[PSYC 3723] Term Test #1

Neuropsychology

• study of the relationship between brain function and behaviour

• helps answer the question “how does the brain work to produce behaviours?”

• can identify the impairments in behaviours 

Mentalism

“of the mind”

Aristotle

proposed that “psyche” (mind) is responsible for human thoughts, perceptions, and emotions

Dualism

behaviour is caused by two things

Rene Descartes

• first neuropsychology text, “Traite de L’Homme”

• proposed that the body is like a machine

Descartes’ Concept of Reflex Action 

heat from the flame causes a thread in the nerve to be pulled, releasing ventricular fluid through an opened pore

Pineal body; pineal gland

• the site of action in the mind was the _____ aka _____

• a small structure in the brainstem

• controls the valves that allowed CSF to flow from the ventricles through nerves to muscles, filling them and making them move

Charles Darwin and Wallace

two naturalists were struck by the many similarities between organisms — nervous system of humans and monkeys are similar

brain is a physical entity

that can communicate and interact with the physical world through the use of the body (i.e. spinal cord, nerves, muscles, etc.)

Stereotaxic device

• holds the head in a fixed position for surgery

• advances in local anesthetics allowed patients to remain awake during surgery

  • Awake patients can communicate what they feel when the surgeon points out the part in the brain; thus surgeon would draw a map of the lesion to discover the exact extent of the damage

Psychometrics

the science of measuring human mental abilities and applying statistical analysis

Francis Galton

• conducted the 1st systematic study of the cause of our individual differences

• paid 3 pennies to participants to allow him to measure their physical features, perceptionism and reaction times

• GOAL: finding individual differences that could explain variations in intelligence = we’re not able to distinguish the people from average to intellectually gifted

• ranked his participants on a frequency distribution graph aka the “bell curve”

• Nowadays, people uses Virtual Reality (VR) to assess/test their behaviour

  • ex: person walk through a VR house and observe the locations of items, then being tested in a memory test

Neuroimaging

technological advances that allows us to observe the living brain

Jean-Martin Charcot

developed a method of collecting symptoms and relating them to brain pathology after death

Multiple Sclerosis (MS)

a degenerative disease characterized by a loss of sensory and motor function results from hardening of nerve-fiber pathways in the spinal cord

Brain imaging

allows for rapid correlation between symptoms and brain pathology and is an essential diagnostic tool 

Structural brain imaging

reveals the structure of the brain, its cells, and their connections

Functional brain imaging

reveals that different parts of the brain are associated with different behaviours

Computerized tomography (CT)

scanning involves passing X-rays through the head

Positron emission tomography (PET)

entails injecting into the bloodstream radioactive substances that then decay in minutes

Structural MRI

can display the structure of the brain based on different tissue densities

Functional MRI

can detect activity based on blood oxygen levels

DTI

can detect the directional movements of water molecules

Franz Josef Gall 

• believed that the cortex and its gyri were functioning parts of the brain and not just coverings for the pineal body

• began with an observation made in his youth (students with good memories had large protruding eyes) which led to his hypothesis called

  “localization of function“

  • that a different specific brain area controls each kind of behaviour

• proposed that a bump on the skull indicated a well-developed underlying cortical area thus a greater capacity for a particular behaviour

  • ex: a person with good memory had protruding eyes, a high degree of musical ability, artistic talent, etc. would have larger bumps in other areas of the skull

Phrenology

• means of conducting personality assessments

• as it flopped, it led to the idea of Distributed Function

Cranioscopy

a device was placed around the skull to measure its bumps and depressions

Flourens & Goltz 

• challenged the idea that brain functions are localized by creating animal models of human clinical cases and removing small regions of the cortex

• expected that the animals would lose specific functions but instead found his animals recovered as nothing happened

localized function; distributed

• brain function have _____ and is _____

• HOCKEY EXAMPLE:

  • their different individuals w/ different roles but has the same goal in hockey

  • one guy is down, but his team are in the ice, but would need to work harder to score a goal

Somatic Nervous System

• brain and spinal cord

• consists of 2 sets of inputs and outputs to the CNS

  • coming into the body (touch, taste, etc.)

Autonomic Nervous System

• controls functioning body of the body’s internal organs to “Rest and Digest” through the parasympathetic (calming) nerves or to “Fight or Flight” through the sympathetic (arousing) nerves

• things that we are not aware of

  • we have nerves, internal organs, etc. but we don’t feel it

Parasympathetic system

• calms the body

• “Rest and Digest”

Sympathetic system

• arouses the body for action

• “Fight or Flight”

Meninges

• outer most layer

• It’s like skin—a protective barrier

Cerebrospinal Fluid

• Fluids that help the brain

  • Think of ice cubes, with water in it, you wouldn’t hear sounds when put in water. That is how important CSF (Cerebrospinal Fluid) is for the brain

• circulates through the brain’s four ventricles, the spinal column, and within the subarachnoid space in the brain’s meninges

Blood-brain barrier

protects the brain and spinal cord by limiting the movement of chemicals from the rest of the body into the CNS and by protecting it from toxic substances & infection

Sensory Neurons

• bring information to the CNS

• projects sensory receptors in the body into the spinal cord

• its dendrite and axon are connected which speeds info conduction

• BACK

Interneurons

• associate/link-up sensory and motor activity in the CNS

• just in-between, they simply connect sensory neuron and motor neuron

  • ex: REFLEX

Motor neurons

• send signals from the brain and spinal cord to the muscles

• located in the brainstem and spinal cord to project to facial and body muscles

• “THE FINAL COMMON PATH”

  • because all movement produced by the brain is passed through them

• FRONT

nuclei; ganglia

a large, well-defined group of cell bodies in the CNS form _____. Within the PNS, such clusters are called _____

tracts

• fibre pathways, bundles of axons

• are large collections of axons projecting toward or away from a nucleus in the nervous system

Afferent fibers

• come towards

• enter the posterior spinal cord to bring info. in from the body’s sensory receptors

Efferent fibers

• to exit/leave

• exits the anterior spinal cord to carry info. from the spinal cord out to the muscles

Brain stem

• begins where the spinal cord enters the skull and extends upward into the lower areas of the forebrain. it consists of: midbrain, pons, medulla oblongata

• many cranial-nerve nuclei are located in the _____ & send their axons to the head muscles

Cerebellum

• plays a role in motor coordination, motor learning, and integrates motor functions w/ mental processes

• damage could result to equilibrium problems, postural defects, and impairments of skilled motor activity

  • Balance

  • Coordination

  • Fine motor skill/control

Diencephalon; hypothalamus; thalamus

• has 2 structures:

  • _____ takes part in nearly all aspects of motivated behaviour, it also connects & interacts w/ the pituitary gland to control many hormonal functions

  • _____ composed of 20 nuclei, all information the cortex receives is first relayed. serves as a “hub” connecting sensory systems to the cortex & serving as a relay from one cortical region to another

Basal Ganglia

• collection of nuclei that form a circuit(s) with the cortex

• connects sensory regions of the cortex to motor regions of the cortex

• regulate movement so that it is fluid

• involved in associative learning

Huntington’s Disease

• a genetic disorder where basal ganglia cells die progressively - individuals experience involuntary body movements

  • ex: twitching, flailing movements, tics

Parkinson’s Disease

• characterized by many symptoms, among which are muscular rigidity and difficulty initiating movement

  • ex: trouble getting up from a chair, reaching for an object

• loss of connections into and out of the basal ganglia, especially connections from the substantia nigra of the midbrain

Limbic System; amygdala; hippocampus

• plays a role in self-regulatory behaviours including emotion, personal memories, spatial and social behaviour

• among its principal structures, _____ nuclei in the base of the temporal lobe participate in emotion

• the _____, a structure lying in the anterior medial region of the temporal lobe participates in personal memory and spatial navigation

cingulate cortex

• 3-layered strip of limbic cortex that lies just above the corpus callosum along the medial walls

• involved in sexual behaviour, among social interactions, and decision making, or executive function

Cortex; cleft; ridge/bump

• consists of 6 layers (_ _ _ _ _ _) and is heavily wrinkled

• a _____ called a sulcus (plural, sulci), if it is shallower, and it’s called a fissure if it extends deeply enough into the brain

• a _____ is called a gyrus (plural, gyri)

Primary areas

receive projections from the major sensory systems or send motor projections to the muscles

Secondary areas

• involved in elaborating information received from primary areas, sending commands to it

  ex: visual aspects that include color, movement, and form

Tertiary areas

encompass all cortex not specialized for sensory or motor function, rather, the association areas mediate complex activities such as language, planning, memory, and attention

Layers I, II, III

typically receive input from other cortical areas and are well-developed in the secondary and tertiary areas

Layer IV

receive input predominantly from the thalamus (bringing incoming sensory information)

Layers V, VI

• typically send signals to other brain areas - cells in these layers are particularly large which sends projections in the spinal cord

• Large size is typical of cells that send info. over long distances

• PREDOMINANTLY

Neurons

• functional unit of the entire nervous system

  • able to generate electrical impulses

  • plastic and have capacity to change

• 3 MAJOR COMPONENTS: cell body, dendrites, axon

• IS HAPPIEST AND CAN REST WHEN ITS INTERNAL CHARGE IS -70mV

  • this contributes to the negative resting potential of the neuron

• 4 MOST NOTABLE IONS: Potassium (K+), Sodium (Na+), Calcium (Cl-), Calcium (Ca+)

Potassium

• referred as leakage channels

• this allows _____ to easily come and go

• when too much K+ ions accumulate inside the cell = CONCENTRATION GRADIENT BECOMES HIGHER

Sodium

• because it is less concentrated, it would be easy to move into the neuron by moving down its concentration gradient

• opposite charges attract

Sodium-potassium pump

• prevents sodium from accumulating and increasing the resting membrane potential

• pump _____ out of the cell

• pump _____ into the cell

• help keep membrane potential at -70mV

synapse

• axon terminals of a neuron and the dendritic spines sit very close but do not touch - it is the space between structures

• information flows into a neuron through dendritic spines → dendrites → cell body

• integrates all incoming signals

Channels

• structured-like hallways that cross through membrane

• in order to pass through a channel, an ion would need to have correct size, shape, and electric charge

Gates

• these structures will change shape when they are open or closed

• function similar to a lock and key mechanism

Pumps

• these structures are also capable of changing their shapes

• they use energy to actively pump ions across the membrane

Graded potential; depolarization; hyperpolarization

• when an incoming signal reaches another neuron, it can cause neuron to deviate from the resting potential

• small change in a cell’s resting potential [-70mV]

• if the neuron becomes more positive (increase in resting potential [-70 to -50] this would be a _____ [EPSP-Excitatory (EPSP)])

• if the neuron becomes more negative (decrease in resting potential [-70 to -90] this would be a _____ [IPSP-Inhibitory (IPSP)])

threshold; voltage-gated sodium

• typically -45mv, if the neuron reaching this voltage, it will send an ACTION POTENTIAL (basis of all neuronal communication)

• when it reaches -45mv, _____ channels open up & allow an influx of sodium into the neuron (neuron becomes more positive)

repolarizing phase; absolute refractory

• if the neuron is stimulated during the _____ of the action potential, it will not respond with another new action potential because the sodium gates are “blocked”

  • this is when the neuron is in its _____ period

hyperpolarization phase; relative refractory

• if the neuron is stimulated during a _____, a new action potential can be generated, but only if the intensity of the stimulation is higher than what initiated the first action potential

• this is referred to as the _____ period

the wave method in unmyelinated axons

• when the action potential signal, leaves the cell body & gets pushed down the axon, it reaches these gated sodium channels in the axon, and they open

  • when it open, more sodium enters the axon

the jumping method in myelinated axons; Nodes of Ranvier

• myelinated axons are covered in chunks/sections of myelin and in between each of these sections are small gaps of unmyelinated axon called _____

• at the nodes, there are high concentration of sodium channels

• it jumps from node to node

neurotransmitter

• used to send signals between two neighbouring neurons

• will leave one neuron, travel across the synapse and pass on a signal to the next neuron

chemical synapse

• uses tiny chemicals to pass the message between the two neurons

• most common type of synapse in the human nervous system

gap junction

• two neurons/cells are physically attached to one another

• form little pores that allow chemicals/ions to pass directly between the two cells

• common example of this would be found between a neuron and glial cell

Transmitter Synthesis and Storage

Neurotransmitters can be made in two ways:

• Some are synthesized as proteins in the neuronal cell body. They then get packaged in membranes and transported to the axon terminal

  • slower-acting transmitters typically made from the cell’s DNA

• Some are synthesized directly in the axon terminals

  • faster-acting transmitters typically made from nutrients

Neurotransmitter Release

• The extracellular fluid surrounding an axon terminal is rich in calcium ions (Ca2+)

• When an action potential arrives at the axon terminal, voltage-sensitive calcium channels open up, allowing an influx of calcium into the axon terminal.

• The incoming calcium ions participate in a reaction by opening vesicles bound to the presynaptic membrane. These vesicles then empty their contents into the synaptic cleft through exocytosis

Receptor-Site Activation

• A neurotransmitter released from the presynaptic membrane diffuses across the synaptic cleft and binds to specialized protein molecules in the postsynaptic membrane

• The type of neurotransmitter and the kind of receptors on the postsynaptic membrane determine which of the following the neurotransmitter does:

  • Depolarizes the postsynaptic membrane (has an excitatory action; EPSP)

  • Hyperpolarizes the postsynaptic membrane (has an inhibitory action; IPSP)

Neurotransmitter Deactivation

• After a neurotransmitter has done its work, it is typically removed quickly from receptor sites and from the synaptic cleft.

  • Diffusion: the neurotransmitter simply diffuses away from the synaptic cleft and is no longer available to bind to receptors

  • Degradation: Enzymes in the synaptic cleft break down the neurotransmitter

  • Reuptake: Membrane transporter proteins specific to that transmitter may bring the transmitter back into the presynaptic axon terminal for reuse

  • Glial storage: Some neurotransmitters may be taken up by neighboring glial cells

1. chemical must be synthesized

2. chemical must be released

3. same response must be obtained

4. mechanism must exist for removing chemicals

Four Criteria for Identifying Neurotransmitters

Small-Molecule Transmitters

• are synthesized from dietary nutrients and packaged for use directly in axon terminals

• When a _____ is released from an axon terminal, it can quickly be replaced at the presynaptic membrane

Neuropeptide Transmitters

• _____ are multifunctional chains of amino acids that act as neurotransmitters

• Their synthesis and transport are relatively slow compared to those of small-molecule transmitters. Consequently, _____ form slowly and are not replaced quickly.

Transmitter Gases

• The water-soluble gases nitric oxide (NO), carbon monoxide (CO), and hydrogen sulfide (H2S) can also be used as _____

• They are neither stored in synaptic vesicles nor released from them in the conventional manner, instead they are synthesized in the cell as needed

Ionotropic Receptors

• a binding site for a neurotransmitter

• a pore or channel through the membrane

• the receptor changes its shape, either opening the pore and allowing ions to flow through it or closing the pore and blocking the ion flow

• bring about very rapid changes in membrane voltage

Metabotropic Receptors

A _____ single protein spans the cell membrane but does not possess a pore of its own through which ions can flow

Sympathetic noradrenergic neurons

• prepare the body’s organs for fight or flight

• contain NE

Parasympathetic cholinergic neurons

• prepare the body’s organs to rest and digest

• contain ACh

Cholinergic System

• plays a role in normal waking behaviour and is thought to function in attention and memory

• People with degenerative Alzheimer’s disease show shrinkage and loss of cholinergic neurons at autopsy.

nigrostriatal pathway

• pathway from the substantia nigra

• takes part in enabling movement

• When DA neurons are lost from the substantia nigra, the result is a condition of extreme muscular rigidity characteristic of Parkinson's disease.

mesolimbic pathway

• pathway from the ventral tegmentum

• Dopamine in the _____ may be the neurotransmitter most affected in addiction — to food, drugs, and behaviours that involve a loss of impulse control.

• “REWARD PATHWAY”

Noradrenergic System

• Typically, behaviors and disorders related to the _____ concern the emotions

• Some symptoms of major depression may be related to decreases in the activity of _____ neurons.

• Conversely, some symptoms of mania may be related to increased activity of these same neurons.

Serotonergic System

• maintains a waking pattern in the forebrain and thus plays a role in wakefulness (sleep/wake cycle)

• SEROTONIN also plays a role in learning, and some symptoms of depression may be related to decreases in the activity of serotonin neurons.

Spinal Cord

• blocks voluntary movements because the brain cannot signal to the motor neurons to initiate movement

• basic reflexes remain intact because sensory information enters the _____ & is processed by neurons in the gray matter to generate motor response

  • ex: a beheaded chicken can still move normal

Hindbrain

• a species is said to be a low decerebrate if their spinal cord and _____ are separated from the rest of their brain

  • lower decerebrate subjects have difficulty remaining awake and conscious

• receives sensory information from the head via cranial nerves and the body

• body rigidity and narcolepsy

Midbrain

• high decerebrate

• visual and auditory input to the tectum

• voluntary movements are intact and possible in such subjects but must be initiated externally

  • automatic movements (e.g., grooming, chewing, rejecting food, lapping water)

Diencephalon

• hypothalamus & pituitary are intact, allowing hormonal signaling and homeostasis

• animals have emotion and motivation in their behaviours but it is often inappropriate to the situation (e.g., aggression)

  • behaviours are characterized by constant activity not directed toward a goal

Basal Ganglia; Decortication

• the presence of the _____ enables animals to link movements in a smooth manner

• _____ is the removal of the neocortex (cerebrum), leaving all the subcortical structures connected to the brainstem and body

• animals are capable of self-care (e.g., feeding, drinking, walking & grooming)

Cortex

• enables all behaviours, along with other executive functions (e.g., planning, some aspects of memory, meaning, attention, importance, etc.)

• animals cannot distinguish complex patterns - rats can perform simple learning such as classical or operant conditioning

Maps

• research has found representations of the body in the motor and sensory areas in Homunculus

• found for auditory and visual sensations

• it represents ways of processing different aspects of sensory information (e.g., visual _____ : color, motion, form)

• more _____ means more representation of the world and ways to interact with the world

  • ex: animals lack in color vision, which interrupts their interaction with the world

  • ex: dogs have better sense of smell than humans

• may vary between person to person depending on the life experience, culture, genetics (friend eats sea urchin for breakfast, while i eat poptart)

Sensory unit

in travelling from primary to secondary to tertiary zones, sensation is elaborated and integrated into information

ex: hugging your mom, you would feel comfort but hugging a stranger, tertiary will process EW! WEIRDO!

Motor unit

info. from the sensory unit travels forward to tertiary motor zones where it is translated into intention and then into patterns of action in the secondary primary motor zones