Unit 1 - Biological Bases of Behavior

Evolutionary Perspective

Evolutionary Perspective

• The study of how psychological traits and behaviors have evolved over time to enhance survival& reproductive success

  • Seek to understand universal human behaviors and mental processes

Natural Selection

• Process by which organisms with traits that are better suited to their environment are more likely to survive and reproduce (passed on those advantageous traits to future generations)

  • Explains how psychological traits & heavies have evolved over time in response to environmental pressures

Natural (genes)

Inherent biological & genetic factors that influence an individual’s psychological development, traits, behaviors, and cognitive abilities.

Nurture (environment)

Environmental influences and experiences that shape an individual’s psychological development, behaviors, and cognitive processes

Heredity

• Transmission of genetic information from biological parents to offspring

  • Helps us figure out how much of our traits come from our genes and how much comes from our environment

Genetic Predisposition

Inherited likelihood of developing specific traits/conditions due to genetic factors from biological parents

• Examples: Anxiety disorders, depression, ADHD

Epigenetics

• Study of heritable changes in gene expression (active vs inactive genes)

• Study of changes in gene expression due from non-genetic causes

Eugenics

Belief in improving the genetic quality of a human population by controlling reproduction to increase desirable traits and decrease undesirable ones

Cerebral Cortex

• Outer layer of the brain

• Responsible for higher-level cognitive functions

  • Thinking, perceiving, decision-making

Association Areas

• Parts of the brain that takes information to all over the place

  • What we see, hear, smell, and touch

  • Eg: specific landmarks/cities

Frontal Lobes

• Front of the brain

• Involve in higher-level cognitive functions

  • Decision-making, problem-solving, planning

Pre-Frontal Cortext

• Region of the brain located in the frontal lobe

• Responsible for higher-level cognitive functions & executive functioning

Executive functioning

• Cognitive processes that enable individuals to plan, organize, strategize, and manage time

Motor Cortex

• Located in the frontal lobe (imagine a headband)

• Responsible for planning, executing, and controlling voluntary movements of the body

  • Sends signals to the muscles, enabling us to perform actions (walking, talking)

Parietal Lobe

• Located on the top

• Primarily responsible for processing sensory information from the body

  • Touch, temperature, spatial awareness

Somatosensory Cortex

• Located in the parietal lobe

• Process sensations from skin, muscles, and joints

  • Interprets touch, pressure, temperature, and pain signals

Occipital Lobes

• Located at the back of the brain

• Process visual information received from the eyes

  • Visual cortex, visual stimuli (shapes, colors, and motions)

Temporal Lobe

• Located on the sides of the brain

• Produce auditory information

• Handle language comprehension

The Brain Stem

• Command center

• Manages vital functions like breathing & heart rate

• Oldest & most primitive part of the brain

• Pathway for neural signals traveling between the brain & the rest of the body

Medulla

• Located at the base of the brain stem

• regulating essential autonomic functions

• Relay station for nerve signals between the brain and the spinal cord

Reticular Activating System

• Network of neurons (nerve cells) located in the brain stem

• Regulating auroral, attention, and consciousness

• Filters sensory information

• Modulates overall brain activity, helping to maintain wakefulness & alterness

Cerebellum

• Located at the back of the brain

• Correlates movement, balance, posture

• Receives input from sensory systems

• Works in conjunctions with motor cortex & somatosensory cortex

Limbic System

• Located beneath the cerebral cortex

• Involves emotions, memory, and motivation

Reward System

• Located in the limbic system

• Network of brain structures, primarily located in the limbic system

• Processes pleasurable experiences &reinforces behaviors associated with them

Thalamus

• Located in the limbic system

• “Relay system” - relays sensory information (sight, sound, touch, taste) to the cerebral cortex

• Directing signals to the appropriate areas of the brain

Hypothalamus

• Located in the limbic system

• Regulates basic drives: hunger, thirst, & body temperature

• Control center: maintaining homeostasis

Pituitary Gland

• Located in the limbic system

• Brain’s master gland: releases hormones that regulates growth

• Located at the base of the brain

Hippocampus

• Located in the limbic system

• Curved structure located within the brain’s temporal lobes

• Forming & consolidating new memories

Amygdala

• Located in the limbic system

• Processes emotions; specially fear & aggression

• Small, almond-shaped structure (deep within the brain’s temporal lobes)

• Central role in the brain’s threat detection system

Plasticity

Brains ability to reorganize and adapt throughout life in response to experiences, learning and environment changes

Corpus Callosum

• Thick band of nerve fiber that connect left and right hemispheres

  • Communication, sharing information between two hemispheres

• Right: spatial tasks

• Left: verbal tasks

Split Brain Research

• undergone surgical procedure (corpus callosotomy)

• Done as a treatment for severe epilepsy (neurological disorder characterized by recurrent seizures)

• Left visual field: right hemisphere

• Right visual field: left hemisphere

Contralateral Hemispheric Organization

Phenomenon where each hemisphere of the brain controls the opposite side of the body

Hemispheric Specialization

• explored though spoilt brain research

• Specialized function for each hemisphere

Linguistic Processing

Complex cognitive processes (understanding & producing language)

Bronca’s Area

• Left hemisphere

• Part of the frontal lobe

• Speech production & language processing

• Bronca’s Aphasia: struggles with speech & pronunciation

Wernicke’s Area

• Left hemisphere

• Temporal Lobe

• Language compression/understanding spoken and written language

• Wernicke’s Aphasia: language disorder caused by damage to Wernicke’s area typically resulting from stroke/brain injury

Nervous system

• Body’s communication network

  • Consists of a complex system of nerves, neurons, and specialized cells

Central Nervous System (CNS)

• Brain & spinal cord

• Command center of the body (responsible for processing information, coordinating response, and regulating body function)

Peripheral Nervous System (PNS)

• Consists of all the nerve and ganglia outside the brain and spinal cord

  • Communication network (transmitting sensor information from the body to the CNS)

Automatic Nervous System (ANS)

• Regulates involuntary bodily functions

• Consists sympathetic nervous system and parasympathetic nervous system

Sympathetic nervous system

• activates body “fight/flight” response to stress/danger

• Increase of heart rate *preparing the body to respond to perceived threats

Parasympathetic Nervous System

• responsible for promoting relaxation and restoring the boy to a calm sate after experiencing stress

• Slows heart rate to conserve energy and recover from stressors

Somatic Nervous System

Division of the peripheral nervous system, responsible for controlling voluntary movements and relaying sensory informations from the body to CNS

Neurons

Specialized cells that serves as a building block of the nervous system, transmitting electrical & chemical signals throughout the body

Glial Cells

Support cells of the nervous system, maintaining brain health and supporting neuronal function

Cell Body (Soma)

House of the nucleus and produces energy from the cell

Dendrites

Receive incoming signals from other neurons

Myelin Sheath

Speeds up electrical signal trasmission

Synapse

• Small gap between neurons where communication occurs

• Transfers signals using neurotransmitters (chemicals) between neuron

Motor Neurons

Transmit signals from the CNS to muscles, glands, and organs, initiating and controlling voluntary and involuntary movements

Sensory Neuron

Transmit sensory information from sensory receptors (skin, muscle, and organs) to CNS

Interneurons

Serve as connectors within the CNS, relaying signals between sensory neurons and motor neurons

Reflex Arc

Neural pathway that control reflex actions, allowing for rapid, automatic responses to sensory stimuli without conscious thought

Neural Transmission

Neurons communicate with each other through electrical and chemical signals

Threshold

Level of stimulation required to trigger an action potential in a neuron

Active Potential

Brief electrical impulse that travels along the axon of a neuron

All-or-nothing-Principle

Once a neuron reaches its threshold of excitation, it will fire an action potential at full strength

Depolarization

Phase of action potential where the inside of the neuron becomes less negative compared to the outside due to the influx of positively charged ions (sodium ions), through ion channels in the cell membrane

Refractory Period

Brief period following an action potential during which a neuron is unable to generate another action potential

Reuptake

Neurotransmitters that have been released into synapse are reabsorbed by the presynaptic neuron from which they were originally released

• Eg: recycling bins where they collect and reuse materials

Multiple Sclerosis (MS)

Chronic autoimmune disease that affects the CNS

• Occurs when the immune system mistakenly attacks the protective myelin sheath causing inflammation & damage

Myasthenia Gravis

Chronic autoimmune disorder that affects the neuromuscular junction

• Occurs when the immune system produces antibodies that block/destroy the receptors for acetylcholine

Excitatory Neurotransmitts

Excite connecting neurons and cause them to fire, more action potentials are triggered

Inhibitory Neurotransmitters

Prevent the next neurons from firing

Serotonin

• Regulated mood, sleep, appetite, and stress (contributes to well-being & happiness)

Noradrenaline

Concentration (affects anemia and responding actions in the brain)

Acetylcholine

• Plays fundamental role in both the central nervous system and the peripheral nervous system

• Learning (thought, learning, memory)

GABA

Calming (calms firing nerves in the CNS)

• High levels: improve focus

• Low levels: causes anxiety

• Contributes to motor control and vision

• Too much: overly relaxed and sedate can often cause normal reactions impaired (sleeping/eating disorders)

• Too little: anxiety, seizures, tremors, and insomnia

Glutamate

• Primary excitatory neurotransmitter in the CNS, playing a key role in synaptic transmission and neuronal communication.

• Memory (released during exercise, excitement, and sex)

• Produced wellbeing and euphoria, reducing pain

Dopamine

Pleasure (feeling of pleasure, also addiction, movement and motivation)

• People repeat behaviors that lead to dopamine release)

• Too much: associated with schizophrenia

• Too little: depression as well as muscular rigidity and tremors found in Parkinson’s disease

  • ADHD, memory problems, anxiety

Substance P(ain)

Neurotransmitter involved in transmitting pain signals in the nervous system

Norepinephrine “Fight/Flight”

Associated with response to danger, helps you stay awake, pay attention, and think clearly

• BOTH A HORMONE AND NEUROTRANSMITTER

Endorphins

• natural pain relievers and mood enhancers

• Released in response to stress, pain, or intense physical activity (exercise/excitement)

• Too much: not giving adequate warning about pain

• Too little: leads to body experiencing pain

Endocrine System

A slower communication system that uses hormones instead of neurotransmitters

Hormones

Chemical messenger that travel through the bloodstream and affect behavior and mood

Gherlin

Stimulates hunger

• Primarily by the stomach and small intestine

  • Increases before meal, decreases after

Leptin

Regulates hunger and fat storage

• Primarily by fat cells that regular energy balance. it acts on the hypothalamus in the brain to suppress appetitive and increase energy expenditure

Melatonin

Regulates sleep-wake cycles

Adrenaline

Increases heart rate and energy (fight/flight)

• Epinephrine - key role in body’s stress response

• Surges during times of stress, fear, or excitement

Oxytocin

Influenced bonding and social behaviors

• Hormone and neurotransmitter (social bonding)

• Referred to as the “love hormone” due to its involvement in forming emotional connections, trust, and intimacy.