Biological Psychology and Research Methods

Biological Psychology

• Biological Psychologists/Neuroscientists study the science of the brain and behaviours.
• The brain consists of ~1.4 kg of protein, fat, and fluid.
• There are about 100 billion neurons or nerve cells within the brain.
• Within neurons, a complex system of communication takes place.

Old and New Brain Research Methods

• Phrenology is the exploration of the cranium size, shape, and protrusions.
• Franz Gall (1758-1828) is known as the "father" of phrenology.
• Gall thought that the brain was the sole organ of the mind, and that traits were inherited.
• Gall also believed that differences between people meant structural brain differences.
• Electrical stimulation studies investigate brain function by stimulating it during neurosurgery.
• Neural communication are electrical
• Wilder Penfield was an American-Canadian neurosurgeon integral to the development of these techniques.
• Penfield developed the "Penfield map" of motor and sensory cortex.
• Deep Brain Stimulation (DBS) uses battery-powered electrodes implanted in the brain.
• Used to treat neuropsychological conditions and give direction to certain brain areas.
• DBS is very invasive; risk of infection, hemorrhage, and more surgery.
• EEG or, Electroencephalography records the brain's electrical activity at the skull's surface.
• EEG advantages are non-invasive, inexpensive, and very high temporal resolution
• EEG disadvantages are that it cannot display individual cell activity or brain region activation.
• Lesion studies assess psychological functioning through lesions to specific brain areas.
• CT or, Computed tomography uses multiple x-rays to build a 3D reconstitution of the brain.
• A CT scan is advantageous because it is good for detecting lesions and skull fractures, also relatively Inexpensive.
• CT scan disadvantages are images are usually in one orientation, exposing the patient to radiation.
• MRI or, Structural MRI creates high-resolution images of the brain using magnetic fields.
• MRIs are better than CT scans at detecting soft tissue with a higher spatial resolution.
• MRI scan disadvantages are more expensive, can't have any metal on you, and causes motion artefacts and claustrophobia.
• PET or, Positron Emission Tomography uses trace amounts of short-lived, radioactively labelled oxygen or glucose to map functional processes.
• PET scan advantage is that they can attach radioactive isotopes to drugs to see where they are used.
• PET scan disdvantages are that are invasive and have poor temporal resolution (30-60 seconds.)
• fMRI or, Functional Magnetic Resonance Imaging detects changes in blood oxygenation in response to activity.
• This is a common technique used in brain-imaging research.
• A fMRI advantage is the excellent spatial resolution.
• fMRI disadvantages are poor temporal resolution (better than PET) and same restrictions as structural MRI.
• MEG or, Magnetoencephalography measures brain activity by detecting tiny magnetic fields generated by electrical signals.
• MEG advantages are excellent temporal resolution and reasonable spatial resolution.
• MEG disadvantages are not great at detecting activity deeper in the brain and they are expensive.
• TMS or, Transcranial Magnetic Stimulation is a strong & quick changing magnetic field to the skull that can enhance or interrupt brain function.
• TMS actively influences functions and gives good temporal resolution
• TMS can only operate on outer layers(cortex) and can cause seizures if used improperly.

Localization of Function

• Localization of function refers to when certain brain areas are greatly active during psychological tasks.
• It is important to be cautious in making such claims
• The areas work together and differ on aspects the task
• An example includes Broca's area

Neural Communication

• A neuron consists of a cell body (soma), dendrites, axon, axon terminals (or buttons), synapse, and action potential
• Information within a cell is communicated electrically
• Information between cells is communicated chemically.
• Glial Cells are important in the nervous system, offering support to Neurons.
• Astrocytes regulate extracellular fluid, forming the blood-brain barrier and synapses.
• Oligodendroglial cells form insulating myelin around axons.
• Multiple sclerosis (MS) is an associated disease.
• Action Potential is within a neuron and is an electrical process.
• Terms that relate are: resting potential, action potential (AP), threshold, refractory Periods.
• Absolute refractory is after 1-2ms and is impossible for another AP after, relative is more stimulation 2-4ms.
• All or None Law is present, stronger signals DO NOT cause action potentials to be stronger, the rate signal is.
• A stronger signal creates MORE action potentials compared to a weaker signal.
• The rate of cell firing is increased.

Chemical Communication

• Communication between neurons is chemical, where neurotransmitters are released from the presynaptic neuron.
• They can be excitatory or inhibitory.
• These bind to receptors on the dendrites of the postsynaptic and are deactivated through reuptake
• When an action potential arrives at the terminal button of the presynaptic neuron, it causes the release of neurotransmitters into the synapse.
• Neurotransmitters move across the synapse and bind to receptors located on the post-synaptic neuron.
• The binding of neurotransmitters to postsynaptic receptors results in a voltage change in the postsynaptic neuron.
• Neurotransmitters deactivate through reuptake

Specific Neurotransmitters

• Main excitatory NT that enables sensory and learning is Gutamate, enhanced in alcohol.
• Main inhibitory NT, GABA is prevalent in alcohol, useful for anti-anxiety.
• Cortical arousal relies on Norepinephrine, enhanced in amphetamines.
• Acetylcholine controls functions like cortical arousal and muscle contraction, and some enhancers are nicotine and Botox.
• Motor function and reward,pleasure with dopamine may need L-dopa with Parkinson, antipsychotics, amphetamines.
• Mood regulation, aggression, sleep-wake cycles, and temperature with Serotonin, need SSRI anti-depressants.
• Endorphins help as Pain killers, needing Codeine, morphine, heroin can help.
• Pain killers with Anandamide as well, with Tetrahydrocannabinol (THC) in marijuana..
• Agonists and Antagonists are types of psychoactive drugs that impact the nervous system.
• An Agonist drug enhances activity and binds receptors, while antagonists block the receptors.

Neural Plasticity

• Neural plasticity means neurons can change over time.
• Plasticity in over development, during learning, or following injury/degeneration
• Growth, Synaptogenesis, Pruning and Myelination.
• Potential creates creation of synapes from new neuron growth and strenght of connection with existing ones.
• During learning, brains change due to the creation of new synapses (synaptogenesis) or Potentiation.
• Potentiation is the changes in the strength of existing connections.
• Hebb's rule dictates that neurons that fire together, wire together.
• Structural plasticity reflects changes in the structure of the neuron.
• A limited ability to regenerate after damage, regions can be repaired by neurogenesis.
• Stem cells are cells are have not yet differentiated, but can become cell types, to repair a place damage.

The Brain

• The nervous system has contralateral organization to the body.
• Left brain hemisphere controls the right side of the body, and vice-versa.
• CNS or, the Central Nervous System contains 8 major areas: cerebral cortex, basal ganglia, limbic system, midbrain(not shown), cerebellum, pons, medulla,spinal cord
• Ventricles are cavities deep inside the brain filled with cerebral spinal fluid (CSF) allowing the brain to float and protect
• Functions are Strategic thinking, Social cognition, language skills, short term memory, motor cortex, visual spatial intelligence
• Damage to primary visual cortex (V1) can lead to blindness.
• It has contralateral organization and blindsight as primary functions.
• The primary cortex controls signals received from receptors in Skin, muscles, joint.
• Damage can also cause problems with processing sensory and spatial negligance issues.
• Auditory function and complex sounds, hearing
• Loss of memory, and anterograde amnesia
• Input from brain regions, can carry our complex Behaviours
• Motor control, primary function, Language and communication.
• Visuospatial intelligene, speech and communication.
• Damage to the ganglia can cause tremors or involuntary movements (Parkinson's or Huntington problems)
• Important for emotion,memory, and learning, and hormone control

The Brain Stem

• Motor responses and eye movement and controls the midbrain
• Essential to awarness and consciousness, along with regulation of sleep functions
• Damage to either can cause death or comma related symptoms
• Controls critical things in system, heart rate and brething, the Hindbrain controls, and link spinal card to the cerebel

The Spinal Cord

• Connected to nervous system, perhipiral system
• protected and supported by vertebrea

The Nervous System

• The Peripheral System as major division. Automatic fuctions
• Two major division include Automatic and Sympathetic response
• Volentary snesorty and movment based repsonse

Automatic System response

Activation ,fight or fly, sleep or rem, digestion.

• Spinal reponse is trigger resposne to brain, with drawl flex exmaple

The Endocrine System

• The endocrine system is a network of glands that release hormones into the bloodstream
• Different from neurotransmitters in that they are carried by blood vessels rather than nerves
• Much slower in their action on the body than neurotransmitters
• Pituitary, is controlled gland to control body fuctions, with hromone oxytocin for trust building.
• The Adrena helps the kidneys perform functions, dealing with stress and corstol control

Heridity and Genes

• Humans contai 46 chomsesomes and DNA They work together to replicate

Genetic research Design

• Study the presence among reletaves. and also look at how those geens are expressed
• Family Studies
• Twin Studies Adoption Studies