MODULE 2 - BIOLOGICAL APPROACH (SN) PDF

Pack: A6 Major Approaches in Psychology Dr.Stephanie Borg Bugeja Dott. Mireille Vila Dr. Olivia Galea Seychell...

Pack: A6 Major Approaches in Psychology Dr.Stephanie Borg Bugeja Dott. Mireille Vila Dr. Olivia Galea Seychell Dr. Miriam Geraldi Gauci Ms.Chiara Borg 1 Additional compulsory reading Chapter: 4 Book: Simply Psychology Author: Michael W. Eysenck 2 Cohort 2024-2025 1  Pack: A6 Biological Approach What is the Biological Approach? - Our behaviour is strongly influenced by the brain - both the structure and the functions of the brain. - The biological approach underpins the importance of the brain and it also focuses on how our nature (hereditary aspects) are significant to the structure and functioning of the brain. - The biological approach was developed in Psychology as a direct influence of the work of Charles Darwin – Theory of Evolution. - This eventually lead to the development of Evolutionary Psychology. 3 Evolutionary Psychology According to Evolutionary Psychology, evolution has shaped the brain, body and behaviour. Because of evolutionary pressures there was no other option but to adapt. So humans inherited characteristics (nature) that were pivotal to their survival in the environment they inhabited. As a result of evolution, the brain has also increased in size over the millenia. The human brain is much larger and more efficient in its functioning than it was. This adaptation was necessary to develop the ability to think and reason. 4 Cohort 2024-2025 2  Pack: A6 A very famous debate: Nature and Nurture Heredity Environment Genetics Experience determine who determines who we we are are 5 Nature vs Nurture (Heredity vs Experiences) Differences in humans can be either due to nature (heredity) or nurture (experiences) or both. The biological approach considers heredity (nature) as being very important. Although there is an amount of instinctive behaviour (e.g. reflexes) in humans, the majority of behaviour is learnt through experiences. However, we cannot ignore innate/genetic (heredity) factors. By means of family and twin studies (monozygotic and dizygotic twins), researchers focused on the way genetic factors affect behaviour. 6 Cohort 2024-2025 3  Pack: A6 Nature vs Nurture (Heredity vs Experiences) Family Studies have focused on how similar are family members with respect to a trait (example: personality or the occurrence of schizophrenia). Twin Studies focused on monozygotic (identical) twins and dizygotic (fraternal) twins and assessed the similarities in both appearance and behaviour (studies on intelligence) amongst others. In some cases, twins were adopted by separate families and so it was possible to research, which traits were a result of heredity and which influenced by the environment. 7 Nature vs Nurture (Heredity vs Experiences) In the discussion about the significance of nature and nurture, the following is pivotal: Active covariation: Children of differing genetic abilities look for situations that reinforce their genetic differences. Passive covariation: Parents of high genetic ability provide a more stimulating environment than parents of low genetic ability. Reactive covariation: Individuals of high genetic abilities receive a different treatment. Their abilities influence how others treat them. They are more often than not treated better or given more opportunities. 8 Cohort 2024-2025 4  Pack: A6 The Nervous System The Nervous system contains all the nerve cells in the body. It is made up of between 15 to 20 billion neurons (nerve cells) and a larger number of glia (small cells). It is is divided in two (2) sub-systems: The Central Nervous System (CNS) The Peripheral Nervous System (PNS) 9 The nervous system 10 Cohort 2024-2025 5  Pack: A6 Central Nervous System The Central Nervous system (CNS) consists of the brain and spinal cord. It is protected by bone and fluid circulating around it. 11 Central Nervous System - – Spinal Cord Spinal cord - nerves running from the brain to the lower part of the back. The spinal cord and brain are interconnected and so they work together. The spinal cord has 2 major functions. 12 Cohort 2024-2025 6  Pack: A6 Transmission of Information Function 1 Sensory information into the Peripheral Nervous system which is then relayed to the brain(CNS). This is done through the use of receptor nerves. Function 2 Motor information from the brain(CNS) to the Peripheral Nervous System. This is done through the effector nerves. 13 Receptor nerves transmit information to the brain via the spinal cord. Instructions from the brain are sent via the effector nerves. However, with reflexes the information does not go to the brain but goes directly from receptor nerves to effector nerves. 14 Cohort 2024-2025 7  Pack: A6 The Inner and Outer Parts of the Nervous System - The - The central peripheral nervous nervous system [CNS] system [PNS] consists of the consists of brain and ‘the rest’ of spinal cord. the nervous system. - The CNS - It gathers makes and sends decisions for information the body. to and from the rest of the body. 15 Peripheral Nervous System (henceforth PNS) The PNS consists of all the nerve cells of the body not contained within CNS. It is used to transmit information between the CNS and receptors and effectors outside the CNS. Peripheral nervous system is linked with external sensory organs and receptors in internal structures. 16 Cohort 2024-2025 8  Pack: A6 Peripheral Nervous System (henceforth PNS) The PNS is composed of the somatic nervous system and the autonomic nervous system. The Somatic nervous system is concerned with interactions with external world and so voluntary movements of the skeletal muscles. The Autonomic nervous system is concerned with body’s internal environment and so involuntary movement of the non-skeletal muscles. 17 Peripheral Nervous System Somatic NS - controls voluntary movements of skeletal muscles. All movement (except reflexes) involve Somatic NS. It consists of nerves carrying signals from eyes, ears, skeletal muscles and the skin to CNS. In turn it also carries signals from CNS to skeletal muscles , skin etc… Autonomic NS - controls involuntary movement of non - skeletal muscles (e.g. heart, lungs, eyes, stomach and blood vessels of internal organs). The Autonomic NS is divided in : - Sympathetic nervous system - Parasympathetic nervous system. 18 Cohort 2024-2025 9  Pack: A6 The somatic nervous system: What happens when you decide to move your fingers? (1)The decision arises in the brain; (2)is transmitted via the spinal cord; (3)transfers to another nerve (or series of nerves); (4)the instruction is transmitted to the skeletal muscles; (5)the muscles contract or relax, moving the fingers. 19 More Parts of the Nervous System 20 Cohort 2024-2025 10  Pack: A6 Peripheral Nervous System - Sympathetic Nervous System (SNS) This function starts working when there is need for awakening, excitement and energy. These changes prepare the body for fight or flight and so it is the arousing system. So what happens when the SNS is affected? Higher heart rate Reduced activity in the stomach Pupil dilation or expansion Relaxation of the bronchi in lungs 21 Peripheral Nervous System - Parasympathetic Nervous System (PNS) This function starts working to calm down and to save energy. It is involved when we rest and digest. So what happens when the PNS is affected? Decreased heart rate Increased activity in the stomach Pupil contraction Constriction of bronchi of the lungs 22 Cohort 2024-2025 11  Pack: A6 Peripheral Nervous System - Autonomic Nervous System Both the Sympathetic NS and Parasympathetic NS are important functions and need to be activated. What happens to the person who has the sympathetic working more than the parasympathetic? The person will feel: Stressed Anxious 23 Central Nervous System - Structure and Functions of the Brain The brain is divided in 3 main regions. Forebrain Midbrain Hindbrain 24 Cohort 2024-2025 12  Pack: A6 Forebrain The forebrain is located towards the top and front of the brain. It has the following main parts: a. Cerebrum – 70% of all neurons in CNS. Crucial role in thinking, use of language and other cognitive skills. a. Limbic system – Amygdala (anger and aggression) and Hippocampus (learning and memory). So it regulates the emotions and is significant for learning and memory. 25 Forebrain cont… c. Thalamus – it is involved in wakefulness and sleep. d. Hypothalamus – control of body temperature, hunger, thirst, sexual behaviour, endocrine system (produces and releases hormones) and reactions to stress. e. Basal Ganglia – voluntary motor control, motor (procedural) learning, eye movements, cognitive function and emotions. 26 Cohort 2024-2025 13  Pack: A6 Midbrain The midbrain is involved in vision, hearing and control of movement. It contains the reticular activating system which regulates sleep, arousal and wakefulness influencing heart rate and breathing rate. The Tectum and Cerebellum are main components of midbrain. The Tectum consists of visual receptors and auditory receptors. The Cerebellum is also part of the midbrain but also the hindbrain. It is involved in balance and coordination. (See details – Hindbrain). 27 Hindbrain The hindbrain is known as the reptilian brain. It consists of three (3) parts: Medulla oblongata – control of breathing, digestion and swallowing. This is also part of the reticular activating system. Pons – control of consciousness (shared with midbrain since - it is also part of the reticular activating system). Also involved with vision and it is a relay station between different parts of the brain. Cerebellum – body balance and coordination. ‘overlearned’ skills are found here e.g. Driving a car, riding a bicycle (also shared with midbrain). 28 Cohort 2024-2025 14  Pack: A6 The Cerebral Cortex ▪ It is the outer layer of the cerebrum, only two millimetres deep. ▪ It is important in terms of our ability to perceive, think, remember and use language. ▪ It consists of four lobes, which have different functions. ▪ The entire brain is divided in two hemispheres. 300 billion synaptic connections The brain has left and right hemispheres 29 The Cerebral Cortex - The lobes consist of: ▪ outer grey “bark” structure that is wrinkled in order to create more surface area for 20+ billion neurons. ▪ inner white stuff—axons linking parts of the brain. ▪ 180+ billion glial cells, which feed and protect neurons and assist neural transmission. 300 billion synaptic connections The brain has left and right hemispheres 30 Cohort 2024-2025 15  Pack: A6 What are the functions of the Cerebral cortex? 31 Frontal lobe Reasoning and abstract thinking, motor processing (planning and control of movement – primary motor cortex). Significant for fine motor skills. Parietal lobe Somatosensory processing - sensations in the skin and muscles of the body. Receives information regarding senses (temperature, pain, pressure). Temporal lobe Auditory processing. Involved with speech perception. Respond to sounds – high or low pitch. Meaning of words and concepts stored here. So if damaged person will have semantic dementia – loss of information about word meaning. Occipital lobe Visual processing. 50% of cerebral cortex devoted to visual processing. 32 Cohort 2024-2025 16  Pack: A6 Hemispheric Specialisation o The brain has two (2) hemispheres. Each hemisphere differs in its function – hemispheric specialisation. o One hemisphere might be more dominant over the other for certain processes. o For example in the great majority of people, language abilities are based mainly in the left hemisphere. 33 The intact but lateralized brain Right-Left Hemisphere Differences Left Hemisphere Right Hemisphere Right Hand Control Left Hand Control Writing Emotional Expression Language Spatial awareness Scientific Skills Music Creativity Mathematics Imagination Lists Dimension Logic Gestalt (Whole Picture) Linear Thinking Mode Holistic Thinking Mode 34 Cohort 2024-2025 17  Pack: A6 Our Two Hemispheres Lateralization (“going to one side”) The two hemispheres serve some different functions. How do we know about these differences? ▪ Brain damage studies revealed many functions of the left hemisphere. ▪ Brain scans and split brain studies show more about the functions of the two hemispheres, and how they coordinate with each other. 35 Hemispheric Specialisation Most of what is know about hemispheric specialisation comes from split-brain patients. Most of these patients suffered from epilepsy (seizures) and their Corpus Callosum (bridge) was cut. Without Corpus Callosum information is not transferred from one hemisphere to the other. 36 Cohort 2024-2025 18  Pack: A6 Split- Brain Studies To end severe whole- brain seizures, some people have had surgery to cut the corpus callosum, a band of axons connecting the hemispheres. Researchers have studied the impact of this surgery on patients’ functioning. 37 Plasticity: The Brain is Flexible If the brain is damaged, especially in the general association areas of the cortex: the brain does not repair damaged neurons, BUT it can restore some functions it can form new connections, reassign existing networks, and insert new neurons, some grown from stem cells This 6-year-old had a hemispherectomy to end life-threatening seizures; her remaining hemisphere compensated for the damage. 38 Cohort 2024-2025 19  Pack: A6 Brain Organisation We have 3 principles about the brain organisation. 1.It is interconnected – modules in the brain are connected. 1.It is hierarchical – processing takes place at various levels. 1.Functional differentiation – certain areas are responsible for specific functions. 39 Ways of Studying the Brain Event-related potentials (ERP) – stimulus is presented and scalp- electrodes record brain activity. Used for timing of cognitive processing. Positron Emission Tomography (PET) – technique that works using the detection of positrons (particles emitted by some radioactive substances). Used to study episodic memory. 40 Cohort 2024-2025 20  Pack: A6 Ways of Studying the Brain cont… Magnetic Resonance Imaging (MRI and fMRI)- radio waves are used to excite atoms in the brain. Thus producing magnetic changes. These changes are recorded on the computer giving a 3d picture. It tells us about the structure of the brain rather than the functions. fMRI are used to understand functions of the brain. T o understand which brain regions are being activated. 41 Further information… http://www.youtube.com/watch?v=_2QFWJQP1Sc https://www.youtube.com/watch?v=olsLiMXjpEs https://www.youtube.com/watch?v=9N5qbMFtKQ4 https://www.youtube.com/watch?v=UbwzyO3qBZU 42 Cohort 2024-2025 21