Definitions of Psychology

Definitions of Psychology

• Psychology is defined as the science of mind and behavior

Structuralism (1879)

• Structuralism is the study of the science of the mind
• Wilhelm Wundt developed the "Science of the Mind" which was the first psychology lab in 1879 in Leipzig, Germany, separating it from philosophy
• Wundt taught Titchener, who had his own view of structuralism focusing on the content of conscious thought
• Titchener believed thought had images with it
• Others did not believe in images with thought, This disagreement led to Watson's behaviorism

Behaviorism (1913)

• Behaviorism is the science of behavior
• John Watson and Broadus advocated for psychology being an observable science
• Behaviorism involved objective data analysis

Cognitivism (1967)

• Cognitivism is the science of mind and behavior
• Cognitivism focuses on attention, perception, language, and memory, similar to how computers process input

The Science of Experimental Epistemology

• Epistemology explores how knowledge is acquired from different sources

Nativism

• Nativism aligns with rationalism and emphasizes nature
• Knowledge is innate, present from birth

Empiricism

• Empiricism aligns with associationism and focuses on nurture
• Knowledge is derived from experience
• Individuals are born as a "tabula rasa" or blank slate
• Knowledge is connecting experiences

The Science of Knowing and Experiencing

• Knowing involves not just storing but understanding information and being aware of how to behave Knowing makes a person understand information
• Experiencing involves more than just knowledge and is different from knowledge and information
• Only tasting salt allows someone to experience it
• Experiences motivate people

Mind and Body Problem

• It explores the relationship between the mind and the body.

Dualism

• Descartes proposed dualism
• Dualism says there are two types of substances in the universe: physical and non-physical that interact
• Non-physical includes soul, mind, and thought.

Materialism

• Materialism says everything in the world is physical
• Thoughts are part of the physical world, specifically electrical signals

Science of Things That Move

• Focuses on matter and motion and that physics cannot explain animate motion

Psychology and Animate Motion

• Psychology accounts for animate motion and behavior

Key Aspects of Psychology

• Psychology includes goals, knowledge of goal success, perception, environmental learning based on behavior, memory, and records of experiences
• These aspects form the foundation of locomotion

Reflexes

• Reflexes are automatic, stereotyped movements in response to a stimulus
• They occur without engagement of the frontal cortex

Knee Tap Reflex Steps

• Follows a series of steps including knee tap, sensory neuron signal through the spinal cord's back, signal to the brain, motor output from the front, and foot kick
• Sensory nerves enter the back of the spinal cord, while motor nerves exit the front

Neuron Structure

• A neuron is a cell that relays information throughout the body

Cell Body (Soma)

• Contains the nucleus of the neuron

Dendrites

• Dendrites take input from presynaptic neurons

Axon

• Axons send signals away from the cell body to the next neuron

Myelin Sheath

• Myelin Sheath is a fatty material insulating the axon
• Insulating it allows for faster and more efficient signal transmission

Nodes of Ranvier

• Nodes of Ranvier are breaks in the myelin sheath where ion exchange happens

Axon Terminals

• Axon terminals connect with other neurons to send signals via neurotransmitters

Synapse

• The synapse is the gap between two neurons where signals are transmitted

Multiple Sclerosis

• Multiple sclerosis is an autoimmune disorder
• The immune system attacks the myelin sheath sheaths in the nervous system
• Demyelination results in impairment of action potentials
• Creates difficulty in movement, sensation, and coordination

Neuron Firing: Action Potential

• Describes how a neuron transmits electrical signals

Resting state

• -70mV, sodium ions are outside the neuron
• Fewer potassium and chloride ions inside the neuron
• More negative ions are inside and more positive ions are outside of the neuron

Neuron Stimulation

• A neuron is stimulated by other neurons
• Sodium ions enter the neuron slowly, causing membrane potential to increase from -70mV to -55mV
• -55mV is the threshold potential needed to trigger an action potential

Depolarization

• With reaching the threshold, the neuron becomes more positive
• Sodium gates open, and sodium ions rush into the neuron
• Causing the neuron to reach +40mV
• Firing action potential is all or nothing

Repolarization/Hyperpolarization

• Potassium ions rush out of the neuron
• making the neuron negative
• May go beyond the resting state

Resting State Restoration

• Returning to resting state involves more sodium ions outside the cell, making it positive
• Involves less potassium ions inside the cell, maintaining a potential of -70mV

Action Potential Propagation

• The action potential travels down the axon through depolarization
• Nodes of Ranvier facilitate ion exchange
• Travels at a rate of 50-100 meters per second

Neurotransmitters

• Neurotransmitters facilitate communication between neurons

Vesicles

• Vesicles in axonal buttons contain neurotransmitters
• Neurotransmitters are released from vesicles at the action potential

Receptor molecules

• Neurotransmitters bind to receptor molecules/ the lock on the dendrites of the postsynaptic neuron
• Neurotransmitters open ion channels for communication by allowing ions to enter

Neurotransmitter Actions

• Neurotransmitters create different channels depending on the function

Reuptake

• Involves reabsorption of neurotransmitters back into the presynaptic neuron for reuse

SSRIs

• Some drugs such as SSRIs prevent reuptake
• SSRIs increase serotonin levels in the synapse, helping to reduce depression

Excitatory and Inhibitory Potentials

• Potential effects on postsynaptic neurons

EPSP - Excitatory Postsynaptic Potential

• An action potential is more likely to fire in the postsynaptic neuron
• Neurotransmitters can open sodium channels to start potential
• The process makes firing more likely by inducing more positive charge (-65, -60, -50)

IPSP - Inhibitory Postsynaptic Potential

• Action Potential is significantly less likely to fire in the postsynaptic neuron
• Neurotransmitters either open a gate for potassium to leave or introduce chloride into the neuron
• Both processes lower the possibility of firing (-75, -80)

Charles Sherrington

• Demonstrated the existence of the synapse

Sherrington's Experiment

• He stimulated a dog and had to scratch it to figure out if they itch
• Cutting the spinal column removed inhibition, showing its effects on behavior

Sherrington Stimulated

• Sherrington stimulated an area overtime to create a scratching reaction

Nervous System Structure & Function

• It consists of the central and peripheral systems

Central Nervous System

• The central system contains the brain and spinal cord
• The brain processes sensory information and initiates responses, and stores memory
• The spinal cord transmits signals and controls reflexes

Peripheral Nervous System (PNS)

• PNS consists of the somatic and autonomic nervous systems

Somatic Nervous System

• The Somatic nervous system controls voluntary movements with muscles and senses

Autonomic Nervous System

• The autonomic system dictates involuntary movements
• Controls vital functions like heartbeat, breathing, digestion, and reproduction

Sympathetic Nervous System

• The sympathetic system is the fight or flight system
• Activated during emergencies, increasing heart rate and inhibits systems

Parasympathetic Nervous System

• The parasympathetic system helps with rest and digest
• Promotes calm state and inhibits sympathetic system to allow for sex, reproduction, and digestion

The Brain Structure

• The structure is divided into the hindbrain, midbrain, and forebrain

Hindbrain

• Medulla, pons, and cerebellum

Medulla

• Regulates breathing, heart rate, and blood circulation

Pons

• Controls arousal and attention

Cerebellum

• Integrates fine motor movements and balance
• Playing piano helps to move certain muscles together
• Neuroplasticity allows brain parts to take over missing brain functions

Forebrain

• The forebrain houses aspects of language production

Midbrain Transepted on cat experiment

• A cat with only a hindbrain and midbrain can only move its limbs
• Cat cannot act without a forebrain and midbrain

Actions of the Midbrain

• The mind brain can take movements to cause walking

Midbrain Functions

• The midbrain controls responses to visual and auditory stimuli
• Houses substantia nigra and superior colliculus

Superior Colliculus

• Receives visual stimuli and reacts to them

Substantia Nigra

• Creates dopamine and sends it to the forebrain

Forebrain Function

• In cat experiments, it was discovered the forebrain helps movements have a purpose

Thalamus

• Relays sensory and motor information to specific parts of the cortex

Hypothalamus

• Controls basic needs like fight, flight, feed, and reproduction
• Regulates temperature, telling the body when to sweat

Limbic system

• The Limbic system controls memory, emotions, and amygdala
• It operates in classical conditioning
• Damage causes inability to form fear response, but has fear response of blue slide

Transected cat experiment

• Midbrain and hindbrain can only move limbs
• Cat cannot act without midbrain and forebrain

Cortex Roles

• Responsible for planning, social behavior and motor control
• Front of the brain

Parietal Lobe

• Responsible for sensory processing
• The location is top of the brain

Occipital lobe

• Important for vision

Temporal Lobe

• Important for memory and comprehension
• Side of your brain

Corpus Callosum

• Corpus callosum connects the hemispheres
• Transports the message from each messages
• The right side of the hemispheres controls the left arms moving down

Frank Joseph Gall discovers

• Cortex is functioning tissue
• Commissures connect the 2 hemispheres
• Ascending the nerve pathway from spinal cord of the brain
• Distribution of distinct pathways that help communicate info to the brain through axons

Phineas Gage

• Had damage right to the frontal lobe
• Had a personality change

Wilder Penfield

• On operating table, patients cannot feel brain

Cortical Functions

• Language Functions in left hemisphere
• Spatial recognition in right hemisphere
• Creation of plans in the front of the lobe
• Back of the brain provides interpretation

Damage to Non-Primary Areas

• Loss of plan from prefrontal cortex
• Apraxia-inability to put movements together
• Agnosia- the person does not understand what they are perceiving

Agnosia

• Don't understand visual or auditory functions

Neglect

• Damage to right parietal lobe
• Forget to shave left side of face and only jeans on the left

Aphasia

• Expressive
• Receptive

Broca's aphasia

• Left hemisphere
• Understand what is being said

Wernicke's aphasia

• Cannot comprehend what is being said to them
• Understand what is being said to them