PS365 -- History of Neuropsychology

What is the Study of Neurophsychology

• Studies the relation between brain and behaviour

  • investigates on an empirical level

  • Early conceptions of the mind as the mind of the seat of all behaviour by Egyptians

• Addresses the mind-body problem

• Term “neuropsychology” is relatively new

  • Used to be psychoneurology or brain pathology

Trephination

• Cutting, scraping, chiselling, drilling

• Relieve pressure, bleeding

• Modern-day shunts focus on CSF

  • Common medical procedure and life-saving treatment for hydrocephalus

  • Drain excess fluid from brain to another part of body where absorbed with circulatory process

Phineas Gage

• Had a 3 foot long rod through his head

  • Outgoing and friendly before injury

• Entered left cheek and exited the midline of skull anterior to the bregma

• Likely involved bilateral and anterior frontal corticices, and the rostral potions of the anterior cingulates gyrus, with underlying white matter

• Change to his personality

• Frontal lobe is critical in emotional regulation and rationality

Encephalocentric Thoery -- Edwin Sutherland

• The source of reason and logic is the brain

• The brain is the organ of the mind

• Localized both the intellect and neurological diseases to the brain

• Argued that epilepsy is due to a problem in the brain and not a “sacred disease”

  • Observed that cutting into one side of the brain produces a bodily spasm on the opposite side of the body

  • Observed that loss of speech is associated with Paralysis of the right side of the body

Cardiac Hypothesis -- Aristotle

• The warmth of the hear elevate it to a higher status over the cold brain

• Heart is affected by emotion -- brain isn’t

• Heart is a source of blood needed for all sensations -- brain is bloodless

• Heart is connected to all sense organs -- brain connections to sense organs were irrelevant

• Heart was essential to life -- brain isn’t 

• Damage to brain does and person may still live (brain-dead)

• Heart is formed first and occupies a central physical location

Dualism -- Plato

• The mind (or soul) and the body are composed of different substance

• The body is material, mind is immaterial

• Plato believe that the soul is immortal and can leave the body

René Descartes -- Pineal Gland

• The mind influences the working of the body through the pineal gland

• Pineal gland is involves in sensation, imagination, memory, and causation of bodily movements

• pineal gland is located beneath the caudal section of the corpus callosum

Monism

• The mind (or soul) and the body are composed of the same substance

• Epicurus is an early Greek thinker who argued for a monistic view

Psychic Pneuma

• Invisible like air

• Responsible for perception, cognition, and action

• Emanates from ventricles and fills the nerves

• In early Greek thoughts, Pneuma is often connected with the soul

Ventricular Hypothesis -- Da Vinci

• Anterior ventricle -- Common sense sensations, images, fantasy and imagination (lateral)

• Middle Ventricle -- Cognition, reasoning, judgement, thought (third)

• Posterior Ventricle -- Memory (fourth)

• Favoured for many reasons:

  • Aligned with doctrine of the circulation of animal spirits

  • Hollow spaces within brain seemed to be the appropriate place for non-corporeal soul to exert an influence on on body

• CSF is produced and stored in ventricle

Andre Versailus of Padua

• Focused on anatomy through public dissections

  • This training continues to this day -- learning through demonstation

    • operating theatres

• Brought focus back to anatomy and away from ventricles

  • detailed drawings gave the first detailed examination of neuroanatomy

Franz Gall -- Phrenology/Cranioscopy

• The act of palpitating the skull to determine individuals differences in function

  • First practice in India way before Gall

• Process that involves observing and/or feeling the skull to determine an individuals psychological attributes

• Determining mental and moral faculties based on external shape of skull

  • Both size and shape of organ mattered

• Suggested that very specific physical traits could be associated with tendencies towards specific crimes

Modularity of Function

Paul Broca and Karl Wernicke

Defecits in Speech Production -- Paul Broca (Broca’s Area)

• Expressive aphasia -- only able to utter single syllables

• Softening of tissue in the 3rd convolution of the inferior frontal gyrus (Broca’s Area)

• As a result of lesions in Broca’s area, there is a breakdown between one’s thoughts and one’s ability to produce speech

  • Patients often know what they wish to say but are unable to produce the words

• Broca introduced the idea of localization of function -- specific brain regions are important for mental function

Decficits is Speech Comprehension -- Karl Wernicke (Wernicke’s Area)

• Patients with damage to the posterior portion of the superior temporal gyrus presented with language comprehension defecits

  • they could say more than one syllable, but nothing made sense

    • Receptive aphasia

• Functions are modular in sense but not strictly confined to dingular brain regions

Korbinian Brodmann

• Cytoarchitectonics

• Brain regions are defined by their anatomical features

• Correlates well with function

• 50 Brodmann areas in total — delineated by virtue of differences in cellular structure

• Created cytoarchitectonic map of the human brain

Reticular Thoery

• Neuron doctrine -- Describes the properties of neurons

• Camillo Golgi developed staining technique called the black reaction

  • Neuron staining technique that allowed for complete visibility of nerve cells

    • Enabled scientists to view a complete neuron cell and its cellular structures

    • Golgi thought axons were physically connected

Santiago Ramón Y Cajal

• Used the black reaction to show the existence of synapses

• Showed that neurons function as discrete and independent cells, not a single network

• Developed a gold stain to illustrate and examine structures of nervous tissue in the brain, sensory centers, and spinal cords of embryos and young animals

  • These nerve-specific stains helped differentiate neurons from others cells and trace the structures and connections of nerve cells in gray matter and spinal cord

• Advanced notion that the brain is made up of discrete cells - neurons - not physically connected

Pyramidal Cells

• Long apical dendrites which exert inhibitory actions on certain neurons, reducing the transmission of nerve impulses

  • enable Purkinje cells to regulate and coordinate motor movements

Homunculi -- Wilder Penfield

• Applied electric shocks to different areas of patients brains

  • Asked patients what they felt

• By applying shocks, he discovered a small area of the brain where a sensory map of our body was established

  • Represented this area as if it were human form

Frontal Lobotomies

• Surgical procedure in which the nerve pathways of the frontal lobes of the brain are severed

  • formerly used as a radical therapeutic measure to help grossly disturbed patients with schizophrenia, manic depression, bipolar, and other mental illnesses

• Walter Freeman streamlines the procedure, replacing it with transoribital lobotomy

  • Pick-like instrment forced through the back of the eye sockets to pierce the thin bone that separates the eye sockets from the frontal lobe

    • Pick’s point then inserted into the frontal lobe and used to sever connections in the brain

• Many lobotomized patients exhibited reduced tension/agitation, but many showed other defects such as apathy, passivity, lack of initiative, poor ability to concentrate, and a generally decreased depth and intensity of emotional responses

  • Some died

Pharmacology

• Replaced frontal lobotomies

Hierarchical Organizations in the Brain

Hughlings-Jackson and Alexander Luria

• The complex human behaviours ewre built up of subsets of units/routines

Hughlings-Jackson

• Began by emphasizing the focal lesions as the key to analyzing patient’s symptoms

Alexander Luria

• Formalized hierarchical organization of brain as an arousal system - the posterior cortices, and the frontal cortex - for planning and executive function

• Developed an extensive and original battery of neuropsychological tests during his clinical work with brain-injured victims of WWII

Immigrants to America

• Immigrants were “processed” at Ellis Island in the shadow of the Statue of Liberty

• Critical need to quickly determine mental health

Army Screening and Intelligence Testing (WAIS)

• Non-verbal tests were developed for non English speaking recruits -- and those suspected of malingering

• Helps legitimize psychology

• Wechsler developed his test in 1993

• Widespread intelligence testing in schools began

• The Wechsler Adult Intelligence Scale is an IQ test designed to meaure intelligence and cognitive ability in adults and older adolescente

Birth of Neuropsychology

• Localization of function

• Screening for function

• All leads to the notion that performance on a test can tell us something about underlying brain function

Advent of Brain Imaging

• Changed the role of the neuropsychologist

  • No longer needed for lesion localization

Mosso -- Controversy

• Roy and Sherrington suggest there’s a relationship between circulation and brain function

• Mosso’s observations led him to believe that alterations in blood flow to the brain were determined by functional changes

  • Conceived plethysmograph -- device that could measure cerevral blood flow variations by recording brain pulsations in patients with skull defects

Plethysmograph

• Measure pulsations in people with skull defects

• Pulsations transformed into ‘waves’ and associated with function

• Only applicable to patients with skull breaches -- could not be used to assess brain flow variations in healthy subjects

Human Circulation Balance

• The ‘machine to weigh the soul’

• Placement was crucial -- the participant had to be centered on the table

• Had a control for the influence of breathing

• Adjusted weights and the amount of water in a bottle attached to the table to ensure the participant was centered on the central pivot of the fulcrum

Artefacts

• Table motion, breathing, pule rate, head motion, changes in volume of feet and hands

• Distinguishing signal from noise

  • “must be distinguished from other, psychically-induced types of blood flow” - Mosso

Experiments

• ‘Resting’ period first -- close to an hour

  • Establish a baseline

• Contrast with…

  • Hitting an electric key

  • Read a page from a novel/newspaper, mathematics or philosophy texts, abstruse language

• Findings…

  • Balance tilts faster to the head side the more complex the task

• Emotional reactivity

  • Reading a letter from a spouse or an angry creditor

    • “balance fell at once” - Mosso

  • Mosso’s balance board would soon fully explain the physiology of the human brain

  • Can fMRI really fully explain the brain’s functions?