Lecture 4 - Biological Basis Of Behaviour by Matt Wilson

Psychology and Counselling: Neuropsychology

ÂŠ Matt Wilson 2010

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Psychology and Counselling: Neuropsychology

Aim: To develop students’ appreciation of the biological basis of various aspects of human behaviour. Objectives: (TSSBAT…) • Explain 3 common biological behaviours; piloerection, the body’s response to stress and jetlag. • Demonstrate an appreciation of the stress response as an adaptive mechanism with a neuropsychological basis • Identify and describe at least 3 effects of jetlag and stress on the human body. • Describe the jetlag phenomenon with reference to the neurology involved, including the suprachiasmatic nucleus. © Matt Wilson 2010 Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)

Psychology and Counselling: Neuropsychology

As living things we are all a direct result of our biology. This determines the countless individual differences between us, even though we belong to the same species (such as eye colour, body shape and size, the tone of our voice etc). This is the same for all living things, although as humans we interact with the environment in far more sophisticated ways, such as written and spoken language.

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Psychology and Counselling: Neuropsychology

Our physical biology plays a crucial role in our behaviour (for example, a small thin person is unlikely to become a weightlifter). The nervous system is crucial to our biology and behaviour, and carries instructions from our brain and spinal cord throughout our whole body. The nervous system also allows us to be fully aware of our surrounding environment (such as heat, smell and touch) through the use of stimuli receptors. ÂŠ Matt Wilson 2010 Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)

Psychology and Counselling: Neuropsychology

Why do we get “goose bumps”? The scientific term for “goose bumps" is PILOERECTION (pil is from the Latin word for hair). We usually get goose bumps when we are either cold or frightened. When this happens the pili muscles at the base of the hairs contract, which causes the hairs to stand up. As we have very short hairs we can see the contracted muscles underneath the hairs, which gives us the “goose bump” look. © Matt Wilson and Holly Donohoe 2010 Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)

Psychology and Counselling: Neuropsychology

All mammals are capable of PILOERECTION, and in hairier mammals such as dogs, cats, and apes piloerection is used as a way of keeping warm. When it is cold piloerection makes the mammals hair stand on end and fluff out, and in mammals with lots of hair or fur this helps to create a protective barrier between the cold environment and the mammalsâ&#x20AC;&#x2122; skin. When mammals (including humans) are frightened piloerection happens as a defense mechanism as when our hair is standing on end we actually look larger, which evolved as a way to try and scare off predators, and was conducive to survival. As humans have evolved we no longer need this function but it has stayed within our genes from millions of years ago. ÂŠ Matt Wilson 2010 Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)

Psychology and Counselling: Neuropsychology

ÂŠ Matt Wilson 2010 Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)

Psychology and Counselling: Neuropsychology

“Stress occurs when pressure exceeds your perceived ability to cope” Palmer (1999) Stress can be defined as any type of change that causes physical, emotional or psychological strain. However, not all types of stress are harmful or even negative. Source: http://stress.about.com/od/stresshealth/a/stresshealth.htm

Psychology and Counselling: Neuropsychology

Eustress: a type of stress that is fun and exciting, and keeps us moving (e.g. skiing down a slope or racing to meet a deadline) Acute Stress: very short-term stress that can either be positive (eustress) or more distressing (“normal stress”). This is the type of stress we most often encounter in day-to-day life. Episodic Acute Stress: where acute stress seems to run rampant and be a way of life, creating a life of relative chaos (e.g. the type of stress that coined the terms ‘drama queen’ and ‘absent-minded professor’) Chronic Stress: seems never-ending and inescapable, like the stress of a bad marriage or an extremely taxing job (this type of stress can lead to burnout) Source: http://stress.about.com/od/stresshealth/a/stresshealth.htm

Psychology and Counselling: Neuropsychology

Sudden and severe stress generally produces: • An increase in heart rate • Changes in digestive activity • Whitening or severe reddening of the skin • Increased sweating • Muscular tension

Psychology and Counselling: Neuropsychology

The FIGHT OR FLIGHT RESPONSE is the body’s response to a perceived threat or danger. During this reaction, certain hormones like adrenalin and cortisol, and sugars such as glucose are released, which vastly speed up our heart rate, slow digestion, divert blood flow to major muscle groups, and change various other autonomic nervous functions, giving the body a burst of energy and strength. Originally named for its ability to enable us to physically fight or run away when faced with danger, it’s now activated in situations where neither response is appropriate, like in traffic or during a stressful day at work. When the perceived threat is gone our bodies are designed to return to normal but in our times of chronic stress, this often doesn’t happen enough, causing damage to the body. Source: http://stress.about.com/od/stressmanagementglossary/g/FightorFlight.htm

Psychology and Counselling: Neuropsychology Nervous System

Peripheral Nervous System

AUTONOMIC NERVOUS SYSTEM

Somatic Nervous System Operates nerves attached to bone

Central Nervous System Brain & Spinal Cord

Muscles not attached to bone (heart, stomach, Diaphragm) Involuntary – happens without thinking

These are 2 key sections in understanding stress

PARASYMPATHETIC NERVOUS SYSTEM

SYMPATHETIC NERVOUS SYSTEM © Matt Wilson and Holly Donohoe 2010 Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)

Psychology and Counselling: Neuropsychology

The AUTONOMIC NERVOUS SYSTEM (ANS) is the part of the nervous system in charge of regulating involuntary vital functions, including the activity of the heart, the digestive system and the glands. It is divided into two subsystems: The SYMPATHETIC NERVOUS SYSTEM, which responds to stress by speeding the heart rate, constricting blood vessels, decreasing digestive activity, and raising blood pressure. Also it tells the adrenal medullar to release adrenaline into the blood, preparing the body for the fight or flight response. The PARASYMPATHETIC NERVOUS SYSTEM, which counteracts this response by slowing the heart rate, increasing digestive and gland activity and relaxing muscles. Source: http://stress.about.com/od/stressmanagementglossary/g/ans.htm

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Psychology and Counselling: Neuropsychology

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Psychology and Counselling: Neuropsychology

Cardio vascular problems: High Blood Pressure, Heart Attack, Stroke, Heart Disease Digestive disorders: Irritable Bowel Syndrome, Ulcers, Constipation Respiratory disorders: Asthma Psychological disorders: Alcoholism, Sexual Dysfunction, Insomnia, Chronic Fatigue Syndrome Skin disorders: Eczema, Psoriasis ÂŠ Matt Wilson and Holly Donohoe 2010 Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)

Psychology and Counselling: Neuropsychology

Cortisol is a hormone produced by the adrenal glands and helps regulate blood pressure and cardiovascular function, as well as the body’s use of proteins, carbohydrates and fats. Cortisol secretion increases in response to physical and psychological stress during the fight or flight response, which is why it’s sometimes called ‘THE STRESS HORMONE’. Source: http://stress.about.com/od/stressmanagementglossary/g/Cortisol.htm

Psychology and Counselling: Neuropsychology

Higher and more prolonged levels of cortisol in the bloodstream (like those associated with chronic stress) have been shown to have negative effects on our health, such as: • Impaired cognitive performance • Suppressed thyroid function • Blood sugar imbalances such as hyperglycaemia • Decreased bone density • Decrease in muscle tissue • Higher blood pressure • Lowered immunity and inflammatory responses in the body. High cortisol levels can also cause increased abdominal fat, which is associated with health problems such as heart attacks, and strokes. © Matt Wilson 2010 Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)

Psychology and Counselling: Neuropsychology

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Psychology and Counselling: Neuropsychology

Jet lag, also called desynchronosis, is a temporary disorder that causes fatigue, insomnia, and other symptoms such as: • anxiety, • constipation, • diarrhoea, • irritability, • nausea, • memory loss Jet lag is a result of air travel across time zones. Source: http://www.medicinenet.com/jet_lag/article.htm

Psychology and Counselling: Neuropsychology

The hypothalamus in the brain acts like an alarm clock to activate various body functions such as hunger, thirst, and sleep. It also regulates body temperature, blood pressure, and the level of hormones and glucose in the bloodstream. To help the body tell the time of day, fibres in the optic nerve of the eye transmit perceptions of light and darkness to a timekeeping centre within the hypothalamus. Thus, when the eye of an air traveller perceives dawn or dusk many hours earlier or later than usual, the hypothalamus may trigger activities that the rest of the body is not ready for, and jet lag occurs. Source: http://www.medicinenet.com/jet_lag/article.htm

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Psychology and Counselling: Neuropsychology

• We are diurnal creatures (geared towards daytime activity) • Our physiological functions including temperature, blood pressure and sleep / wake cycle all have rhythms of approx 24hrs (These are called Circadian rhythms) • These rhythms are synchronised by the body’s internal biological clock (Suprachiasmatic nucleus) and reset by external cues such as light and darkness. • Light is the primary zeitgeber (time-giver) that cues the sleep/wake rhythm

Psychology and Counselling: Neuropsychology

Daylight stimulates photosensitive retinal cells and these relay information to the SCN. The SCN then signals the pineal gland and inhibits secretion of MELATONIN, a hormone that causes drowsiness. The production of melatonin by the pineal gland is stimulated by darkness and inhibited by light

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Psychology and Counselling: Neuropsychology

Links to help you revise for the exam can be found here: Read about piloerection in more detail here: http://www.wisegeek.com/what-is-piloerection.htm The following video on how our bodies respond to stress may be a bit old and comical but the information it contains is excellent, accurate and very easy to remember: http://www.youtube.com/watch?v=RyP8L3qTW9Q The explanation of jetlag in this book covers everything you will need to know for the exam. However, if you want some further reading on the topic, the following is a great website: http://www.sleepdisordersguide.com/jet-lag.html ÂŠ Matt Wilson 2010 Create PDF files without this message by purchasing novaPDF printer (http://www.novapdf.com)