Intro to Psychology basic processes - Chapter 3: Biological bases of behaviour (con't)

Myelination

This process produces the myelin sheath

Myelination (con’t)

Has small gaps that save lots of energy during the resting potential process

Synthesis

Neurotransmitters, or at least parts of them, are made in the cell body of each neuron

Transportation and storage

When neurotransmitter molecules are transported from the cell body to the axon terminal for storage

Release

When the synaptic vesicles fuse with the cell membrane, causing the release of the neurotransmitter into the synapse after an action potential reaches the axon terminal

Binding

When neurotransmitter molecules bind to specialized proteins called receptors

Receptors

Allow neurotransmitter molecules to influence whether the next cell, the postsynaptic cell, will have its own action potential.

Deactivation

One type of neurotransmitter that an enzyme can destroy in the synapse

Autoreceptor activation

Some neurotransmitters bind to receptors on the same neuron that released it (autoreceptor)

Autoreceptor

Only respond to neurotransmitters that have been released by the same neuron on which it is situated.

e.g. This binding can decrease the synthesis and release of the neurotransmitter

Reuptake

When leftover and excess neurotransmitter molecules can be brought back into the presynaptic region of the cell.

Degradation

When enzymes in the presynaptic region break down excess neurotransmitter molecules, which are then eliminated

Graded potential (con’t)

A neuron must integrate signals arriving at many synapses before it “decides” whether to fire an action potential

Normal development

Is characterized more by the elimination of old synapses than the creation of new synapses

Long-term potentiation

Refers to a long-lasting increase in neural excitability in synapses along a specific neural pathway

Transcranial magnetic stimulation (TMS)

A technique that permits scientists to temporarily enhance or depress activity in a specific area of the brain

Transcranial magnetic stimulation (TMS) [con’t]

It’s been used to explore whether specific areas of the brain are involved in visual–spatial and sensorimotor processing short-term memory, and language

Transcranial magnetic stimulation (TMS) process

A magnetic coil that creates a magnetic field that penetrates to a depth of 2 centimetres gets mounted on a small paddle is held over a specific area of a person’s head

Transcranial magnetic stimulation (TMS) process (con’t)

A researcher can either increase or decrease the excitability of neurons in the local tissue through varying the timing and duration of the magnetic pulses

Transcranial magnetic stimulation (TMS) limitations

It can’t be used to study areas deep within the brain. Still, its potential as a research tool is enormous

Neuroscientists

Investigators who conduct research on the brain or other parts of the nervous system

Neuroscientists (con’t)

Involves collaboration by neuroscientists from several disciplines,

e.g. Anatomy, physiology, biology, pharmacology, neurology, neurosurgery, psychiatry, and psychology.

Lesioning

Destroying a piece of the brain by inserting an electrode into a brain structure and passing a high frequency electric current through it to burn the tissue and disable the structur

Electrical stimulation of the brain (ESB)

When a weak electric current is sent into a brain structure through an implanted electrode to stimulate (activate) it

CT (computerized tomography) scan

A computer-enhanced X-ray of brain structure. X-rays are taken from many angles, and the computer combines these images to create vivid, albeit two dimensional pictures of cross sections of the brain

MRI (magnetic resonance imaging) scan

Uses magnetic fields, radio waves, and computerized enhancement to map out brain structures in three dimensional pictures with more detail than a CT scan

Electroencephalograph (EEG)

A device that monitors the electrical activity of the brain over time to show the functioning of the brain

Electroencephalograph (EEG) [con’t]

Uses small electrodes attached to the scalp to measure electric potentials (primarily graded potentials) occurring in thousands of brain cells

PET (positron emission tomography)

Uses radioactive markers to map chemical activity in the brain over time.

PET (positron emission tomography) [con’t]

Can provide colour-coded maps indicating which areas of the brain are active when people clench their fist, sing, or contemplate the mysteries of the universe

Functional magnetic resonance imaging (fMRI)

Consists of new variations of MRI technology that monitor blood flow and oxygen consumption in the brain to identify areas of high activity

e.g. Researchers have identified patterns of brain activity associated with specific creative-thinking tasks, the contemplation of complex decisions related to gambling, reactions to pictures of alcoholic beverages

Hormones

The chemicals released by the endocrine glands

Hormones (con’t)

Have a similar job as neurotransmitters, but are much slower

Oxytocin

A hormone released by the pituitary gland, which regulates reproductive behaviours

Oxytocin (con’t)

Triggers contractions when a woman gives birth and stimulates the mammary glands to release milk for breastfeeding

Oxytocin (III)

Fosters fidelity and loyalty to partners in men, as it may facilitate the development of a sense of security, feelings of safety, and a highly tuned sensitivity to and empathy for others

Spinal cord

Connects the brain to the rest of the body through the peripheral nervous system, and transmits signals from the brain to the neurons that allow our muscles to move

Behavioural genetics

An interdisciplinary field that studies the influence of genetic factors on behavioural traits.

Perceptual asymmetries

Left-right imbalances in visual or auditory processing

The left brain hemisphere

The left hemisphere is usually better at tasks involving verbal processing,

e.g language, speech, reading, and writing.

The left brain hemisphere (con’t)

Is connected to the right side of the body

The right brain hemisphere

The right hemisphere exhibits superiority on many tasks involving nonverbal processing

e.g. Spatial, musical, and visual recognition tasks and tasks involving the perception of emotions

The right brain hemisphere (con’t)

Is connected to the left side of the body

Split-brain surgery

When the bundle of fibres that connects the cerebral hemispheres (the corpus callosum) is cut to reduce the severity of epileptic seizures

Chromosomes

Threadlike strands of DNA (deoxyribonucleic acid) molecules that carry genetic information

Genes

DNA segments that serve as the key functional units in hereditary transmission

Polygenic traits

Characteristics that are influenced by more than one pair of gene

Phenotype

The ways in which a person’s genetic makeup is manifested in observable characteristics

Heredity and the environment

Heredity and experience jointly influence most aspects of behaviour

Epigenetics

The study of heritable changes in gene expression that do not involve modifications to the DNA sequence

e.g. Chemical events at the cellular level like stress exposure and poor nuturing, leading to alterations in traits, health, and behaviour

Epigenetics (con’t)

Epigenetic changes may contribute to many psychological disorders, including drug addiction, (intergenerational) trauma, schizophrenia, etc

Family studies

Researchers assess hereditary influence by examining blood relatives to assess how much they resemble one another on a specific trait

Family studies (con’t)

If heredity affects the trait under scrutiny, phenotypic similarity should be higher among relatives, and, there should be more similarity among relatives who share more genes

e.g. Siblings should exhibit more similarity than cousins

Family studies usages

They’re used to estimate the risk of a relative developing a mental health disorder based on whether other family members suffer with this disorder and see whether a trait runs in families

Twin studies

When researchers assess hereditary influence by comparing the resemblance of identical twins and fraternal twins with respect to a trait

Adoption studies

Assess hereditary influence by examining the resemblance between adopted children and both their biological and their adoptive parents

Adoption studies (con’t)

If adopted children resemble their biological parents in a trait, even though they were not raised by them, this suggests that genetic factors may influence that trait

Adoption studies (III)

If adopted children resemble their adoptive parents, even though they inherited no genes from them, environmental factors probably influence the trait

Genetic mapping

A tool to determine the location and chemical sequence of specific genes on specific chromosomes

CRISPRs (clustered regularly interspaced short palindromic repeats)

Store a small section of harmful viruses to recognize them next time you are attacked and precisely snip the DNA of an invading virus so that it can’t replicate