PSYB65: Lecture 1 – History of Neuropsychology “Psychology has a long past, but a short history” – Hermann Ebbinghaus

Written record of the understanding of our selves is limited, only 10,000 years Humans have developed to be the only species that think about dying and death. Trephination

Surgical procedure that a hole is made in the skull, and some people survive. Reasons: medical or magical?

o After trauma, swelling occurs and removing part of the skull can help during the healing process.

o Maybe they were trying to understand psychological phenomena but actually going into the skull.

Modern Neurosurgery

Craniotomy/ectomy removing the brain flap (same idea) o Depressed skull fractures which is pushing the bone into the brain, removing the bone

helps as treatment o ICP monitoring/treatment swelling in the brain and relieving the pressure

Subdural/epidural hematomas o Deep brain stimulation for people with Parkinson’s

Biological Basis of Human Experience/Behaviour 2 themes in Western:

Cephalocentric – behaviours are caused from inside the brain o Alcmaeon of Croton

o Hippocrates o Plato

Cardiocentric – behaviours are caused from inside the heart it has nothing to do with the heart but it is part of our culture

o Empedocles of Acragas o Aristotle

Western Philosophy

Philosophy Natural Science

Ancient Egyptian, Greek & Roman Thinkers

Nature and locus of the mind very based on what they were exposed to at the time Advances in mathematics and philosophy

Early Greek Medicine

Prior to 500 BCE, medical practice was controlled by priests / Templar physicians Alcmaeon of Croton

Objectively dissected animals Established medical school to stop priests, etc. Holistic approach if sick, there’s some sort of imbalance in the universe or their universe

Hippocrates (460-377 BCE)

Founder of Modern Medicine Hippocrates oath – “First, do no harm”.

Brain hypothesis; Believed the brain was the seed of behaviour and experience. He based it on his own experience Eg. observing getting someone get hit in the head.

Contralateral organization in the brain Right side of the brain affects left side of the body, left side of the brain affects the right side of the body.

Epilepsy; he believed it is a natural cause, not divine cause. Believed the brain is the most powerful organ of the human body.

Aristotle (384-322 BCE)

Philosopher Conceptualized “Tabula Rasa” – we all start out as blank slates NOT true Psyche:

o Nonmaterial o Responsible for human thought, perception and emotion o Theological approach o Psyche = “Mind” o Position of Mentalism – thinking about the mind as an abstract concept, NOT tissue.

First true Empiricist – everything is learned through experience; this is how we become who we are.

Cardiocentric philosopher; put forth that the heart was the seed of though, perception and emotion.

o Eg. Belief that when they take out the heart, they die. Heart races because of emotion.

Life: Ladder of Creation – understood life as a continuum or hierarchy o Darwin used this understanding ancestor

Galen (130-200 ACE)

Physician/Anatomist Brain hypothesis; brain responsible for thought, emotion and perception Ventricular localization; thought the ventricles pushing through allowed for thought, emotion

and perception.

Bodily fluids/humors; thought the health and balance of the body was due to these fluids dominated for about 1000 years.

Rene Descartes (1596-1650)

Philosopher, he’s a thinker “I think, therefore I am” How can nonmaterial mind produce movement in the material body? Dualism – the mind and the body are separate but interact Mind

o Nonmaterial o Decides on bodily/machine movements

Body o Material o Analogous to a machine (reflexive)

In Paris, he saw a statue that moved due to hydraulic pressure. o He believed that ventricles of the brains and connectivity of tubes of fluid allowed for

behaviour to become animated. Similar to machines

o He attributed this to “The Pineal Gland” (a tiny structure which releases substances at the centre of the brain) one part that isn’t split down the middle.

FALSE

There will never be another Einstein, never another Darwin because before the technological age, people were allowed to study things and thought about things alone. Today, the world is an entire brain, and people collectively create ideas.

Lecture 2: Introduction to Neuropsychology Descartes: Pineal gland an essential structure in the central nervous system, it was located in the ventricle system necessary for the interaction to occur.

Roman Empire Dissolution of the roman empire; it was a secular nation; it was very successful. The fall of the Roman empire was known as the Dark Ages; no recorded history of any findings. History of Neuropsychology Dark Ages Psychological questions were often the province of religion 12th Century Cultural and economic revival Establishment of universities first universities were born into religious institutions.

Prior to Renaissance, there was a period of terrible strife the Black Plague were 1/3rd of the population were killed. 15th & 16th Centuries Periods of exploration, discovery, artistic achievement

Columbus, DaVinci – cast of the human ventricles, etc. Invention of Mass Printing*

Johann Gutenberg developed the first mass printing press he spread the word of God Nicolaus Copernicus (1473-1543) Astronomer “The Place of Human Beings in the Universe” He countered the idea that the Earth was the centre of the Universe AKA Geocentric viewpoint using

objective findings. He stated that the earth (and other planets) rotated around the Sun AKA Heliocentric viewpoint He published it on his death bed, so when others came to punish him, he’d already be dead. Galileo Galilei (1564-1642) Astronomer Dialogue on the Two Greatest Systems of the World, the Ptolemaic and the Copernican (1632) Character: Simplicio (he wrote his findings as a type of dialogue) He adopted the Heliocentric viewpoint. He perfected the telescope and could make more observations and findings. When he published his work 1633 - Tried and found guilty by the Vatican Avoided torture through indefinite house arrest and became almost totally blind 1992 - Pope John Paul II acknowledged that the Vatican had erred in convicting Galileo

Utilized method of manipulating, defining and measuring variables.

He dropped items from the leaning tower of Pisa and wrote about gravity Advocate for freedom of inquiry you could study what you wanted without worrying about authority Andreas Vesalius (1514-1727) Anatomist Successor to Hippocrates and Galen He dissected the brain, using amazing cuts, and found that the ventricular system was important in mind vs. behaviour interface. William Harvey (1578-1657) Physician & Scientist

Function of the heart as an organ untill this point in time, heart was thought as the “mind” and he showed that it was just a organ that pumped blood. Rene Descartes (1596-1650)

Theory for the Presence of Mind

Language Test Action Test for children, mentally ill, etc. Negative Outcome (of the test)

Bad results were thought to mean that these people didn’t have a mind. Treatment of children, animals, mentally ill resulted in inhumane treatment vivisection –

dissecting animals while they were alive, and the animals reaction were mechanical Descartes skull was separate from his body his dualistic viewpoint was true even after his death Evolution of the Human Brain & Behaviour Origins of the Human Brain and Behavior Cladogram – Graph that illustrates the relative time of origin of various closely related groups

We all have a common ancestor.

Primate Order

Excellent color vision, enhanced depth perception Hand-eye coordination

Females produce one infant per pregnancy Can operate the world with their upper extremities Females typically produce one offspring at a time more time is invested in their growth

Hominids

Humanlike ancestors that diverged from the ape lineage Changes in hand structure and brain structure

Species Comparison Why Study Nonhuman Animals?

Brain similarities and differences in humans and animals provide insight to brain-behavior relationships

Animals have less complex anatomy a lot easier to understand meaning they could represent the earlier development of humans

Genetic basis of behavioral can be studied in animals with short lifespans (Eg. fruit flies) Identify how the brain has evolved

Brain Evolution Sophistication of behaviour evolved.

Eg. fish having very basis need and behaviours Eg. Parrots able to mimic human speech

Questions Addressed by Studying Nonhuman Animals Understanding brain mechanisms

Uses cross species comparisons to understand basic brain function for a given behavior Designing animal models of human neurological disorders

L2

Origins of the Human Brain and Behavior

• Cladogram

–Graph that illustrates the relative time of origin of various closely related groups

16

L2

Brain Evolution

19

Researchers produce a human neurological disorder an in animal o Eg. dementia in older dogs

Cause and treatment for the disease can be examined through manipulation of variables o Eg. box apparatus to remember where something was kept as a test for dementia

Describing the phylogenetic development of the brain

Looks at animals in their environments to see how the environment shapes evolution of the brain and behavior

Makes comparisons between humans and other mammals Differences in brains and behaviors provide insight into how those differences appeared

Human Origins Hominid Evolution

Evolution is not linear Humans today are the only surviving member of the hominid branch

Human Evolution

Studied through archeological, biochemical and genetic, and behavioral evidence Human Evolution: Archeological Research Examine the bones, skulls, and habitat of hominids to reconstruct features of their brains and behaviors with limitations. How did the brain evolve with those artifacts? The brain was accommodating the challenges in the environment with a sophisticated behavioural expression. Human Evolution: Biochemical and Genetic Research Examines the amino acid sequence of a cellular protein in different species to determine when species diverged from each other. provides more evidence about our ancestral line. Relatedness of species can be determined by comparing their deoxyribonucleic acid (DNA)

Humans and Chimps have 99% of their genes in common Human Evolution: Behavioral Research

Compares behavior of one species to another species Jane Goodall

Observed behavior in chimpanzees Found strikingly similar behavior in chimpanzees and humans Great research models because they’re so similar to humans but banned because they have

similar human experiences. Stages of Human Evolution Four steps

1. An upright posture in which hands were free 2. Extensive tool use 3. A traveling life style

4. An elaborate culture Origins of Humans H. Neanderthals have on average larger brains than H. Sapiens but it’s relative to body size. Intelligence correlates with the brain components not size. Stages of Human Evolution Australopithecus: Upright Posture

Discovered by Raymond Dart Lived in eastern Africa Walked upright

“East Side Theory”

Yves Coppens Production of the Great Rift Valley in Africa

o Apes lived to the west unchanged o In the east apes had to evolve rapidly to new environment

Homo habilis: Tool use

Discovered by Louis Leakey and Olduvai Gorge Found in Tanzania Used stone tools Appeared after climatic change Were scavengers and involved the entire community to butcher and carry animals

Homo Erectus: The Traveler

Significantly larger brain than its ancestors Remains found in east Africa, Java, and China some sort of migration

Homo Sapiens: Elaborating Culture

Have various cultures, political organizations, agriculture, and economic relations Alan Thorne and Mildred Wolpoff

o Modern humans evolved from Homo Erectus

Rebecca Cann - “Out of Africa” Hypothesis o All modern people descended from “Eve”

The Origins of Larger Brains Larger brains:

Use more energy, expensive to maintain Must provide advantages in adaptations

Dean Falk

Changes in blood flow in Homo erectus allowed for increases in brain size Encephalization Quotient Encephalization Quotient (EQ)

Developed by Harry Jerison Ratio of actual brain size compared to expected brain size

Average mammal has an EQ of 1.0

Greater than 1.0 bigger brain than expected Less than 1.0 smaller brain than expected

Brain size vs. body size cats are exactly at 1, but Humans are high above 1, elephants brain size may be large but their corresponding body size resulting in almost 1. Brain is getting bigger. The Origins of Larger Brains Early hominids brain size = 440 cubic centimeters (cm3) Modern humans brain size = 1350 cm3

Rapid increase due to:

Hominids were getting larger Brains were getting larger

o The increases in size were not occurring at the same rate Changes in the Cortex As EQ increases, most of the increase of brain size occurs in the cortex Neoteny, animals Variation in Cortical Structure Areas of mammalian cortex are specialized for certain functions As areas of cortex grow and specialize they allow for the development of new behaviors

Examples: Use of the forepaws in animals, color vision in humans Eg. Dog’s olfactory systems are larger enabling great smell

Brain Size and Intelligence Is brain size related to intelligence? Is brain size related to intelligence between sexes or races?

Poor correlation between brain size and intelligence between people, races and sexes Why are brain size and intelligence unrelated in the same species?

Within-species behavior is uniform IQ tests are biased measures of intelligence humans are limited in understanding what

intelligence really is

Brain organization Brain size is influenced by injury and environmental experience

Intelligence is not higher in males, as Broca argued, because males typically have larger bodies. Structural Neuroanatomy Neuroanatomy: Finding Your Way Around the Brain

Locations of layers, nuclei, and brain pathways are described by their placement with respect to other body parts, with respect to their relative locations, and with respect to viewer perspective Frequently Used Anatomical Terms Rostral – closer towards the front of the nose Caudal – closer towards the tail to the spinal cord Dorsal – the top or superior surface, it follows along the central nervous system to the brain to the spinal cord Ventral – the bottom surface, and the more anterior aspect of the spinal cord Anterior or frontal Posterior = Caudal, towards the back

Lateral – sides towards the ears Medial – closer to the centre of the body Frequently Used Brain Sections Coronal - half way down Horizontal – half way across Sagittal – down the middle from the nose to the cortex and back Neuroanatomy: Finding Your Way Around the Brain Symmetrical Organization

Structures on the same side are Ipsilateral Structures on the opposite side are

Contralateral

Structures that lie in both hemispheres are Bilateral

Structures that are close together are Proximal Structures that are far apart are Distal Efferent – Movement away from the brain Afferent – Movement toward the brain An Overview of Nervous System Structure and Function Functional Divisions of the Nervous System

Central nervous system (CNS) o Brain and Spinal Cord

Somatic nervous system (SNS) o Spinal and cranial nerves

L2

Functional Divisions of the Nervous System

55

L2 51

Autonomic nervous system (ANS) o Balances the internal organs through the parasympathetic

and sympathetic nerves

Support and Protection CNS

Brain enclosed in the skull Spinal cord encased in bony vertebrae Meninges

o Three layers of membranes inside the skull and vertebrae o Dura Mater – thick like vinyl o Arachnoid Membrane – spider like web of material that encases the vascular parts of

the brain o Pia Mater – like cellophane

Cushioned by the cerebrospinal fluid (CSF) that continuously circulates. It provides a buoyant atmosphere for the brain.

Hydrocephalus PNS

Lies outside of bony encasements and protection of the meninges More vulnerable to injury, because it doesn’t have protection

Blood Supply Two carotid arteries and two vertebral arteries supply blood to the brain Connect at the base of the brain and branch off into the:

Anterior Cerebral Artery Middle Cerebral Artery Posterior Cerebral Artery

L2 57

Lecture 3: Structural Neuroanatomy Chapter 10 NOT included as testable material. Make sure to log on to Neuroscience for bonus marks access code is available on blackboard

Check out the Companion website – textbook outline, quizzes and flashcards Video: http://www.ted.com/talks/vs_ramachandran_the_neurons_that_shaped_civilization.html

One man puts it into perspective. A 3 pound lump of flesh can contemplate the universe, have emotion, produce movements, etc. There is quick revolution in terms of our abilities specifically in humans. Just by learning through mirror neurons (watching other people do things), neurons are activated, and acquisition of skills is enabled. Also, empathizing with other people also cause our neurons to fire, but we don’t actually experience it BUT if the arm is anesthetized, then one can actually experience the feeling of another person being touched.

Humans are literally connected through neurons.

(Continuation from the last lecture) Functional Divisions of the Nervous System Central Nervous System – brain & spinal cord Somatic Nervous System – highway between the central nervous system and the rest of the body Autonomic Nervous System – fight or flight systems and the regulation of the body Thick skull around our brain emphasizes how much protection our brain needs. The spinal cord is an intricate connection of vertebral segments. It’s exposed to enable movement, but still quite protected. Meninges form around the brain and spinal cord, continuously. It is the medium with which we have the cerebral vascular system providing nutrients and removing waste products from the brain.

Support and Protection CNS

Hydrocephalus – the ventricles are blocked during developmental phase or injuries/cancer, so the building pressure on the surrounding brain tissue can cause symptoms such as loss of consciousness or even death.

PNS is continuous with CNS; receiving and affecting the environmental stimuli Blood Supply for the Brain:

2 pairs arteries that perfuse the brain: o 2 from the back: Basilar arteries – Carotid arteries o 2 from the front: internal carotid artery - Vertebral arteries

Connect at the base of the brain and branch of into the:

o Anterior Cerebral Artery Along the middle of the

brain o Middle Cerebral Artery

Lateral aspect of each hemisphere

Stroke: language deficits o Posterior Cerebral Artery

Provides perfusion to the occipital lobe & the lateral and ventral aspect to the ventral lobes.

o These work to provide nutrients to those parts of the brain.

NOT covering developmental neuroscience (This week’s Lecture) Neurons and Glia Neural Stem Cells

Undifferentiated Capacity for self-renewal

Progenitor Cells

Develop from stem cells Give rise to blasts, primitive types of

nervous system cells

Blasts

Develop into neurons or glia 4 Results: Interneuron – common in the spinal cord Projecting neuron – commonly found in the brain Oligdendroglia – within the CNS Astrocyte Sensory Neurons

Biopolar Neuron Somatosensory Neuron

Interneuron

Link up sensory and motor neurons Reflex arc that does not have mediation from the brain itself

Motor Neurons

Project to muscles from the motor strip

B) Interneurons

Stellate cell in the thalamus o It’s detailed dendrites; it’s connected to many different neurons

Pyramidal cell in the cortex o Dendrites; Arburization – a fine branching structure at the end of a neuron

Purkinje cell in the cerebellum o Extremely detailed dendrites

The structure of the neurons are in this way to enable a specific function.

Glial Cells (just know the different types, but know function for the stars):

Ependymal Astrocyte

Microglial Olingodendroglial* Schwann*

*Difference between Olingodendroglial & Schwann O is found only in the central nervous system, S is found only in the peripheral nervous system. Gray, White and Reticular Matter Gray Matter

Colour from capillary blood vessels and neuronal cell bodies White Matter

Colour from axons covered in an insulating layer of glial cells Reticular Matter

Colour and appearance from cell bodies and axons; mix of both colours

Layers, Nuclei, Nerves and Tracts Gray matter can be divided into layers or nuclei. Layers or Nuclei

Well-defined group of cell bodies Most common nuclei: Basal nuclei Nuclei – large globs that perform functions they are distributed closely to perform functions

as groups layers

Tracts

White matter pathways or large collection of axons projecting to or away from a layer or nucleus within the CNS; CNS & PNS are continuous with these tracts.

Nerves

Fibers and fiber pathways that enter and leave the CNS Development of the brain:

As the embryo develops it starts to differentiate in the front end forming our sophisticated structures. *don’t have to know details.

The Origin and Development of the Central Nervous System Ventricles

Hollow pockets within the brain filled with CSF Numbered 1-4

o Lateral ventricles (1 & 2)

o 3 & 4 ventricles extend into the brainstem and spinal cord

continuous with the inside & outside of the brain

The Spinal Cord Spinal cord structure and the spinal nerves

Receives fibers from the afferent sensory receptors Send efferent fibers to control muscles If fibers are on the anterior aspect of the spinal cord, the

brain is sending information out to it.

30 spinal cord segments divided into 5 regions: o Cervical (8) o Thoracic (12) o Lumbar (5) o Sacral (5)

o Coccygeal Segment

Damage in these segments cause lots of problems One cannot necessarily have numbness across the continual area, it would be parts that follow a logical segment. Dorsal Root

Strand of afferent fibers entering the spinal cord Carrier sensory information to the brain

Central Root

Strand of efferent fibers leaving the spinal cord Carries motor information to the body

Cross section of a spinal cord:

This may occur during a reflex situation, Eg. pulling away from a hot stove.

Spinal Cord Function and the Spinal Nerves Bell-Magendie Law

Francois Magendie and Charles Bell Principle that the dorsal part of the spinal cord is sensory and the ventral part of the spinal

cord is motor Spinal cord is capable of complex actions

Reflexes

Specific movements elicited by specific stimuli the reflexes cause the muscles to go in one direction either withdraw or extend.

Eg. Stimulation of pain receptors = Flexion (withdraw), Stimulation of fine touch = Extension (extend)

Connections Between Central and Somatic Nervous System Cranial Nerves

12 pairs, overseen by the brain can have afferent functions, efferent functions or both

Where the nerves are connected to the face Not too much detail in the Cranial Nerves:

Autonomic Nervous System Connections Two Divisions; they oppose one another (when one is on the other is off):

Sympathetic o Arouses the body for action

When activated, the thorax system shuts down (the digestion shuts down), but heart rate increases (more breathing).

o Fight or flight Eg. running away from a large dog

o Spinal nerves in the thoracic and lumber regions are connected to the sympathetic ganglia

Parasympathetic o Calms the body down o Rest and digest o Connects with parasympathetic ganglia near target organs

We need this because if one or the other don’t shut down, constant sympathetic system harms your body.

The Brainstem Three regions:

Diencephalon Midbrain

Hindbrain Produces more complex movements than the spinal cord. The more vital functions are you move down the spinal cord. Hindbrain Cerebellum

Surface fathered into folia Coordinates and helps learn skilled movements Very sensitive to the affects of alcohol =

problems walking Reticular Formation

Maintains general arousal

Formation of the brain cells that’s responsible for sleep, wake and arousal Makes sure that you shut down during sleep, so we don’t act out our dreams

o Problems would be caused by some sort of trauma

Pons & Medulla

Serve many functions, including waking, sleeping and locomotion

Midbrain Tectum

Located dorsally “roof” sensory input from the eyes and ears

Tegmentum

Located ventrally “floor”

Composed of the superior colliculi, input from the eyes (visual), & inferior colliculi, input from the ears (audition)

Colliculi mediate orientation of movement to sensory input

Red Nucleus

Limb movements Substania Nigra (means dark because the structure is dark)

Reward and initiation of movement Clinical syndrome, Parkinson’s disease is associated with it; they have difficulty initiating and

coordinating movement

Periacqueductal Gray Matter

Species-typical behaviours Eg. sexual behaviour Modulating pain response

Lecture 4: An Introduction to Human Neuropsychology NTK is all ready to go, first activity is due Sunday, October 6th. Diencephalon

Hypothalamus

Interacts with the pituitary gland Participates in nearly all aspects of motivated behavior Involved in host activities: hunger, thirst

Epithalamus

Poorly understood; Biorhythms, hunger, thirst

Thalamus

Relays sensory information to appropriate targets

Relays information between cortical areas

Relays information between forebrain and brainstem

Forebrain Three main structures:

Basal Ganglia Subcortical Limbic System Cerebral Cortex

Basal Ganglia

Collection of nuclei that includes the: o Putamen o Globus Pallidus o Caudate Nucleus

Supports stimulus-response learning Functions in sequencing movements These form 3-d type of format

Diseases of the Basal Ganglia

Huntington's Chorea o Genetic disorder o Cell death in the basal ganglia o Involuntary “dance like” movements

Parkinson’s Disease o Projection from the substantia nigra (small group of cells with dark presentation) to the

basal ganglia dies o Rhythmical tremors in hands and legs o Rigid movement and difficulty maintaining balance

Start shuffling their feet Pill rolling

Diseases of the Basal Ganglia o Tourette’s Syndrome – inability to control one’s behaviour in a socially appropriate way

Eg. yelling, no social function, motor ticks Basal ganglia diseases are disorders of controlling movement, not producing movement

LEC4 8

LEC4 3

Limbic System (limbic lobe)

They are associated with forming memories. Amygdala, specially related to emotional memories; overly active with PTSD.

o Amygdala o Hippocampus o Septum o Cingulate Cortex (cingulate gyrus)

Neocortex (cerebral cortex)

Has expanded the most during evolution Comprises 80% of the human brain Six layers involved in different levels of processing *don’t have to know details* Two cerebral hemispheres, four lobes

EXAM: pictures such as these with blanks Fissures, Sulci, and Gyri Fissure

A cleft in the cortex that is deep enough to indent the ventricles

Sulci

A shallow cleft in the cortex Gyri

A ridge in the cortex

LEC4 10

LEC4 12

LEC4 14

Organization of the Cortex in Relation to its Inputs and Outputs Projection Map

Map of the location of the inputs and outputs to the cortex

Primary Areas (allows conscious & collective experience)

Frontal lobe - Motor functions Parietal lobe (behind the central sulcus) - Body senses Temporal lobe - Auditory functions Occipital lobe - Visual functions

Secondary Areas

Adjacent to primary areas (involved in solitary or isolated function)

Receive input from the primary areas and provide additional processing

Engaged in interpreting sensory input or organizing movements

Tertiary Areas (Association Cortex)

Located between secondary areas o Largest area is in the parietal lobe

Mediate complex activities Cellular Organization of the Cortex Cytoarchitectonic Map

Map based on the organization, structure, and distribution of cortical cells

Brodmann’s Map o Most widely used cytoarchitectonic

map o Shows that cells closer together tend

to perform the same functions Connections Between Cortical Areas Neocortical regions are connected by four types of axon projections:

Long connections between one lobe and another o Fibers going from the white matter to parietal lobe

Relatively short connections between one part of a lobe and another o U-shaped fibers connecting gyri

Interhemispheric connections o Cerebral hemispheres communicate through the corpus callosum

Connections through the thalamus o Small bands of fibers where these structures communicate with one another

*Don’t need to know where the tracts & fibers are, just know what they are and the type of function*

LEC4 16

LEC4 19

LEC4 21

The Crossed Brain Brain has contralateral organization

Each symmetrical half responds to sensory stimulation from the contralateral side or controls musculature on the contralateral side

Decussations

Crossings of sensory or motor fibers along the center of the nervous system Largest is in the lower brainstem where white matter pathways cross over

Neuroimaging Procedures Video: why do we study brain structure & function?

Wisconsin card-sorting task Healthy twin shows more activity in the brain than unhealthy twin

Video: Observing Electrical Activity in the Brain: The Magnetoencephalogram (MEG)

MEG picks up small electrical activity; showing how the brain works together and what parts are used

Different areas “light up” very quickly Video: Touching the Brain: Electrically Stimulating the Speech Regions of the Brain

Removal of tumor near language regions of the brain The patient must be awake; so they can continuously test the language capabilities throughout

the surgery so that they don’t damage critical language areas. She counts till 5, but when they electrically stimulate a critical part of language, she is unable to continue till 10.

Imaging the Brain’s Activity Electrical Recording

Detect changes in the electrical activity of the neurons o Animals mostly

Brain Stimulation

Induce changes in the electrical activity of the neurons o Surgical procedures; uniqueness of each patient o Conservative treatment – they just monitor the patient (used when critical parts of the

brain may be affected and this prevents further damage)

o Liberal treatment– actually conducting surgical procedures and invasive procedures X-Ray Imaging

Sensitive to the density of different parts of the brain Dynamic Imaging

Records and manipulates ongoing changes in brain activity Recording the Brain’s Electrical Activity Three techniques for electrical recording (while it’s working or baseline activity):

Single Cell Recording Electroencephalograph (EEG) Recording Event Relate Potential (ERP) Recording

Single Cell Recording (animals mostly) An electrode is inserted into the brain, adjacent to a neuron, the neurons activity is recorded

LEC4 23

Many individual neurons can be recorded simultaneously Can record a single action potential or many action potentials

The Neuronal Code Neurons exhibit different firing patterns in different species, in different circumstances and during

different behaviors (shown experimentally) Information can be encoded in several ways:

Time code Event code Frequency of firing

Levels of Neural Processing Brain uses codes to represent information Single-cell recording in the visual system

Ganglion cells and LGB (lateral geniculate body) cells respond to dots of light Cells in primary visual cortex respond to bars of light of specific orientation Higher visual areas respond to more complex stimuli

o Eg. Prosopagnosia – unable to recognize faces; small lesion in the brain that doesn’t allow them to recognize faces which is encoded this information in the fusiform gyrus

Well-learned behavior = few neurons “refined” Newly learned behavior = widespread activity

Electroencephalographic (EEG) Recording EEG records electrical potentials “brain waves” in the brain Generator – neurons that regulates oscillations within the brain; reviving the brain and keeping it in sync EEG used for:

Sleep studies: o Completing REM sleep means

that you had a good sleep o Problems in the brain can cause bad sleep patterns

Depth of anesthesia o Makes sure people wont wake up during a surgery

Studying normal brain function EEG patterns are associated with particular behavioral states:

Beta Rhythm – alert & conscious Alpha Waves – more relaxed

Theta Waves – sleeping Delta Waves – deep sleep

LEC4 28

LEC4 33

LEC4 35

EEG can be used to diagnosis epilepsy Forms of epilepsy

Petit Mal – small seizures

Grand Mal – drop to the ground, foaming on the mouth, full blown out seizure

EEG is used to provide information about cause and location of problems Event-Related Potentials (ERPs) – event is presented to the individual and wave forms that follows are tracked by the EEG Brief change in a slow-wave EEG signal in response to a discrete sensory stimulus is classified as an ERP Stimulus is presented repeatedly and the recorded responses are averaged. Changes in the brain are seen instantly*

Can be used to produce maps of cortical function Different groups of neurons respond successively to the stimulus producing positive and negative waves. We can generate characteristic wave forms representing internal events.

People shown new images show characteristic wave forms, but if they’ve seen it before, knowingly or not, the wave forms are typical and non-characteristic.

Multiple recording

Records ERPs from many different cortical sites

Can indicate which area of the brain is responding the most

ERPs used to study:

Normal function of brain pathways Cognitive processing during learning about the stimulus Hemispheric differences Planning and execution of movement

o Readiness potential: you can see the brain preparing to act

Magnetoencephalograpy Records magnetic fields of neurons Permits 3-D localization of the cell groups generating the magnetic field Pro: High resolution; Con: Expensive SQUID

Superconducting coils that detect the brain’s magnetic field Isocontour Map

Chart with concentric circles representing intensity of magnetic fields Video: Perception and Recall of Faces

LEC4 39

LEC4 41

LEC4 37

LEC4 43

Lecture 5: An Introduction to Human Neuropsychology NTK: complete it; it will get harder, but it will help with the exams

Functional brain imaging is important* Magnetoencephalograpy (MEG)

Exploits the relationship between electric fields/signals and magnetic fields o Eg. when an axon has a electrical signal travelling down it, which also has an impact on

the environment, magnetically.

Records magnetic fields of neurons Permits 3-D localization of the cell groups generating the magnetic field

o Greater depth than an EEG, and better triangulation (tracking the neurons)

Pro: High Resolution Con: Expensive

SQUID: high-resolution magnetic field sensitization technique, producing an Isocontour map: showing the surface of the brain in concentric circles which represent levels of activity (better to track processing)

Brain Stimulation

Electrical current is used to stimulate brain tissue Intracranial Brain Stimulation

o Deep Brain Stimulation (DBS) Electrodes implanted in the brain to stimulate the tissue Used as a treatment for Parkinson’s disease

Presents itself with motor impairment Treatment activates parts that aren’t normally activated; improving their

brain and movement

Transcranial Magnetic Stimulation (TMS) o Stimulation of the brain using a magnetic stimulator

Magnetic stimulator – small wire coil in the shape of a figure 8 Has an impact on the brain around it, and shuts it down

o Non-invasive Used for depression, all types of things.

o Can be used to map functional regions of the brain

o

X-Ray Imaging Techniques

First methods for imaging the brain; first non-invasive method Produce static 2-D image of the brain Conventionally radiography

o Passing x-rays through the skull onto an x-ray sensitive film; x-ray = radiation = health problems

o Different types of tissue absorb the rays to different degrees producing an image that show the tissue location; “squishes it together”

o Still used for examining the skull for fractures and looking for gross brain abnormalities

Pneumoencephalography o Small amount of cerebrospinal fluid (CSF) is removed from the subarachnoid space and

replaced by air o X-rays are taken as the air moves upward and into the ventricles o Ventricles stand out in the image due to air; NOT squished together o Painful (injecting fluid and impacts the brain) o Currently, not used much

Angiography o Substance that absorbs x-rays is injected into the bloodstream o Produces an excellent image of the blood vessels (dye is absorbed); assume the more

absorption, the more “activated”

o Can be dangerous and painful o Used for aneurisms and strokes

o Computerized Tomography (CT Scan)

o Passes narrow x-ray beams through the brain at different angles to great different images and then combines the images to create a 3-D image of the brain

o Cannot discriminate between gray and white matter; but it’s cheaper, faster and can show acute trauma faster than an MRI

o Ventricles and major fissures can be seen

o

Functional Brain Imaging

Provides a way to look at the brain without using dangerous or unpleasant procedures

MRIs are becoming more popular; but it’s more expensive and lots of more processing BUT it’s a very good scan technique

Positron Emission Tomography (PET) o Radioactive molecules injected into the bloodstream or inhaled; it quickly spread o Molecules release particles that are detected by the PET camera; we assume that parts

of the brain that is used more, absorbs more molecules

o An image representing areas of high and low blood flow is produced o They use different experimental designs; subtraction technique person is in a block

where they do nothing and one design where they do everything but the thing that experimenters are interested in.

o o modern PET cameras obtain multiple parallel brain slices o images consist of voxels: 3-D imaging regions that are 2 mm3 (adjacent to one another)

allows lots of ways to show the maps o PET does not measure neural activity, it infers it through the assumption that blood

flow increases in areas where neural activity increases o Parallel Slices through the brain; shows whatever part of the brain is responsible for the

activity (mostly focused on language) & the molecules breaking down over time:

o

o use the subtraction method

they subtract blood flow pattern at rest from the pattern while the subject is engaged in an experimental task; dark areas = less active, bright areas = more active

Occipital lobe:

o Advantages

Can detect a wide range of radiochemicals Can detect relative amounts of a neurotransmitter, density of receptors,

degenerative processes or metabolic activities that occur during learning Widely used to study cognitive function

Eg. language o Disadvantages

Indirect measurement of neural activity Subtraction process Images not great with resolution

Magnetic Resonance Imaging (MRI) o Uses a large magnet and a specific radiofrequency pulse to generate a brain signal that

produces an image; very uncomfortable experience (loud, big machine, small space) o Magnets – variations in strength (Tesla) o High resolution, voxel size better PET o The head coil fired in radio frequency waves, and then flips the protons, and the energy

given off from the flips is captured but the coil. The board presents a magnetic field that orients the protons in one direction. But it's the coils that are important, based on the direction of the energy fired out = image.

o

o Advantages

Can display changes in neural activity No subtraction process; block designs still used to magnify and isolate the signal High spatial resolution

No averaging across subjects o Disadvantages

Poor temporal resolution 8-9 seconds ago, that change is recorded When firing in the brain; the blood-oxygen level in the brain; has shifts in

oxy-hemoglobin and de-oxy-hemoglobin related to it’s use and activity; rest means these 2 are equal, but when active oxy is up.

Looking for these differences showing what areas of the brain are active and which aren’t

Expensive Difficult to ensure

MAGNETIC; meaning the board had a huge magnetic field, that gravitates everything METAL towards it.

Diffusion Tensor Imaging (DTI) o Based on properties of water molecules around axons. o MRI method that images fiber pathways by detecting directional movements of water

molecules o Movement of water tends to follow the longitudinal axis, referred to as anisotropy o Can detect these changes showing degeneration of axons, distortion of fibers and

damage to fibers o Can be combined with MRI, fMRI, and ERP o Lots of data; colour overlay

o

o Shows the connection and how it is recorded with DTI

Some Brain-Imaging Techniques Compared

Single-cell recording

o Highest resolution o Lowest generalizability o Invasive

o Research done with animals (primates)

EEG o Little information about activity of a single neuron o Uncomplicated, inexpensive and noninvasive o Great to understand brain-behaviour relationship

X-Ray o Quick static snapshot but it’s collapsed o First for medical application

MRI & fMRI (best at the moment) o High resolution

PET o Biochemical status of the brain

Toward Multimodal Atlases of the Brain

Brain-imaging atlases can represent neural structures and their pathways Brain-imaging methods can then be used to document the progress of the brain disorders Computing methods now allow for more sophisticated brain atlases

NOT TESTABLE: Whole Brain Atlas online at the Harvard Medical School website: http://www.med.harvard.edu/aanlib/ EXPLORE: Multiple Sclerosis and Cancer

MIDTERM: Saturday October 26th 2013 He’ll be adding a lecture (online) to make up for missed lectured chapters. He won’t be cutting down more chapters (other than chapter 10). He’ll be posting sample questions, to help practice for the exam. Questions are memory based and concept based. Side note: He’ll be referring to clinical cases throughout the rest of the course to apply our knowledge. VIDEOS:

MRI video about language abilities o Anna speaks 2 languages and was found to have a brain tumor, but found that those

who’ve learnt a second language, each language is controlled by a separate region of the brain. They wanted to know that the tumor removal wouldn’t affect languages; so they used fMRI approach as saw that the removal wouldn’t have an impact.

Electroconvulsive Therapy o Electrodes are applied to the head, and the patient is shocked to help with lesions. The

patient becomes rigid and has intense muscle spasms. The firing of the brain results is this pathological response.

Lecture 6: Completing Last Few Chapters He’s posting sample questions throughout the week! He’s focusing on the main concepts*

History of Neuropsychology Thomas Willis

“Circle of Willis” – Blood supply system at the base of the brain forming this circle The seat of the brain for him was the corpus striatum – deep within the brain (don’t need to

know detail). He proposed that deep large structure in both hemispheres as the “centre” instead of the pineal body.

Guillotine – French were famous for using this device to chop off people’s heads

People were very interested in this public display During the beheading, they would make faces, utter words, etc. Where does the body and

head begin how is the head able to talk?

Robert Whytt

Decapitated frogs if you pinch the leg, the leg still reacts without the head attached

An Essay on the Vital and Involuntary motions of Animals The Spinal Cord & Peripheral Nervous System

People studied animals’ spinal cord (it’s exposed, and they could experiment with it, and the animal could still stay alive ACCESSABILITY)

What sort of dissections resulted in different behavioural impairments? Charles Bell (1774-1842)

Idea for a New Anatomy of the Brain Dissected rabbits and figured out the spinal cord system: Dorsal root dissection responsible for

o Involuntary behaviour

Ventral root dissection responsible for o Voluntary behaviour

TODAY, it’s the OPPOSITE Francois Magendie (1785-1855)

Journal of Physiology and Experimental Pathology Vivisection (live) research with puppies (blame Descartes – animals are machines) Dorsal root dissection responsible for

o Sensation

Ventral root dissection responsible for o Movement

ACCURATE CONCLUSION = Bell-Magendie Law

ventral and dorsal roots differ in their functional abilities Johannes Peter Muller (1801-1858)

Confirmed Bell-Magendie Law Law of Specific Nerve Energies** on EXAM

o Each nerve imposes its own specific quality on what we perceive o Eg. if you poke your eye and see the black circle, the black circle is not real o Eg. head injuries with stars circling o We activate the nervous system!

o The doctrine predicted that different stimuli acting on the same nerve should produce the same sensation.

Franz Joseph Gall (1758-1828)*

Father of Phrenology Speculated that individual characteristics were associated with

external features of the skull

Underneath the skull, the skull formation reflected the brain’s abilities Johann Caspar Spurzheim (1776-1832)

Partnered to develop a perfect knowledge of human nature based upon the study and measurement of the skull

They collected a sample database PHRENOLOGY WAS DISPROVED Phrenology Disproven

Richard Porson o Professor of Greek o University of Cambridge o Postmortem, his skull was found to be thicker than any previous person dissected in

Europe. As well, his brain was the smallest.

Spurheim his skull was even thicker. Emphasized that we must find a real brain behaviour relationship

Marie-Jean Pierre Flourens (1794-1867)

Worked with animals Methodology of Ablation (surgical removal of body tissue, specifically brain tissue in his case) Two Guiding Principles to study the nervous system:

o The parts of the brain to be studied should be anatomically separate and distinct

So they can be replicated o Behavioural analysis needs to take place before and after surgical intervention

In order to compare analysis, otherwise you don’t know whether the animal was able to do something before the surgery

Concluded: o Cerebral lobes = voluntary actions o Cerebral lobes = perception o Cerebellum = motor coordination o Medulla oblongata = “vital knot” (because it was responsible for homeostatic actions

that keep us alive)

For Flourens, the unity of the brain was the reigning “grand principle” – the brain is an entire structure, in unison acting.

Contributed to the concepts of equipotentiality – theory that it doesn’t matter what aspect of the cerebrum that you remove from an animal or human, it matters what the amount is; the amount of tissue removal tells us the amount of damage caused, instead of localization. BUT it’s animal research, they can’t inform us the actual damage not applicable to humans.

Concluded that the brain is the seat of the mind through his animal research Phineas Gage

the steak went through his head and his didn’t have a functioning right eye, but his intelligence was intact, but he lost social skills.

Language

Separates us from other species and gives us a symbolic interpretation

Egyptian script explains how we should conduct ourselves in society interesting how we were able to communicate such a complex concept in ancient times

Pierre-Paul Broca (1824-1880)

President of the French anthropological society Proponent of Flourens (believed in equipotentiality but he was against localization) 1861- Climactic debate regarding localization Patient named Leborgne

o History of epilepsy, right hemiplegia, and lost his speech 21 years earlier o He couldn’t speak, could utter “TAN” and profane words BUT he could comprehend and

understand language but couldn't’ vocalize. o Broca’s postmortem examination changed his opinion and arguably affected

neuropsychology more than any other finding to date. o The lesion of the frontal lobe was the cause of the loss of speech

Change the way of thinking for scientists all over the world Carl Wernicke (1848-1905)

Understood language could be associated with different parts of the brain

Some people could speak, but it didn’t make sense and they couldn’t comprehend any information new lesion.

Receptive aphasia Associated with damage to the superior portion of the left temporal lobe Speech output was rapid and effortless but conveyed

little meaning

There must be a connection between Broca and Wernicke’s area if severed = conduction aphasia – theyre able to speak and understand, but the

connection is broken down = deficits o Arcuate of Fasciculus connects it

Primary motor cortex near Broca’s area = vocalization of speech Primary auditory cortex near Wernicke’s area = receptive of sensory information from the ears (language being received) Hemispheric Specialization Behavioural Asymmetry

The brain (like the body) is bilateral but there is some asymmetry o Left hemisphere and right hemisphere is different

The cortex is connected underneath o Cerebral cortex is most evolved = functional abilities that make

us uniquely human

Connections between hemispheres: Anatomical Asymmetry

RH is larger and heavier, LH is more dense Differential protuberances: in the frontal (RH) and occipital (LH)poles Frontal operculum (Broca’s area): larger subcortical component in LH more complicated

speech, RH just has more surface area

Parietal lobe: larger in RH

Temporal lobes have a marked asymmetry Lateral fissure is longer on the LH, RH is

shorter and steeper (but parietal lobe has

more space)

Above, the hemispheres are compared and there are more dendrite branches in the LH

than the RH

Differences must occur from the genetic level

Asymmetry in Neurological Patients

Double Dissociation o Two areas of the cortex are functionally dissociated o Each test is affected by a lesion in one zone but not in the other o Used to prove that one area is functionally specialized; Eg. lesion in the right frontal

lobe vs. left frontal lobe produces differential deficits (in left you can do X not Y and right vise versa)= double dissociated

Corpus Callosum o Millions of fibers connecting the two cerebral hemispheres cutting these connections

= experience the world in a sensory perspective in a separate fashion occurs to treat epilepsy when the seizures generalize and cross the corpus callosum causing a full blown out seizure (no localization in the brain).

o Park & Kim: conducted a corpus callosotomy

o Both eyes receive information from both sides of the visual field after the corpus callosotomy the

information is received but the information cannot go between hemispheres for processing:

Video: Corpus Callosotomy o Words on the right of the screen goes to his left hemisphere is read easily, but on the

left side of the screen, he doesn’t see it. However he can draw what word he saw with his left hand, but cannot recall what it is. Example of free will: when two words flash at the same time “HOUR GLASS” he only saw glass, but his right hemisphere still processes HOUR and he ended up drawing an hour glass, and was able to name it, even though to him, he never saw HOUR.

Brain Stimulation

Penfield o Neurosurgeon o Did brain stimulation procedures with open-brain and researched Homunculus

representation The WADA Test

Injection of sodium amobarbital to produce a period of anesthesia in one hemisphere; you can shut the hemisphere to sleep

Allows for the study of each hemisphere (epilepsy – test to make sure that language doesn’t get affected before treatment)

Useful for determining lateralization of speech What about hemispheric specialization in the intact brain or non-invasive approaches?

Non-Invasive Approaches

Asymmetry in the Visual System o Tachistoscope can bee used to present information to each hemisphere independently

Asymmetry in the Auditory System o Dichotic listening

Simultaneous presentation of two different stimuli to the left and right ears Subjects report which stimulus they heard most clearly; tells us which ear is

most dominant

Asymmetry in the Somatosensory System o Dichaptic Test – subjects feel objects and then identify those that they touch o Right hand better at reading braille & feeling objects that have symbolic representation:

letter, symbol or a number.

Asymmetry in the Motor System o Direct Observation

Watch subjects performing different tasks to see which hand is more active

BUT some people are ambidextrous and some people are completely dominant in a certain hand

o Goodale: MABOPI Saying a word; shown in slow motion, this showing the

left hemisphere is more dominant in the motor aspect of speech

Emotional expression are more quickly expressed on the left side of the face than the right side of the face; corresponds to the right hemisphere

Lasson: Speaking and listening activities***:

What factors account for cerebral asymmetry and corresponding behavioural differences? Gender Differences (he’s focusing on this at least for the lecture) Sex differences in Behaviour

Motor skills o Men superior at throwing and intercepting objects o Women superior at fine motor tasks

o Both present in young children (genetic or environmental influence)

Spatial analysis o Men superior at mental rotation (neuropsychological test that men were able to rotate

objects in their head) and in spatial navigation o Women superior at spatial memory

Mathematical Aptitude o Men superior at mathematical reasoning o Women superior at computation

Perception o Women more sensitive to all sensory stimuli except vision o Men superior at drawing mechanical objects

*Read through descriptions*

Verbal Ability o Women superior verbal fluency and verbal memory

Aggression o Physical aggression more prevalent in men than women

*Briefly look over this*

Sex Differences in Brain Structure

Male brain larger than female brain Females: larger volumes in areas associated with language, in medial paralimbic regions and

some frontal lobe regions

Men larger: o Medial frontal and cingulate region o Amygdala and hypothalamus (aggressive fight or flight response)

o Ventricles and overall white matter

Differences in volume and organization in gray matter Influence of sex hormones*

o Sex differences in the brain appear due to the distribution of estrogen and androgen receptors during development

Established asymmetries o Larger left planum temporale (Wernicke’s area) found more often in men o Men have larger asymmetry in the Sylvain fissure larger parietal lobe o Planum parietale is about twice as large in men o Women have more Interhemispheric connections

Hormonal Factors

The Homosexual Brain

Homosexual men outperform all groups on verbal fluency Homosexual women throw more accurately than heterosexual men Research: that larger the litter of humans more likely to have a homosexual child because

less testosterone for men or left over testosterone for women

Transgender: the person had double XX or YY the hormones during their development has a large impact on their psychology and causes them to identify with the opposite sex

Hormone studies done with animals have these same affects Sex Differences: Hormonal Theories

Organizing effect o Effects of hormones on brain organization o Leads to sexual differentiation

o Assumed to take place during development

Functional effects of hormones seen in adulthood o High estrogen associated with depressed spatial ability

o Low testosterone associated with high spatial ability in men o Hormone replacement in women increases verbal fluency and verbal and spatial

memory

Conclusions: o Six significant behavioural differences appear between men and women

Verbal ability Visuospatial analysis Mathematical ability Perception Motor skills Aggression

Neurophysiology The Neuron: Structure & Function

How the neuron is special * Cell membrane, dendrites, axon, etc.

Cell Membrane

Extracellular fluid Cellular membrane: comprised

of a phospholipid bilayer: lipid component moves away from aqueous environment and the phosphate component go

toward the outside or inside of the cell = sandwich layer

Intracellular fluid or cytoplasm How do substances cross the membrane? (action potential) Channels

o Protein structures through which a substance can pass through o Specific for proteins

Gates o Some proteins can change shape, thus creating a gated channel o Differences types of stimulus Eg. temperature

Pumps o Act as a transporter molecule against a gradient that requires energy to move

substances across the membrane Briefly talked about it:

Action Potential

Saltatory Conduction & Myelin ** MIDTERM o insulation around an axon created by the Schwann

cells in the PNS and the oligodendroglia in the CNS

Jumping of the action potential from one node of Ranvier to the next

o increases the rate of transmission of the action potential

Neural Transmission

Focus on the process of synaptic transmission** The 4 steps & the different systems:

NTK QUIZZES WILL BE UP SOON!

MIDTERM EXAM THIS SATURDAY, OCTOBER 26TH, 2013 AT 9AM FOR 90 MINUTES, LOCATION WILL BE POSTED!