Memory, Mental Health, and Beyond Flashcards
Diagnostic and Statistical Manual of Mental
Disorders (DSM)
by the American Psychiatric Association. It is used to diagnose and classifymental health conditions using a common language and set of criteria (i.e., standardization). The DSM is not a fixed document as it is updated every so often to reflect new knowledge and to adjust terminology. They are currently at Version 5.
● DSM has faced important and well deserved criticism over the years.
● It is important for mental health professionals to continue advocating for inclusive and
affirming (supportive) language in the DSM
Memory and Post-traumatic Stress Disorder (PTSD)
● Intrusive memories or flashbacks (can feel like it is happening now)
● Avoidance of reminders (cues) of the trauma
● Possible fragmentation for aspects of the memory (evidence of completely forgetting trauma is less clear) - missing some peaces in the memory
● Memory of trauma feels self defining - life changing event
● Nightmares of the trauma memory (Video)
● Reduced memory for neutral to every day material
the difference between someone who has ptsd and someone who dont is that for one it interfears with their daily life and cant function
Definitional Challenges in the DSM: But what is a trauma?
● Hard to define
● Definition has changed with different versions
● Current DSM: Exposure to actual or threatened death, serious injury, or
sexual violence (personally experienced or witnessed)
● Why is the addition of “witnessed” important?
-powerful imagination
- we are empathetic creatures
What Causes PTSD?
● Unclear
● Only a subset of people exposed to trauma develop PTSD
● There could be predisposing biological or cognitive factors
PTSD, Sleep, and Dreams
● During certain stages of sleep, memories are consolidated, particularly emotional ones
● During rapid eye movement (REM) sleep, noradrenaline (NE) levels dramatically drop.
○ Some research suggests that this allows the brain to process emotional memories, without the same intensity (thereby taking away the emotional charge).
○ One hypothesis is that in PTSD, this process is altered: NE does not decrease as much during REM sleep, leaving in the charge of emotional memories. Manifests
as intrusive memories and nightmares
CS-US linking: A model for PTSD?
● Fear conditioning has been used as a model for PTSD
● According to this theory, neutral stimuli become associated with strong fear responses.
● Unconditioned Stimulus (US): A vicious dog bite, which naturally evokes fear.
● Conditioned Stimulus** (CS)**: The sight of that dog (a previously neutral stimulus).
● After the trauma: The person now fears dogs** (conditioned response; CR)**.
● -The CS-US linkages may be stronger in those with PTSD-
Strengthening the CS-US Further
A person relives the memory, which reinforces the CS-US connection. What is more, new thoughts get linked to the memory, creating more CS stimuli. This makes the memory stronger.
More Than a Strong CS-US relationship?
● Another prominent theory of PTSD suggests that PTSD is associated with an overgeneral fear response.
ex: A person with PTSD may show a conditioned response to
all breeds of dogs.
Can the Strong Conditioned Response be Extinguished?
● In PTSD there may be more difficulty breaking the CS-US link.
- using extinction
● Not clear if this idea best captures PTSD
Limitations to Popular Models of PTSD
- Largely based in non-human animal work, where the focus is on implicit (non- declarative) memory.
- They do not provide a full understanding of PTSD in humans,
which also involves declarative, episodic memory. - They also do not account for other memory differences (e.g., reduced memory for neutral material).
Therapeutic Approaches
There are different types of therapies with different theoretical traditions and practices but many involve memory.
The goal is to reduce the emotional impact of traumatic
memories in a way that diminishes their negative impact
you might still have the memory but to stop hurting or feeling so much stress
when people who have ptsd,playes tetrues reduce their ptsd symptoms
Some theories are challenging to test because we do not have a baseline.
We often study people after a trauma has occurred.
Why is this a limitation to understanding causes and mechanisms?
- is difficult to know if the symptoms are due to trauma or to something else
ptsd tend to have lower of declaritive memory. we dont know if this casues ptsd or the other way around
Substance Use Disorder
● Substance Use Disorder refers to a maladaptive pattern of substance use that leads to clinically significant impairment or distress.
● Addictive substances (e.g., drugs) target different neurotransmitter systems in the
brain.
Operant or Instrumental Conditioning
● One learning model to understand drug use or substance use disorder is operant or instrumental conditioning.
● But classical conditioning is also highly relevant. Let’s visit these in turn.
First: A Primer on How Drugs Change Neurotransmission
A) A presynaptic dopamine- producing neuron releases dopamine into a synapse.
These molecules activate dopamine receptors on the postsynaptic neuron
Unused molecules are broken down and taken back into the presynaptic
neuron, a process called reuptake.
(B) Amphetamine works by causing dopaminergic neurons to make and release more dopamine
Cocaine works by blocking the
reuptake of unused dopamine molecules
Both drugs thus increase the amount of dopamine in the synapse, increasing the chance that dopamine molecules will activate receptors on the
postsynaptic neuron
Dopamine: How the Brain Signals “Wanting”
● The incentive salience hypothesis of dopamine function states that one role of dopamine is to signal how much the animal “wants” a particular outcome—
that is, how motivated the animal is to work for it
○ According to this hypothesis, an ability to motivate responding—is
reduced in dopamine-depleted animals. Dopamine does not have as much to do with “liking” something (the so called pleasure idea). “Liking” is linked to opioid receptors
is not liking it has to do with wanting!!!!
come back to this! is important
Dopamine: How the Brain Signals “Wanting”
● Animals with depleted dopamine will not lever press for food but they will
consume it if its freely available (still “like” food). Animals with increase
dopamine will lever press more. This is operant conditioning.
● S = The lever
● R = The act of lever pressing
● O = The food
● Drugs that affect the dopamine system change the manner of responding “R”.
Substance Use Disorder
● It is not known whether a particular individual who starts using a particular
drug will form an addiction, and it is also hard to know how difficult it will be for a particular individual to respond to treatment.
● Some theories of learning and memory can help us answer these questions and ultimately help individuals live better lives.
● In the last slide we saw the role of S-R-O (operant conditioning). What about classical conditioning?
Example: Tolerance to Addictive Drugs
Classical Conditioning might help us understand certain symptoms, such as cravings.
○ Environmental cues (people, places, etc.)act as CSs associated with the drug (the US).
○ The intense craving felt in response is the CR
- results from the body’s conditioned compensatory response of lowering the levels of the brain chemicals enhanced by the drug in anticipation of the drug’s arrival.
○ Example: if the drug typically speeds up heart rate, your body will compensate by decreasing
heart rate and breathing (other examples, lowering blood pressure, body temperature) or vice
versa in response to environmental cues (CSs).
confused!!!
Conditioned Compensatory Response in the Lab
○ Inject adrenaline (US) > heart rate increase (UR).
○ Repeat the procedure in the same testing chamber (CS).
○ Eventually, CS comes to produce a decrease in heart rate (CR) that helps maintain homeostasis (balance) against expected adrenaline injection.
○ Testing chamber evokes a CR that weakens the overall effects of the drug.
○ Needle can also be a CS!
Implication: A New Location is Not a Strong CS!
- Familiar drug taking location (park bench)
- Novel drug taking location (hotel)
Implication: A New Location is Not a Strong CS! - experiment
- condition 1: In first-time dose rats,
large heroin dose led to:* 96 percent fatal overdose - condition 2:In rats with small
dose before larger dose in the same
location: only 32 percent overdose - condition 3:In rats with small
dose before larger dose in a different
location: 64 percent fatally overdose
Implications
This study **demonstrates the risk of overdose is higher when the drug is taken in a novel environment **(e.g., hotel).
This is because the novel environment lacks the environmental cues (CSs) to initiate compensatory responses.
Extinguishing a Drug Habit
● Substance use can be partially reduced through Pavlovian extinction:
- ** repeated nonreinforced exposure to experimentally manipulated cues that had previously been paired with administration of alcohol or drugs**
Outside the laboratory it can be difficult to extinguish a habit.
○ Cue-exposure therapy should be conducted in as many different contexts as possible, including contexts where original habits were formed.
○ It should be spread out over time, rather than conducted all at once.
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Parkinson’s Disease
● In Parkinson’s Disease, there is a loss of dopamine input to the basal ganglia from the brainstem, leading to profound movement impairments.
● Learning is also affected, especially procedural learning and operant or instrumental conditioning
Why This is Important
● Understanding patterns of spared and impaired memory can help with
rehabilitation. (like semetic learning is kept while episodic most ofetn fades)
