Week 4 - Higher Cognitive Function

Question 1

What is learning

Answer 1

acquisition of new information

Question 2

What is memory

Answer 2

retention of learned information
lifelong adaptations of our brain’s circuitry in response to our environment
- lifelong adaptations of our brain’s circuitry in response to our environment

Question 3

What are the 2 types of long term memory

Answer 3

1. Declarative (explicit)
2. Non-declarative memory (implicit)

Question 4

What is declarative (explicit) memory

Answer 4

Memory that requires conscious recall; it involves facts and experiences that you can deliberately remember and describe e.g. facts, events

• Consciously encoded long-term memory that can be retrieved when needed
• Often formed deliberately through rehearsal
• Encoding can be tied to emotions
• May be drawn into awareness through associations

Question 5

What is non-declarative (implicit) memory

Answer 5

Memory that does not require conscious recall; it influences behavior and skills without intentional recollection e.g. skills, habits, conditioning

• Not part of our consciousness
• Becomes automatic over time with repetition
• Begins with learning skills and mastering a task

Question 6

What are the temporal domains of memory

Answer 6

• short term memory
• long term memory

Question 7

What is short term memory

Answer 7

• temporary information storage space - information cannot be manipulated
• Receives and processes incoming sensory information
• 15-30 sec and capacity of 7 +- 2
• Working memory - temporary storage of information that can be manipulated (short term memory which can be manipulated )

through memory consolidation short term memory turns into long term memory

Question 8

What is long term memory

Answer 8

• continuous storage of information
• no capacity or time limits
• can be weak or strong memories

2 types

• explicit - declarative memory
• Implicit - nondeclarative

Question 9

What is the process which turns short term memory into long term memory

Answer 9

memory consolidation

Question 10

What is atkinson-shiffrin 3 stage model of human memory

Answer 10

describes memory as a three-stage process, where information moves through different storage systems:

1. Sensory Memory (Immediate, very short-term storage)
2. working memory (Temporary storage, limited capacity)
3. Long-Term Memory (LTM) (Permanent storage, unlimited capacity)

Question 11

What is attention

Answer 11

Attention = process of (or mechanism) for selection of information to be processed with priority

= the ability to focus on specific stimuli or tasks while ignoring others

the selection of information into working memory is a form of controlled attention
limited attentional resource at least in part responsible for capacity limit of working memory

Question 13

What is working memory

Answer 13

the mechanisms and processes that hold the mental representations currently most needed for an ongoing cognitive task available for processing

= the temporary storage and manipulation of information for cognitive tasks. It holds and processes information for short periods, allowing problem solving, decision making and learning

Question 14

What are the 4 steps to forming a memory

Answer 14

1. Attention
2. Encoding
3. Storage
4. Retrieval

Question 15

What is attention in the formation of memory

Answer 15

• Acts like a filter that lets important information into the brain
• Without attention we remember very little

Question 16

What is encoding as part of memory formation

Answer 16

• Assigning meaning and context to information
• Use of chunking mnemonics etc

Question 17

What is storage as a step in memory formation

Answer 17

• Reviewal and rehearsal
• Association with pre-existing knowledge
• Much of it happens during sleep

Question 18

What is retrieval as a step in memory formation

Answer 18

• Copied from LTM (long term memory) to STM (short term memory)
• Use of encoding indices
• Active (recall) or passive recognition

Question 19

How does forgetting occur

Answer 19

a failure in any of the 4 steps of memory

Question 20

How is sleep important in memory consolidation

Answer 20

• During sleep the brain ‘replays’ recent events to memories them
• Neurons that were involved in an experience fire again in the same order - helps to solidify a memory and prepare it for long term storage

Question 21

Why don’t new memories override old ones

Answer 21

Mice experiment showed that

• the brain’s replay of experiences takes place during the deep phases of sleep
• Established memories are processed during other sleep phases

Question 22

What is neural plasticity

Answer 22

the ability of the nervous system to change its activity in response to intrinsic or extrinsic stimuli by reorganizing its structure, functions or connections

the brain’s ability to change and adapt in response to experience, learning, injury, or environmental influences. It involves changes in neural connections, including the strengthening, weakening, creation, or reorganization of synapses.

Question 23

What is temporary neural plasticity

Answer 23

• changes in electrical activity in the brain
• altered levels of secondary messenger molecules
• modification of existing synaptic proteins

short-term changes in neural connections that occur in response to experiences, stimuli, or environmental factors but are not permanently maintained

Question 24

What is permanent neural plasticity

Answer 24

Alterations of synapse structures - protein synthesis and reinforcement of existing circuits

Question 25

Explain classical conditioning

Answer 25

A type of learning where a neutral stimulus becomes associated with an unconditioned stimulus to produce a conditioned response. This learning happens automatically without conscious awareness This is a type of implicit memory because it occurs unconsciously

Question 26

What is the Hebb Rule

Answer 26

If two neurons are active at the same time the synapses between them are strengthened "Neurons that fire together, wire together." When two neurons are activated simultaneously, the connection (synapse) between them strengthens. If this activation happens repeatedly, the synapse becomes more efficient at transmitting signals. Conversely, if neurons rarely fire together, the connection weakens or disappears (synaptic pruning). - suggests neural plasticity

Question 27

What is long term potentiation

Answer 27

the process by which synaptic connections between neurons become stronger with repeated activation. It is a key mechanism underlying learning and memory in the brain - belief, high frequency electrical stimulation of excitatory pathways ⇒ strengthening of the stimulated synapses - Supports Hebb’s idea of neural plasticity

Question 28

What is the sequence of events in LTP

Answer 28

1. Presynaptic neuron is repeatedly stimulated leading to the release of glutamate which binds to AMPA 2. AMPA receptor allows Influx of Na+ ions initiates depolarisation in post synaptic neuron 3. Sufficient depolarisation and glutamate binding to NMDA receptor displace Mg2+ block 4. Ca2+ enters and triggers biochemical events, resulting in strengthened synapse and LTP + - Ca2+ influx -> activation of kinases (CaMKII, PKC, PKA) - Early LTP - AMPA receptor phosphorylation and insertion of more AMPA receptors - Late LTP -> CREB activation, protein synthesis, and structural synaptic changes

Question 29

When does calcium trigger events in LTP What is the Ca2+ intracellular signaling cascade

Answer 29

1. Ca2+ ions bind to and activate the enzyme calmodulin 2. Ca2+/calmodulin activates enzymes adenylate cyclase and CaM kinase II (CaMKII) 3. CaMKII promotes insertion of additional AMPA receptors and increases channel conductance

Question 30

What is the function of calcium in LTP and LTP ( long term depression)

Answer 30

- central role in learning - important secondary messenger - link electrical activity with long term changes in the brain - Determine orientation of plasticity towards potentiation (LTP) or depression (LTD)

Question 31

What is long term depression (LTD)

Answer 31

- the reverse of LTP - the long term weakening of a synaptic connection - involves the decrease in AMPA receptors in the membrane making the postsynaptic neuron less responsive to glutamate released from the presynaptic neuron

Question 32

What happens in the early phase of LTP

Answer 32

- phosphorylation of existing AMPA receptors to increase their activity - not permanent and can be reverted - Insertion of additional AMPA receptors (from pool) into the postsynpatic membrane - Increased efficiency and number of AMPA receptors at the synapse → larger postsynaptic responses

Question 33

What happens in the late phase of LTP

Answer 33

- Persistent activation of protein kinases → de novo protein synthesis and changes in gene expression - Structural changes including increase in dendritic spine numbers, surface area and post synaptic neurotransmitter sensitivity → strengthened synapse - If stimulation continues Ca2+ also activates protein synthesis pathways and changes in gene expression Leading to: - growth of new dendritic spines (synapses) - increase in synapse surface area - increased post synaptic neurotransmitter sensitivity - permanent changes in synaptic strength

Question 34

How is the hippocampus a structure in explicit memory

Answer 34

- not the location of short term or long term memory but important in consolidation - Processes and links information from different regions - controls the transformation of declarative memories into permanent storage - controls memory consolidation - Until transformation is complete, hippocampus also involved in retrieval of memories

Question 35

What is the papez' circuit

Answer 35

A neural pathway in the limbic system that plays a crucial role in emotion, memory and learning The circuit follows a looped pathway connecting key brain regions - hippocampus - formix - mammillary bodies (hypothalamus) - Anterior thalamic nuclei (thalamus) - Cingulate gyrus (cortex) - Entorhinal cortex (Para hippocampal region) * dont need to remember the structures

Question 36

What is the role of the basal ganglia in procedural memory

Answer 36

Mostly independent of declarative memory Facilitate execution of motor programs but also important for - Planning and modulation of movement pathways - decision making - working memory - eye movements - motivation (dependent on dopamine levels)

Question 37

What is the role of the cerebellum in procedural memory

Answer 37

- Receives information from other regions of the brain nervous system including the brain stem, spinal cord and cerebrum - coordinates and controls voluntary movements Key functions of the cerebellum include: - Balance and posture - mental function - movement - motor learning - vision

Question 38

What is the signaling loop in procedural memory

Answer 38

The signaling loop involved in procedural memory mainly relies on the basal ganglia-thalamocortical circuit, which enables automatic and repetitive movements.

Question 39

What are emotions

Answer 39

- personal and subjective sensations - cannot measure the emotional experience - but can record an individual’s response or expression of that emotion e.g. heart rate or facial expression of that emotion e.g. heart rate or facial expression - Processed by the limbic system - Feeling are conscious experience of emotional reactions

Question 40

What is the limbic system involved with

Answer 40

- Involved in emotional processing - amygdala and cingulate gyrus particularly important - Interacts with prefrontal lobes to integrate thoughts and feelings - interaction will determine whether logic or emotion prvails - Most output relayed through hypothalamus - Important for dentists - physical expression of emotions

Question 41

What is pain

Answer 41

- Pain is an alarm mechanism - painful experiences teach us to avoid certain behaviours for fear of being hurt

Question 42

What is fear

Answer 42

natural emotional reaction to a specific, identifiable and immediate threat → defensive behaviours, autonomic reflexes, arousal and alertness, corticosteroid secretion

Question 43

How do memories of fear develop

Answer 43

- Neurons “learn” to respond to painful stimuli - after this learning these stimuli will evoke a fearful response - Memories of emotional events form quickly and are particularly vivid and long-lasting - *Amygdala seems central to the formation of emotional memories

Question 44

What is the amygdala

Answer 44

Small, almond shaped structure located deep in the medial temporal lobe of the brain. It is a key part of the limbic system and is primarily responsible for processing emotions, emotional memory and threat detection

Question 45

how is the amygdala and anterior cingulate gyrus involved in pain and learned fear

Answer 45

- Amygdala is involved in both pain and fear related negative emotions - Anterior cingulate gyrus (ACC) - cortical area most, frequently linked to the experience of pain, appears to be involved in the emotional reaction to pain - Fear learning and memory mediated by changes in synaptic strength (LTP) in the amygdala and ACC - Amygdala active in response to contextual fear conditioning

Question 46

What are fear inducing stimuli in dental care settings

Answer 46

- lying back in the chair, pain, anticipation or memory of pain, sight and sound of hand-pieces and receiving local anesthetics injection - Environmental factors e.g. lack of predictability and control, inability to escape or leave

Question 47

what is a key strategy for preventing dental anxiety

Answer 47

effective pain control

Question 48

Visceral and sensory signals are input into the amygdala which then outputs them where (3)

Answer 48

- Hypothalamus - autonomic response “fight or flight” - Brainstem - behavioral responses e.g. aggression - Cortex - conscious emotional experience - feeling

Question 49

What is aggression

Answer 49

not a personality trait but a behaviour and can take on many forms including defensive behaviour

Question 50

What is affective (impulsive) aggression

Answer 50

more for show and involved high levels of sympathetic activity - targeted towards perceived source of distress

Question 51

What is a key mediator in affective aggression

Answer 51

serotonin

Question 52

What does the limbic system interact with to determine whether logic or emotion will prevail in a given situation

Answer 52

prefrontal lobes