Neuroscience: Memory and Brain Function

The process of converting light energy into electrical signals in the retina.

Photoreceptor cells responsible for low-light vision and detecting shades of gray.

Photoreceptor cells responsible for color vision and fine detail.

The area of the visual field that, when stimulated, causes a specific neuron in the retina to respond.

Receptive fields where multiple photoreceptor cells converge onto a single bipolar cell, increasing sensitivity to light.

Receptive fields where each photoreceptor cell has a separate pathway to a bipolar cell, maintaining individual detail.

Interneurons in the retina that connect photoreceptors to ganglion cells.

Neurons in the retina that receive signals from bipolar cells and transmit them to the brain.

A state where the neuron's membrane potential becomes more negative than its resting potential (-70mV). This happens because potassium voltage-gated channels close slowly, allowing more potassium ions to leave the cell.

A period during which a neuron is less likely to fire another action potential. This is due to the sodium-potassium pump restoring the neuron's resting potential.

A time during which the neuron absolutely cannot fire another action potential. This occurs between depolarization and repolarization, from the opening of sodium activation gates to the closing of inactivation gates.

A time period during which a neuron can only be stimulated to fire another action potential with a stronger-than-usual stimulus. This occurs after the absolute refractory period, and is characterized by sodium gates being closed and potassium gates being open.

The rapid transmission of nerve impulses along a myelinated axon, where excitation only occurs at the nodes of Ranvier.

The movement of molecules from an area of high concentration to an area of low concentration.

A type of ion channel that is always open, allowing ions to pass through the membrane continuously.

A type of ion channel that opens in response to a change in membrane potential.

The hippocampus is responsible for forming and consolidating new long-term memories, specifically episodic memories (personal experiences) and semantic memories (general knowledge).

The frontal lobe is responsible for higher-level cognitive functions like decision-making, planning, and regulating emotions. It helps us evaluate the importance of actions and connect them to our goals, values, and feelings.

The occipital lobe is responsible for processing visual information, including color, form, and motion.

The membrane potential refers to the electrical difference across the cell membrane of a neuron, caused by the uneven distribution of ions. It plays a critical role in communication between neurons.

Depolarization is the process where the inside of a neuron becomes less negative, shifting closer to zero mV. This occurs when sodium ions (Na+) rush into the cell, driven by both the electrochemical gradient.

Repolarization is the process where the inside of a neuron returns to its resting potential (negative charge) after depolarization. This occurs when potassium ions (K+) move out of the cell.

Neurons communicate through two main processes: electrical signaling, which involves the flow of ions across the cell membrane, and chemical signaling, which involves the release of neurotransmitters.

The action potential involves three key stages: depolarization (the neuron becomes less negative), repolarization (the neuron returns to its resting potential), and the refractory period (a brief time where the neuron is less likely to fire another action potential).

Short-term memory (STM) is a temporary storage system, while long-term memory (LTM) is a permanent storage system. STM is limited in capacity, while LTM has a vast capacity. This case shows the differences between these two memory types.

Working memory is a type of short-term memory that actively holds and manipulates information needed for current tasks. It's like a mental workspace where you process information.

Long-term memory is divided into declarative and non-declarative memory. Declarative memory is explicit and conscious, like facts and events. Non-declarative memory is implicit and unconscious, like skills and habits.

The brain forms, stores, and retrieves memories through three stages: encoding, storage, and retrieval. Encoding is the initial processing of information into memory. Storage is the retention of information over time. Retrieval is the accessing and recalling of stored information.

Cognitive control, also known as executive function, refers to the mental processes that allow us to plan, manage tasks, make decisions, and adapt to changing circumstances. It helps us stay focused, solve problems, and control our impulses.

A complex system of nuclei that acts as a "volume control" for movement. It helps initiate voluntary actions and prevent conflicting commands.

The cerebellum is responsible for coordinating movements, timing, and precision. It also plays a vital role in balance and posture.

A condition resulting from cerebellum damage, characterized by uncoordinated movements, unsteady gait, and difficulty with fine motor skills.

A representation of the human body in the primary motor cortex, where areas with finer motor control (e.g., fingers) occupy more space.

The premotor cortex plans and sequences movements, while the supplementary motor area (SMA) initiates internally generated movements.

The spinal cord transmits signals from the brain to muscles, enabling voluntary and reflexive movements. It's also responsible for controlling rhythmic movements like walking.

A simple neural pathway involving sensory and motor neurons that allows for rapid responses to stimuli, like the knee-jerk reflex or withdrawal from a painful object.

Damage to the spinal cord can result in loss of voluntary motor control, altered reflexes, and potentially paralysis depending on the severity and location of the injury.

The frontmost part of the frontal lobe, responsible for complex cognitive functions like decision-making, planning, and working memory.

A region within the PFC involved in goal-directed behavior, working memory, and cognitive control.

A region within the PFC involved in emotion regulation, social cognition, and decision-making under uncertainty.

A region in the medial prefrontal cortex involved in monitoring performance, detecting errors, and adjusting behavior.

A neuropsychological test that measures cognitive flexibility and interference control. Participants are asked to name the color of ink used to print a word, which may be incongruent with the written word.

In a Stroop test, when the color of the ink matches the written word.

In a Stroop test, when the color of the ink does not match the written word.

A disorder characterized by impulsive behavior, inappropriate social interactions, and difficulty controlling actions.

A disorder characterized by difficulty planning, organizing, and carrying out tasks.

A condition where individuals lose the ability to understand and respond to social norms and cues due to brain damage.