Behavioural Neuroscience: History and Today

Behavioural Neuroscience Prof Olivia Carter 1 History of Behavioural Neuroscience 2  Learning Objectives Introduce Behavioural Neuroscience as a discipline Consider factors that limit advances in scientif...

Behavioural Neuroscience Prof Olivia Carter 1 History of Behavioural Neuroscience 2  Learning Objectives Introduce Behavioural Neuroscience as a discipline Consider factors that limit advances in scientific understanding Summarise the history and evolution of ideas over time that underpins the field of behavioural neuroscience as it stands today. 3  What is Behavioural Neuroscience? Neuroscience = study of the function and structures of the nervous system (e.g. brain, neurons, synapses etc) 4  What is Behavioural Neuroscience? Behaviour = relates to the observable actions of humans, animals (or artificial systems). In psychology there is a history of using behaviour as an indicator of internal mental processes, thoughts, emotions desires (“behaviourism”). 5  What is Behavioural Neuroscience? It is now clear that behaviour is really only half the story and a complete understanding of the internal workings of the human mind (i.e. perceptions, thoughts and emotions) cannot be achieved by observing behaviour alone. Brain Behaviour Mind From the perspective of Human Psychological Sciences, Behavioural Neuroscience = Biological Psychology = Physiological Psychology Behavioural Neuroscience is the most common term used to describe research in this field involving animals, but all are interested in how the activity of the brain impacts both mental processes and behaviour 6  History of Behavioural Neuroscience Changes to our understanding of the brain are limited by § Religious or moral views § Methodological limitations § Serendipity - reliance on chance discoveries § Scientific conservatism 7  Linking the mind to the brain Many ancient cultures (Egyptian, Indian, Chinese) believed heart to be seat of the mind constantly beating faster during heightened emotional states A papyrus scroll from Egypt dating back to ~1600BCE, represents first link between brain damage & mental symptoms Describes the symptoms and diagnosis of two individuals with brain injuries Edwin Smith Papyrus – ~1,600 BCE 8  Hippocrates, Ancient Greece § Considered father of modern medicine. § First to propose brain controls the body § Our brain is the command centre of body (not heart) ‘…nothing else but the brain come joys, delights, laughter and sports, sorrows, griefs, despondency, and lamentations…” § Noted the behavioural effects of brain damage § Dissection not allowed in Greece Observed anatomy through open wounds after traumatic head injury of soldiers and Hippocrates 460-370 BCE gladiators 9  René Descartes, France § French philosopher formulated the mind-body problem § Was the first to discuss interactions between mental and physical “I think therefore I am” § Considered humans and animals like machines René Descartes 1596-1650 § Interested in involuntary reflexes and believed behaviour was driven by a system of fluid and pistons 10  Luigi Galvani, Italy § First to suggest nerve signals are electrical (not fluid) § Rejected the idea of animal spirits flowing through hollow nerves § Made a chance discovery that an electrical charge applied to a frog’s leg made the muscle contract § Suggested that nerves must be coated in fat to prevent electricity from leaking out Luigi Galvani 1737-1798 § Inspired books like ‘Frankenstein’ 11  Luigi Galvani, Italy Watch Movie https://www.youtube.com/watch?v=A312PsGlMTk 12  Luigi Galvani, Italy Leyden jar Friction machine (stored charge) (static electricity) Frog legs (nerves attached) Serendipity and advances in science allowed Galvani’s discoveries 13  Franz Joseph Gall, Germany § Moving beyond “Mind” and “Brain,” Gall was first to propose idea of a modular brain § Was interested in relationship between brain and personality § Influenced by physiognomy - the art of ascribing personality characteristics to facial features Franz Joseph Gall 1758-1828 14  Franz Joseph Gall, Germany § Proposed that the brain is composed of several distinct ‘organs of thought’or faculties - reflected by characteristic patterns of bumps on the skull - skull maps could be used to “read” a person’s character § He compared animal and human skulls as well as people from “extremes” of society such as criminals or famous artists § Gall’s method was termed phrenology. It is flawed, but Gall introduced the important notion of “cortical localisation of function” - Modular organisation 15  Paul Broca, France § Provided first solid evidence of brain modularity § First described in patient named Leborgne - Unable to speak after damage to left frontal lobe - Normal chewing & language comprehension - Similar patients subsequently seen with damage in the same area Broca’s Aphasia is Caused by damage to Broca’s area Paul Broca 1824-1880 Note: before brain scans, unusual deficits described patients required subsequent investigation through autopsy – supported views of “localisationists.” 16  Carl Wernicke, Germany § Soon after Boca’s discovery, Wernicke described patient with - Unable to comprehend speech - Normal hearing & language production - Similar patients subsequently seen with damage to posterior part of the superior gyrus Wernicke’s Aphasia Carl Wernicke 1848-1905 is caused by damage to Wernicke’s area Note: today the general focus on linking brain damage to altered behaviour or cognition sits within the discipline of neuropsychology. 17  Section Summary § Behavioural neuroscience - scientific study of the relationship between the nervous system and both the mind and behaviour - Links between function & structure / Mind & body Brains show a high degree of modularity § Throughout history increased understanding of brain function has followed from technical or methodological advancements as well as some lucky observations. § The same will likely be true in the future with advances in AI and computing. Section Reading: Physiology of Behaviour, EBook Global Edition By Carlson & Birkett (2016). Chapt 1 p 15-22 https://ebookcentral.proquest.com/lib/unimelb/reader.action?docID=5187674&ppg=16 18 Behavioural Neuroscience Today 19  Learning Objectives Learn some basic facts about the scale and complexity of the brain. Consider the different terminology used for allied disciplines relevant to Behavioural Neuroscience today Discuss different career paths and professions that relate to Behaviour Neuroscience. 20  Brain Facts Today a lot is known about the human brain. It is generally believed to be the most complex system in the known universe. § Adult brain weighs ~1,400 grams § 3% of body weight § 100 billion neurons § 1,000,000 billion synapses § 101,000,000 possible circuits 21  Brain Facts § consumes 20% of energy resources of entire body § Is also remarkably energy efficient running on 20Watts (equivalent to simple light globe) § Information processing within the human brain is much more efficient than equivalent processing by computer systems 22  Allied Disciplines § Behavioural Neuroscience, Behavioural Physiology, Physiological psychology and Biological psychology - all can be synonymous - animal research typically emphasises the term “Behaviour” - human research typically emphasises the term “psychology” e.g. 1st year Behavioural Neuroscience > 2nd year Biological Psychology § Neuropsychology - Research and clinical speciality - links brain damage (lesions) with psychological processes - assess risk (before surgery), - assess impairments and improvements (after damage) - behavioural and neuroimaging measures 23  Allied Disciplines § Psychopharmacology - the role of neurochemistry in mind and behaviour - natural = neurotransmitters & Hormones - artificial = drugs § Comparative neuroanatomy and psychology - Brain evolution - origin (and purpose) of behaviours - commonalities across species - links between brain regions and behaviour 24  Allied Disciplines § Cognitive Neuroscience - neural basis of cognition (memory, language, perception, decision making etc) - functional connectivity (how multiple brain regions work together to support complex functions) - functional brain imaging (fMRI) a common tool § Psychophysiology - links electrical activity within the brain to cognitive functioning - Electroencephalography (EEG) a common tool - Today typically included within Cognitive Neuroscience. - Has a longer history and includes more basic responses such as “startle” 25  Allied Disciplines § Neuromorphic computing - Began in 1980’s with the goal of using electronic circuits to emulate neural structures in the human brain § Cognitive computational Neuroscience - attempts to characterise the neural computations that underlie complex behaviour (first CCN conference held in 2017) § In Silico Neuroscience - Another term related to the two areas of research above. In silico refers to silicon in computer chips but is now used broadly to refer to use of computer modelling or computer simulations 26  Career Paths § Clinical Careers - Clinical Neuropsychology - (+MD > Neurology, neurosurgery & psychiatry) § Research Careers - honours, Masters, PhD - Psychology, Neuroscience, Neuroengineering, computer science & Clinical Professions § Other Careers - Marketing, Education, Computer science - anything interested in the associations between the brain, thoughts and behaviour (positive or negative) 27  Section Summary § Several key facts about the brain are now understood in terms of the number of neurons and connections as well as incredible efficiency. § The basic research questions and methods in Behavioural Neuroscience or shared across a number of allied disciplines. § There are many career paths and professions that build on knowledge from behavioural neuroscience. Section Reading: Physiology of Behaviour, EBook Global Edition By Carlson & Birkett (2016). Chapt 1 p 31-34 https://ebookcentral.proquest.com/lib/unimelb/reader.action?docID=5187674&ppg=32 28