Timeline of the History of Psychology Philosophers of science 16th century – present Francis Bacon: In the 16th century, Francis Bacon popularised the ‘new science’ and purported the inductivist view—that knowledge (which he called ‘laws of nature’) is inferred from observations, which could be confirmed (or not) by future observation. Inductive reasoning moves from observations of specific instances to a generalised conclusion. Bacon was also the first to attempt to codify scientific practice —he wanted to know what it was about the methods of science that led to scientific advances and progress. Bacon argued that by unlocking nature’s secrets, humans would gain power over nature and improve the human condition. Many so-called ‘laws’ in the early phase of psychology were expressed this way. Karl Popper: In the 1930s–60s, Karl Popper challenged the inductivist view of science, advocating instead for a deductivist view. A deductive view claims that knowledge is derived from testing instances against a theory or general law. Therefore, deductive reasoning moves from generalised principles or theories to specific conclusions. Popper proposed that a theory is a bold conjecture about the world that can never be confirmed; however, it can be falsified. Science progresses by continually testing theories and discarding those that have been falsified. 1930s – present Behavioural neuroscience Karl Lashley: Was a pioneer of neuroscience in the 1930s–50s, before the term existed. He was the first to map brain regions involved in specific psychological functions through experiments in which rats were required to complete tasks such as mazes or visual discrimination, before and after specific areas of their brains were damaged. Lashey demonstrated that the cortex processed information through neural activity and connectivity. David O. Hebb: Working from the 1930s–72, Hebb saw a need for psychology to be viewed as a scientific discipline, and believed this could be achieved by merging psychology with neurology and physiology, to explain human behaviour in a more objective, scientific manner. Hebb argued that the abstract notion of the ‘mind’ was in fact an entity that could be studied through physical, biological brain functions. He proposed that changes in connections between nerve cells provide the biological basis for learning, perception and memory. His theory lead to the discovery of neurotransmitters. What is science? Definitions and key concepts Science is defined as consisting of two aspects: 1. A mental activity: The first aspect concerns science as an attempt to understand the natural world through reason (thinking about things rationally), based on evidence (what you can actually observe). Therefore, science is something that you ‘do’. The ancient Greeks were the first to show that it is possible to obtain a good understanding of the natural world based on observation and reason, therefore science as a practice is thousands of years old. 2. A social activity situated in historical time: The second aspect concerns science as a social activity or a set of cultural practices that occur in a historical time. This is tied up with something called the ‘scientific revolution’. This is the name historians have given to a set of changes in intellectual outlook that occurred in Europe the 16th and 17th centuries – ushering in what we now know as ‘science’ – the legacy of which has continued to the present day. It is called a ‘revolution’ as it involved a radical change in thinking and the invention of a new methodology that we now call science. Some of the key figures at the beginning of this revolution are Nicholaus Copernicus, Johannes Kepler, Galileo Galilei and Isaac Newton. Another important person at the forefront of the revolution was Francis Bacon. Bacon characterised the ‘new science’ as gaining knowledge (called ‘laws of nature’) through observation. He argued that by unlocking nature’s secrets, humans would gain power over nature and improve the human condition. None of this was really apparent at the time, and it is only in the period since then that we have seen that scientific advances have indeed given humanity power over nature and arguably improved the human condition. Bacon was also the first (and not the last) to attempt to codify scientific practice. He wanted to know: what was it about the methods of science that led to these advances and this progress? This leads us to what we believe to be the principles of the scientific method. Principles of the scientific method One way of thinking about the scientific revolution (and science in general) is to regard it as having a commitment to the following principles. Empiricism The first key idea is that all knowledge is derived from sensory experience. Claims to knowledge must ultimately be based on personal observation, not authority, a priori reasoning, intuition, revelation, or even common sense. Experimentation The second key principle is experimentation – that knowledge can be more surely gained from planned interaction with nature (rather than random interactions or observations). We can think of an experiment as a procedure for gathering observations to test a hypothesis or theory. Mathematisation Mathematisation refers to the idea that the observed regularities in nature can be described by mathematics. Although people hope to understand science without mathematics, mathematisation has always been a central facet of the scientific revolution. In fact, the early proponents of the scientific revolution relied heavily on mathematics to understand the regularities of nature. Mechanical philosophy The next principle of the scientific revolution (and science in general) was the idea of mechanical philosophy, which states that events in nature only have material causes. This view purports that there are no ‘magical’ or ‘supernatural’ elements in nature. So, when we experience phenomena, we try to determine the material causes – what is it about other aspects of the world that could lead to this particular phenomenon occurring? What is Science? Goals and Scientific Method The goals of science The goals of science are typically seen to include one or more of the following: 1. Provide an accurate description of the world. 2. Provide an accurate prediction of phenomena. 3. Produce explanations of phenomena. 4. Exercise control over phenomena. Description Description is what many people think scientists do most of the time. Description also involves measurement: the recording of quantitative and qualitative features of phenomena of interest. A good example of description, including measurement, can be observed in Charles Darwin’s careful measurement of the different types of finches on the Galapagos Islands. These descriptions and measurements were instrumental in his development of the theory of evolution. Prediction There are two kinds of prediction in science: 1. Inductive – predictions based on descriptive regularities. We make an inductive prediction when we suppose (based on prior experience) that if we drop something, it will fall to the ground. 2. Deductive – predictions derived from theories, often used to test the theory in question. For example, Einstein’s general theory of relativity predicted that the orbit of the planet Mercury would change in a particular way over time. This prediction was confirmed, thereby supporting Einstein’s theory. Explanation When we learn about science, mostly we learn about explanations. For example, we have weight because of the force of gravity. Explanations are appealing because they appear to provide new knowledge and they help us to understand phenomena and the regularities of nature. They are often the product of theories. Notably, many people believe that explanation is the main goal of science. Control Control is about how we use scientific knowledge derived from descriptions, predictions, and explanations. We exercise control when we are able to construct new things, such as bridges, mobile phones, and medicines. In psychology, we control when we use knowledge to affect outcomes as in marketing, persuasion, and psychotherapy, to name a few. The Scientific method Starting with Francis Bacon, there have been many attempts to codify the scientific method, which usually involves the following steps: 1. Identify a question of interest. 2. Gather information and form a hypothesis. 3. Test the hypothesis by conducting research. 4. Analyse the data, draw tentative conclusions, and report findings. 5. Build a body of knowledge. Ethics in Psychology In the following presentation on Ethics in Psychology, you will learn about the main principles that you need to adhere to when conducting research with human participants (and also with animals); you will also hear about the importance of gaining informed consent from participants when conducting research, and how to go about this when participants are unable to provide such consent on their own. You will learn about the development of ethics in psychological research, and hear about some early studies that would not get ethical approval today, demonstrating how and why it became apparent that a code of ethical conduct was necessary when conducting research with human participants. WARNING: the presentation contains a description of an old psychology experiment on Classical Conditioning, that was conducted on a baby - Little Albert - which you may find upsetting. If you are interested in hearing about other psychological experiments that would be considered unethical today, you can watch a YouTube video (Links to an external site.) that talks about five well-known experiments that highlighted the need for an ethics code of conduct in psychology. Please be aware that this video talks about ethical standards in the US context. The Australian system is slightly different, so be sure to focus only on the Australian standards for your studies. You may also be interested in reading the National Health and Medical Research Council’s National Statement on Ethical Conduct of Human Research (Links to an external site.). An understanding of ethics is important because you may be participants in, consumers of, and conductors of human research studies. This is a long document — the sections below are most relevant to the content covered in this course, but the basic tenets of the entire document will be of benefit to you over the course of your studies in the Graduate Diploma in Psychology. Note: there is also the summary that can be downloaded. Section 1 Values and principles of ethical conduct Section 2 Themes in research ethics: risk and benefit, consent, specifically 2.1 Risk and benefit 2.2 General requirements for consent Section 4 Ethical consideration specific to participants specifically 4.2 Children and young people 4.3 People in dependent or unequal relationships 4.5 People with a cognitive impairment, an intellectual disability, or a mental illness Biological Bases of Behaviour The Neuron – The main ‘brain cell’ The nervous system is made up of neurons — or what might commonly be referred to as 'brain cells'. These cells specialise in the transmission of both electrical and chemical signals. Reading: Read the following section of your text book on neurons. This reading will provide a full description of structure and function of the neuron. You will use the information to complete the activity on the following page. Chapter 4: Section LO 4.1.: Neurons — NOTE only read the section on neurons. Chapter 4: Section LO 4.2.: How neurons communicate: Synaptic transmission There are over 100 billion neurons in your brain, and they are all connected through a vast network of circuits that communicate with one another through a process of electrical transmission. In this section, you will read about how this process occurs. In the nervous system, the body uses transduction (i.e. the conversion of sensory stimuli from one form into another) to send signals to and from our brain. It involves the translation of a physical event, such as touch, into an electrical signal in the brain, which travels along the axon of a neuron. The electrical energy reaches the end of the neuron where it needs to convert the electrical energy again to communicate to the next neuron. This is known as an action potential. This electrical energy is used to release chemical messengers that cross the space between the two neurons. Neurotransmitters Adrenaline Adrenaline is our ‘fight or flight’ neurotransmitter that sends important signals around the body, preparing different organs for attack or preparing muscles to flee. Unfortunately for sufferers of panic attacks, the body can suddenly fill with adrenaline (without the presentation of danger) which can make it feel as though the person is experiencing a heart attack. This can last around 40 minutes. Dopamine Dopamine is responsible for emotional regulation, our sense of pain and pleasure – so, you can see how this neurotransmitter is involved with addiction. Dopamine is also important for movement. When the body does not produce enough dopamine, you can observe the movement disruption as observed in Parkinson’s disease. Serotonin Serotonin is vital for the maintenance of mood. Typically, depression can be the result of low serotonin levels in the brain. Interestingly, low serotonin is also related to other depression symptoms such as sleep problems, memory dysfunction, and withdrawal from social situations, suggesting that it plays a key role in these functions also. Gamma-aminobutyric acid (GABA) Gamma-aminobutyric acid (GABA) is an important chemical that regulates signals between neurons. Low levels of this neurotransmitter can be associated with anxiety, depression, and schizophrenia (due to its role in the vision system). Acetylcholine Acetylcholine is a chemical released at the junction between the neuron and the muscle cells to stimulate muscles. Glutamate Glutamate acts like acetylcholine, but works at the junction between brain neurons — the typical neuronal communicator chemical. Due to this, it plays a vital part in memory and learning. Endorphins Endorphins play a role in the reduction of pain and increasing feelings of pleasure. They also reduce pain within the body — known as the body’s natural ‘pain-killers’. Reading: Chapter 4: Section LO 4.1. Neurons – NOTE only read the following section: a. The electrical activity of neurons Chapter 4: Section LO 4.2.: How neurons communicate: Synaptic transmission The Neuron The Brain Read the following section of your textbook which will help you complete the interactivity: Chapter 4: Section LO 4.5: Structures and functions of the brain The Brain and Neurons – Neuroplasticity There is a famous saying: “Neurons that fire together, wire together.” – Donald O. Hebb But luckily for us, it is possible to alter (to some extent) the way our circuits are wired. When the brain demonstrates the forming of new pathways (connections), this is known as neuroplasticity. Take a moment to stop and consider how those working in psychology use this knowledge in both research and practice. Researchers can discover how to make these changes and determine when these are adaptive or problematic. Then, practitioners can work with patients to change the way that neurons fire together. This could help patients to respond to a fearful stimulus in a more adaptive way, or to understand how patterns of attachment affect future relationships. One way to think about this is with an analogy: “The well-worn path” When our brains are used to travelling down the same paths, it can feel like we cannot change. But with effort and conscious practice, we can make a new path that our brain will travel down (just as easily), in time. You may have heard about the concept of neuroplasticity through a very well-known book that was published in 2007 called The Brain That Changes Itself, by Norman Doidge, MD. This book presents several case studies of people who have been able to re-wire their brains back to healthy functioning after a loss brain function due to some form of brain injury.
