Technology in brain research Brain-imaging technologies

Invasive techniques Instead of invasive techniques such as ablation (removing) and lesioning (scarring), which raise serious ethical concerns due to: damage cannot be reversed Causing pain Potential harm unknown One can use…

Brain Scanning Techniques EEG (electroencephalogram) PET (positron emission topography) FMRI (functional magnetic resonance imaging)

EEG (electroencephalogram) The EEG registers patterns of voltage change in the brain Help the researchers in the Study of sleep, emotions and epilepsy Weaknesses are: provide only limited information cannot reveal what is happening in the deeper brain regions Cannot show the actual functioning of the brain

PET (positron emission topography) Monitors glucose metabolism in the brain (using up energy) The patient is injected with a harmless dose of radioactive glucose The scans produce coloured maps of brain activity Used to: diagnose abnormalities like tumours, Alzheimer’s, schizophrenia, compare sex differences Greatest advantage is: can record ongoing activity in the brain, such as thinking

FMRI (functional magnetic resonance imaging) Provides three-dimensional pictures of the brain structures, using magnetic fields and radio waves Shows actual brain activity Higher resolution than PET scans and easier to carry out The most frequently used today

Evaluation of brain scans Weakness: not a natural environment, low ecological validity The use of colours may exaggerate the different activities of the brain Brain activates for various reasons – parts can be “lighted” but not necessarily used in the response …“we know that it is not possible to definitively determine whether a person is anxious or feeling connected simply by looking at activity in a particular brain region.” …“a one-to-one mapping between a brain region and a mental state is not possible.” Michael Shermer © 2008 SCIENTIFIC AMERICAN

Section A markbands SAQ app. 250 words/20 min Marks Level descriptor The answer does not reach a standard described by the descriptors below. 1 to 3 There is an attempt to answer the question, but knowledge and understanding is limited, often inaccurate, or of marginal relevance to the question. 4 to 6 The question is partially answered. Knowledge and understanding is accurate but limited. Either the command term is not effectively addressed or the response is not sufficiently explicit in answering the question. 7 to 8 The question is answered in a focused and effective manner and meets the demands of the command term. The response is supported by appropriate and accurate knowledge and understanding of research. Command terms with definitions handout

Three parts-test on Thursday Be ready on Thursday to answer two SAQs from this chapter (will be graded): The effect of cognition on physiology The localization of function of the brain Could be asked to explain or examine and to know a study as reference 3. A multiple choice test on the whole chapter