Exam 4 (Final) Flashcards
What is typically measured in a sleep lab?
brain waves, muscle activity, eye movement
What is the rhythm for the waking state?
Beta, small-amplitude with a fast frequency (15-30Hz)
What is the rhythm for the relaxed state?
Alpha, large amplitude, slow frequency (7-11Hz)
What is the rhythm for the drowsy state?
Theta, slower frequency (4-7 Hz)
What is the rhythm for the sleeping state?
Delta, slow, large waves (1-3 Hz)
What type of rhythm is seen in REM sleep?
fast waves
What are the stages of sleep and how are they distributed?
Stages 1-4, predominantly non-REM sleep, alternate cycles roughly every 90 min
How does age affect sleep?
Waking increases and REM decreases
What happens during N-sleep?
Talking or grinding teeth, kicking a foot, temp decreases
What are some theories as to why we dream?
Freud: symbolic fulfillment of unconscious wishes
Jung: expressions of our “collective unconscious”
Why might sleep have evolved?
energy-conserving strategy, sleep during times they cannot travel as easily
How can you support an adaptational view of sleep?
Prey sleep less than predators
What is the basic rest-activity cycle?
recurring cycle of temporal packets, about 90 min periods in humans, during which an animal’s level of arousal waxes and wanes
Pros and cons of the theory of sleep being restorative?
Pros: chemical events that provide energy to cells are reduced during waking and are replenished during sleep; shown by semi-homeostatic regulation of sleep
Con: fatigue and alertness may simply be aspects of the circadian rhythms and have nothing to do with wear and tear on the body
What are the effects of sleep deprivation?
no marked physiological effects, at least in the periods studied (up to 18 days); does lead to decreased cognitive performance
What is the role of sleep and memory storage?
sleep plays a role in solidifying and organizing events in memory
What is consolidation?
process of stabilizing a memory trace after learning
What is reconsolidation?
process of restabilizing a memory trace after the memory is revisited
What are the theories of memory storage in sleep?
Multiple Process Theories: different kinds of memories are stored during different sleep states
Sequential Process Theory: memory is manipulated in different ways during different sleep states
Storage Process Theories: brain regions that handle different kinds of memory during waking continue to do so during sleep
What is the role of the reticular activating system?
stimulation produces a waking EEG; damage to it produces a slow-wave EEG and can result in a coma
What is the role of the basal forebrain in EEG changes?
contains cholinergic cells that secrete ACh onto neocortical neurons that stimulate a waking EEG when animal is still and alert
What is the role of the median raphe nucleus (midbrain) in EEG changes?
Contains serotonin neurons that project widely
throughout the neocortex; when stimulated,
neocortical cells produce a waking EEG when the
animal is moving
What is the role of the peribrachial area in REM sleep?
cholinergic nucleus in the dorsal brainstem has a role in R-sleep behaviors; projects to the medial pontine reticulum
What is the role of the medial pontine reticular formation (MPRF)?
nucleus in the pons participates in R-sleep; projects to several other brain areas that produce REM-related behaviors (atonia)
What happens if there is damage to the peribrachial area of the MPRF?
loss of REM sleep
What is insomnia?
disorder of slow-wave sleep resulting in prolonged inability to sleep
What is drug-dependency insomnia?
condition resulting from continuous use of “sleeping pills”; drug tolerance also results in deprivation of either REM or NREM sleep, leading the user to increase the dosage
What is narcolepsy?
slow-wave sleep disorder in which a person uncontrollably falls asleep at inappropriate times; may be due to mutations in the gene that produces hypocretin/orexin peptides
What is sleep apnea?
inability to breathe during sleep; person has to wake up to breathe
What is a conditioned stimulus?
cue the predicts an unconditioned stimulus
What is an unconditioned stimulus?
biologically important stimulus that elicits an unconditioned response
What is an unconditioned response?
innate response to something like food or pain
What is a conditioned response?
the learned response to a formerly neutral conditioned stimulus
What is the CS and US in the eyeblink conditioning test?
Tone - CS
Air puff - US
Describe implicit memory?
unconscious memory; subjects can demonstrate knowledge but cannot explicitly retrieve the information
Describe explicit memory?
conscious memory; subjects can retrieve an item and indicate that they know that the retrieved item is the correct item
What is the difference in encoding for implicit and explicit memory?
Implicit is processed “bottom-up”
Explicit is processed “top-down”
What is involved in short-term memory?
information held only briefly then discarded; involves frontal lobes
What is involved in long-term memory?
held indefinitely; involves the temporal lobe
How are memories stored?
information from each sensory modality is processed and stored in different neural areas
What is episodic memory?
autobiographical memory for events pegged to specific place and time contexts
What is episodic amnesia?
inability to recall any personally experienced events; associated with frontal lobe injuries or reduced blood flow to the frontal lobes
What happened to patient H.M.?
had no explicit memory after surgery; could still recall memories from childhood; implicit memory was unaffected
What brain areas are thought to have been affected in H.M.?
entorhinal cortex, hippocampus, amygdala
What happened to patient J.K.?
developed Parkinson’s (damage to basal ganglia) resulting in impaired implicit memory
What are the prime structures for explicit learning?
Medial temporal region (hippocampus, amygdala, entorhinal cortex, parahippocampal cortex, perirhinal cortex)
Frontal cortex
What is the role of the hippocampus in spatial memory?
serves as the basis for visuospatial memory; lesions to this area cause difficulty locating objects
How does hippocampal size vary in animals?
those with good spatial memory (animals who store food) have larger hippocampi than those who don’t
What is the reciprocal neural circuit for explicit memory?
the neocortex projects to the entorhinal cortex which projects back to the neocortex
Benefits: keep the sensory experience “alive” in the brain
What is the role of the frontal lobe in short-term memory?
all sensory systems project to the frontal lobes; involved in working memory
What is Korsakoff’s Syndrome?
permanent loss of the ability to learn new information (anterograde) and to retrieve old information (retrograde) (although unusual to cause both); caused by diencephalic damage from chronic alcoholism or malnutrition that produces a vitamin B1 deficiency
What is the role of the hippocampus in explicit memory?
consolidates new memories; once consolidate, no longer needed
What is the neural circuit for implicit memory?
basal ganglia, ventral thalamus, substantia nigra, premotor cortex
Is the implicit memory neural circuit unidirectional or bidirectional? What does this mean?
Unidirectional; you do not know what you know until you do it
What is the pathway of the implicit memory neural circuit?
basal ganglia receive input from the entire neocortex and send projections first to the ventral thalamus and then to the premotor cortex
What is emotional memory and what structure is the most important?
memory for the affective properties of stimuli or events; can be implicit or explicit; amygdala is critical
Describe Long-term Potentiation (LTP).
in response to stimulation at a synapse, changed amplitude of an excitatory postsynaptic potential that lasts for hours to days or longer; plays a part in associative learning
How do you measure LTP?
stimulating electrode; field potential recording electrode
Describe long-term depression (LTD).
decrease in EPSP size; could be a mechanism for clearing out old memories; neuron becomes less active in response to repeated stimulation; requires Calcium entry
What two types of receptors act on the postsynaptic membrane?
AMPA - normally responds to glutamate
NMDA - double gated channels, normally blocked by Mg ions
What must happen for NMDA receptors to open?
- Depolarization of postsynaptic membrane, displaces Mg from pore (strong electrical stimulus)
- Activation by glutamate from the presynaptic neuron (weak electrical stimulus)
- Strong and weak stimuli have been paired
What happens after NMDA receptors are open?
Ca enters the postsynaptic neuron, altering it
Increased responsiveness of AMPA receptors to glutamate; formation of new AMPA receptors; retrograde messengers that trigger more glutamate release from presynaptic neuron
What is the evidence for neurogenesis in adult brains?
olfactory bulbs, hippocampal formation, and possibly the neocortex
How do you show neurogenesis?
done with stain Brdu, which can only be taken up when cells are dividing; use NeuN stain for neuronal tissue; when the two stains show on the same neuron that means a new neuron was created
What are the effects of enriched environments on the brain?
increased brain weight, more dendrites, more astrocytes, more capillaries, increased mitochondrial volume; NOT an increase in neuron number
What is the relationship between experience and motor cortex mapping?
Experience shapes the mapping; relationship between the complexity of dendritic branching and the nature of the computational tasks performed by a brain area
What are the effects of estrogen on the brain?
High: more dendritic spines in the hippocampus
Low: more dendritic spines in the neocortex but fewer in the hippocampus
What are the effects of glucocorticoids on the brain?
released from the adrenal cortex in times of stress; assist in the metabolism of proteins and carbs and the control of sugar levels; steady levels of glucocorticoids are seen with prolonged stress may be neurotoxic
What is the role of nerve growth factor (NGF)?
neurotrophic factor that stimulates neurons to grow dendrites and synapses and, in some cases, promotes the survival of neurons
What is the role of brain-derived neurotrophic factor (BDNF)?
may enhance plastic changes, such as the growth of dendrites and synapses; increased levels when animals learn to solve problems
What is behavioral sensitization?
escalating behavioral response to the repeated administration of a psychomotor stimulant; associated with an increased number of receptors, synapses, and dendrites; these changes were localized to regions that receive a large dopamine projection
What are the effects of sex on the brain?
leads to increased dendritic spine growth in the same brain regions as behavioral sensitization
What are the 3 ways to recover from brain injury?
Learn new ways to solve problems
Reorganize the brain to do more with less
Generate new neurons to produce new circuits
What is a unique characteristic of human language?
syntax: word order determines meaning
What is the association cortex?
Neocortex outside the primary sensory and motor cortices that functions to produce cognition
What is the binding problem?
philosophical question focused on how the brain ties single and varied sensory and motor events together into a unified perception or behavior
What type of processing is associated with the temporal regions?
Visual and auditory
What type of processing is associated with the parietal cortex?
somatosensation and movement control
What type of processing is associated with the frontal cortex?
coordinates information from parietal and temporal with the subcortical regions
What happens if the temporal association cortex is damaged?
visual agnosia (lose all visual knowledge about objects)
Where does the ventral stream project?
Temporal lobe
What is spatial cognition?
a range of mental functions, from the ability to navigate from point A to point B, to the representation of complex visual arrays
What did Moran and Desimone find?
neurons in areas V4 could be trained to respond selectively to information in their receptive field
What is the frontal association cortex?
people with frontal lobe injuries tend to be overly focused on environmental stimuli; seem to selectively direct attention to an object after it is no longer relevant, or to have difficulty shifting attention
What is the parietal association cortex?
damage can produce contralateral neglect; ignoring a part of the body or world on the side opposite that of the brain injury
What is the effect of frontal lobe damage?
inability to organize behavior
What is perseveration?
the tendency to repeat the same verbal or motor response to varied stimuli
What are mirror neurons?
cells in the primate premotor cortex that fire when an individual observes a specific action taken by another individual
What is the brain connectome?
mapping functional connections in the living brain
What is hyperconnectivity?
increased local connections between two related brain regions
What percentage of neurons are contained in the cerebellum?
80%
What is Theory of Mind?
the attribution of mental states to others; empathy is correlated with increased activity in the dorsolateral prefrontal cortex
What is self-regulation?
ability to control our emotions and impulses as a means for achieving long-term goals (pre-frontal regions)
What is neuroeconomics?
interdisciplinary field that seeks to understand how the brain makes decisions
What is the reflective system?
deliberate, slow, rule-driven, and emotionally neutral (ventromedial prefrontal cortex); effortful
What is the reflexive system?
fast, automatic, emotionally biased (lateral prefrontal, medial temporal, and posterior parietal cortex); effortless
Describe the cerebral asymmetries.
region of the sensorimotor cortex representing the face is larger in the left hemisphere than the right
What happens if there is damage to the right parietal lobe?
difficulty coping drawings, assembling puzzles, and navigating around familiar places
What happens if there is damage to the left parietal lobe?
difficulty with language, copying movements, reading, math, and generating names of objects or animals
What is dichotic listening?
experimental procedure for simultaneously presenting a different auditory input to each ear through stereophonic earphones
What is split brain?
surgical disconnection of the two hemisphere in which the corpus callosum is cut
What can split brain individuals not do?
cannot name objects that are presented to their right hemisphere
Why is the left hemisphere specialized for language?
The left hemisphere plays a role in the control of fine movements, and fine movements are necessary for the production of language
Why is the right hemisphere specialized for spatial abilities?
The right hemisphere plays a role in the control of actual movements in space and in mental imagery of such movements (the elaboration of the functions of the dorsal stream)
What are female sex differences in cognitive organization?
typically better at short-term-memory tasks and verbal-fluency tasks
What are male sex differences in cognitive organization?
typically better at spatial-relation tasks and mental-rotation tasks
What are sex differences in the damage done to the left hemisphere?
Male: more likely to be aphasic and apraxic after left posterior cortex
Female: more likely to be aphasic and apraxic after left frontal cortex
What is synesthesia?
ability to perceive a stimulus of one sense as the sensation of a different sense
What are the proposed 7 types of intelligence?
Linguistic
Musical
Logical-Mathematical
Spatial
Bodily-Kinesthetic
Intrapersonal
Interpersonal
What is convergent thinking?
form of thinking that searches for a single answer to a question; temporal and parietal
What is divergent thinking?
form of thinking that searches for multiple solutions to a problem; frontal lobe
What is Intelligence A?
Hebb’s term for innate intellectual potential, which is highly heritable and cannot be measured directly
What is Intelligence B?
Hebb’s term for observed intelligence, which is influenced by experience as well as other factors in the course of development and is measured by intelligence tests
How do smart brains differ?
differences in intelligence are linked to structural and functional variations in the lateral prefrontal cortex. medial prefrontal cortex, posterior parietal cortex, and sensory areas in the occipital and temporal lobes
What is consciousness?
level of responsiveness of the mind to impressions made by the senses
Why do we need consciousness?
As the amount of information about an event increases, it becomes advantageous to produce a single complex representation and
make it available for a sufficient time to the
parts of the brain
Why are we conscious?
allows us to select behaviors that correspond to an understanding of the nuances of sensory inputs
What did Freud believe the id (unconscious) was?
primitive functions, “instinctual drives” of sex and aggression
What is the ego?
rational part of the mind, believed to be partly unconscious
What is the superego?
carries morals, acts to repress the id and to mediate ongoing interactions between the go and the id
What are the 6 causes of behavioral disorders?
genetic errors
progressive cell death
rapid cell death
loss of neural connections
life stress
epigenetics
What is behavior modification?
therapists apply the principles developed from laboratory studies of learning by reinforcement, including operant and classical
What is cognitive therapy?
thoughts intervene between events and emotions; challenge a person’s self-defeating attitudes and assumptions; important with people with brain injuries
What is neuropsychological therapy?
aims to retrain people in the fundamental cognitive processes they have lost
How is fMRI used in treating behavioral disorders?
individuals learn to change their behavior by controlling their own patterns of brain activation; form of neural plasticity in which the individual learns new strategies guided by brain activation information
How is schizophrenia diagnosed?
Delusions: beliefs that distort reality
Hallucinations: distorted perceptions
Disorganized speech: incoherent statement
Disorganized behavior or excessive agitation
Catatonic behavior
Negative symptoms: blunted emotions or loss of interest and drive; the absence of some normal response
What percent of schizophrenia does genetics explain?
80-90%
When is schizophrenia diagnosed?
young adulthood; but it is thought it emerges earlier
What happens in child-onset schizophrenia?
suggests that the condition begins in utero and is characterized by excessive pruning of short-distance cortical connections
What was the first neurochemical to be linked with schizophrenia?
dopamine
What is major depression?
prolonged feelings of worthlessness and guilt; disruption of normal eating habits; sleep disturbances; general slowing of behavior; frequent thoughts about suicide
What is mania?
characterized by excessive euphoria, which the subject perceives as typical; affected person often formulates grandiose plans and is uncontrollably hyperactive
What is bipolar disorder?
mood disorder characterized by alternating periods of depression and mania
Describe the HPA axis.
controls the production and release of hormones related to stress; if stress is intense, excessive cortisol can wield a negative influence on the brain, damaging the feedback loops the brain uses to turn off the stress response
What is cognitive-behavioral therapy?
problem-focused, action-oriented, structured treatment for eliminating dysfunctional thoughts and maladaptive behavior; arguably the best therapy for depression
How many types of anxiety disorders does the DSM-V list and how prevalent are they?
10 classes; 15-35% of the population
What drugs have been shown to be useful for treating anxiety?
GABAergic drugs, SSRIs, CBT
What parts of the brain are more active in patients with anxiety?
cingulate cortex and parahippocampal gyrus
Describe traumatic brain injury.
most common form of brain injury in people younger than 40; results from the head hitting objects; also follows blows to the chest that result in a rapid increase in BP; most TBIs in males 15 to 30 result from car accidents
What is chronic traumatic encephalopathy?
progressive degenerative disease caused by multiple concussions and other closed-head injuries, characterized by neurofibrillary tangles, plaques, cerebral atrophy, and expanded ventricles due to cell loss
What is the coup in brain trauma?
site of impact
What is the countercoup in brain trauma?
opposite site of impact
What happens as a result of TBI?
loss of complex cognitive functions, including reductions in mental speed, concentration, and overall cognitive efficiency
Describe the recovery of TBI.
may continue for 2 to 3 years or longer; most cognitive recovery occurs in the first 6 to 9 months; recovery of memory functions appears to be slower than recovery of general intelligence
Describe a stroke.
an interruption of blood flow from either blockage or bleeding of a vessel
What is ischemia?
lack of blood to the brain as a result of stroke, sets off a cascade of cellular events that cause the real damage to the initial site and surrounding areas
What is diaschisis?
areas distant from the damage are functionally depressed; areas related to the damaged region undergo sudden withdrawal of excitation or inhibition
What are the treatments for a stroke?
t-PA (clot-busting); must be administered within 3 to 5 hours
Rehab therapies for the impaired limb and speech
What is a focal seizure?
arise from a synchronous, hyperactive local brain region
What is a generalized seizure?
Start at a focal location, then spread rapidly and bilaterally to distributed networks in both hemispheres
What causes MS?
a loss of myelin in the motor and sensory nerves; oligodendroglia are destroyed
What is dementia?
acquired and persistent syndrome of intellectual impairment; loss of memory and other cognitive deficits
What are nondegenerative dementias?
a heterogenous group of disorders with diverse etiologies
What are degenerative dementias?
presumed to have a degree of genetic transmission
What percent of dementia cases are Alzheimer’s?
65%
What are some risk factors for Alzheimer’s?
genetics
toxins
trace elements in blood
autoimmune response
slow-acting virus
reduced blood flow
What brain areas are affected most in Alzheimer’s?
Neuritic (amyloid) plaques in the cerebral cortex
Neurofibrillary tangles in the cerebral cortex and hippocampus
Cortical degeneration (most affected are the limbic cortex, inferior temporal cortex, and posterior parietal cortex)
The entorhinal cortex
What neurotransmitters are affected in Alzheimer’s?
Acetylcholine
Noradrenaline
Dopamine
Serotonin
NMDA and AMPA glutamate receptors
What is Parkinson’s?
related to the degeneration of the substantia nigra and to the loss of dopamine released in the striatum
What are some positive symptoms of Parkinson’s?
Tremor at rest
Muscular rigidity
Involuntary movements
What are some negative symptoms of Parkinson’s?
disorders of posture
disorders of righting (standing)
Disorders of locomotion
What are some treatments of Parkinson’s?
L-Dopa (dopamine precursor)
Anticholinergic drugs
Surgery: lesion of the internal part of the globus; transplantation of embryonic dopamine-producing cells
What is the role of Lewy bodies?
Circular fibrous structure found in several neurodegenerative disorders; forms within the cytoplasm of neurons and is thought to result from abnormal neurofilament metabolism
