Biopsychology I

BIOPSYCHOLOGY I COURSE STRUCTURE
There are seven lessons in this module as follows:

1. Introduction   Types of external and internal stimuli, mind-body debate, introduction to the nervous system.
2. The senses  Sensory input, sensory perception, description of the major senses.
3. The Nervous System   Description of the neurons, the central nervous system, peripheral nervous system, including the autonomic nervous system.
4. The Endocrine System    Effect of hormones on behaviour and physiology, association of endocrine system and nervous system, connection between external and internal stimuli.
5. Stress  Types of stressors, physical affects of stress, personality & stress.
6. Emotions  Homeostasis, eating disorders, physiological responses to emotions, theories of emotion.
7. Consciousness   Degrees of consciousness, awareness & attention, altered states of consciousness.

AIMS

• Explain what is meant by the mind-body debate and consider various theories.
• Explain how different people can perceive the same stimulus in different ways, due to biological differences between them.
• Explain how the condition and functioning of the nervous system can affect the psychology of an individual.
• Explain the function of sensory and motor neurons.
• Explain the functioning of the cerebellum, the hypothalamus and the thalamus.
• Identify which brain structures are present in the limbic system, and their main functions.
• Explain how dopamine, norepinephrine and epinephrine act as neurotransmitters.
• Explain how the condition and functioning of the endocrine system can affect the psychology of an individual.
• Describe the relationship between psychological stress and the physical response of the body.
• Discuss the relationship between emotions and the physical nature of the body.
• Discuss the relationship between consciousness and the physical nature of the body.
• Describe the effect of three psychoactive drugs on the Central Nervous System.
• Explain how the autonomic nervous system works in terms of its sympathetic and parasympathetic divisions.

Extract from Course:
RESEARCH METHODS OF BIOPSYCHOLOGY

Neuroanatomical Techniques

There are many different techniques used in research in biopsychology. These are only a few of them. Many of these techniques make use of studies on animals. The ethics of animal research is discussed further in the ethics section of this lesson.
*Histological Procedures - Tissue preparing techniques. We cannot see the cellular detail of the brain by just looking at it, and even with a microscope we need fixation and staining of the neural tissue.
*Fixation - To study an organism as it was at the time of death, we must destroy the autolytic enzymes (self-dissolving enzymes), which cause tissue to decompose. The tissue is preserved by use of a fixative, such as formalin (the aqueous version of formaldehyde - a gas)
*Staining - Without staining, no details of the brain are revealed. The study of neuroanatomy requires special histological stains. The basic types used are - cell-body stains, myelin stains, membrane stains and degenerating-axon stains.
*Tracing Neural Pathways - Staining does not help to show the detail of neurons, as a tangle of neurons is shown. Special techniques are required to make the connections being studied stand out from all others.
*Degenerative Studies - When a cell body is destroyed, the distal portion of the axon quickly dies and disintegrates - this is called anterograde degeneration. A degenerating-axon stain will identify the dying axons as trails of black droplets.
*Amino acid autoradiography - Amino acids are transported via special means cause axoplasmic flow. This technique uses the axoplasmic flow. A researcher will inject radioactive amino acids into the brain of an animal and allows the animal to live for a couple of days. The cell bodies will take up the radioactive amino acids and incorporate them into proteins. The animal is then killed and the brain studied. The radioactive proteins show up as black spots.
*Horseradish Peroxidase (HRP) is an enzyme - a protein capable of splitting certain peroxide molecules and turning them into insoluble salts. HRP is injected into the brain. It eventually reaches the cell bodies of neurons that send axons into the region of the brain that received the injection. After a day or so, the animal is killed and the brain studied. The HRP technique permits identification of neurons that project axons to a particular area.
These techniques can show us the source of inputs to particular parts of the brain and the location to which axons are sent. So the interconnectedness of some parts of the brain can be studied with great accuracy.
*Studies with Living Brains

BRAIN SCANS can study cortical functioning. They include -

CAT scans (computerised axial tomography) - An x-ray beam goes through an individual's head and a level of radioactivity is detected. The level is lower when the X-ray passes through dense material. CAT scans are useful for detecting tumours, brain abnormalities and clots. They do not show precise locations of brain damage or show the actual functioning of the brain. They are also very expensive.
CAT scans (below) provide 3D images for easy observation of brain abnormalities.
PET scans (positron emission tomography) Shows the brain in action and also what part of the brain is active in certain tasks. It only shows activity over a 60 second period. PET scans display differences in brain regions through blood flow and fuel metabolism. Differences can be observed between different individuals and within an individual both in terms of time and brain region. A radioactive tracing substance is administered either into the blood stream via injections or inhalation, or by administering an artificial substance similar to glucose (a brain fuel), then the activity in different brain regions is observed. Areas involved in motor control and sensory stimulation can be observed.
MRI scans (magnetic resonance imaging) - Produce clearer and more detailed pictures than CAT scans. MRI is used to detect structural details of the brain. Some substances contained in water molecules in the brain, such as hydrogen atoms, respond to magnetic fields. When a magnetic field is applied, the interaction between molecules and this field are monitored, allowing different tissues to be distinguished, based on their constituent molecules. These changes are interpreted by a computer. They can be used to detect very small tumours. They can still only tell us about the structure of the brain rather than its functioning.
Functional MRI This produces images of the brain with areas of high activity indicated, so we can get a picture of the brain whilst functioning. This provides more spatial information than PET scans and shows changes over shorter periods of time.
Squid magnetometry (superconducting quantum interference devices) - This measure the magnetic field produced by neuron activity in the brain. Irrelevant magnetism may interfere with results and the machine has to be kept at extremely low temperatures. This course is available as a written correspondence course, as downloadable modules and on CD.