0-1.4c Biology of Behavior: Genetics, Brain Structures, and Nervous System

nature

the belief that heredity is an influential factor in traits and behaviours of a person

nurture

the belief that the environment is an influential factor in the traits and behaviours of a person

genetic predisposition

we are genetically predisposed to think and act in ways that promoted survival for our biological ancestors

evolutionary perspective

the study of evolution of behaviour and the mind, using principles of natural selection. Studies how behaviour and mind are alike

natural selection

the principle that the inherited traits that cause an organism to survive and reproduce in an environment with competition will be passed onto future generations

eugenics

the study of how to rearrange genes in a population to increase the occurrence of a heritable characteristic regarded as desirable

twin studies

control heredity and change, vary the environment; in explaining individual differences, identical genes matter more than parental treatment

family studies (genetic)

examines how conditions or behaviours are transmitted through family to understand the roles of both genetics and environmental factors

adoption studies

control home environment, vary heredity; personality is more similar to biological parents and siblings

CNS (central nervous system)

brain and spinal cord; decision maker

PNS (peripheral nervous system)

transmits CNS decisions to other parts of the body and includes everything except the brain and spinal cord

SNS (somatic nervous system)

Branch of PNS; voluntary control of muscles

ANS (autonomic nervous system)

Branch of PNS; involuntary (controls glands and muscles of the internal organs)

Parasympathetic

Branch of ANS; responsible for body's 'rest and digest' functions

Sympathetic

Branch of ANS; responsible for body's 'flight or fight' response

neurons

a nerve cell, the basic building block of the nervous system

glial cells

cells in the nervous system that protect, support and nourish neurons, they may also play a role in learning, thinking and memory

reflex arc

the neural pathway controlling an involuntary, rapid response to stimulus, like the knee-jerk reflex, without direct brain involvement

neural transmission

the way neurons communicate by passing a signal across a synapse; small gap between cells

resting potential

the steady, negatively charged state of a cell's membrane when it is not actively transmitting a signal

threshold

the minimum level of a stimulation or change needed for a stimulus to be detected or to trigger a response

action potential

rapid, all or nothing electrical impulse that neurons generate to communicate information throughout the nervous system, enabling feeling, thought and action

depolarization

the step in an action potential where a neuron's membrane potential becomes less negative and even positive due to an influx of proton ions

all-or-nothing principle

a neuron or muscle fiber will either fire or contract completely at full strength or not at all

refractory period

the temporary state following a neurons firing during which it is unresponsive to further stimulation

neurotransmitter

endogenous chemicals that allow neurons to communicate with each other throughout the body; chemical messengers that cross the synaptic cleft between neurons

reuptake

the absorption by a presynaptic nerve ending of a neurotransmitter that it was secreted

multiple sclerosis

a disease wherein the immune system eats away at protective covering of neurons

myasthenia gravis

a chronic autoimmune disorder that affects the neuromuscular junction, where nerves communicate with muscle

excitatory

increased likelihood of a neuron firing an action potential

inhibitory

decreased likelihood of a neuron firing an action potential

hormones

chemical messengers produced by the endocrine glands in the body that regulate various physiological processes

adrenaline

helps prepare for stressful situations

leptin

tells you when you are full

ghrelin

tells you when you are hungry

melatonin

plays a role in sleep

oxytocin

plays a role in aspects of behaviour and reproduction = love hormone

psychoactive drugs

a chemical substance that alters the brain, causing changes in perceptions and moods

agonist

a molecule that increases a neurotransmitter's actions

antagonist

a molecule that inhibits or blocks a neurotransmitter's actions

reuptake inhibitor

a class of drugs that work by blocking the brains reabsorption of neurotransmitters like serotonin and norepinephrine increasing availability in synaptic cleft to improve mood

brainstem (including medulla)

central core of the brain, beginning where the spinal cord swells as it enters the skill; the brainstem is responsible for autonomic survival functions

RAS (reticular activating system)

network of neurons in the brainstem that act as a filter for sensory information, controlling consciousness, and regulating wakefulness and attention (brain's reward center)

cerebellum

the hindbrain's 'little brain' at the rear of the brainstem; its functions include processing sensory input, co-ordinating movement output and balance and enabling non-verbal learning and memory.

thalamus

the forebrain's sensory control center, located on top of the brainstem. It directs messages to sensory receiving areas in the cortex and transmits replies to the cerebellum and medulla.

hypothalamus

a limbic system neural structure lying below the thalamus, it directs several maintenance activities, helps govern endocrine system and is linked to emotion and reward.

pituitary gland

produces and releases hormones that control growth, metabolism, reproduction and the activity of other endocrine glands.

hippocampus

a neural center in the limbic system that helps process explicit or conscious memories for storage.

amygdala

two lima-bean sized neural clusters in the limbic system that are linked to emotion.

corpus callosum

plays a crucial role in the communication between the hemispheres, allowing the two sides of the brain to share information and co-ordinate their actions.

occipital lobe

the portion of the cerebral cortex lying at the back of the head, receives information from visual fields.

temporal lobe

the portion of the cerebral cortex that's roughly above the ears, includes auditory areas, each receiving information primarily from the opposite ear. also enabled language processing.

parietal lobe

the portion of the cerebral cortex lying at the top of the head and toward the rear, it receives sensory input for touch and body position

somatosensory cortex

a cerebral cortex area of the front of the parietal lobe that registers and processes body touch and movement sensations

wernicke's area

located in the posterior portion of the left temporal lobe. Plays a crucial role in language comprehension and speech production

frontal lobe

the portion of the cerebral cortex lying just behind the forehead, enables linguistic processing, muscle movements, higher-order of thinking and executive functioning.

motor cortex

cerebral cortex area at the rear of the frontal lobes that controls voluntary movement

broca's area

region in the left frontal lobe that plays a crucial role in language production and comprehension.

cerebral cortex

brain's outermost layer, responsible for higher-level functions like thought, memory, emotion, and language, and it's divided into four major lobes: frontal, parietal, temporal, and occipital.

limbic system

complex set of interconnected brain structures located deep within the cerebrum that are primarily responsible for emotions, memory, motivation, and learning

Biopsychology

The branch of biology concerned with its biological and physiological aspects.

Plasticity

Refers to the brain's ability to change and adapt throughout life.

Phineas Gage Case Study

Describes how railroad foreman survived a severe accident when a tamping iron pierced his skull and brain. After, he underwent a dramatic personality change.

H.M. case study

His severe memory impairment was due to experimental neurosurgery to control seizures.

EEG

Medical test that measures electrical activity of the brain. Electroencephalography

fMRI

Neuroimaging technique that measures brain activity by detecting changes in blood oxygenation levels. Functional Magnetic Resonance Imaging

Lesioning

The deliberate destruction or damage of specific brain tissue to study the resulting changes in behaviour or cognition or to treat certain neurological or psychiatric disorders.

Split-Brain Research

Studies patients who have had their corpus callosum severed to treat epilepsy

Cortex Specialization: Left Hemisphere

Specialized for language function including speech, reading, writing, and memory retrieval for verbal information.

Cortex Specialization: Right Hemisphere

Specialized for spatial reasoning, face and emotion recognition, and processing nonverbal aspects of communication such as tone of voice and music.

What two association areas do we learn about in this course?

Broco's area is responsible for speech production and Wernicke's area is responsible for understanding language.

What is the term for damage to an association area?

Agnosia

Contralateral Hemispheric Organization

The principle that the brain's left hemisphere controls the right side of the body and the right hemisphere controls the left.