Psych Test 1: Neuropsychology

Neuroscience

The study of how nerves and cells send and receive information from the brain, body and spinal cord 

Phrenology

Early pseudoscience suggesting that mental abilities and personality traits could be read by measuring bumps on the skull (Franz Gall)  

Holists

Proposes that the whole brain takes part in every mental activity

Localizationist

Different tasks are allocated to different parts of the brain

Neuropsychology

Studies the brain's workings by examining its altered function following brain damage 

Cerebral cortex

Outermost layer of the brain, supports higher cognitive skills, complex emotion, complex mental activity (sense of mind and self), memory, thought 

Neocortex

Develops through adolescence and young adulthood, evolutionarily the newest. The largest part of the cerebral cortex and supports the most complex functions, like language, thought, problem solving and imagination. Extensively folded to fit the huge number of neurons in your head.  

The cortical lobes

Occipital, Temporal, Parietal, Frontal and Insular lobes  

Occipital lobe

Devoted to vision (object movement, depth perception, beginnings of identifying objects and reading comprehension.) Many visual areas including the primary visual cortex. The eyes communicate light to the visual cortex, which allows you to see.  

Fact: When you hit the back of your head and see stars, this is because of stimulation to your occipital lobe  

Temporal lobe

Contains the primary auditory cortex which is responsible for hearing and understanding language. Allows you to recognize objects and faces. Includes Broca's and Wernicke's areas 

Broca's area

Responsible for speech production 

Broca's aphasia (expressive aphasia)

Understanding speech but not being able to produce it 

Wernicke's area

Responsible for language comprehension

Wernicke's aphasia (receptive aphasia)

Being able to produce speech, but not being able to comprehend language  

Parietal lobe

Supports a map of our body's skin surface and the sense of touch through the primary somatosensory cortex. Helps you pay attention to and locate objects, spatial awareness, perception of touch, pain and temperature. 

Frontal lobe

Movement and planning. Contains the primary motor cortex and a map of the body's muscles and works with the spinal cord to control movement. The rest of the lobe is the prefrontal cortex which is responsible for thought, planning, self-control, emotional-control and decision making (executive functions) Associated with the self and personality.

Inhibitory control

The last checkpoint in choosing to act and understanding your actions implications, will and conscience. 

Insular lobe

Perception of the inside of our bodies. Includes the primary taste cortex (perception of what is in our mouths) and it allows us to perceives the states of our body's organs (like your heart racing)   

Primary sensory area

The first region in each lobe to receive signals from its associated sensory nerves Ex The primary visual cortex receiving input from the optic nerve

Primary motor cortex

(Frontal lobe)

The cortex responsible for voluntary movements. Connects with motor neurons that make the body move.  

Association cortex

(Frontal lobe)

Integrates information coming in from the senses with existing knowledge to produce meaningful experiences of the world and how to navigate it Ex Recognizing faces and associating information about the person  

Motor projection areas

Where nerve impulses originate that prompt voluntary movement. Parts that require more muscle control take up more space

Subcortical brain

Below the cerebral cortex. Includes the limbic system, brainstem.

Limbic system

Associated with emotion, bridges the newer, higher brain structures that are more related to complex mental functions with the older, lower brain regions that regulate your body and its movement. Includes the hippocampus, amygdala, basal ganglia, thalamus and hypothalamus 

Hippocampus

Aspects of memory, ability to navigate the environment. Creates memories of an event's time and place, helps remember emotionally prominent events and hopes and desires for the future.

Amygdala

Registering the emotional significance of events

Psychic blindness

Due to abnormalities in the amygdala, the psychological importance of what you see is absent 

Basal ganglia

Group of interconnected structures that are necessary for planning and executing movement. Bridges the moto regions of the cerebral cortex with nuclei that communicate with the spinal cord, sending signals to your muscles to act. 

Thalamus

Communicates information to and from all of the sensory systems except the olfactory system 

Brainstem

Ensures the brain gets the oxygen it needs. Regulates functions like breathing and heartrate so that you don't have to think about them. Connection with the spinal cord and collects sensory signals from the body and sends signals from the brain to create movement. Includes the midbrain, hindbrain and cerebellum. 

Midbrain

The uppermost region of the brainstem, includes the tegmentum, ventral tegmental area and the substantia nigra. 

Tegmentum

Reflexively moves the head and eyes towards sudden sights and sounds

Ventral tegmental area

Part of the motivation and reward system that motivates us to move through its connections with the basal ganglia. 

Substantia nigra

Regulates movement. 

Hindbrain

Part of the brainstem, includes the pons, medulla oblongata and the cerebellum.

Pons

Controls breathing and relays sensations such as hearing, taste and balance to the cortex and subcortex. 

Medulla oblongata

Involved in controlling autonomic functions such as heart rate and blood pressure as well as critical reflexes such as coughing and swallowing.  

Reticular formation

Runs through the brainstem and is connected to many different parts of the brain. Plays a central role in arousal and attention. Regulates sleep and wakefulness and is critical to maintaining cognitive abilities as we age. Both the pons and medulla contain it.  

Cerebellum

Contributes to coordination, precision, balance and accurate timing.  

Corpus callosum

A bridge of fibers that connects the two halves of the brain. Allows the two halves of the brain to share information and supports contralateral communication. 

Interhemispheric transfer

Rapid exchange of information between two hemispheres  

Contralateral organization

The opposite-side organization of the brain, one side of the body is connected to and controlled by the opposite brain hemisphere 

Split-brain procedure

Severing of the corpus callosum to reduce the spread of seizures across the hemispheres  

Brain networks

Collections of brain regions that are connected  and work together to support brain functions. Small-scale (within brain regions) and large-scale (between brain regions)  

Lesion

Abnormal tissue resulting from disease, trauma or surgical intervention  

Dissociation

The neuropsychological evidence, following brain damage/lesion, that a particular brain region is involved in a particular function but not in others 

Neural plasticity

The brain's ability to physiologically modify, regenerate and reinvent itself over the course of a lifetime 

Critical periods

Periods in early life during which specific experiences must occur to ensure normal development. The environment therefore plays an important role 

Damage plasticity

Neural modification following injury. Largely takes on the form of brain reorganization in response to learning or following injury or damage. Ex If you lose a finger, the neurons responsible for feeling in the other fingers will take over its place in the brain or how blind people use portions of their visual cortex to read braille. 

Phantom limb

The place in the brain for the limb is still reserved for some time, so the capacity to feel remains

Adult plasticity

Refers to the shaping/reshaping of neural circuits throughout adulthood 

Stem cells

Cells that have not yet undergone gene expression to differentiate into specialized cell types 

Synaptogenesis

The process by which neurons frequently generate new synapses. Supports learning and memory.  

Neurogenesis

The birth of entirely new neurons takes place over the life span

Neurons

Cellular building blocks of the brain

Three basic classes of neurons

1) Motor neurons: Neurons in the brain that send messages to the whole body, involved in interaction with the environment and motor-movement  

2) Sensory neurons: Send information from the body and the outside world back to the brain. Senses changes in the body and environment  

3) Interneurons: Connect other neurons, interpret store and retrieve information about the world  

Dendrites

Receive chemical messages from other neurons  

Cell body (soma)

Collects neural impulses, contains the nucleus and provides life-sustaining functions for the cell  

Axon

Transports electrical impulses to other neurons vis the terminal branches

Terminal branches (terminal buttons)

Convert electrical impulses into chemical messages 

Myelin sheath

Layer of fatty tissue that covers and insulates the axon. Ensures electrical messages are kept intact and travel quickly. Gives white matter its light appearance. Made up of glial cells 

Demyelination

Degradation of myelin, central to neurodegenerative diseases  

Glial cells (Glia)

Insulate, support and nourish neurons. Vacuum up neuronal debris and serve as cellular glue between neurons.  

Neural networks

Clusters of cells that work together as a unit  

How neurons fire

Voltage threshold (the voltage necessary to start an action potential (-50 millivolts) Cause voltage controlled ion channels to open, allowing positive ions to flood in, the neurone voltage surges rapidly and becomes more positive) —> Depolarization (The result of the chain reaction of ion channels, moving the resting potential towards 0 (more positive)) —> Action potential (Neurons fire an electrical impulse called an action potential down the axon, this creates the voltage needed to communicate with other neurons) —> Membrane repolarization (The flood of ions is complete and it reverses, causes repolarization in which the membrane rapidly returns to its resting potential) —> Refractory period (The period of time it takes for a neutron to return to it’s resting state and be able to fire another action potential (only a few milliseconds))

Resting potential

A resting (non-signalling) neutron has a voltage across its membrane called the resting membrane potential

Excitatory messages

Moving the neuron closer to its voltage threshold 

Inhibitory messages

Moving it farther away from its voltage threshold 

Synapse

The gap between the sending neuron's terminal branches and the dendrites or cell body of the receiving neuron. 

Presynaptic neuron

Sends information/transmits chemical messages  

Postsynaptic neuron

The cell that receives information/chemical messages 

Neurotransmission

Allows the electrical message to bridge the synaptic gap by converting it into a chemical signal. 

Neurotransmitters

Chemical messengers released at the terminal branches across the synaptic gap towards the receiving neuron. 

How neurotransmission happens

Receptors on the target neuron recognize and bind with specific neurotransmitters. The receptor produces and excitatory or inhibitory signal.  

Ions channels open, inducing changes in ion flow moving it closer or farther away from its action potential threshold. The receptor's response to the neurotransmitter is what is excitatory or inhibitory.  

Diffusion

The neurotransmitters drift out of the synapse over time 

Degradation

A chemical reaction breaks down the neurotransmitter 

Reuptake

Neurotransmitters are reabsorbed into the terminal branches of the neuron that originally released them 

Three major classes of neurotransmitters

Amino acids, Monoamines and acetylcholine

Glutamate

(Amino acids)

Binds to excitatory receptors, helps form long-term memories

GABA (Gamma-Aminobutyric Acid)

(Amino acid)

Binds to excitatory receptors, influences muscle tone

Norepinephrine

(Monoamine)

Involved in fight or flight response activation

Dopamine

(Monoamine)

Associated with reward and pleasurable experiences

Serotonin

(Monoamine)

Contributes to feelings of happiness and well-being, appetite and sleep

Acetylcholine

Binds to inhibitory and excitatory receptors, contributes to muscle control

Psychoactive drugs

Artificial chemicals introduced into the body that take advantage of the infrastructure used by neurotransmitters

Analgesics

Drugs used to relieve pain Ex Morphine 

Endorphins

Naturally occurring endorphins are neurochemicals produced during pain. "Feel good" chemicals. 

Agonist

Chemical (drug) that can mimic the action of a neurotransmitter Ex Heroin

Antagonist

Competes with a neurotransmitter (naturally occurring or psychoactive drug) by preventing it from binding with its target receptor. It occupies the receptor, but doesn't activate it, the receptor isn't overstimulated Ex naloxone 

Neurodiversity

The inherent differences among individuals in how their brains function 

Gregor Mendel

Hypothesizes that organisms carry two (or more) genes for a given trait, like pea color, and they passed along only one to their offspring. The combination of the parents' traits determines the trait the offspring with express 

Phenotype

The observable characteristic of an individual resulting from genotype and environment 

Genes

Biological units of inheritance that are passed from your parents to you. Basic physical and functional units of heredity, made up of DNA. Present in the nucleus of every cell (including neurons). They are located on chromosomes that reside in a cell's nucleus. Humans have 46 pairs of chromosomes in every cell (23 from mother, 23 from father)  

Deoxyribonucleic acid

(DNA)

Composed of hundreds of thousands of genes, makes up chromosomes

Genotype

All the biological material an organism inherits 

Allele

Each variant of a gene, two alleles per gene, one inherited from each parent. Influence phenotype by either having dominant or recessive influence 

Gene expression

The turning on and off of genes by proteins in a particular cell to determine how that cell functions  

Epigenetics

The study of how interactions between genes and the environment can affect gene expression  

Behavioural genetics

How genetic factors influence psychological trait variation between individuals

Heritability

How much variation in phenotype across people is due to differences in genotype. Proportion ranging from zero (no contribution to difference) to one (genetic factors are responsible for difference)