NEUROPSYCHOLOGY AND COGNITION (PSYC210)

ZETHU MEMELA

B10 (MTB)

The brain is a wonderful organ. It starts working the moment you get up and does not stop until you stand up to speak in public.

George Jessel

1

NEUROPSYCHOLOGY AND COGNITION (PSYC210)

COGNITIVE NEUROPSCIENCE AS A DISCIPLINEUnderstanding how the brain works, how its structure and function affect behavior, and ultimately how it enables the mind (Gazzaniga, Ivry& Mangun, 2009)

Cognition: the process of knowing, what arises from awareness, perception, and reasoning.Neuroscience: the study of the nervous system

Understanding how the function of the physical brain can yield thought and ideas of an intangible mind

Psychology – study of human behavior and mental processes

Neuropsychology – understanding interrelationship between neurological processes and behaviour

2

QUESTIONS:

What other fields of study have influenced Neuropsychology? And How?

What are ongoing debates in the field of Neuropsychology?

What have we learnt from history?

Draws information from many disciplines

Philosophy – Reasoning, thinking, morality

Evolution – Paul MacLean’s triune brain

Anatomy /Biology/ Physiology/Biophysics

Ethology – ethics, comparative psychology/ genetics & environmental factors

Pharmacology – neurochemistry

3

Psychiatry – abnormal behavior/ psychopathology Religion

Ongoing Debates

Localization versus Equipotentialsm/ dynamic equipotentialism

Brain versus mind

Issues and controversies regarding plasticity of the brain

Stem cell research

Development of Neuropsychology(Brief History)

Theoretical & Experimental arguments

To keep in mind:

Localization EquipotentialismQuestions asked

Is function localized (in specific areas of the

4

cerebral cortex) or is any area of the cortex capable of taking over function after a brain lesion?

Influences to the prevailing thought of the time (context)

Influences of Methods used to study brain

Using the brain to study the brain

Making mistakes & learning from them

Different Hypotheses

- Cardiocentric view (Cardiac hypothesis)- Cephalocentric view (ventricular

hypothesis)- Localization Theory (Phrenology & Faculty)- Equipotentialism Theory- Integrated Theories (functional theories)- Dynamic Equipotentialism/ pluripotentiality- Modern Neuropsychology

5

INFLUENTIAL PEOPLE (SCIENTISTS)

Hippocrates – (Father of modern medicine)

Brain controls all senses

Contralateral relationship between brain & body (Not ipsilateral)

All pleasures, pain, grief, amusement originating from the brain

Identified epilepsy as an ordinary disease not sacred)

Galen of Pergamum: (AD 130-201) First Experimental Physicist

Focused on clinical observations / clinical studies

Identified major brain parts

6

Association between Head injuries and behaviour (by observing Gladiators)

Influence of the church

Supported the ventricular localization hypothesis

Physical functions – Balance of body fluids (humors)

Andreas Vesalius (1514 – 1564)

Corrected Galen’s mistakes

Importance of overall brain mass in mediating mental processes

Anatomical theater – dissections / scientific observations

Precise drawing of human anatomy

7

Rene’ Descartes (1596 –1650)In search of the site of mental processes/ seat of the soul (church influence)

Anatomist and philosopher

Mind – body dualism (descartism)

Machinistic understanding of body / brain

Importance of mind in separating humans from animals

Importance of Language and reason

Pineal gland as the seat for mental processes

Intelligent behavior – interaction between ventricles & brain tissue

Animal spirits in ventricles

8

Thomas Willis (1621 – 1675)

English Anatomist

Linked brain damage to behavioral deficits

Difference between animal & human cortex- intelligence

Blood circulation in brain (Circle of Willis )

Identified and named a number of brain structures

Discovered symptoms of myasthenia gravis (neuromascular disease)

Identified brain abnormalities of people with congenital MR

Corpus striatum (Movement & sensation)

9

LOCALIZATION OF FUNCTION/ THE PHRENOLOGISTS

Franz Joseph Gall & Johann Casper Spurzheim

Faculty Psychology Size of brain amount of skill

Mental faculties innate & depend on topical structures

Bumps and depression of skull/ “Science” of Phrenology

Cranioscopy – device to measure bumps & depressions

Cortex & gyri – functioning parts of the brain not just covering for Pineal Body

10

Symmetrical spheres interact through Corpus callosum

Complexity of the Frontal lobes – Intelligence

RECOVERY OF FUNCTION

Pierre Flourens – demolition of phrenology

Controlled laboratory experiments

Animal experiments – removing parts of the cortex

Recovery of function

Some specialized (localization) brain stem & cerebellum

Paradox of recovery of function – brain works as a whole (simplistic)

11

CORTICAL LOCALIZATION

PIERE PAUL BROCA (1824 – 1880)

Paul Broca’s clinical cases – Monsieur Leborgne (Tan) & Lelong

Localization of speech – (motor speech)

Expressive speech – controlled by specific brain area

Posterior third of the L frontal convolution

Broca’s area

Broca’s Aphasia / non fluent aphasia

“a” – Greek for “not” phasia = speech

“ The third left frontal convolution plays No Particular role in the function of language”

Pierre Marie

12

Tan’s Posterior Damage ignored

Lelong general atrophy – senility

Broca – strict localizationist

Carl Wernicke (1848 – 1904)

Disagreed with Broca’s strict localization

Identified the role of the auditory cortex (sensory pathways from the ear)

Located in Temporal lobe - Superior, posterior

Relationship between hearing and speech

Damage in the first temporal gyrus

Patient could speak but confused

Could hear – not understand/ repeat

13

Wenicke’s Aphasia – fluent aphasia

No contralateral Paralysis (Broca- right arm)

Identified a dis/connection

John Hughlings Jackson – Nervous system organized in functional hierarchy

Cerebral cortex (higher level) controlling lower structures & other complex functions

Brodmann’s cytoarchitecture

Wilder Penfield’s motor and sensory homunculus

14

General Layout of the nervous system

Central Nervous System (CNS) + Peripheral Nervous system (PNS)

CNS – Brain (skull) and Spinal cord (spine)

Roles: Sensation, movement, information processing

body reflexes, communication between brain and peripheral nervous system

15

Peripheral Nervous System – outside skull & spine

Somatic NS + Autonomic Nervous system(SNS) (ANS)

- SNS is part of PNS that interacts with environment

- Composed of Afferent and Efferent nerves

Afferent Nerves – Sensory signals from skin, skeletal muscles, joints, eyes, ears etc.

Efferent Nerves – Motor signals from CNS to the skeletal muscles

Autonomic Nervous system

Sympathetic Parasympathetic NS

Lumbar & Thoracic regionBrain & sacral(spinal cord)

16

3 important principles of Para/Sympatheic NS

1.Sympathetic nerves stimulate, organize & mobilize energy resources in threatening situations

- parasympathetic nerves conserve energy

2. Each autonomic target organ receives opposing sympathetic & parasympathetic input

3. Sympathetic changes indicate psychological arousal – parasympathetic psychological relaxation

17

Autonomic Nervous System

18

NERVOUS SYSTEM

CENTRAL PERIPHERALNERVOUS NERVOUS SYSTEM SYSTEM

BRAIN +SPINAL AUTONOMIC+ SOMATIC NS CORD (int environment - skin, joints, sk eletal musc)

(motor + sensory comp. each)

AFF+EFF N AFF + EFF NERVES(sensory + motor nerves)(12 Pairs of Cranial Nerves)

(31 Pairs of spinal nerves)

SYMPATHETIC + PARASYMPATHETIC NS(lumbar + thoracic area) (sacral region of spinal cord) Response to emergencies Return to normal

19

RESPECTIVE FUNCTYION OF SYMPATHETIC + PARASYMPATHETIC NERVOUS SYSTEM3 IMPORTANT PRINCIPLES

1. Sympathetic N Stimulate, organize, mobilize energy resources in threatening situations

Parasympathetic N Conserve energy

2. Each autonomic target organ receives opposing sympathetic + parasympathetic input3. Sympathetic changes psychological arousalParasympathetic changes Psychological Relaxation

Psychological Conditions associated with PNS impairmentMotor related disorderGeneralized anxiety disorderPTSDPanic disorderObsessive compulsive disorder (OCD)Phobias etc.

20