Neuropsychology

Prepared by:Cicilia Evi GradDiplSc., M. Psi

The Development

• “Psychology has a long past but a short history” (Ebbinghaus)

• The same thing can be said for Neuropsychology

Historical Roots - Egyptians

• Ancient Egyptians believed that heart and diaphragm were the seats of mental life (Feinberg & Farah, 1997)

• Heart, liver, spleen and other organs were carefully removed from dead body and stored in separate jars while the brain was simply discarded considered unimportant (Rains, 2002)

• The first recorded evidence on brain – behavior relationship: The Edwin Smith Surgical Papyrus (2000 B.C.) was misleading

• The impairments were ipsilateral to the lesion (same side) rather than contralateral (opposite side)

• Egyptian observers didn’t take theoretical leap despite their findings

Historical Roots – Greeks

• Alcmaeon of Croton (500 BC) the first neurologist or neuropsychologist proposed that the brain is ‘the seat of the soul’

• Plato (400 BC) similar proposal: the head is part of the body closest to heaven and therefore most likely to contain the most divine organ

• On the other hand pitfalls of rationalism • Empedocles (500BC) heart was ‘the seat of

the soul’ • Aristotle (400BC) agreed: – Brain with its elaborate network of blood vessels

and its position near the surface of the body served to cool the blood

– Heart, being an active and central structure was more suitable as the organ of feeling and thinking

• Hippocrates (400 BC) had his brain hypothesis brain was responsible for the intellect, senses, knowledge, emotions and even mental illness (Adams, 1932)

• In ‘On The Sacred Disease’ epilepsy is a medical condition, not demonic possession

• Found contralateral relationship – Head injury on the left side seizure on the right side– Head injury on the left side speech impairments

Historical Roots

• Romans accepted the brain hypothesis • Localization of function where in the brain

various psychological functions (perception, memory and thinking) take place?

• Galen of Pergamus cerebral ventricles, fluid-filled cavities deep within the brain, were the structures in which thinking and other psychological processes were localized

• Nemesius (4th century) ventricular hypothesis assigning different psychological processes to locations within different ventricles – Cellula phantastica seat of perception – Cellula logistica seat of reasoning and cognition– Cellula memoralis seat of memory

• This theory was lack of empirical support … until 19th century

Mind – Body Problem

• Monism hold to one belief, either physical (materialism) or spiritual (idealism)

• Dualism Rene Descartes there is brain and there is mind, independent of each other but they interact. – Pineal gland organ that mediate the interaction– No localization of function because the mind

was not localized, wasn’t in space at all • Holism whole brain mediates all functioning

Modern Neuropsychology

• Franz Joseph Gall and Johann Casper Spurzheim phrenology relating specific brain regions to particular faculties or functions no precise definition or empirical basis

• Jean Baptiste Bouillaud left-hemisphere specialize for motor dexterity, underlying right-handedness, also specialized movements involved in speech

Modern Neuropsychology (2)

• Paul Broca • A patient, Leborgne called ‘Tan’ epileptic, right

hemiplegia and loss of speech for over 20 years understood language, not demented, responded accurately to questions asked through gestures, such as his age after his dead, found a lesion on his left hemisphere

• In 1865 Broca concluded that left hemisphere is dominant for language

• Marc Dax’s view

Definition

• Meier (1974) Neuropsychology is the scientific study of brain – behavior relationships

• Subfields: clinical neuropsychology, experimental neuropsychology, behavioral neurology, and behavioral neuropsychology

Clinical Neuropsychology

• The application of our understanding of human brain – behavior relationships to clinical problems (Horton, Wedding & Phay, 1981)

• Clinical Neuropsychologist is a professional psychologist with diagnostic skills and psychometric expertise applicable to behavioral dysfunction associated with CNS dysfunction

• Halstead – Reitan Neuropsychology Battery and Luria – Nebraska Neuropsychology Battery

Experimental Neuropsychology

• Elucidation of basic brain – behavior relationship (Horton, Wedding & Phay, 1981)

• Focus on theoretical questions rather than practical ones nonhuman subjects

• Degree of generality depends on the species and area of psychology under study

Behavioral Neurology

• Concerned with clinical application of scientific knowledge using qualitative, intuitive approach

• Contrast with clinical neuropsychology which used psychometric and quantitative approach

• Traditional medical case study approach assumes the practitioner has considerable clinical expertise and thorough understanding of neural structure and function

Behavioral Neuropsychology

• Horton (1979) the application of behavior therapy techniques to problems of organically impaired individuals while using a neuropsychological assessment and intervention perspective

• Emphasis on the problems of management, retraining, and rehabilitation

Psychometric Approach to Neuropsychology

• Case study approach revealed in-depth study of single individual case but we need more …

• Group Studies started at 40-50s allowed the formation of control groups to reveal the nature of impairments associated with a particular lesion result: quantitative definitions of impairments and sensitivity of specific tests to the presence of impairments

• Statistical analyses used to quantify the probability that a group with a particular lesion is performing at a lower level than a control group on a particular task help us to understand cerebral organization of psychological processes

• Also provide a basis for making inferences regarding the presence of cognitive impairments and associated cerebral abnormality in that individual (Reitan & Davidson, 1974) provide a set of procedures in diagnosis and rehabilitation (Lezak, 1995)

Case Study?

• Still effective in very rare disorders (agnosia or aphasia) provide a vivid and detailed description of the impairment that is often lost in the analysis of group data

• Individual differences and avoid overgeneralized appraisal of the effects of particular lesions

• Group study defined on the basis of lesion sites may comprise subjects with widely varying lesion sites erroneous interpretation

Summary

• Erroneous idea of mind-body relationship can remain widely accepted for long periods

• Establishment of localization of function within cerebral cortex and the specialization of left hemisphere for language mid 19th century

• An awareness of historical antecedents of current controversies helps place them in perspective and provides a framework for possible resolutions