Textbook Notes (368,013)
Canada (161,562)
Psychology (9,695)
PSYB65H3 (479)
Ted Petit (185)
Chapter 3

Human Brain - Chapter 3.docx

7 Pages
122 Views
Unlock Document

Department
Psychology
Course
PSYB65H3
Professor
Ted Petit
Semester
Fall

Description
Chapter 3 – Techniques in Neuropsychology MODULE: Study of Damaged Nervous System The Scientific Mind - brain and beh can be investigated in at a variety of complexities and time scales which depend primarily on the question that is being investigated - some questions > minutiae of their properties others by their nature - scientific method > objective and replication or confirmation of results - standardized tests and measurements - empirical method, replication [so initial results did not occur by chance and generalizable] - best term to describe the scientific method > control, o refers to the ability to manipulate something of interest and determine its effects o the ability to exclude unwanted variable [confounding variables] o appropriate comparison sample so deviations can be observed - hypothesis directs the research [statement that can be rejected] o eliminates vague question o avoids questions that cannot be disproved - independent [manipulated] and dependent variables [response beh] - much of research in neuropsychology is quasi-experimental > ethically and practically we cannot manipulate the independent variable directly - may be few of the kinds of people we want to see, man confounding var - cannot rely on single experiment for conclusions - we rely on convering operations > a common conclusion is reached by examining a # of studies that approach the question in a variety of diff perspectives [if consensus > confident we have learned an imp feature] Nonhuman Animal Models - 1930-65, dominated by the study of white lab rats - assumption that there are minimal basic diff btwn most mammals - nonhuman studies > allowed to control all of the aspects of the life cycle o greater objectivity and precision that is not in human experiments - now know imp diff among species which also tells us something - reduces variability that is attributable to extraneous variables - allows for random selection - can isolate causal conclusions - examination of discrete lesions >insight into relationship brain and beh - Tinberg > imprinting and that of Diamond effects on enriched enviro - teratogenic/beh effects of alcohol was first done in nonhuman animals - limitations > focus on one facet of the organism and ignore the others o delayed nonmatching to sample task > after observing reqrd paired with stimulus A, then one is required to pick a novel stimulus to receive the reward o ethological validity> do animals exhibit this beh in natural setting o tasks may be so novel > do not provide info on real world func o not easily generalizable to other species [human too complicated at time may be better to examine simpler systems] - nonhuman animal experimentation has provided critical info regarding how, why, and where psychological phenomena such as learning occur within the nervous system - mammalian systems are remarkably conserved > great degree of overlap among basic properties of the nervous system - thus, at the most basic level of life, DNA, there is remarkable conservation of systems across species and the understanding of how one species solves a prob posed b the enviro may lead to understanding other solutions to the same prob - learning principles generalize to other species > humans included - cogn not generalize to humans - semantic categorization > pigeons, rats, chimps, gorillas, parrots o suggest > unlikely that lang is developed in a ontogenic and phylogenic isolation form other cogn abilities - limitations > important diff btwn mammalian species [complexity of NS] o some questions are quite difficult to in humans not to mention nonhuman animals > consciousness Cognitive Testing - Mini-mental state exam > how well people answer a series of question o designed to examine cogn func > lang, orientation ot location, attention, orientations to time - ppl w/ injury first beh test in emergency room - neurological not as detailed as neuropsychological > but give gross appreciation to the degree to which the NS is involved in a injury - this is a generalization but only trying to see the degree basic neurological func have been affeed - neuropsychological testing is a detailed examination of higher cognitive functions o personal interview > medical history, probs/concerns o series of tests > standardized cogn tests [given in same way to everyone and always score din the same manner] o test of general cogn > specific cogn func - used to help in diagnosis, intervention and rehabilitation - limitations > if not given/scored standardized manner > meaningless - some test have issues in generalizablity MODULE: Brain Imaging - current neuroimaging techniques have technical and methodological limitations [no ultimate investigative tool] - the type of tool used must suit the problem to be sovled - common problem > everyones brain is different o might demostrate similar patterns of activiation but the boundaries of functional brain areas are not exactly the same location for everyone  average? or each separately? Structural imaging - image of the structure of the brain > before lots of tests - inform about location of abnormalities - beh assessments now > rehabilitation, management of deficits - paradigm shift > initiated by the 1960s x-ray combined with computer X-Rays - neuroradiology > studying the NS w/ imaging made possible by serendipitous discovery by Wilhelm Conrad Rontgen - X-rays > cannot pass through all material with the same ease - medical > less dense body parts absorb less and vice versa o thus the amount of radiation that passes through a region provides a measure of the density of the structures within the region - principle: send a beam of X-rays into a structure > see how many stick by detecting the oens that pass through on a photographic plate o more dense > lighter [2D] - allowed ot look for pathology in noninvasive way - h levels of x-rays also used to destroy unwanted tissues - conventional x-rays not useful for neural imaging > soft tissue encased in bone> only give info about entry wound not what has occurred inside skull - cannot differentiate btwn CSF and brain structures Computed Tomography [CT] - 1 good way to image live brain tissue - 1960/70s > combined x-rays and computing - uses same radiation and methods as X-ray but CT involves the projection of x-rays from multiple angles followed by the computerized reconstruction of the measures into 3D images - reasonably accurate 3D representation - constructed in slices > 9-12 per scan - spatial resolution is adequate from clinical purposes - ability to differentiate btwn grey/white matter is poor - painless, little time, can be done on unconscious person - lie flat on bed > slide into scanners x-ray source and detector arrays > array rotates > images can be computed in any of 3 planes - CAT scan > images being constructed on the axial plane [run parallel w/ the horizon] - now all 3 planes used - coronal plane > slices perpendicular to the horizon, taken along the superior-inferior axis - sagittal plane > perpendicular to the horizon, taken along the dorsal-ventral axis o useful in clinical and research applications o in clinical shows abnormalities if they are reflected in changes in tissue density [not always the case] - multi-infarct dementia rarely diagnosed before CT - revolutionized research > didn’t have to wait to do autopsy to see deficits Magnetic Resonance Imaging [MRI] - Felix Bloch and Edward Purcell > based on nuclear magnetic precision measurement - fundamentally diff in the ways CT and MRI image the brain - MRI > replace CT due to superior resolution - exploits the fact elements can be influenced by magnetic fields - hydrogen > normally atoms not polarized > magnetic field > polarizes all in same direction and > once aligned can be perturbed in a uniform direction through the application of a radio freq pulse - diff pulse freq are better at perturbing hydrogen atoms w/I diff types of substances, depending on what you want to see - MRi machine measures reaction time that follows the pulse > which is the time taken by the atoms to return to their normal, random state - MRI’s receiver coil measures the info about the intensity of the signal but the spatial info is provided from variations in the gradient field over the imaged area [combo of these type of info allows > 3D images
More Less

Related notes for PSYB65H3

Log In


OR

Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


OR

By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.


Submit