Older Brain Structures

Older Brain Structures

• The brain's oldest and innermost region is the brainstem, which is responsible for automatic survival functions such as:
  • Heartbeat control
  • Breathing control
  • Sleep control
  • Movement coordination
• The brainstem is divided into two parts:
  • Medulla: the base of the brainstem, which controls heartbeat and breathing
  • Pons: the part of the brainstem that helps coordinate movements and control sleep

The Thalamus

• The thalamus is a pair of egg-shaped structures that act as the brain's sensory control center, receiving information from all senses except smell
• The thalamus routes sensory information to higher brain regions and receives some of the higher brain's replies
• It is compared to London's Heathrow Airport, where traffic flows in and out on its way to various locations

The Reticular Formation

• The reticular formation is a nerve network that travels through the brainstem into the thalamus
• It filters incoming stimuli and relays important information to other brain areas
• It is also involved in controlling arousal and plays a crucial role in multitasking

The Cerebellum

• The cerebellum is a baseball-sized structure located at the rear of the brainstem, which is involved in:
  • Nonverbal learning and skill memory
  • Judging time and modulating emotions
  • Discriminating sounds and textures
  • Coordinating voluntary movements
• The cerebellum is also involved in balance and coordination, and damage to it can lead to difficulties in walking, keeping balance, or performing fine motor skills

The Limbic System

• The limbic system is a neural system located below the cerebral hemispheres, which is associated with emotions and drives
• It consists of three key structures:
  • Amygdala: involved in aggression and fear
  • Hypothalamus: involved in various bodily maintenance functions, such as hunger, thirst, and body temperature
  • Hippocampus: involved in processing conscious, explicit memories of facts and events

The Amygdala

• The amygdala is a structure involved in emotions, particularly fear and aggression
• Research has shown that damage to the amygdala can reduce aggression and fear responses
• Electrical stimulation of the amygdala can provoke angry reactions

The Hypothalamus

• The hypothalamus is a neural structure involved in various bodily maintenance functions, such as:
  • Hunger regulation
  • Thirst regulation
  • Body temperature regulation
  • Sexual behavior
• It is also involved in emotion and reward processing

The Hippocampus

• The hippocampus is a structure involved in processing conscious, explicit memories of facts and events
• Damage to the hippocampus can lead to difficulties in forming new memories
• The hippocampus decreases in size and function as we grow older