PSY 430 Exam 1

What is the mind-body problem?

Are the brain and body two separate entities, or the same

How does the mental stuff interact with the physical stuff

Dualism

The mind is separate from the brain but somehow controls the brain and rest of the body.

a physical substance and separate mental substance

pineal gland is where they meet

Monism

there is only one substance, conscious experience is inseparable from the physical brain

Idealism

type of monism

The view that everything is mental

“life is but a dream”

Materialism

(a type of monism),

The view that everything is physical

mind-body identity theory falls under this

Descartes' perspective on the mind-body problem

dualism

physical substance exists in 3D

mental substance does not exist physically

Mind-body identity theory

The mind is the brain (brain states)

Holism

The entire brain is responsible for cognitive functions

Localism

Specific brain areas are responsible for specific functions

Pierre Flourens

Holist

showed main divisions of the brain are responsible for different functions

critized for crude techniques and relying on small animals

Effect of Flourens removing the cerebellum/brainstem

cerebellum: loss of coordination and balance

brainstem: death

Phrenology

Discovered by Gall (localist)

The analysis of the shapes and lumps found on the skull that reveal a person's personality and intellect

Bouillaud

Localist

Patient was Marc Dax

Discovered speech loss with the appearance of lesions on the frontal cortex.

Similiar to Broca

Paul Broca

Localist

Localized brain area for speech production

Patient (Tan) had lesions in left frontal lobe

Broca’s area = language production

Carl Wernicke

Localist

Damage to left posterior created deficits in language comprehension

Wernicke area = language comprehension

Brodmann

Localist

created the cytoarchitectonic map of the brain

Cytoarchitectonic map

Brodmann

Divided the brain into 52 distinct areas based on the type/organization of neural cells in each region

Camillo Golgi

Discovered that we can use silver staning tissue slices to visualize every cell in detail

Santiago Ramón y Cajal

Illustrated neurons

Neuron doctrine

The idea that the nervous system is made of individual cells rather than one continuous network

Idea came from Cajal’s oberservations

Brain lesion method

studies brain function

If Function X is disrupted by lesion to Region A

Then brain Region A supports Function X

Animal brain lesion procedure

uses stereotaxic instrument

very specific part of rats brain is targeted by electrode to cause damage

rats are tested in tasks against control group to determine function of brain area

Human brain lesion studies

Site of damage is determined

Must be acquired brain damage

These are single-case or group studies that are not under manipulation of the experimenter, so can only be correlational

Phineas Gage

Man has iron rod driven through head on accident, it destroys most of his frontal lobe, produced significant changes in his personality and behavior. He was no longer himself.

Single and multiple unit recording

A technique where electrodes are inserted to record the electrical (action potential) activity of one neuron (single unit) or many neurons simultaneously (multiple-unit)

Receptive field

The area of space in which a neuron can be maximally influenced/activated

Determined via single-unit recording.

Single dissociation

damage to Area X impairs Function A but not Function B

Example of single dissociation

Broca's aphasia; the patient can comprehend language but has difficulty producing it.

Double dissociation

Damage to Area X impairs Function A

but not Function B

AND damage to Area Y impairs Function B

but not Function A

Limitation of lesion studies

Animal brain structure may not be the same as human brain structure. Also the brain undergoes many changes as humans age.

Electrical stimulation

Used to control or correct abnormal brain activity in disorders such as Parkinson's disease, essential tremor, epilepsy, treatment-resistant depression, and OCD.

Chemical stimulation

Psychologically active medications

Recreational drugs

More used in animals

Deep brain stimulation (DBS)

Implanted electrodes deliver ongoing electrical stimulation to targeted brain structures

Used especially to treat Parkinson's disease tremor; acting like a “brain pacemaker.”

Magnetic stimulation (TMS technique)

Application of an intense magnetic field to a portion of the scalp that temporarily inactivates neurons

Electroencephalography (EEG)

Brain electrical activity, Captures cheering crowd

Functional

LOW spatial resolution

HIGH temporal resolution

What is EEG important for studying?

Sleep, epilepsy and brain damage

ERP (event-related potentials)

filters an EEG to measure exact timing of specific brain processes

CAT scan

A large series of 2d X-ray images that combine to create a 3D image.

Structural

Low spatial resolution

MRI (magnetic resonance imaging)

Studies brain anatomy through distribution of magnetic materials

Structural

High spatial resolution

fMRI (functional MRI)

Measures the BOLD signal (Blood Oxygen Level Dependent), increased neural activity leads to increased blood flow/oxygen; which increases the fMRI signal.

fMRI scans show BRAIN FUNCTION.

LOW TEMPORAL RESOLUTION.

Magnetoencephalography (MEG)

records brain electrical activity

High spatial resolution

High temporal resolution

Functional

Expensive

PET scan

Traces isotopes in blood flow

High spatial resolution

Low temporal resolution.

Functional

Can diagnose Alzeihmers

PET scan limitations

invasive, limites number of uses

Cell body

contains nucleus

processess info is collected from dendrites

Dendrites

Branch-like extensions lined with synaptic receptors

they receive input from other neurons

Greater surface area = more information received.

Axon hillock

The point near the cell body where the electrical signal (action potential) begins.

Axon

Extends from the cell body

conducts the electrical signal from the cell body toward the terminal boutons

often wrapped in myelin.

Myelin sheath

Glial cell wrapping around the axon

increases conduction speed

reduces signal loss

Synaptic terminals/Terminal Boutons

The endpoints of the axon where neurotransmitters are released to communicate with the next neuron

Synapse

The gap between the terminal bouton of one neuron and the dendrite of the next

Neuron

The basic unit of structure and function in the nervous system.

Order of info flow through a neuron

Dendrites (collect input) - Cell body (processes it) - Axon (carries signal) - Terminal boutons (pass it to the next neuron)

Glial cells

Cells in the nervous system that support, nourish, and protect neurons

Astrocytes

Glial cell

star-shaped

absorb/release ions, remove waste, regulate nutrients, recycle glutamate

Microglia

Glial cell

very small

removed toxic material in injured/damaged brain areas

Oligodendrocytes

Glial cell

Form myelin sheath in the central nervous system

Schwann cells

Glial cell

Form myelin sheath in the peripheral nervous system

Radial glia

Glial cell

guide neuronal migration and neural development

Blood-brain barrier

protective mechanism that blocks most harmful substances (chemicals, bacteria) in the blood from entering brain tissue

Needed substances are brought in throgh active transport

A neuron at rest

Polarized, inside a neuron to -70mV

Membrane is selectively permeable (lets in O, CO2, H2O) (blocks large ions)

sodium channels are closed, potassion channels are leaky

Electrical gradient

The difference in electrical charges between the inside and outside of the cell

Concentration gradient

A difference in the concentration of a substance across a distance.

Sodium Gradients

Concentration and electrical push sodium into the neuron

Potassium gradients

concentration: pushes potassium out

electrical: pulls potassium in

Hyperpolarization

Negative change in the internal charge of a neuron

Depolarization

A positive change in the internal charge of the neuron

Threshold

The level of depolarization the membran must reach to trigger an action potential

Action potential

happens when depolarization reaches threshold

sodium channels open and cause rapid depolarization, then stop while postassium channels open, and cause repolarization, then potassium channels close slowly, and the pump returns to balance

Absolute refractory period

The minimum length of time after an action potential during which another action potential cannot begin.

because the sodium channels are inactivated

Relative refractory period

Period when the neuron can fire again, but only if the stimulus is stronger than the normal threshold

because the neuron is hyperpolarized from slowly closing potassium channels

All-or-none law

principle that the action potential in a neuron does not vary in strength; the neuron either fires at full strength or it does not fire at all

Saltatory conduction

action potential jumps from node to node, which speeds up the impulse.

Benefits of the myelin sheath

Faster conduction

little loss of signal strength

energy efficient

Synapse

A junction where information is transmitted from one neuron to the next.

Synaptic transmission

The relaying of information across the synapse by means of chemical neurotransmitters.

Postsynaptic potential

A voltage change at a receptor site on a postsynaptic cell membrane.

Temporal summation

Repeated stimuli within a brief time combine their effects on a neuron.

Spatial summation

Synaptic inputs from separate locations combine their effects on a neuron.

Excitatory postsynaptic potential (EPSP)

depolarizing

sodium channel opens, making neuron more likely to fire

Inhibitory postsynaptic potential (IPSP)

Hyperpolarizing

happens when potassium/sodium channels open

because neurons are less likely to fire

Dopamine

A neurotransmitter associated with movement, attention and learning and the brain's pleasure and reward system. Synthesized in the ventral tegmental area, released in the nucleus accumbens,

Law of specific nerve energies

Proposed by Muller

All nerves produce the same action potentials.

Dorsal

Above.

Ventral

Below.

Anterior

Front.

Posterior

Tail end.

Medial

Middle.

Lateral

Side.

Central Nervous System (CNS)

Brain and spinal cord.

Peripheral Nervous System (PNS)

Sensory systems, somatic nerve system, autonomic nervous system

Sympathetic nervous system

A set of nerves that prepares the body for action in challenging or threatening situations (fight or flight)

Parasympathetic nervous system

A set of nerves that helps the body return to a normal resting state

Spinal cord

A major part of the central nervous system which conducts sensory and motor nerve impulses to and from the brain. INJURY RESULTS IN PARALYSIS

Medulla

controls heartbeat and breathing. Damage can be fatal.

Pons

relays information from the cerebellum to the rest of the brain; damage could impair sense of balance.

Cerebellum

controls balance and coordination

Thalamus

The brain's sensory switchboard the cortex and transmits replies to the cerebellum and medulla; damage could lead to coma.

Hypothalamus

directs eating, drinking, body temperature;

helps govern the pituitary gland, and is linked to emotion.

Damage results in disruption in growth and sleep cycle disruption.

Basal ganglia

A three-part structure in the forebrain that helps control movement and reward learning; damage could lead to Parkinson's disease.

Hippocampus

A neural center in the limbic system that helps process explicit memories for storage; damage leads to memory impairment.