Neuroscience: Modern Technology & Research (KMF1014) PDF

Unit 3: Neuroscience: Modern Technology & Research KMF1014 Introduction to Cognitive Science PART 2 Insights into the Human Mind: Peering of the Brain Neurologists Brain Mapping Psychologists...

Unit 3: Neuroscience: Modern Technology & Research KMF1014 Introduction to Cognitive Science PART 2 Insights into the Human Mind: Peering of the Brain Neurologists Brain Mapping Psychologists (Selected Subjects ) Techniques Intrusive techniques of Treatment of selected Wider population – healthy investigation subjects & conditions & those in need of treatment Observation of location & intensity of activity in living brain Capturing brain in action Brain Mapping?  Attempt to provide a complete picture about how the brain works  Relate the brain's structure to its function  Find what parts of the brain give us certain abilities. Brain Mapping?  Goal = to achieve a 3 dimensional (3D) map of the brain, representing the surface, the structures within, and the functions performed by components of structures. Structures = where the components of the brain are located Functions = how the components act and interact to receive and integrate information and to produce behavior Sobel p. 115  Brain Mapping Techniques: Structural & Functional Structural Functional  X-ray Techniques  Electrophysiological Techniques  Cerebral Angiography  Electroencephalography  Computed Tomography  Event-Related Potentials (EPRs)  Computer Axial Tomography  Blood-Flow Techniques (CAT)  Positron Emission Tomography  Magnetic Resonance Imaging (PET) (MRI)  Single Photon Emission Computed Tomography (SPECT)  Functional Magnetic Resonance Imaging (fMRI) Structural Brain Mapping Techniques Structural brain mapping techniques X-ray techniques Magnetic resonance imaging (MRI) techniques X-ray Techniques: Cerebral Angiography  Useful in detecting disorders associated with abnormalities in brain arteries  Example: hemorrhage (heavy bleeding)  Loss of oxygen in that area  A procedure that uses a special dye (contrast material) and x-rays to see how blood flows through the brain.  Paths of arteries surrounding brain tissue  X-rays of skulls then locate malfunctioning artery – damaged area Sobel p. 117 X-ray Techniques: Computed Tomography  Tomography?  (Greek) Tomos = cut, section  Graphein = to write  Representation of a section  Tomograph?  An image slice through an organ (i.e. cross section), without the interference of all layers of tissue present in X-ray images  X-ray films appear blurry because they are 2- D rendition of our 3D body  Thus, focus on one plane (slice) Sobel p. 117 X-ray Techniques: Computer Axial Tomography (CAT)  Developed in early 1970s  Less radiation than traditional x-ray.  Computer technology enable ‘deblurring’ of picture & reconstruction of a complete brain image from multiple views  How?  Rotation of fan shaped X-ray beam around a single cross section  Development of CAT enable process of imaging brain internal structure to become safer & more precise– 3D For scanning bones and organs. Sobel p. 118 Computer Axial Tomography (CAT) Advantages Disadvantage  Safer - The fan shaped beam  Doesn’t indicate when an exposes the body to less radiation than traditional x- activity is occurring in the brain rays  More precise - only takes a cross section of an organ, avoiding problem of interference of all the layers of tissue present in x-ray images  Clearer image of brain structures – ‘deblurring’ by computer technology – 3D Sobel p. 118-119 Magnetic Resonance Imaging (MRI)  New method of neuroimaging, emerged in mid 1980s  Uses a magnetic field to take images of the inside of your body.  Assumes atoms in the body will react to magnetic field  Based on radio signals emitted by the protons in the human body Sobel p. 120-121 Magnetic Resonance Imaging (MRI) Sobel p. 120-121 Magnetic Resonance Imaging (MRI) Advantages Disadvantages  No X-rays or radioactive  Slow – for an image to be material is used (unlike generated. CAT or PET)  An image generated at a given  Resolution of the image is time will no longer depict a sharper / clearer than situation precisely as it was at the CAT scans time of the imaging  Flexibility – allows the  Cannot be used in patients with researcher to distinguish metallic devices, like different structures of the pacemakers brain – gray/white matter  May cause claustrophobic and cerebrospinal fluid reaction in some patients (option = open MRI) Sobel p. 120-121 Meaning of claustrophobia http://heroeswiki.com/User:Piemanmoo/Claustrophobia  Brain Mapping Techniques: Structural & Functional Structural Functional  Electrophysiological Techniques  X-ray Techniques  Electroencephalography  Cerebral Angiography  Event-Related Potentials (EPRs)  Computed Tomography  Blood-Flow Techniques  Computer Axial Tomography (CAT)  Positron Emission Tomography (PET)  Magnetic Resonance Imaging (MRI)  Single Photon Emission Computed Tomography (SPECT)  Functional Magnetic Resonance Reveals where reactions are taking Imaging (fMRI) place in the brain as parts of the body move or external events affect it Allows identification of regions involved in particular functions Functional Brain Mapping Techniques Functional brain mapping techniques Electrophysiological techniques Blood-flow techniques Electroencephalography  A test of the function of the brain itself  records the electrical activity on the brain's surface.  image the brain while it is performing cognitive task.  detect the location and magnitude of brain activity involved in the various types of cognitive functions  Non-invasive and painless procedure  Take brief patient history  Apply electrode leads to the patient's scalp  Run the test. Sobel p. 122-124 Electroencephalograms (EEGs)  Tracings/Recordings of excited patterns of electrical activity in the brain relaxed  view and record the changes in brain activity during drowsy performance of cognitive task asleep  Provide fine-tuned reading of rapidly occurring changes (MRI too slow to Deep sleep do this) Electroencephalography Advantages Disadvantages  Able to trace rapid changes  Invasiveness – relative in neural activity  May affect data validity  Can record activations in  Possible interference from brains of people who are movement, heartbeats – fully conscious & engaged blur reading in various activities in natural environment Event-Related Potential (ERP)  Subject presented with a stimulus during EEG process  Record voltage change around the stimulus (before and after it ends)  Repetitions of event – average the values  Evoked response provides a picture of neural activity changing over time as the brain processes information Sobel p. 124-126 Positron Emission Tomography (PET scan)  Method of measuring cerebral blood flow while subject carries out cognitive tasks  Uses radioactive isotopes (i.e. positrons)  PET scans look at bodily process by detecting the decay products from radioactive tracers injected into the body. Sobel p. 126-128 Positron Emission Tomography (PET scan) Blood flow in brain shifts to different locations, depending on task being performed E.g. : Positron Emission Tomograph (PET)  This image is used to show the brain activity of the development of a child from 1 month until 12 months of age. This method can be used to investigate the problems of developmental growth in children. Julia A.C. Lee Julia A.C. Lee Positron Emission Tomography (PET scan) Advantages Disadvantages  Provides an image of brain  Requires the use of cyclotron, activity as a cognitive task is an expensive equipment to occurring – locate activity in provide the radioactive isotopes specific parts of the brain (decay easily and needs to be produced each day)  Not as sensitive to changes over milliseconds (in comparison to electrophysiological techniques)  not as precise for analyzing cognitive tasks involving changes within milliseconds  Radioactive material used Functional Magnetic Resonance Imaging (fMRI)  Also known as real time or dynamic MRI – available in 1990s  Decade of the Brain  Detect changes in magnetic state of blood using MRI scanners with fast imaging techniques  Record changes in oxygen level & blood flow in various brain locations as subjects perform various cognitive tasks Sobel p. 129-130  Functional Magnetic Resonance Imaging (fMRI)  FMRI is a technique for determining which parts of the brain are activated by different types of physical sensation or activity, such as:  sight  sound  movement of a subject's fingers  mental imagery  calculation Julia A.C. Lee Functional Magnetic Resonance Imaging (fMRI)  Advantages?  Provides information about brain structure and function  Safer- Less harm to patients as no X-rays or radioactive material is used  Allows researchers to infer which locations are involved in specific activities that searching online may be a simple form of brain exercise that might be employed to enhance cognition in older adults.” (55 – 78 yr) Functional Magnetic Resonance Imaging (fMRI) Julia A.C. Lee This image shows what This 3-D image of a regions in a subject's subject's brain shows brain were involved in that the primary visual a memory task. This cortex becomes kind of study leads to activated while the improved subject, who is inside understanding of an MRI scanner, looks working memory. at the whirling pattern. Julia A.C. Lee Summary: What does brain mapping mean?  Structure  where the components of the brain are located.  Function  how components act and interact to receive and integrate information and to produce behavior.  Major direction taken by contemporary neuroscience research Julia A.C. Lee Brain Mapping Research Insights into Human Cognition Evidence from Brain Mapping Research: Insights into Human Cognition Concept Language Memory Disorders Categories Aphasia Functions of Categorization Bipolar & Working Unipolar (ASL) Memory Task Disorder Localization Role of of Brain Hippocampus Name finding Schizophrenia Implicit & Brain Explicit Autism Plasticity Memory Processing of Content & Long Term Memory Dyslexia Function Words Insights on Language  Neural organization of language quite similar for language learned in ordinary way (i.e. hearing & speaking) and for signed language acquired by deaf individuals  Insight from fMRI images on Broca’s & Wernicke’s Areas confirm hypotheses about involvement of these areas in human language function  Left hemisphere’s involvement in language is the same, whether the language is seen or heard  The intact hemisphere can take over tasks of damaged/removed brain hemisphere  Different parts of brain involved in processing content (nouns) & function words Language  Questions neuroscientists ask:  Brain activity:  Speaking  how words and meanings are accessed in the brain during reading  Effects on the brain after language training due to a stroke Julia A.C. Lee *Language  Loss of speech production – due to the damage to the left frontal lobe.  Broca’s area  Loss of language comprehension – due the damage on the upper back of the left temporal lobe.  Wernicke’s area Julia A.C. Lee Language Julia A.C. Lee  Region in temporal lobe Insights on Memory associated with memory  Two distinct functions of working memory (i.e. retrieval & coding) are performed in different locations within the brain area associated with working memory  working memory NOT generalized; different sorts of processes carried out in different regions  Investigate role in explicit (i.e. conscious recollection) & implicit (i.e. unconscious recollection) memory of events  Activation associated more with actual/explicit recollection of event (i.e. conscious) rather than in effort trying to remember it  Significant role of prefrontal cortex in explicit memory  Greater activation at higher levels of load (higher memory load lasts longer - continuing activation)  Amount of memory load = amount of information to be remembered Sobel p. 138-148 Insights on Concepts & Categories  Different areas activated depending on nature of categorization task  Increased cerebral blood flow  Broca’s area alone not responsible for name finding  Other regions of the cortex are involved in semantic associations  Name finding depends not simply on some specific name finder function in restricted area, but rather part of complex system of concept/categorization that has neural components in various regions of the cortex Brain Mapping: Insights on Disorders  Bipolar and Unipolar Disorder  Mood – Bipolar (normal mood alternated with both depression & mania) & Unipolar (only depression)  Role of neurotransmitter - Missing or deficient chemical level or substances  Neurochemical and autonomic abnormalities.  Schizophrenia - severe mental disorder (hallucinations & delusions)  Structural image differences between patient with childhood onset schizophrenia & adult  Medication has effect in patients’ brain (caudate – basal ganglia)  Language dysfunction due to deficit in language processing ability (unable to integrate context – incoherence) Sobel p. 153-156 Schizophrenia  A mental disorder characteristically marked by:  Illusions: sensory stimulus is present but is incorrectly interpreted by the individual.  Delusions: false personal beliefs that are not subject to reason.  Delusions that they are being cheated, poisoned. Julia A.C. Lee Brain Mapping: Insights on Disorders  Autism  developmental brain disorder affecting brain function – affect social interaction (social & communication deficits)  Greater brain volume found in autistic subjects – possible causes Increased production of neurons  Neurons do not die off in great numbers as in normal development  Increased production of non-neural brain tissue (e.g. blood vessel)  Dyslexia  Brain-based type of learning disability – affect reading  Unawareness of associations between phonological segments (sounds) in construction of words  Inability to decode Autism  Autism Spectrum Disorder (ASD)  What is autism?  Neurological/brain disorder that affects the functioning of the brain  autism impacts the normal development of the brain in the areas of social interaction and communication skills. Sobel p. 158-161 Julia A.C. Lee  Autism  What is autism?  Children and adults with clear evidence of the following:  Poor or limited social relationships. Are unable to form emotional bonds with others.  Repetitive behaviors, interests, and activities. Engage in repetitive activities like rocking or banging their heads.  Rejection of physical and emotional closeness.  Underdeveloped communication skills. Typically have difficulties in verbal and non-verbal communication  Intellectual functioning varies greatly: very high level to very low level. Julia A.C. Lee Autism  Volume of the brain is larger in male subjects with autism.  Enlargement of the total brain volume occurs because of enlargement of both the volume of the brain tissue. Example of children with autism  Alan, run from room to room turning lights on and off.  Alison, obsessed with digital watches, grabs the arms of strangers to look at their wrists.  Highly sensitive to certain sounds, textures, tastes, and smells- vacuum cleaner, telephone ring, distant airplane. Julia A.C. Lee  Jane with autism  From the day she was born, Jane seemed different from other infants.  Jane sat motionless in her crib and didn’t respond to the rattle of her toys.  By 30 months old, she wasn’t talking.  Instead, she grabbed things or screamed to get what she wanted.  Immense powers of concentration, sitting for hours looking at a toy in her hand. Julia A.C. Lee Dyslexia  Is not due to mental retardation  Is not due to inadequate schooling  Is not due to poor vision  Is not due to hearing defect Sobel p. 161-163 Julia A.C. Lee Dyslexia  What is it?  Difficulties with  recognizing printed words accurately and fluently  spelling Video: https://www.youtube.com/watch?v=SaQfuxODpog  End of Unit 3 Read Sobel: Chapter 3 Group project: Week 13 and 14  Bipolar & Unipolar Disorder  Dyslexia  Schizophrenia  Neuroscience and eating disorder (society issue).  Review of Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (known as DSM-V for short).  Mental disorder in the society  Dyslexia among workers in the organization  Aging, memory, and the brain. Group project: also consider topics on  Linguistics  The role of language use in the workplace: Raising the standards of written and oral communication.  Language acquisition in children.  Acquisition of second language  Natural language processing in the workplace.  Artificial Intelligence  The role of artificial intelligence in the workplace  Philosophy  The art and science of critical thinking at the workplace: Insights from Philosophy