CNS cognitive Flashcards
What is consciousness?
The state of being aware of and able to think about one’s own existence, thoughts, feelings, and surroundings.
What does ‘state of consciousness’ refer to?
Level of arousal (awake, asleep, etc.)
How is consciousness measured?
By behavior and brain activity.
What constitutes conscious experience?
Thoughts, feelings, desires, ideas, etc.
What distinguishes conscious experience from automatic responses?
The capacity to experience one’s existence rather than just recording it or responding to stimuli like an automaton.
True or False: A laptop has a mental life similar to humans.
False
Fill in the blank: Conscious experience refers to _______.
[thoughts, feelings, desires, ideas]
What does a ‘mental life’ imply?
The ability to have thoughts and experiences.
What does an electroencephalograph (EEG) mainly measure?
Activity of neurons located near the scalp in the gray matter of the cortex
EEG is a non-invasive method used to record electrical activity in the brain.
What does the EEG record in terms of electrical activity?
Changes in Voltage
The voltage typically ranges from 20 to 100 microvolts.
What is the typical voltage range measured by an EEG?
20-100 microvolts
This range indicates the electrical activity of the brain’s neurons.
What level of synchrony is present in normal EEG activity?
Low synchrony
Low synchrony is associated with normal brain function.
What does an increase in synchrony in EEG activity indicate?
Potential seizure activity
Increased synchrony occurs when too many neurons work at the same time.
What is the relationship between frequency in EEG and levels of responsiveness?
Frequency is related to levels of responsiveness
Different frequency bands correspond to different states of brain activity.
What does amplitude in an EEG relate to?
Synchronous neural activity
Higher amplitude indicates more synchronous activity among neurons.
Fill in the blank: Too much synchrony in EEG can lead to _______.
seizure
Seizures occur when excessive numbers of neurons fire simultaneously.
What is a spike in the context of EEG?
A sudden increase in voltage that indicates abnormal brain activity
Spikes can signify seizure activity or other neurological issues.
What does EEG stand for?
EEG stands for electroencephalogram.
What mental state does the alpha rhythm reflect?
The alpha rhythm reflects a relaxed mental state with eyes closed.
What mental state does the beta rhythm reflect?
The beta rhythm reflects an alert mental state.
What is the relationship between frequency and amplitude in EEGs?
There is an inverse relationship: as frequency increases, amplitude decreases.
What is the characteristic of slow frequencies in EEGs?
Slow frequencies are associated with big amplitude.
What is the characteristic of fast frequencies in EEGs?
Fast frequencies are associated with low amplitude.
What does NREM stand for?
Non-Rapid Eye Movement
What does REM stand for?
Rapid Eye Movement
How many times do we cycle through stages of sleep during a typical night?
5-6 times
What is the first stage of NREM sleep?
Stage 1
What is the second stage of NREM sleep?
Stage 2
What are the stages of NREM sleep?
Stage 1, Stage 2, Stage 3, Stage 4
What type of sleep is characterized by low amplitude and high frequencies?
REM sleep
What is the duration of a typical REM sleep period?
30 to 45 minutes
True or False: REM sleep is similar to being awake.
True
Fill in the blank: The sleep stage characterized by high amplitude and low frequencies is _______.
NREM sleep
What is another name for REM sleep?
Paradoxical sleep
What is the primary characteristic of Stage 4 NREM sleep?
High amplitude and low frequencies
T or F, dream state is found in REM sleep
True
Stages of sleep sequence
- NREM: stage 1 - stage 4
- Stage 4 - stage 1
- Stage 1 - REM sleep
- REM sleep - NREM sleep
What is the full form of REM?
Rapid Eye Movement
REM is a stage of sleep characterized by increased brain activity and vivid dreams.
What are the stages of sleep that we cycle through?
Stage 1, Stage 2, Stage 3, Stage 4, REM
Sleep consists of NREM (non-rapid eye movement) and REM stages.
What characterizes the NREM stages of sleep?
Stages 1 to 4 without REM
NREM includes lighter sleep stages leading to deeper sleep.
What physiological changes occur during REM sleep?
- Increased eye movement
- Increased heart rate
- Increased respiration rate
- Inhibition of skeletal muscle
Low muscle tone
REM sleep is associated with vivid dreams and muscle atonia.
What is sleep apnea?
Sudden reduction in respiration
Sleep apnea disrupts sleep and prevents recovery benefits.
True or False: During REM sleep, the tongue can relax too much, partially blocking airways.
True
This can lead to sleep disruptions and apnea.
What is the effect of increased heart rate during REM sleep?
It reflects increased brain activity and physiological arousal
This is a normal part of the REM sleep cycle.
What is circadian rhythm
internal process that regulates sleep-wake cycle
repeats around every 24 h
what regulates circadian rhythm
nuclei in the :
reticular activating system
preoptic area of hypothalamus
suprachiasmatic nucleus of hypothalamus
actions of Hypothalamus during waking stage
decrease GABA
which increases Histamine
activates thalamus + cortex
effects of hypothalamus on REM sleep
increases GABA
inhibits histamine release
Thalamus + cortex not activated
Effects of antihistamine drugs
lowers histamine release
can cause to fall asleep
Brainstem : reticular activating system involves which type of neurons
aminergic neurons
to wake up
cholinergic neurons
to enter REM sleep
When aminergic neurons are active, what happens to neurotransmitters
Increase in norepinephrine + serotonin
decrease in acetylcholine
When cholinergic neurons are active, what happens to neurotransmitters
Decrease of norepinephrine + serotonin
increase of Acetylcholine
What is the mesolimbic dopamine pathway?
A neural pathway involved in the processing of rewards and pleasure
What is the role of the reward pathway?
It reinforces behaviors by providing feelings of pleasure
Which part of the brain is associated with higher cognitive functions and decision making?
Prefrontal cortex
What is the function of the midbrain in relation to dopamine?
It contains neurons that release dopamine, influencing reward and addiction
What is the locus ceruleus?
A nucleus in the reticular activating system that is involved in arousal and stress responses
What is the effect of drugs that mimic dopamine?
They activate the mesolimbic pathway and can lead to addiction
Fill in the blank: Dopamine is the primary _______.
[neurotransmitter]
True or False: Amphetamines can replicate the effects of dopamine.
True
How do drugs affect the mesolimbic dopamine pathway?
By continuously activating it, which can create addiction
What is the limbic system?
A complex set of structures in the brain that deal with emotions and memory
The limbic system includes various components such as the hippocampus and amygdala.
What role do emotions play in the limbic system?
They are processed and regulated within the limbic system
Emotions influence behavior and decision-making.
What is the function of the olfactory bulb?
Processes smell information from the nose
It is part of the limbic system and closely linked to emotional responses.
What is the primary function of the hippocampus?
Involved in the formation and retrieval of memories
The hippocampus plays a crucial role in learning and memory.
What is the role of the amygdala?
Processes emotions, especially fear and pleasure
The amygdala is essential for emotional learning and memory.
what is declarative memory
conscious experiences that can be put into words (emotions)
what is procedural memory
memory associated with learning new skills en implementing them in regular behavior
what is consolidation
process of transforming short term memory into long-term (can happen through sleep)
declarative memory, short-term to long-term
From hippocampus to cerebral cortex
procedural memory, short-term to long-term
from multiple brain regions to basal nuclei, cerebellum, premotor cortex
Where are usually the regions responsible for language
left hemisphere
What happens if Broca’s area is damaged
Difficulties to articulate
articulation not possible
cannot speak
What happens if Wernicke’s area is damaged
comprehension difficult or not possible
What is Aphasia
Language deficit
What is sensory neglect
ignorance of the contralateral side after parietal damage
agonist muscle vs antagonist
agonist contracts
antagonist relaxes
What type of neurotransmitter do motor neurons use?
Only excitatory (ACh)
ACh stands for acetylcholine, which is the neurotransmitter involved in stimulating muscle contraction.
What do alpha motor neurons innervate?
Skeletal (extrafusal) muscle
Alpha motor neurons are responsible for causing the contraction of skeletal muscles.
What do gamma motor neurons innervate?
Muscle spindle (intrafusal)
Gamma motor neurons play a role in regulating the sensitivity of muscle spindles.
Where are the cell bodies of motor neurons located?
Ventral horn of spinal cord (spinal nerves) or brain stem (cranial nerves)
The ventral horn contains the cell bodies of motor neurons that send out signals to muscles.
From where do motor neurons receive most of their inputs?
Mostly from interneurons
Interneurons facilitate communication between motor neurons and sensory neurons.
What type of sensory inputs do muscle spindles provide?
Proprioceptive inputs
Proprioception refers to the body’s ability to sense its position and movement.
Proprioceptive inputs from muscle spindles travel up which part of the spinal cord?
Dorsal columns
The dorsal columns carry sensory information regarding proprioception and fine touch to the brain.
T or F reflexes can be overridden
True
What is the characteristic of the withdrawal reflex that involves flexor muscle contraction and extensor muscle relaxation?
Ipsilateral
In the contralateral component of the withdrawal reflex, what happens to muscles involved? What is this reflex called
Flexor muscle relaxation and extensor muscle contraction
This is referred to as the cross extensor reflex.
What type of characteristic is the presence of interneurons between sensory input and motor output?
Polysynaptic
What phenomenon describes the increase in rate and magnitude of the withdrawal response with increased stimulus strength?
Irradiation
What is the term for the response that is maintained after the termination of a stimulus due to spinal feedback loops?
Afterdischarge
