Cognition & the Brain: An Overview

Cognition & the Brain

• Human cognition is understood by examining physiological factors.
• Neuroscience is a field that studies the biochemistry of the human body.
• It began over 100 years ago.
• Early ideas about how the brain works include Leonardo da Vinci's hydraulic system and Descartes' concept of "animal spirits."
• It aims to understand brain biochemistry.
• Cognitive neuroscience is a branch focused on studying the human brain.
• It examines how the brain constructs intelligence, creativity, emotions, consciousness, memory, etc.
• This object in the universe is approximately 1400g and has a length of 15cm.
• It's comprised of trillions of cells and interconnected neuronal networks
• These networks produce various complex actions.

The Mind's Computer

• Neurophysiology and neuroscience provide a background on the brain's workings.
• The nervous system utilizes electrical signals.
• Neural communication processes information efficiently.

The Brain's Structure

• The brain and spinal cord, as a unit, form the central nervous system.
• The brain includes major parts like the cerebrum, cerebellum, and medulla.
• The cerebrum is for thinking, movement, and sensation.
• The cerebellum controls balance and muscle coordination.
• The medulla regulates crucial functions like heartbeat and breathing.
• The brain has two symmetrical hemispheres.

Cerebral Cortex

• The wrinkled outer layer of the brain is known as the cerebral cortex.
• It's around 3mm thick.
• It's responsible for higher-level cognitive functions.
• The cortex is divided into four lobes—frontal, parietal, occipital, and temporal—each with specific functions.
• The Frontal lobe is associated with language, memory, hearing, and vision.
• The Parietal lobe receives sensory input (touch, vision, and attention).
• The Occipital lobe is the primary visual processing area.
• The Temporal lobe is involved in language, memory, hearing, and vision.
• Two hemispheres are connected by the corpus callosum.

Subcortex

• Structures within the cerebral cortex are part of the subcortex, including the thalamus, amygdala, and hippocampus.
• The thalamus processes sensory information (vision, hearing, and touch).
• The amygdala manages emotions and emotional memories.
• The hippocampus is crucial for forming memories.

Neurons

• Neurons are the basic units of the nervous system.
• They have cell bodies, dendrites, and axons that allow for communication.
• Dendrites receive signals; axons transmit them.
• Cell bodies house the nucleus, which maintains the cell's functionality,
• There are billions of neurons, forming complex networks.
• Synapses, the connections between neurons, facilitate information transmission.

Electricity in the Nervous System

• Receptors transform environmental energy into electrical energy to send information to the brain.
• Transduction is when environmental energy (e.g., light) is transformed into an electrical signal, used by neurons.
• Action potentials are electrical signals that travel along neurons, enabling communication.
• Measuring action potentials involves electrodes placed near axons to observe voltages.

Neurotransmitters

• Neurotransmitters—dopamine, acetylcholine, serotonin—act as chemical messengers between neurons.
• They impact feelings, thoughts, and actions.

How Neurons Work

• Neurons are stimulated and transmit signals via dendrites to the axon hillock.
• Action potentials occur, triggering signals down the axon to the synapse.
• Synaptic communication involves releasing neurotransmitters from presynaptic neurons to stimulate postsynaptic neurons.
• Neural circuits are groups of interconnected neurons performing complex processes.

Studying Physiological Cognition

• Single-unit recording involves studying individual neuron activity, typically in animals.
• Event-related potentials (ERPs) measure average electrical activity in the brain in response to specific events.
• Brain imaging methods like PET quantify brain function (blood flow).
• fMRI tracks blood flow in the brain.
• Brain lesions examine the effects of damage to specific brain areas

Brain Lesions

• Removing parts of the brain in specific individuals (especially in the hippocampus) can reveal its role in memory formation.

Neuropsychology

• It examines the behavioral effects of brain damage in humans, often caused by accidents or strokes.
• This analysis and understanding of individual brain injuries/differences allows for the understanding of human cognition.
• Double dissociations describe situations where a function is lost while another remains intact in an individual.
• These occurrences highlight the localization of function within the brain, and how specific areas contribute to cognitive processes.

Explore the fascinating world of human cognition and its physiological foundations. This quiz delves into the principles of cognitive neuroscience, examining how the brain influences intelligence, memory, and emotions. Understand the historical perspectives and modern neurophysiology that shape our comprehension of the brain's intricate workings.