Anatomy Lab 1
What is the wave frequency of the delta brain state?
0.5 to 4 Hz
What stages are relatively light sleep?
1 and 2
What are the current suppositions about consciousness?
1. it involves simultaneous activity of large areas of the cerebral cortex. 2. it is superimposed on other types of neural activity. (Neurons are involved both in motor control and cognition) 3. it is holistic and totally interconnected
What is the way frequency of the beta brain state?
13 to 30 Hz
Delta activity predominates in what stages?
3 and 4
How many times is the sleep cycle repeated over the course of eight hours of sleep?
4 to 6 times
What is the wave frequency of the theta brain state?
4 to 8 Hz
What is the wave frequency of the alpha brain state?
8 to 13 Hz
REM occurs about every ___ minutes?
90
What is psychophysiology?
A branch of science, that is concerned with the physiological basis of psychological processes
What is syncope or fainting?
A brief loss of consciousness
What do the alternating cycles of sleep and wakefulness reflect?
A natural 24 hour circadian rhythm
What do eccrine sweat glands respond to?
A persons mental state
What are artifacts?
A range of unwanted interfering influences that can spoil recordings
What is sleep?
A state of partial unconsciousness, from which a person can be aroused by stimulation
What is epilepsy?
A torrent of electrical discharges that interrupts the normal functioning of neurons, so no other information can be processed through these neurons
What do brain waves change with?
Age, sensory stimuli, brain disease, and chemical state of the body
What is the highest state of consciousness and cortical activity?
Alertness
What does the production of language mostly involve?
All of the left side of the association cortex
What is clinical evidence of brain death?
An absence of spontaneous brain waves (flat EEG)
What is essential for recording EEGs?
An amplifier
What is the most depressed state of consciousness and cortical activity?
Coma
What does consciousness encompass?
Conscious perception of sensations, voluntary initiation and control of movement, and capabilities associated with higher mental processing
What drives the resistance reaction to stress?
Cortisol
What brain state has the highest amplitude of any EEG wave?
Delta
What rhythm is the dominant rhythm in sleep stages three and four?
Delta
What is distraction?
Divided attention of an individual from a particular task onto the source of distraction
When does sleep spindles and K complexes occur?
During NREM stage 2
Is oxygen used by the brain more during REM or during the awake state?
During REM
When does most dreaming occur?
During REM sleep
When are delta waves seen?
During deep sleep, and when the reticular activating system is damped, such as during anesthesia
When are theta waves normal in all ages?
During sleep at all ages
What is electroencephalography used to diagnose?
Epilepsy and brain death
What moves rapidly during REM?
Eyes
What do we use the pre-frontal area of our brain for?
For executive functions like prioritizing tasks and assigning resources to them
What do we use the parietal lobe for?
For location for visual attention
What does digital filtering allow?
For the EEG signal to be analyzed into the component frequencies of interest
What do we use the occipital lobe for?
For vision and our ability to locate objects and identify colors
What brain state is controversial?
Gamma
How would you characterize delta waves?
High amplitude waves
What is the amplitude or intensity of a wave represented by?
How high the wave peaks rise, and how low the troughs dip
When may night terrors, and sleepwalking occur?
In stages 3 and 4
Where do the rhythmic events that these large amplitude waves in EEG often arise?
In the thalamus
What is aphasia?
Inability to produce coherent language
What usually causes syncope?
Inadequate blood flow to the brain due to low blood pressure
In REM sleep does the heart rate, respiratory rate and blood pressure increase or decrease?
Increase
What information can an EEG provide?
Information about different brain activities
What is an aura?
Sensory hallucinations that happen before the seizure begins
What is procedural memory?
Skilled memory, such as that used to play the piano or type on the keyboard. (It is practiced over and over again.)
What is emotional memory?
Memory associated with the sentiments of an event, like the memory of the feelings you felt the last time you visited your parents
What is also called slow wave sleep?
NREM stages 3 and 4
What are the two methods of recording for electromyography?
Needle electrodes inserted through the skin into the muscle or electrodes placed on the skin surface
Does most of our short term memory get committed to long-term memory?
No
Are brain wave patterns the same for everyone?
No, everyone has a unique brain wave pattern
What are the two major types of sleep that alternate during the sleep cycle?
Nonrapid eye movement (NREM) and rapid eye-movement (REM)
What is related to the increase storage of information?
Norepinephrine release when stressed because it is a neurotransmitter associated with memory
What do psychophysiology is typically measure?
Skin conductance, or the electrodermal response
How is consciousness defined clinically?
On a continuum that greets behavior in response to stimuli such as 1) alertness, 2) drowsiness or lethargy, 3) stupor 4)coma
Where are eccrine sweat glands present? What are they innervated by?
On the palmar surfaces of the hands, and on the bottom of the feet Innervated by the sympathetic branch of the autonomic nervous system
Where are alpha waves the strongest?
Over the occipital cortex and over the frontal cortex
After someone goes through the first stage four of the sleep cycle what happens?
Sleepers then move back through the stages except that rather than stage one, REM sleep occurs
What does the EEG result from?
Slow changes in the membrane potential of cortical neurons (especially EPSPs and IPSPs)
When deprived of sleep, what do people spend more time in during the next sleep episode?
Slow wave sleep
What state is most associated with dreaming?
REM
What type of sleep is reverse learning?
REM So we dream to remove unneeded synaptic connections or to forget
What is bottom up attention?
Reflective attention to sensory information like loud noises or bright colors
What facilitates the conversion from short-term to long-term memory?
Rehearsing and repeating and looping new info to old info
How would you characterize beta waves?
Rhythmic, but not as regular as alpha waves, and have a higher frequency
What is the Brocas area of the brain involved with?
Speaking language, but not necessarily understanding it
The EEG of REM sleep is similar to what stage?
Stage 1
What is marked with drowsiness and drifting in and out of consciousness?
Stage 1
What are K complexes?
Sudden increases in wave amplitude
What do psychophysiologists focus on?
System innervated by the autonomic nervous system
During REM sleep, what is secreted and what hormone levels increase?
Testosterone is secreted and norepinephrine and corticosteroid levels increase
In the later sleep cycles what happens to the REM component and stages three and four?
The REM component becomes longer and stages 3 and 4 become shorter
What do eccrine glands do?
The act as variable resistors, so as they fill with fluid, skin resistance, decreases, and skin conductance increases
What does the EEG reflect?
The algebraic, some of the electrical potential changes occurring from large populations of cells
What does an EEG measure?
The electrical potential differences between cortical areas
In general, if the brain is more active, what happens to the frequency and amplitude of the EEG?
The frequency increases, and the amplitude decreases
What happens to the frequency and amplitude of the EEG waves as someone falls into deeper sleep?
The frequency of the waves decline but their amplitude increases
What is responsible for the timing of the sleep cycle?
The hypothalamus
What is electromyography?
The measurement of the electrical activity of the skeletal muscles, reflecting the activity of the nerves controlling them
What is motor memory?
The memory associate with the ability to repeat the same muscle movements (how to control the muscles to repeat an action) Ex: riding a bike the same way
What is declarative memory?
The memory of fact, such as words, names, faces, and dates
What is the wave frequency?
The number peaks in one second
What are brain waves?
The parents of neuronal electrical activity
By inhibiting the brain stem's reticular activating system what happens?
The preoptic nucleus puts the cerebral cortex to sleep
What is the preoptic nucleus?
The sleep inducing center
What happens after each REM episode?
The sleeper descends towards stage four again
What are EEG signals affected by?
The state of arousal of the cerebral cortex
What is a coma?
The state of unconsciousness for an extended period of time, from which a person cannot be aroused, by even the most vigorous stimuli
What regulates the preoptic nucleus?
The suprachiasmatic nucleus (biological clock)
What does the amplitude of brain waves reflect?
The synchronous activity of individual neurons
How would you characterize theta waves?
They are irregular
What happens to brainstem functions like control of respiration, and heart rate during sleep?
They continue
In non-rem sleep stages 1 to 4 what happens to serotonin levels?
They increase
How is declarative memory formed?
Through two stages, short term, and long term memory
What does REM sleep allow the brain to do?
To analyze the days events and work through emotional problems in my dream imagery
What do we use the frontal lobe for?
To know what we are doing with an environment or consciousness (judgments)
What is Wernickes area of the brain involved with?
Understanding language in producing sentences that are structured with logical thought
What happens in the first 30 to 45 minutes of the sleep cycle?
We pass through the first two stages of NREM sleep, and into NREM stages three and four
When are alpha waves seen?
When a person is in a calm, relaxed state of wakefulness
When do beta waves occur?
When we are mentally alert, such as concentrating on a problem or visual stimulus
What is top down attention?
Willful, goal, oriented, attention, like reading
Are spontaneous brain waves present, even during unconsciousness and coma?
Yes
Do you sleep patterns change throughout life? If so how?
Yes (REM and stage 4 sleep declines with age)
What are sleep spindles?
waves of 12-14 Hz that occur in bursts
What does the EEG show?
Characteristic changes in different stages of sleep
How long does one sleep cycle last?
Approximately 90 minutes
How would you characterize alpha waves?
As relatively regular and rhythmic, low amplitude, synchronous waves
What are theta waves uncommon in, but may still appear in?
Awake adults, but may appear when concentrating
What are Theta waves common in?
Awake children
Why are the voltage signals of EEG recordings small?
Because the recording electrodes are separated from the brain's surface by the scalp, the skull, and a layer of cerebrospinal fluid
What is the dominant rhythm in awake alert individuals with their eyes open?
Beta
What can be accentuated by sedative hypnotic drugs like barbiturates?
Beta activity
What may be absent or reduced in areas of cortical damage?
Beta activity
What is the wave frequency of the gamma brain state?
Between 30 and 50 Hz
What greatly inhibits the ability to transfer information from short term memory to long-term memory?
Bilateral damage to the medial temporal lobes and hippocampuses
What decreases with deeper sleep?
Blood pressure and heart rate
What do delta waves indicate in awake adults?
Brain damage
How are brain waves generated?
By Synaptic activity at the surface of the cortex
When stressed what is released and how?
Catecholamines (epinephrine and norepinephrine) are released by the adrenal medulla, which receives signals from the sympathetic nervous system
When cortical activity increases what happens to beta wave activity?
It Increases
What can epilepsy be caused by?
It can be genetically inherited or be caused by injuries (to the head)
About 90 minutes after sleep begins after NREM stage four has been achieved, what happens to the EEG pattern?
It changes abruptly, becoming very irregular, and backtracking quickly through the stages, until alpha waves appear indicating the onset of REM sleep
As the cortical activation increases, what happens to Alpha wave activity?
It decreases
What happens to cortical activity during sleep?
It is depressed
What happens to motor activity during REM sleep?
It is inhibited
What is the importance of slow wave sleep?
It is restorative, or when most neural activity can wind down to basal levels
When does temporary paralysis occur during sleep? What does it prevent?
It occurs during REM and prevents us from acting out our dreams
What is long-term memory?
Large sums of information
What is short term memory?
Limited to 7-8 parts of information (Used for remembering directions)
What does normal brain function involve?
continuous electrical activity
What are the different kinds of memory?
declarative, procedural, motor, emotional
When do most nightmares and night terrors occur?
during NREM stages 3 and 4
What stages are deep sleep?
stages 3 and 4
What do large amplitude waves require?
synchronous activity of a large number of neurons