Neuroscience Flashcards
What is psychobiology?
The study of the role of physiology and anatomy in the regulation and execution of behaviour
What do neuroscientists study?
The brain and spinal cord - the CNS (of any organism)
What do psychophysiologists study?
Physiological processes such as heart rate, hormone secretion, brain electrical activity and skin conductance and the conditions in which these change
How much does the average brain weigh?
1400g
How many nerve cells does the brain contain?
10 - 100 billion
What is modularity?
The idea that clusters of nerve cells (modules) have specific features
What are the 3 main parts of the brain?
The brain stem, cerebellum and the cerebral hemispheres
What is the function of the brain stem?
Primarily the control of physiological functions and automatic behaviours such as breathing and swallowing
What is the function of the cerebellum?
Control and coordination of movements, recent research highlights its importance in language and thinking
What is the cerebral cortex?
The structure where perceptions take place, memories are stored and plan are formulated/executed, often referred to as grey matter
What is white matter?
A layer of nerve fibres coated in a shiny white insulating layer, which connects the nerve cells of the cerebral cortex to other parts of the brain
What are gyri?
Bulges on the cerebral cortex
What is a fissure?
Large grooves in the cerebral cortex
Why do we have gyri and fissures?
To increase the surface area and so increase the number of nerve cells it contains
What do the spinal nerves serve?
The body below the neck, conveying sensory information from the body and carrying messages to muscles and glands
What do the 12 pairs of cranial nerves serve?
The muscles and sense receptors of the head and neck
What does the soma/cell body do?
Contains mechanisms that control metabolism and maintenance of the cell, also receives messages from other neurons
What do dendrites do?
Receive messages from other neurons and transmit this information down their trunks to the soma
What does the axon/nerve fibre do?
Carries messages away from the soma towards cells with which the neuron communicates, these action potentials cause brief changes in electrical charge of the axon
What are terminal buttons and what do they do?
The ends of the branches off the axon, they secrete a chemical called a transmitter substance (neurotransmitter) when the axon fires which affect the activity of other cells
What are the brain’s two roles?
- Control of physiological functions
- Control of motor functions
The surface of the cerebral hemispheres is covered by the?
Cerebral cortex
Many axons are insulated with a substance called?
Myelin
Failure on the Wisconsin Card Sorting Test is likely to indicate damage to the __________ lobe
Frontal
During periods of relaxation, EEG recordings of the brain’s electrical activity generally show __________ activity
Alpha
A primary function of the thalamus is to?
Relay information from the sensory organs to the cerebral cortex
During a night’s sleep, how many cycles of REM and slow-wave sleep will a person typically experience?
4 or 5
Which stages of sleep are referred to as slow-wave sleep?
3 and 4
If you woke up during __________ sleep, you would recall any dream that you were having at that time
REM
According to Freud, dreams represent…
Unfulfilled wishes
If sleep repairs the wear and tear of the day’s activities on the body, then
Active people should need more sleep each night than sedentary people
Eating and drinking are examples of __________ behaviours
Regulatory
The idea that a drive produces an unpleasant internal state that causes an organism to engage in behaviours that remove this unpleasant condition is called the
Drive reduction hypothesis
__________ thirst is caused by dehydration within cells; __________ thirst is caused by dehydration outside the cells
Osmometric; Volumetric
A deficit in the body’s level of nutrients will
Cause a search for food
Social and cultural factors influence our learning of __________ to eat
What, when and how often
Our short-term store of nutrients contains
Glycogen
What is functional hemispheric asymmetry?
Some functions are located primarily on one side of the brain
The two cerebral hemispheres are connected by _____
The corpus callosum
The corpus callosum can be cut to alleviate the symptoms of ____
Epilepsy
What are the three structures in the brain stem?
- The medulla
- The pons
- The midbrain
What does the medulla control?
- Blood pressure
- Heart rate
- Respiration
- Crawling or swimming motions
What does the pons control?
- Some of the stages of sleep
What does the midbrain control?
- Movements used in fighting and sexual behaviour
- Decreases sensitivity to pain when engaging in these activities
What does the cerebellum do?
- Monitors information regarding posture and balance
- Stops us from falling down when walking/standing up
- Produces eye movements to compensate for changes in head movements
Underneath the cerebral cortex lies the _______
White matter
What are the functions of the thalamus?
- Receive and integrate sensory information, and assist the control of movements
- Receives sensory information and passes the results onto the primary sensory cortex
What does the hypothalamus do?
- Homeostasis
- Controls the pituitary gland and therefore the whole endocrine system
What is the amygdala associated with?
Emotional behaviour
What is the hippocampus involved in?
Memory
What does the basal ganglia do?
- Influences sensory and cognitive behaviour
- Movement of head and eyes
- Some aspects of locomotion and posture
High-frequency, low amplitude electrical activity is called ____ activity
Beta
Medium-frequency, medium amplitude activity is called ____ activity
Alpha
When a person is alert the EEG shows ____ activity
Beta
When a person is relaxed and drowsy, the EEG shows ____ activity
Alpha
Stage 1 of sleep is marked by ____ activity
Theta
What is theta activity
3.5 - 7.5 Hz
How does the frequency and amplitude of the EEG change when going through stages 2, 3 and 4
- Frequency gets lower
- Amplitude gets higher
What activity characterises stage 4?
Delta
What are stages 3 and 4 called?
Slow-wave sleep
How long does it take to reach stage 4?
Less than 1 hour
How long does stage 4 sleep last?
Up to half an hour
How long is an average sleep cycle?
90 minutes
How long does the first REM sleep last?
20 - 30 minutes
How many cycles of sleep are there in a typical night?
4 - 5
Motor skills appear to be consolidated after ____ sleep
Stage two/non-REM
Visual discrimination tasks are better remembered after _____ sleep and ____ sleep.
Slow-wave; REM
Slow-wave sleep appears to be beneficial for remembering _____, ______ and ______
Word pairs; spatial locations; recognising words
REM sleep appears to be beneficial to ______ and _____
Non-declarative memory; emotional memory
When do most traffic accidents occur?
Between 4 and 6am
When is the second peak of road traffic accidents?
In the middle of the afternoon
Fatigue appears to have the same negative effect on driving as does ____
Alcohol
According to Freud dreams arise out of….
Our inner conflict between our unconscious desires and prohibitions of acting out these desires.
REM sleep begins ____ after conception and peaks at around _____
30 weeks; 40 weeks
Approximately ____ of a new born infant’s sleep is REM
70%
By 6 months old the amount of REM sleep is around _____
30%
By 8 years old the amount of REM sleep is around ____
22%
By late adulthood the amount of REM sleep is less than _____
15%
What were the results of Mirmiran’s study (1995)?
- Rats showed behavioural abnormalities during adulthood
- Their cerebral cortices and brain stems were smaller than those of controls
What did Mirmiran (1995) do?
Pharmacologically suppressed REM sleep in rats during the 2nd and 3rd week of life
What was the finding of Mirmiran’s study (1995)?
REM sleep may have an active involvement in brain development in infants
What is the clock that controls the circadian rhythm and where is it found?
- The suprachiasmatic nuclei (SCN)
- Found at the bottom of the hypothalamus
How often does the SCN oscillate?
Once a day
What is the basic rest-activity cycle?
The 90 minute cycles of rest and activity in activities such as eating, drinking, smoking, attention, urine production etc.
What are sleep inertia effects?
- Poor psychomotor performance
- Poor thinking
- Poor vigilance
What is the general definition of insomnia?
The inability to initiate or maintain sleep over at least 3 nights
What is REM sleep behaviour disorder?
- The absence of the paralysis usually seen in REM sleep
- Causes people to act out their dreams
- Could be due to damage to the pons
What is cataplexy?
- Sudden onset of paralysis when fully conscious going about daily activities
- Usually triggered by strong emotional states such as laughter
What stage does sleepwalking occur?
Stage 4 of slow-wave sleep
What stage does sleeptalking occur?
Sometimes during REM but most often as part of other stages of sleep
Why do night terrors occur?
Due to the sudden awakening from the depths of stage 4 sleep
What is enuresis?
Bed wetting
What is the drive reduction hypothesis?
Biological needs, caused by deprivation of the necessities of life, are unpleasant, and so we are motivated to reduce these drives
What is the optimum-level hypothesis?
When an individual’s level of arousal is too high, less stimulation is reinforcing and when it is too low, more stimulation is reinforcing
What is osmometric thirst?
Thirst caused by dehydration within cells
How is osmometric thirst caused?
Sodium outside the cell moves water from the intracellular fluid to the extracellular fluid, causing dehydration inside the cell
What is volumetric thirst?
Thirst caused by dehydration outside the cells, a reduction in blood plasma
What can cause volumetric thirst?
- Bleeding
- Low levels of salt
Which organ plays a role in the regulation of volumetric thirst?
The kidney (through the RAAS)
Which receptors alert the body of volumetric thirst?
Baroreceptors
What is the long-term store of nutrients?
Fat
What is the glucostatic hypothesis of hunger?
Hunger occurs when the level of glucose in the blood becomes low
What is sensory specific satiety (SSS)?
The decrease in pleasantness and consumption of a food after eating it to satiety, but not the decrease in eating other foods
Which psychological variables may be a cause of obesity?
- Lack of impulse control
- Poor ability to delay gratification
- Maladaptive eating styles (eating too fast)
What is leptin?
A protein which is secreted by fat cells which have absorbed a large amount of triglyceride
The ion channels found at excitatory synapses allow….
Sodium to enter the neuron
When are we most likely to experience sleep inertia effects?
Within the first 20-30 minutes of waking up
The nerve cells in the cerebral cortex are connected to other parts of the brain by a layer of nerve fibres called…
White matter
The human cerebral cortex is full of bulges called ____, and grooves called ______
Gyri; fissures
Eating is controlled primarily by
Both external and internal variables
REM sleep behaviour disorder involves….
The absence of the paralysis that normally occurs during REM sleep
_______ thirst is caused by dehydration within cells; ______ thirst is caused by dehydration outside of cells
Osmometric; volumetric
