50’s, on patients with “mental illness”
• Thought that mental illness was due to networks of neurons becoming “caught in fixed destructive circuits leading to obsessive ideas and deliria”
• Surgical severing of major tracts in prefrontal cortex
• Following the procedure death was common, most survivors were confused, emotionally blunted, major personality changes (because damage to prefrontal cortex).

Question 8

What did Pinneas Cage show?

Answer 8

• Railway worker that had rod but through prefrontal cortex in accident but survived
• Showed huge personality changes : became irreverent, profane, disinterested, obstinate, unreliable

Question 9

What hemisphere is language concentrated to in most people?

Answer 9

In the left for 90% of people

Question 10

What are the language areas of the brain close to?

Answer 10

Language areas of brain close to areas responsible for sensory
and motor functions of lips, tongue, mouth, and to auditory cortex

Question 11

What is Wernicke’s aphasia?

Answer 11

• Defect in comprehension speech due to damage to Wernicke’s area.
• Known as fluent aphasia because individuals can still speak in perfect sentences the content just doesn’t make sense. They are also often unaware (no stress).

Question 12

What is brocca’s aphasia?

Answer 12

• Defect in speech production due to damage to Brocca’s area
• This is a non-fluent aphasia (expressive) as causes stunted, stammering speech that makes perfect sense just is slow to get out
• Patients aware and often frustrated cause they know what they want to say just can’t get it out.

Question 13

What is learning?

Answer 13

• Learning is the acquisition & storage of information as a result of experience.
• Results in a change in likelihood of a behaviour in response to a stimulus

Question 14

What is memory?

Answer 14

Memory is the storage mechanism for what is learned.

Question 15

What are the two types of memory? What key areas of the brain are important for them?

Answer 15

-Declarative memory – retention & recall of conscious experiences
that can be put into words (declared) : Hippocampus, amygdala, limbic
system crucial in making them, though not in storing (long term storage in many cortical regions, incl. pre-frontal & association
cortex)

-Procedural memory - memory of how to do things independent of
conscious understanding (know how to walk, talk without thinking about it): Sensorimotor cortex, cerebellum, basal nuclei crucial

Question 16

What is the difference between short term and long term memory?

Answer 16

-Short-term memory records & retains info for seconds-minutes. Typically associated with ability to focus attention. Requires ongoing electrical activity. Involves hippocampus typically limited to recall of
about 5 items.

-Long-term memories may be stored for years. Requires permanent changes in brain function and/or structure. Likely involves long-term changes in strength of specific synapses (Long-term potentiation).

Question 17

What is the term for short-term memories to be converted to long term memories and what effects this occurring?

Answer 17

May be converted to long-term memories by consolidation

• Emotional impact
• Survival value
• Repetition
• Links to existing memories

Question 18

What are the two types of amnesia?

Answer 18

• Retrograde amnesia: loss of memories held from a period before the incident that caused the memory los. Typically short term memories gone and long term retained e.g. can’t remember events right before the accident.
• Anterograde amnesia: inability to consolidate short term into long term memories. Typically due to damage to limbic system & hippocampus

Question 19

What famous patient showed anterograde amnesia?

Answer 19

-HM had amygdala & hippocampus removed as treatment for
epilepsy.
-Result: able to make normal short term memories, but no long
term ones
-Could recall events from years ago, but nothing beyond a minute or two post-surgery

Question 20

What is long term potentiation?

Answer 20

• Increase in synaptic strength as a consequence of recent activity (burst)
• Usually results in long lasting improvement in signal strength at the potentiated synapses
• A lot of different forms of LTP and cellular mechanisms exist.

Question 21

What is the opposite of LTP?

Answer 21

LTD: long term depression

Question 22

What is long term potentiation the early phase?

Answer 22

• Not protein synthesis dependent
• Glutamate acts on NMDA receptor , Ca influx at post- synaptic site, CaMKII activated, AMPA receptors (nonNMDA glutamate receptors) phosphorylated & inserted into membrane.
• Cell becomes more sensitive to Glutamate, so future Glutamate release leads to larger postsynaptic response
• Other mechanisms may lead to enhanced release of neurotransmitter

Question 23

What is long term potentiation the late phase?

Answer 23

• Requires transcription and protein synthesis
• Protein kinases activated by early LTP events

-Extracellular signal- regulated kinase (ERK) activates transcription
factors that initiate synthesis of proteins that support long-term changes to synaptic structure and morphology

-This process important for maintenance of long-term memories