Exam 2 Flashcards
What is working memory?
Working memory^ (short-term memory)*
• A system for processing information so that it can be acted upon, manipulated, or rehearsed sufficiently that consolidation can begin
• Focuses* perception (about seven bits)
• From few seconds to <2 minutes
Know that recalling digits forward or backwards and performing mental arithmetic are tasks that require working memory.
Encoding^ (acquisition*)
o Input from cortical area are filtered, sent to structures for initial memory processing
Attention* or perception* may affect this stage
Consolidation/storage
o Expression of genes, protein synthesis (for long-term memory), alternation and strengthening of synapses
o Creates a “permanent” record, which may have to be renewed in order to not be lost (unable to be retrieved)
Memorizing the information in this course and autobiographic memory are examples of what type of memory?
Explicit memory*
Retrieval^ (from long term memory)
- A memory is retrieved* and reconsolidated*
- Is an active constructive* process
- During reconsolidation*, the memory is liable and then is restored as a new memory
- Reconstruction often strengthens* “memory”
Which structure/area is particularly critical for associating stimuli and forming long-term, episodic memories?
• Hippocampus
Consolidation
Both “Involves gene expression” and “May also occur during retrieval, given that there may be reconsolidation”
Explicit memory^:
Ability to store and retrieve a memory and to know that one has retrieved it.
- Encoding is improved if individual actively reorganizes* information
- Specific structure* and circuits specialize in specific explicit memories*
- Example: memorizing information from this course
Explicit memory^:
Ability to store and retrieve a memory and to know that one has retrieved it.
- Encoding is improved if individual actively reorganizes* information
- Specific structure* and circuits specialize in specific explicit memories*
- Example: memorizing information from this course
Hippocampus/temporal lobe* (explicit long term memory)
Responsible for episodic* memory (memory of episodes) for autobiographical episodes
Hippocampus* sends info* to VMPFC*
o Results in awareness of self with a past and future (autonoetic awareness)
• In sum, the hippocampus* and the medial temporal cortex* are involved in forming, maintaining, and retrieving* explicit* memories
o One recollects* having encountered the item, not just that it seems familiar
Semantic memory*
Facts, general knowledge
The prefrontal cortex is involved in encoding and retrieving semantic and episodic memory, especially autobiographic memory.
True
Amnesia
loss of memory
Anterograde amnesia*
impairment in learning* new information after^ a lesion in the hippocampus or medial temporal cortex
Anterograde amnesia*
impairment in learning* new information after^ a lesion in the hippocampus or medial temporal cortex
o Confabulation*: imaginary (but plausible) memories to fill in memory gaps; not intentional
o Failure to learn new events (of self or others), words, routes
o But normal at learning motor skills, faces, working memory tasks
“Anterograde amnesia” refers to memory loss of information learned prior to a lesion.
False
Anoxia/hypoxia
oxygen deprivation
- particularly effects the hippocampus
- Cause of amnesia
Anoxia/hypoxia
oxygen deprivation
- particularly affects the hippocampus
- Cause of amnesia
Alzheimer’s disease initially is anterograde amnesia due to the dysfunction of the hippocampus/ medial temporal cortex.
T
• Eventually, retrograde* amnesia with temporal gradient that worsens with time
o Eventually severe dementia*
Anoxia or hypoxia may cause amnesia (dysfunction of explicit memory) due primarily to decreased oxygen in the
Hippocampus
Selective attention
focuses on what is most relevant at the moment, including features and location
o May be nonconscious or conscious
o Underlies other mental functions
o Impairment* is common* in patients with brain lesions or mental disorders
Selective attention is critical for many other mental functions but is seldom impaired in patients with brain injury or dysfunction.
False
Attention networks
- Alerting
- Orienting
- Executive
Alerting system
RAS, releases NE from locus coeruleus, for fast alerting* to novel stimuli
o Prepares prefrontal, posterior parietal cortices
o Activates ACC to suppress unneeded circuits
Level of alertness
o Can vary over a continuum
o May be affected by metabolism, circadian rhythms, fatigue, drugs, medical conditions, brain lesions
o Precisely measured by EEG
o Observe changes in level in your clients (e.g. drugs, delirium)
Two orienting networks:
o Dorsal frontoparietal attention system*
- Orienting to space/location*
o Ventral frontoparietal attention system*
- Orienting to features*
Orienting: Dorsal network
Dorsal* network
o Frontal eye fields, posterior superior parietal cortex
o Top-down process for visuospatial orientation* to space/location*
o Goal-directed* maintaining attention*
o Right* parietal is dominant
Orienting: Ventral network
o Posterior portion of ventral parietal cortex* and ventral prefrontal cortex*
o Activated by sensory input to orient* to relevant features*
o Reorientation* to unexpected stimuli
Executive* control networks
DLPFC-parietal* for transient control at beginning* of tasks
- Prefrontal lesions may cause difficulty alternating attention
Cingulo-opercular* network for sustained* control
- Compromised of ACC and frontal operculum (medial prefrontal plus anterior insula)
Of the three orienting networks, the _________ directs attention to space and keeps us focused, the ____________ directs attention to features, and the ______________ control attention at beginning of tasks and when attention must be alternated.
dorsal network; ventral network; executive control networks
Attention* may increase…
Synchrony*
- Attention causes simultaneous* action potentials to be sent to relevant neurons making them more likely to fire
May occur optimally at 40Hz (gamma frequency)
May be major key to the binding problem
May be deficient in schizophrenia
DLPFC* and ACC* are critical for self-control of…
Emotion* and cognition*
- Children’s attentional systems do not begin to develop until ages 3-4
- Until then, they respond to sensory events in primarily a reflexive manner
Failures of attention:
- Stress* interferes with executive control
- Divided attention*
Much more limited* and difficult* than people think
DLPFC is involved, but its capacity is limited
Often Impairs* attention to both tasks
Divided attention is a function that normal individuals can do quite well.
False
Attention: DMN
Attention networks compete with the default mode network
- Natural tendency is for DMN and social cognition to dominate
- Must be deactivated when it may interfere
Neurodevelopment* starts on…
Day 18 of gestation
Particularly critical to avoid stress, most drugs, toxins* during the first trimester*
Neurogenesis* gliogenesis*:
Growing new neurons, glia
- Mostly complete by end of second time
Which period is the most critical for a woman to avoid drugs, stress, or toxins?
First trimester, especially the first 18 days of pregnancy
Neuronal selection*
Selecting best neurons
Mostly complete by end of second trimester
Migration*
Moving to destinations
Starts by eight weeks; mostly complete by birth
Differentiation*
Specializing
Myelination*
Forming myelin
Synaptogenesis*
Forming synapses:
- Occur before birth
- But many new synapses* are formed during childhood, especially in the prefrontal cortex*
Competitive elimination*
Reorganization, restructuring, pruning
o Started at age six in prefrontal cortex, but is particularly intense during late childhood, adolescence
50% of synapses eliminated by late adolescence
From age 6-19
o Decrease* in prefrontal excitatory* synapse
o Increase* in prefrontal inhibitory* synapse
Most myelination* of prefrontal cortex* not complete* until …
Early adulthood*
Genetics*
The study of genes.
o Gene: a DNA sequence coding for transcription into mRNA that will be translated into a specific protein* (a sequence of amino acids)
Genotype
The specific gene or set of genes related to a phenotype (observable physical property related to gene or genes)
Genome*:
The sequence* of DNA that you inherited.
- The genome is the same in every cell in one’s body
- There are 23,000 genes in the human body (<2% of DNA)
- Much of DNA transcribes mRNAs that do not get translated into specific proteins that help to control the expression* of genes
Epigenetics*
is the study of chemical modifications to chromatin (the composition of chromosomes made of DNA plus proteins)
Epigenome*
Chemicals and proteins that can attach to chromatin and control gene expression.
Whether specific genes are expressed (turned on) or silenced* (turned off
Phenotype:
The observable physical property which is the result of the genome and epigenome
Epigenome may be…
o Permanent* for the life of the cell and its progeny
- Cell differentiation determined during development
o Temporary*
o Heritable* (passed on to offspring)
May occur during development* (in utero) or later*
Caused by Neurocommunication, genes, drugs, environment
- Early trauma, stress, toxins, drugs of abuse
- Leading to psychiatric disorders*
o Therapy, Rx drugs, learning
- Leading to a better life
Epigenomics
The study of the epigenome
Either in a particular type of cell or entire body
Is providing insights into an individual’s health status or possible response to therapies
Epigenetic factors…
Both “Can affect phenotypes” and “Include chemical modifications to chromatin”
Epigenetic factors can increase the risk for psychiatric disorders but cannot lead to positive changes.
False
Epigenetic effects can affect an individual but cannot be passed to one’s offspring.
False
Aversive* environments during pregnancy* or postnatal* period cause…
Teratogenicity, learning disabilities
Toxins, stress, certain drugs (including alcohol, nicotine, caffeine) injury, hormones, microbiota (gut bacteria, vaginal tract)
o May cause epigenetic* effects
The combination of early trauma and adult stress
Both “Can accelerate aging (and associated diseases)” and “Increase the risk for mental disorders”
Aversive Events
Effects of learning disabilities* early* in life may impair mental physical health in adulthood*
Fetal Alcohol Spectrum Disorder (FASD)*
Small brains, learning disabilities, low IQ’s, hyperactivity, physical abnormalities
o Worse if mother drinks during first trimester, particularly if binge drinks or smokes cigarettes
o The leading* cause of mental retardation*
o Even one drink per day lowers IQ
o Epigenetic abnormalities in male sperm
Combination of early trauma* (emotional, sexual, physical) + adult stress*:
o Accelerates aging, as measured by epigenetic changes
o May involve many diseases associated with aging
o Is not considered a major risk* factor for various mental disorders* (e.g. mood and anxiety disorders)
Closed Head Injury^ (CHI)
Much more common* and complicated* than penetrating head injury.
- Direct Impact Effects Acceleratiion/deceleration effects • Contusions (bruising) and bleeding • Shearing/tearing • Linear and rotational forces (torque) • Metabolic disturbances o Excitotoxicity: Glu hyperactivity, resulting in a toxic level of free radicals
• Axonal shearing or injuries* to cytoarchitecture*
o Primarily affect* processing speed/efficiency, attention, working memory, executive functions
• Brain swelling, edema
Coup*
where the initial impact takes place
Contra Coup*
Second impact - both damage to cells and vessels
Most impacted lobes…
Primarily to frontal and temporal lobes, causing attention, memory, emotional, executive deficits
For which of the following conditions is comprehensive neuropsychological assessment most important due to the potential severity and complexity of impairment?
CHI
mTBI (concussion)
- May occur w/o LOC or direct head impact
- But may be significant* (deficits in processing speed, attention, word retrieval, short-term memory, PTSD, fatigue, irritability; depression, anxiety)
- Symptoms usually last fewer than
Persistent Postconcussion Syndrome*
• Symptoms, deficits that last >three months (10% of patients)
Good predictors:
o Poorer premorbid neuropsychological status, personality traits, maladaptive coping style early after injury, preinjury mental health problems, lower education
o Stress at the time of injury
o Current emotions, environmental demands, lack of social support
• Consider emotional, secondary gain, litigation factors
Chronic Traumatic Encephalopathy* (CTE)
- Progressive neurodegenerative disease caused by multiple concussions* or head impacts
- Accumulation or defensive* tau* (a protein that stabilizes microtubules in neurons; also occur in Alzheimer’s disease)
• Cognitive, affective, behavioral (disinhibition, emotional lability) motor symptoms
• Pathology and symptoms often overlap with other neurodegenerative disorders
o Makes clinical diagnosis unfeasible; made only at autopsy
• Most commonly associated with football (North American), ice hockey, boxing, mixed martial arts, wrestling, rugby
• Some experts believe that multiple* head impacts* pose greater* risk than concussions per se
Some experts believe that multiple head impacts pose a greater risk than concussions per se for developing CTE.
True
Diathesis-stress model^
Vulnerability + stress may be a major* factor in many mental disorders
• Diathesis
- Genetic, epigenetic, biological factors
• Stress
- Especially early stress/trauma or chronic
Stressor^
event that has an arousing effect
Stress responses^
Behavioral, physiological responses to cope with stressor
- context* and degree of control* matter
o Degree of response
o When it occurs and with what other factors (diathesis-stress)
• Physically* stressors also exist
- Surgery, excessive exercise
Chronicity*
Chronically* being stressed - major* problem today in humans
Stress: “Fast” Response Biochemical Pathway
o “Fast” response by norepinephrine (NE)* and epinephrine (adrenaline)* released via the sympathetic* nervous system (SNS)
Effects* in seconds, only lasts minutes*
Prepares body for sudden burst* of activity
Stress “Slow” Response Biochemical Pathway
- Slow response by cortisol released via the hypothalamic-pituitary-adrenal (HPA) axis*
- Starts in minutes* to hours, may last hours*
The “slow response” to a stressor involves the release of norepinephrine and epinephrine (adrenaline) and the “fast response” by cortisol
False
Cortisol: Normal
• Prepares body for longer-lasting* adaptations
• Restore* energy that has been expended
- By increasing glucose* (which enters cells and is converted to energy)
- Promotes gluconeogenesis* (making glucose), lipolysis (converting fat to glucose) or protein catabolism* (converting protein to glucose)
- Decreases inflammation
• Cortisol shuts down* systems not immediately needed to deal with a stressor
- Inhibits* immune system
- Can lead to infections if excessive or chronic
High Cortisol Effects
High cortisol and CRF/CRH (corticotropin-releasing factor/ corticotropin-releasing hormone) inhibit* reproductive system
• Decrease libido
• Cause amenorrhea or dysmenorrhea
• Cause infertility
Excessive cortisol inhibits* slow wave sleep
• Decreases* restorative* functions (restoring energy and repair, especially in neurons)
• Predisposes* to depression/mania*
High cortisol increases*
o Appetite/ weight gain*
o Glucose intolerance*
Increased risk* of insulin-resistant diabetes* (Type 2 diabetes), NIDDM)
• Type 2: resistant to insulin
• Type 1: body does not produce insulin
• Insulin is needed to help glucose get into cells/ and decrease high glucose levels in blood
High cortisol suppresses* thyroid* function
• Making someone have hypothyroid function
• Thyroid is crucial for healthy metabolism
o Cortisol increases abdominal fat*
Particularly dangerous for cardiovascular* system, predisposes body to insulin-resistant diabetes
Damages arteries, leading to atherosclerosis, hypertension
Inhibited Slow-Wave Sleep
• Decreases* synthesis of proteins*
o Causes muscle weakness*
• Decreases release of growth hormone* which leads to osteoporosis
o Student growth and failure to thrive in children
Cortisol from stressed mother crosses* placental barrier
Stress/cortisol (especially if excessive or chronic) may increase the risk for depression, anxiety, and cognitive dysfunction, but, fortunately, it does not inhibit the immune and reproductive systems because these systems are not part of the CNS.
False
