Psyc110 Final Exam Notes

How the Brain Understands Space

Hippocampal Place Cells: These brain cells in the hippocampus help track locations. They activate when an animal or person is in a specific place, helping create a mental map of the environment.

Grid Cells: Found in the entorhinal cortex, grid cells fire in a triangular pattern, allowing the brain to measure distances and movement.

Habit Learning vs. Spatial Learning:

• Habit Learning: Actions become automatic through repetition (e.g., driving a familiar route or typing on a keyboard).

• Spatial Learning: Learning about the environment and remembering locations, often requiring the hippocampus.

Key Experiments on Memory and Learning

Morris Water Maze: A test where rats learn to find a hidden platform in water. It helps scientists study spatial memory and how the hippocampus is involved.

Hippocampus and Learning:

• If the hippocampus is turned off, animals can still follow habits but struggle with learning new locations.

• Damage to the hippocampus makes it hard to form new spatial memories but does not affect motivation or motor skills.

Different Types of Memory

• Episodic Memory: Personal memories of events (e.g., remembering what you ate for breakfast).

• Semantic Memory: General knowledge and facts (e.g., knowing that the Earth orbits the sun).

• Declarative Memory: Requires conscious effort to recall (e.g., remembering historical dates for a test).

• Implicit Memory: Works without conscious effort (e.g., knowing how to ride a bike or type on a keyboard).

Famous Memory Case Studies

Patient H.M.:

• Had his hippocampus removed to treat epilepsy, leading to severe memory loss.

• Could not form new long-term memories but could still learn motor skills, proving different brain areas control different types of memory.

Patient E.P.:

• Suffered brain damage from a virus, leading to memory problems similar to H.M.

• Could remember past events but could not form new memories.

Brain Structures Involved in Memory

• Hippocampus: Forms new memories and helps with navigation.

• Amygdala: Processes emotions, especially fear, and helps store emotional memories.

• Prefrontal Cortex: Controls planning, decision-making, and working memory.

• Basal Ganglia: Helps with habit learning and movement control.

• Thalamus: Sends sensory information to different brain areas and helps with alertness.

Sleep and Memory Strengthening

• Slow-Wave Sleep (Deep Sleep): Strengthens new memories by replaying them in the brain.

• REM Sleep (Dream Sleep): Helps process emotions and integrate new information into long-term memory.

How the Brain Controls Attention

• Frontal Eye Field (FEF): Helps focus attention on important visual information.

• Pulvinar Nucleus: Directs attention to significant stimuli in the environment.

• Locus Coeruleus: Releases norepinephrine, which keeps the brain alert and responsive.

• Superior Colliculus: Helps shift attention quickly to important visual or movement-related stimuli.

The Role of Dopamine in Motivation and Learning

• Dopamine reinforces behaviors by making actions feel rewarding.

• Low dopamine levels (such as in Parkinson’s disease) make it harder to start movements and stay motivated.

• High dopamine release (such as in drug addiction) creates strong habits and cravings.

Decision-Making and the Prefrontal Cortex

• The Prefrontal Cortex helps with goal-setting, planning, and self-control.

• The Striatum helps decide which action to take based on past rewards.

• The Winner-Take-All System ensures that the brain chooses the most important action while suppressing others.

How the Brain Chooses Actions

The Direct and Indirect Pathways of the Striatum:

• Direct Pathway: Encourages movement and decision-making by reducing inhibition in the motor system.

• Indirect Pathway: Restricts unnecessary movements and prevents unwanted actions.

• These pathways work together to help the brain make smooth, controlled movements.

Dopamine’s Effect on Action Selection

• Dopamine excites neurons in the direct pathway and inhibits neurons in the indirect pathway.

• In Parkinson’s disease, dopamine-producing cells in the substantia nigra die, leading to difficulty in initiating movement.

• In drug addiction, dopamine release becomes tied to specific cues (such as seeing drug-related objects), leading to cravings.

How Learning and Rewards Shape Behavior

• Instrumental Conditioning: The process of learning which actions lead to rewards.

• Dopamine levels increase when an unexpected reward appears.

• Over time, dopamine release shifts to cues that predict rewards (e.g., hearing a bell before food arrives).

How Drugs Affect Dopamine

• Drugs like cocaine and amphetamines increase dopamine release, reinforcing drug use.

• Cues linked to drug use (such as certain locations or objects) can trigger dopamine release, increasing cravings.

• The Ventral Striatum is heavily involved in reward-seeking behaviors and addiction.

The Prefrontal Cortex and Executive Function

• The Prefrontal Cortex helps plan actions, regulate emotions, and adjust to new information.

• Damage to this area can cause impulsive behavior and difficulty in adapting to change.

The Wisconsin Card Sorting Test

• This test is used to study cognitive flexibility (the ability to adapt to new rules).

• People with prefrontal cortex damage struggle to switch strategies when the rules change.

Working Memory and Brain Activity

• The Prefrontal Cortex is responsible for keeping information temporarily available (e.g., remembering a phone number before dialing it).

• Certain neurons remain active during delay periods, helping maintain working memory.

How Sleep and Memory Are Connected

• The brain replays important experiences during sleep to strengthen memory.

• Synaptic Consolidation: Strengthens connections between neurons to store long-term memories.

• Systems Consolidation: Transfers memories from the hippocampus to the neocortex for permanent storage.

The Role of the Striatum in Learning and Decision-Making

• The Dorsal Striatum is involved in learning habits and motor functions.

• The Ventral Striatum is linked to motivation, reward-seeking, and addiction.

• Dopamine release in the ventral striatum can create preferences for certain environments (e.g., a place associated with drug use).

How Fear Memories Are Stored

• The Amygdala helps store memories related to fear.

• Contextual Fear Conditioning: The brain learns to associate a place with danger.

• Auditory Fear Conditioning: The brain learns to associate a sound with danger.

The Importance of Attention and Arousal

• The Reticular Formation in the brainstem helps control wakefulness and alertness.

• The Thalamus plays a role in shifting attention between different tasks.

• Damage to the Prefrontal Cortex can make it harder to focus or switch attention.