Chap 3: Biological Bases of Behaviour

The study of the parts and functions of neurons

Individual nerve cells

• Root-like parts of the cell that stretch out from the cell body.

• Grow to make synaptic connections with other neurons

Contains the nucleus and other parts of the cell needed to sustain its life

Wire-like structure ending in the terminal buttons that extends from the cell body

A fatty covering around the axon of some neurons that speeds neural impulses

The branched end of the axon that also contains neurotransmitters

• Chemicals contained in terminal buttons that enable neurons to communicate

• Fit into receptor sites on the dendrites of neurons like a key into a lock

Space between the terminal buttons of one neuron and the dendrites of the next neuron

A place on the dendrites where neurotransmitters fit into

The amount of neurotransmitters needed for firing

When a neuron sends information down an axon, away from the cell body

A neuron either fires completely or it does not fire at all

Excite the next cell into firing

Inhibit the next cell from firing

• A neurotransmitter involved in motor movement

• Lack of acetylcholine is associated with Alzheimer’s disease

• A neurotransmitter involved in motor movement and alertness

• Lack of dopamine is associated with Parkinson’s disease

• An overabundance of dopamine is associated with schizophrenia

A neurotransmitter involved in pain control and addictions

• A neurotransmitter involved in mood control

• Lack of serotonin is associated with clinical depression

• An important inhibitory neurotransmitter

• Involved in seizures and sleep problems

• Excitatory neurotransmitter

• Involved in memory, migraines, and seizures

A neurotransmitter involved in alertness/arousal, can cause depression

Take information from senses to brain

Once info reaches the brain or spinal cord, interneurons take the messages and send them elsewhere in the brain or onto efferent neurons

Take information from the brain to the rest of the body

Consists of brain + spinal cord (all nerves encased in bones)

• All nerves not encased in bone

• Somatic and autonomic nervous systems

Controls voluntary muscle movements

• Controls automatic functions of our body

• Controls response to stress

• Contains parasympathetic and sympathetic nervous systems

• Mobilizes body to respond to stress

• Alert system - accelerates some functions (e.g. heartbeat) but conserves resources needed for a quick response by slowing down other functions (e.g. digestion)

Causes body to slow down AFTER a stress response (break pedal)

Reactions that occur the moment sensory impulses reach the spinal cord

By observing the brain damage and behaviour after an accident, researchers can determine the functions the damaged part played in behaviour.

• The removal or destruction of part of the brain

• Observe behaviour afterwards to determine function of that part of the brain

• Frontal Lobotomy (In the past, lesioning of frontal lobe was used to make the patients calm and relieve symptoms)

• Detects brain waves

• Examine what type of waves the brain produces during different stages of consciousness and use this information to generalize about brain function.

• Several X-ray cameras that rotate around the brain and combine all the pictures into a detailed 3D picture

• Only show structure, not the functions or activity

• Uses magnetic fields to measure the density and location of brain material.

• Only show structure, not functions or activity

• Shows what areas of the brain are most active during certain tasks

• Measures how much of a certain chemical parts of the brain are using

• Combines elements of MRI and PET scans

• Show details of brain structures with information about blood flow in the brain

• Controls basic biological functions that keep us alive

• Contains medulla, pons, and cerebellum

Part of hindbrain that controls blood pressure, heart rate, and breathing

Part of hindbrain that controls facial expressions

Part of hindbrain that coordinates habitual muscle movements

Coordinates simple movements with sensory information

A netlike connection of cells throughout the midbrain that controls general body arousal and the ability to focus our attention

• Controls thought and reason (what makes us human)

• Contains thalamus, hypothalamus, amygdala, and hippocampus

Receives the sensory signals coming up the spinal cord and sends them to the appropriate areas in the rest of the forebrain

• Metabolic functions

• e.g. body temperature, sexual arousal (libido), hunger, thirst, and the endocrine system

Vital to experiences of emotion

Processes memory to be permanently stored in other areas of the cerebral cortex

• Grey wrinkled surface of the brain (layer of densely packed neurons)

• Contains 8 lobes, 4 in each hemisphere (frontal, parietal, occipital, temporal)

• Overtime, the dendrites of the neurons grow and connect with other neurons to form the complex neural web

Wrinkled surface of the cerebral cortex to increase surface area

• The two halves of the brain (right and left)

• Theories: Left = logic and sequential tasks, Right = spatial and creative tasks

• LEFT hemisphere: sensory and motor functions of RIGHT half of body

• RIGHT hemisphere: sensory and motor functions of LEFT half of body

• Specialization of function in each hemisphere

• Research is done by examining split-brain patients

• Corpus callosum is cut to treat severe epilepsy

• Operation pioneered by Roger Sperry and Michael Gazzaniga

• Cannot orally report info only in the right hemisphere since spoken language is in the left hemisphere

Any area of the cerebral cortex that is not associated with receiving sensory information or controlling muscle movements

Large areas of the cerebral cortex located at the top front part of the brain behind the eyes

• Anterior / front of frontal lobe

• Critical role in thought directing process

• Frontal lobe

• Responsible for controlling muscles involved in producing speech

• Temporal lobe

• Responsible for understanding of spoken and written language

• Thin, vertical strip at the back of the frontal lobe

• Sends signals to our muscles, controlling our voluntary movements

• Top of the body is controlled by neurons at the bottom of this cortex, progressing down the body as you go up the cortex

• Located behind the frontal lobe but still on the top of the brain

• Contains the sensory cortex

• A thin, vertical strip that receives incoming touch sensations from the rest of our body

• Top of sensory cortex receives sensations from the body of the body and vice versa

• At the very back of our brain, farthest from our eyes

• Interpret messages from our eyes in our visual cortex

  • Impulses from right half of each retina are processed in the visual cortex in the right occipital lobe

  • Impulses from left half of each retina are processed in the visual cortex in the left occipital lobe

• Process sound sensed by our ears (auditory cortex)

• Sound received by either ear is processed in both auditory cortices

• Damage to this area affects ability to interpret spoken language (Wernicke’s area)

The ability of the nervous system to change its activity in response to intrinsic or extrinsic stimuli by reorganizing its structure, functions, or connections.

• A system of glands that secrete hormones that affect many different biological processes in our bodies

• Controlled by hypothalamus

• Produce adrenaline

• Signals body to prepare for fight or flight (autonomic nervous system - involuntary responses)

• Produce sex hormones

• Levels of estrogen and testosterone may explain gender differences (Developmental Psychology)

Identical twins (same genetic material)

• Studied monozygotic twins raised in different families to see if traits were nature or nurture

• Criticized because twins share the same physical characteristics, thus causing others to treat them in similar ways (effective psychological environment).

Single X chromosome instead of a 23rd pair

Extra X chromosome, thus XXY pattern

Extra chromosome on 21st pair