2. Limbic System

What is the function the limbic system?

Hippocampus, amygdala & more! Regulates emotions, motivation, memory & some behaviors like:

• Feeding & thirst

• Seeking pleasure & rewards

• Forming memories (esp. emotional ones)

• Reacting to danger (fight or flight)

What is the limbic circuit?

What is the function of the cingulate cortex? Anterior vs Posterior?

helps people understand how to alter behavior in a variety of situations, recognize alternatives

PACE - Posterior for Autobiographical & Cognitive, Anterior for Emotion

• Posterior cingulate cortex (PCC): Focuses on autobiographical memory, spatial memory, active when dreaming.

  • Imagine using the PCC to PACE yourself back through your memories and experiences.

• Anterior cingulate cortex (ACC): Plays a bigger role in processing emotions, error detection, anticipation of tasks, attention, motivation.

What is the function of the parahippocampal cortex?

important for memory storage, encoding, and retrieval

What structure is the major input to the basal ganglia?

striatum

What is the function of the nucleus accumbens (ventral striatum)?

Plays a major role in the brain's reward system, motivating us to seek pleasurable experiences.

Lesion → anhedonia

What is the function of the amygdala?

Emotions & Memory Hub

• Processes emotions (esp. fear & pleasure)

• Helps us remember emotional experiences

Imagine the amygdala as a fire alarm in your brain. When it senses danger (fire!), it triggers the alarm (fight-or-flight response) almost instantaneously and remembers the event vividly (emotional memory)

What is the function of the dorsolateral prefrontal cortex?

CEO of the Brain!

• Working memory (holding info in mind)

• Planning & decision-making

• Reasoning & problem-solving

• Inhibiting impulses & controlling emotions

• Attention & focus

Memory control processes that cause confabulation are associated with which part of the brain?

right lateral prefrontal cortex

What is the function of the orbitofrontal cortex?

Judge for Rewards & Decisions

• Values rewards (like a critic)

• Helps choose best option

• Learns from experience

• Regulates emotions tied to rewards

What is the function of the ventromedial prefrontal cortex?

Conductor for Social & Emotional Decisions

• Makes social judgments and decisions

• Processes and regulates emotions (esp. in social situations)

• Involved in social reward processing

• Contributes to self-perception

Stimulation of _ via the ipsilateral frontal cortex elicits aggression

amygdala

Why do children have less control over their emotions?

• axons that send info from cortex to limbic system are not fully developed

• neurons of the prefrontal cortex that provide rational control over emotions doesn’t mature until early 20s

What is Kluver-Bucy syndrome?

Rare brain disorder caused by bilateral lesion of the amygdala. Due to lobectomies, encephalitis from Herpes simplex, stroke, or Alzhemier’s. Causes abnormal behaviors and memory problems:

• Putting objects in mouth (hyperorality)

• Excessive touching of objects (hypermetamorphosis)

• Increased sex drive (hypersexuality)

• Binge eating/purging (bulimia)

• Difficulty recognizing objects (visual agnosia)

• Memory problems (amnesia)

What structure has the function of reducing unpleasant effects of stress, psychological resistance, and formation of new memories?

hippocampus

What is the difference between declarative and procedural memory?

Feature	Declarative Memory	Procedural Memory
Type of information	Facts, events, experiences	Skills and procedures
Retrieval	Conscious effort	Automatic, triggered by cues
Examples	Recalling historical dates, remembering birthdays, describing events	Riding a bike, tying shoes, playing an instrument

What is the fornix of the hippocampus?

Hippocampus output pathway (C-shaped)

• Connects hippocampus to hypothalamus/mamillary bodies

• Carries information to and from hippocampus

• Important for memory consolidation and retrieval

What is this?

hippocampal fornix

How does the hippocampus form memories?

Association areas activate the hippocampus, which reverberates in the Papez circuit until information is stored permanently

Hippocampus → fornix → mamillary bodies → anterior thalamic nucleus → cingulate cortex → hypothalamus

What is Korsakoff syndrome?

Memory disorder from thiamine (vitamin B1) deficiency. Often linked to chronic alcoholism.

• Symptoms: anterograde amnesia (can't form new memories), confabulation (making up memories), disorientation, apathy.