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.