Brain and behavior Flashcards
Technological methods that allows researchers to build a more accurate understanding of how our brains work
- the encephalogram (EEG)
- magnetic resonance imaging (MRI)
- functional magnetic resonance imaging (fMRI)
- positron emission tomography (PET)
Although all of these have the same goal they differ in the type of image produced
What does each technological device scan?
- MRI -> scans can only show brain structure and therefore produce static images
- EEG -> shows brain activity
- PET + fMRI -> can show structure + brain activity as it changes over time
magnetic resonance imaging (MRI)
These scans are able to produce static 3D images of the brain. They use a magnetic field and pulses of radio wave energy to make pictures of organs and structures inside the body (including brain). This technique is used to find problems such as tumors, bleeding, injury, blood vessel diseases or infection. Highly useful to neuropsychologists studying brain-damaged individuals because they have the advantage of being more detailed and in 3D format hence localization of damage is more precise.
Limitation of MRI scans
people with heart pacemakers, metal places or screws in their bodies may not be scanned. This could, therefore, mean the loss of potential participants in psychological studies. Also, some people suffering from claustrophobia/dementia may find it difficult to tolerate the procedure. If people move during the scan, the images are unclear and difficult to interpret reliably.
functional magnetic resonance imaging (fMRI)
This is non-static brain imagery that uses magnetic resonance imaging to measure the metabolic changes that take place in an active part of the brain. When neurons in a particular region are active, more blood is sent to that region. The fMRI machine maps changes in the brain’s metabolism (chemical changes within the cells) and uses radio waves and magnetic fields to generate a 3D time map to show which parts of brain are active during a range of tasks. fMRI scans are also used to help assess the effects of stroke, trauma or degenerative diseases on brain function.
PET scans
is a type of nuclear medicine imaging. Nuclear medicine is a branch of medical imaging that uses small amounts of radioactive material to diagnose + determine the severity of a variety of brain diseases + cancer + neurological disorders. A radioactive substance is injected into the patient. This is usually a form of sugar that produces measurable gamma rays as it is metabolized in the brain. A PET scan detects these rays and turns them into computer images of brain activity. These scans are used to examine functions such as blood glow, oxygen use and glucose metabolism, to help doctors evaluate how well the brain is functioning. Because they are able to pinpoint molecular activity within the body, they offer the potential to identify a disease in its earliest stages. They are useful for showing abnormalities in brain activity levels in diseases that do not show structural changes until much later.
What is localisation?
Localisation of function refers to the theory that the mechanisms for thought, behavior and emotions are located in different areas of the brain. To what extent certain functions are located in their own areas, and activity in this area can therefore be seen as evidence of a behavior/thought/feeling, is the subject of localization of brain function.
What do specific parts of the brain do?
- Frontal lobe -> Planning, decision-making, problem-solving, voluntary movement, emotional control, and personality.
- temporal lobe -> Auditory processing, memory, language comprehension, and emotion.
- parietal lobe ->Processing sensory information like touch, temperature, and pain; spatial awareness and perception.
occipital lobe -> visual processing
Limitations of the localisation approach
- Oversimplification of Brain Function, localization treats the brain like a puzzle where each piece has one fixed role, ignoring how complex and interconnected cognitive processes really are.
- Lack of Consideration for Interaction Between Brain Areas
Cognitive tasks often involve multiple brain regions working together. Localization doesn’t fully account for this interaction or integration.
-Neglect of Brain Plasticity
Localization assumes that only certain areas can perform specific functions, but research shows the brain can adapt—other areas can take over if one is damaged. - Variability Between Individuals
Localization doesn’t fully account for individual differences—brain function can vary slightly from person to person, and what’s “localized” in one brain may be more distributed in another.
-Task Complexity
Simple tasks may rely on specific areas, but complex ones—like decision-making or navigating a maze—engage many areas at once, which localization underrepresents.
What is a neuroplasticity?
is the ability of neural networks in the brain to change through growth and reorganization. this process is very significant in your children (early brain development)
What is neural pruning?
Neural pruning is the process through which excess or unused neural connections are removed by the brain to reduce neural density for efficiency. This begins early in childhood and adolescence and throughout life, the brain refines itself, as useful pathways become stronger and unnecessary ones weaken and get dropped.
what are neural networks?
Neural networks are a highly complicated system made of neutrons that perform similar functions to neurons in the brain and one of the work is transmission of information and through this process allowing learning, data management and decision making that is learning to strengthen or reduce connections through experience.
What are neurons?
Neurons are nerve cells. Neurons carry information as electrical impulses but neurone communicate with each other by an additional process involving neurotransmitters.
What is neurotransmission and how can it be affected?
Neurotransmission is the process by which neurons communicate using chemicals called neurotransmitters. While neurons carry information as electrical impulses, they send signals to other neurons chemically across the synapse. The neurotransmitter is released by one neuron and received by another via receptors. Neurons are specific in which neurotransmitters they release and receive, and this process can be influenced by drugs—both medical and recreational—by affecting release, uptake, or reuptake of the neurotransmitter.
How are excitatory and inhibitory synapses created?
When the neurotransmitter combines with a molecule at the receptor site it causes a voltage change at the receptor site called a postsynaptic potential (PSP). There are 2 type;
- excitatory
- inhibitory
What is a excitatory synapse?
Is a type of postsynaptic potential that increases the probability of producing an action potential in the receiving neutron.
What is a inhibitory synapse?
Is a type of postsynaptic potential that decreases the probability an action potential
What is the meaning of endogenous?
this is produced by the body and act inside the body
What is a antagonist?
they are chemical substances, both naturally found in food/medicines/artificially manufactured. They also bind to synaptic receptors but they decrease the effect of the neurotransmitter. Therefore, if a neurotransmitter is excitatory, an antagonist will decrease its excitatory characteristics,
What does alcohol bind with?
alcohol binds with dopamine receptor sites, causing neurons to fire. The firing of these neurons results in the activation of the brain’s reward system, the nucleus accumbens, and a feeling of pleasure.
What is a chemical agonist?
are substances that bind to synaptic receptors and increase the effect of the neurotransmitter. They do this by imitating the neurotransmitter. Agonists oil the lock and make it easier for the neurotransmitter to have an increased effect (lock and key mechanism)
info about neurotransmitter; Acetylcholine (ACh)
- Function: Responsible for stimulation of muscles, for some memory functions, and has a role in sleep.
There is a link between ACh and Alzheimer’s disease; there can be up to a 90% loss of ACh in the brains of people suffering from this disease.
Usually excitatory
Scopolamine = antagonist
info about neurotransmitter; Dopamine
- Strongly associated with reward mechanisms in the brain. Drugs like cocaine, opium, heroin and alcohol increase the levels of dopamine, as does nicotine. Low dopamine levels are associated with Parkinson’s disease, and too-high levels have been correlated with schizophrenia and social anxiety.
usually inhibitory, but can be excitatory, depending on receptors
Alcohol = agonist
Antipsychotic drugs (Haloperidol) = antagonist
info about neurotransmitter; noradrenaline
- increases heart rate and blood pressure. Plays a role in wakefulness and arousal, eating, depression and mania
usually excitatory
Amphetamines (‘speed’) = agonist
