3. How are Memories Formed?
The brain simmers with activity. Different groups of neurons (nerve
cells), responsible for different thoughts or perceptions, drift in and out
of action.
Memory is the reactivation of a specific group of neurons, formed from
persistent changes in the strength of connections between neurons. But
what allows a specific combination of neurons to be reactivated over
any other combination of neurons?
The answer is synaptic plasticity. This term describes the persistent
changes in the strength of connections – called synapses – between
brain cells. These connections can be made stronger or weaker
depending on when and how often they have been activated in the past.
Active connections tend to get stronger, whereas those that aren’t used
get weaker and can eventually disappear entirely (pathways)
4. A connection between two neurons becomes stronger when
neuron A consistently activates neuron B, making it fire an
action potential (spike), and the connection gets weaker if
neuron A consistently fails to make neuron B fire a spike.
Lasting increases and decreases in synaptic strength are called
long-term potentiation (LTP) and long-term depression (LTD).
Changing the strength of existing synapses, or even adding
new ones or removing old ones, is critical to memory
formation.
But there is also evidence that another type of plasticity, not
directly involving synapses, could be important for memory
formation.
5. In some parts of the adult brain, such as the important
memory structure known as the hippocampus, brand new
neurons can be created in a process called neurogenesis.
Studies in older mice have shown that by increasing
neurogenesis in the hippocampus, memory can be improved.
In humans, exercise has been shown to increase the volume of
the hippocampus – suggesting new neurons are being created
– and at the same time improve performance in memory tasks.
6.
7. Where are memories stored
Memories aren’t stored in just one part of the brain.
Different types are stored across different, interconnected
brain regions.
For explicit memories – which are about events that happened
to you (episodic), as well as general facts and information
(semantic) – there are three important areas of the brain: the
hippocampus, the neocortex and the amygdala.
Implicit memories, such as motor memories, rely on the basal
ganglia and cerebellum.
Short-term working memory relies most heavily on the
prefrontal cortex.
8.
9.
10. Explicit memory
There are three areas of the brain involved in explicit memory:
the hippocampus, the neo-cortex and the amygdala.
Hippocampus
The hippocampus, located in the brain's temporal lobe, is
where episodic memories are formed and indexed for later
access.
Episodic memories are autobiographical memories from
specific events in our lives, like the coffee we had with a friend
last week
11. The amygdala, an almond-shaped structure in the brain’s
temporal lobe, attaches emotional significance to memories.
This is particularly important because strong emotional
memories (e.g. those associated with shame, joy, love or grief)
are difficult to forget.
The permanence of these memories suggests that interactions
between the amygdala, hippocampus and neocortex are crucial
in determining the ‘stability’ of a memory – that is, how
effectively it is retained over time.
12. Over time, information from certain memories that are
temporarily stored in the hippocampus can be transferred to
the neocortex as general knowledge – things like knowing
that coffee provides a pick-me-up.
Researchers think this transfer from hippocampus to
neocortex happens as we sleep.
There's an additional aspect to the amygdala’s involvement in
memory.
The amygdala doesn't just modify the strength and emotional
content of memories; it also plays a key role in forming new
memories specifically related to fear. Fearful memories are
able to be formed after only a few repetitions.
13. Implicit memory
There are two areas of the brain involved in implicit memory:
the basal ganglia and the cerebellum.
The basal ganglia are structures lying deep within the brain
and are involved in a wide range of processes such as emotion,
reward processing, habit formation, movement and learning.
They are particularly involved in coordinating sequences of
motor activity, as would be needed when playing a musical
instrument, dancing or playing basketball. The basal ganglia
are the regions most affected by Parkinson’s disease. This is
evident in the impaired movements of Parkinson’s patients.
14. Implicit memory
The cerebellum, a separate structure located at the rear base of
the brain, is most important in fine motor control, the type that
allows us to use chopsticks or press that piano key a fraction
more softly.
A well-studied example of cerebellar motor learning is the
vestibulo-ocular reflex, which lets us maintain our gaze on a
location as we rotate our heads
.
15. Working memory
The prefrontal cortex (PFC) is the part of the neocortex that
sits at the very front of the brain. It is the most recent addition
to the mammalian brain, and is involved in many complex
cognitive functions.
Human neuroimaging studies using magnetic resonance
imaging (MRI) machines show that when people perform tasks
requiring them to hold information in their short-term
memory, such as the location of a flash of light, the PFC
becomes active. There also seems to be a functional separation
between left and right sides of the PFC: the left is more
involved in verbal working memory while the right is more
active in spatial working memory, such as remembering where
the flash of light occurred
16. Orientation
Orientation functions
General mental functions of knowing and ascertaining one's
relation to self, to others, to time and to one's surroundings.
Problems with orientation lead to disorientation, and can be
due to various conditions, from delirium to intoxication.
Typically, disorientation is first in time, then in place and
finally in person.
17. Information Processing
- Our ability to make sense of the world
- Process of taking information in, creating meaning from it,
and usually includes choosing a response – therefore all
cognitive processes involve information processing
There are 3 components:
- Capacity of thinking
- Speed of thinking
- Control of thinking
19. Encoding
- Input or learning stage
- Information briefly registered in sensory memory
- Information categorized and organized according to what
we already know
Level of encoding depends on:
- Attention
- Intention to learn (motivation)
- Organization of material
- Depth of processing
20. Deeper encoding can be enhanced by:
- Elaboration –considering detail, assigning more meaning
to item
- Compatibility– linking with existing knowledge
- Self-reference– personally relevant
21.
22. Storage
- Retention of information, which has been achieved through
the encoding process
- Held in the brain for a prolonged period of time until it is
accessed through recall
- Requires consolidation, rehearsal and/ or practice to
remain in long term memory
- Retention is subject to decay over time & interference from
new memories
23. Retrieval
- In memory refers to the recall of events or information
from the past
- Retrieval is assisted by context and cues
- Retrieval involves active cognitive processing -Recall and
Recognition
25. Sensory Memory
- Stores exact replicas of sensory input in sensory registers.
Lasts from less than 1 sec to several secs.
26. Short Term/Working Memory
- Involves short term storage and active manipulation of
new information
- Allows you to hold several bits of information in your mind
at once to allow information processing
- Functional importance in cognitive processing
- Uses and manipulates memory from sensory and long term
memory
- Either decays over time or stored in long term memory
27.
28. Deficits in Short Term / Working Memory
Impact variety of activities / tasks
- Communication
- Reading
- Dialing phone numbers
- Copying
- Self-reflection
- Problem solving
- Multi-tasking
29. Long Term Memory
- It includes the accumulation of information over a
lifetime.
- Also called secondary memory
- Permanent storage / learnt information
- Unlimited capacity
- Constantly updated
30.
31.
32. Prospective Memory
Memory for intentions
- Time
- Event Based (response to external trigger)
Remembering to carry out planned activities
- Routine tasks require implicit procedural memory
- Non-routine tasks require conscious planning/ prospective
memory
- Requires executive functions (planning, prioritizing)
- Important for independent living, work, social
relationships
33.
34. Prospective Vs Retrospective Memory
Retrospective – recall of previously learnt information or
events
Example
- Remembering that I called my mother yesterday is a form
of retrospective memory
- Remembering to call my mother tomorrow is a form of
prospective memory.
35. Why should OT’s assess Memory?
- Memory impairments can cause great difficulty in
occupational performance of everyday tasks.
- Memory impairments can be a major barrier to
rehabilitation - individual is unable to learn or carry over
the techniques taught in the therapy
40. Non-standardized Ax/Occupation based Ax
- Client / Family / staff reports.
- Occupation based e.g. washing, dressing, meal prep,
shopping, managing finances, route finding.
- Non-occupation based e.g. copying diagrams, letter
cancellation, categorizing objects, basic math's, mazes etc.
- Observation of performance in all interactions identifying
clients’ level of awareness of impairments (metacognition)
and spontaneous use of coping strategies.
41. Why Standardized Ax?
- Guide decision making
- Justify efficacy of intervention
- To identify specific underlying impairments to make rehab
more targeted
- Seek measure of capacity/level of ability in optimum
environment
- Provides quantitative data
- To use as baseline and outcome measure
- For research purposes
- To predict performance in another area- if Ax researched
to be valid for this purpose
42. Non-standardized/Occupational based Ax
- Guide decision making re. intervention and/or discharge plan
- Justify efficacy of intervention
- Identify specific underlying impairments -to target in rehab (more
subjective than standardized Ax)
- To assess performance in specific occupations
- Easier to ensure client-centered and occupation focused
Provide information about:
- The types of cues that facilitate Occupational Performance (OP)
- The types of errors the client is prone to making during OP
- The client’s awareness of their own abilities during OP
- Client does not meet a criteria for standardized assessment
- Lack of access to, training in, time for standardized measure
- No standardized measure that meets your specific purpose
43. Standardized Assessment
1. Allen Cognitive Level Screen (ALCS)
2. Westmead Post Traumatic Amnesia (PTA) Ax
3. Westmead Head Injury Matrix (WHIM)
4. Lowenstein Occupational Therapy Cognitive Assessment (LOTCA-
G)
5. Assessment of Motor and Process Skills (AMPS)
6. Cognitive Assessment of Minnesota (CAM)
7. Middlesex Elderly Assessment of Mental State (MEAMS)
8. Cognistat
9. Rivermead Behavioural Memory Test (RBMT)
10. Independent Living Scale (ILS)
11. Kohlman Evaluation of Living Skills (KELS)
44. Cognitive Rehab Therapy (CRT)
The 4 Approaches:
1. Education
2. Process Training (Remedial)/Restorative)
3. Strategy Training (Compensatory/Adaptive)
4. Functional Activities Training (Can be both)
- Best outcome if all 4 approaches used
- To be used simultaneously, not sequentially
The degree to which each these approaches are utilized
depends on:
- Cause of cognitive impairment
- Individual client factors
45. Process Training
- Process training more appropriate during early recovery
Phase
- Targets specific impairments
e.g. computer memory training, tabletop exercises
- Need to have it’s own Smart goals, Functional goals linked
(pictures of steps of a shower tasks)
Note: The evidence supports a more compensatory based
approach for intervention for memory impairments
- Could use process training to enable regular practice of
strategy training
46. Strategy Training
- Context dependent – need to train for generalization
- Should be as functional as possible and incorporated into
daily routines and life
- Involve client and carer/family in development and
implementation of strategies
- Try to choose strategies similar to client’s past approaches
47. Internal Strategy
- Rehearsal, Progression, Sequencing
- Making associations
- Personally relevant
- Letter cueing
- Writing things down
- Interested
- Retrieval cues
- Story memory
- Priming
- Visual picture
- Mind maps
- Chunking (focus one section at the time)
- Putting things into categories
48. External Strategies
Prospective Memory Strategies
Memory for future intentions
- Calendar, Diary, Memo’s, Timer, Write Down, Apps phone
Retrospective Memory Strategies
Memory of previously learnt info. or events
- Diary, Photo’s, Videos, Voice recorder
49. Errorless learning
- Opposite to trial and error approach
- Avoiding mistakes, which can be more memorable and lead
to learning the wrong thing- (very challenging to
completely errors)
- Clients who struggle to recognize errors could have
difficulty learning from trial and error approach
- Errorless learning is most successful with specific low
level tasks e.g. use a memory book, remember home
address, name of family members
- Best results when combined with other strategies and
interventions
51. Delirium
Definition
- Delirium is a state of mental confusion that develops
quickly and usually fluctuates in intensity.
Description
- Delirium is a syndrome, or group of symptoms, caused by a
disturbance in the normal functioning of the brain.
It differs from dementia in 2 important ways
- Speed of onset: The mental changes in delirium develop
quickly, dementia evolves over months or years.
- Level of consciousness In delirium, consciousness is either
clouded or fluctuates between drowsiness and alertness.
Dementia doesn’t level of consciousness.
52. Delirium Symptoms can include:
- Reduced awareness of and responsiveness to the
environment
- Disorientation
- Incoherence
- Memory disturbance
- Hallucinations
- Delusions
- Agitation
Note:
- Delirium affects about 10% of hospitalized patients, and is
common in many terminal illnesses.
- Delirium is more common in the elderly and associated
with a poorer prognosis
53. Reduced awareness of the environment
This may result in:
- An inability to stay focused on a topic or to switch topics
- Getting stuck on an idea rather than responding to
questions or conversation
- Being easily distracted by unimportant things
- Being withdrawn, with little or no activity or little response
to the environment
54. Poor thinking skills (cognitive impairment)
This may appear as:
- Poor memory, particularly of recent events
- Disorientation — for example, not knowing where you are
or who you are
- Difficulty speaking or recalling words
- Rambling or nonsense speech
- Trouble understanding speech
- Difficulty reading or writing
55. Behavior changes These may include:
- Seeing things that don't exist (hallucinations)
- Restlessness, agitation or combative behavior
- Calling out, moaning or making other sounds
- Being quiet and withdrawn — especially in older adults
- Slowed movement or lethargy
- Disturbed sleep habits
- Reversal of night-day sleep-wake cycle
56. Emotional disturbances These may appear as:
- Anxiety, fear or paranoia
- Depression
- Irritability or anger
- A sense of feeling elated (euphoria)
- Apathy
- Rapid and unpredictable mood shifts
- Personality changes
57. Types of delirium
Experts have identified three types of delirium:
- Hyperactive delirium. Probably the most easily recognized
type, this may include restlessness (for example, pacing),
agitation, rapid mood changes or hallucinations, and
refusal to cooperate with care.
- Hypoactive delirium. This may include inactivity or
reduced motor activity, sluggishness, abnormal drowsiness,
or seeming to be in a daze.
- Mixed delirium. This includes both hyperactive and
hypoactive signs and symptoms. The person may quickly
switch back and forth from hyperactive to hypoactive
states.
58. Delirium and dementia
- Dementia and delirium may be particularly difficult to
distinguish, and a person may have both. In fact, delirium
frequently occurs in people with dementia. But having
episodes of delirium does not always mean a person has
dementia.
- So a dementia assessment should not be done during a
delirium episode because the results could be misleading.
- Dementia is the progressive decline of memory and other
thinking skills due to the gradual dysfunction and loss of
brain cells. The most common cause of dementia is
Alzheimer's disease.
59. Some differences between the symptoms of delirium and
dementia include:
- Onset. The onset of delirium occurs within a short time,
while dementia usually begins with relatively minor
symptoms that gradually worsen over time.
- Attention. The ability to stay focused or maintain attention
is significantly impaired with delirium. A person in the
early stages of dementia remains generally alert.
- Fluctuation. The appearance of delirium symptoms can
fluctuate significantly and frequently throughout the day.
While people with dementia have better and worse times of
day, their memory and thinking skills stay at a fairly
constant level during the course of a day.
60. Delirium Causes
- Certain medications or drug toxicity
- Alcohol or drug abuse or withdrawal
- A medical condition
- Metabolic imbalances, such as low sodium or low calcium
- Severe, chronic or terminal illness
- Fever and acute infection, particularly in children
- Exposure to a toxin
- Malnutrition or dehydration
- Sleep deprivation or severe emotional distress
- Pain
- Surgery or other medical procedures that include
anesthesia
61. Several medications or combinations of drugs can trigger
delirium, including some types of:
- Pain drugs
- Sleep medications
- Medications for mood disorders, such as anxiety and
depression
- Allergy medications (antihistamines)
- Asthma medications
- Steroid medicines called corticosteroids
- Parkinson's disease drugs
- Drugs for treating spasms or convulsions
62. Risk factors
- Any condition that results in a hospital stay, especially in
intensive care or after surgery, increases the risk of
delirium, as does being a resident in a nursing home.
Delirium is more common in older adults.
Examples of other conditions that increase the risk of
delirium include:
- Brain disorders such as dementia, stroke or Parkinson's
disease
- Previous delirium episodes
- Visual or hearing impairment
- The presence of multiple medical problems
63. Complications
- Delirium may last only a few hours or as long as several
weeks or months. If issues contributing to delirium are
addressed, the recovery time is often shorter.
- The degree of recovery depends to some extent on the
health and mental status before the onset of delirium.
People with dementia, for example, may experience a
significant overall decline in memory and thinking skills.
People in better health are more likely to fully recover.
64. Complications
- People with other serious, chronic or terminal illnesses may
not regain the levels of thinking skills or functioning that
they had before the onset of delirium.
Delirium in seriously ill people is also more likely to lead to:
- General decline in health
- Poor recovery from surgery
- Need for institutional care
- Increased risk of death
65. Prevention
- The most successful approach to preventing delirium is to
target risk factors that might trigger an episode.
- Hospital environments present a special challenge —
frequent room changes, invasive procedures, loud noises,
poor lighting, and lack of natural light and sleep can
worsen confusion.
- Evidence indicates that certain strategies — promoting
good sleep habits, helping the person remain calm and
well-oriented, and helping prevent medical problems or
other complications — can help prevent or reduce the
severity of delirium
66. Treatment
- The first goal of treatment for delirium is to address any
underlying causes or triggers — for example, by stopping
use of a particular medication, addressing metabolic
imbalances or treating an infection.
- Treatment then focuses on creating the best environment
for healing the body and calming the brain.
67. Supportive care
Supportive care aims to prevent complications by:
- Protecting the airway
- Providing fluids and nutrition
- Assisting with movement
- Treating pain
- Addressing incontinence
- Avoiding use of physical restraints and bladder tubes
- Avoiding changes in surroundings and caregivers when
possible
- Encouraging the involvement of family members or
familiar people
68. Promote good sleep habits
To promote good sleep habits:
- Provide a calm, quiet environment
- Keep inside lighting appropriate for the time of day
- Plan for uninterrupted periods of sleep at night
- Help the person keep a regular daytime schedule
- Encourage self-care and activity during the day
69. Promote calmness and orientation
To help the person remain calm and well-oriented:
- Provide a clock and calendar and refer to them regularly
throughout the day
- Communicate simply about any change in activity, such as
time for lunch or time for bed
- Keep familiar and favorite objects and pictures around, but
avoid a cluttered environment
- Approach the person calmly
- Identify yourself or other people regularly
- Avoid arguments
- Use comfort measures, such as reassuring touch, when
appropriate
- Minimize noise levels and other distractions
- Provide and maintain eyeglasses and hearing aids
70. Prevent complicating problems
Help prevent medical problems by:
- Giving the person the proper medication on a regular
schedule
- Providing plenty of fluids and a healthy diet
- Encouraging regular physical activity
- Getting prompt treatment for potential problems, such as
infections or metabolic imbalances
71.
72. Amnesia
Two types of amnesia
Retrograde – loss of memory of prior events
- Impairment primarily a retrieval problem
Anterograde – loss of memory of ongoing events
▫ Impairment in learning/encoding/storage
Linked to damage in two areas
- Diencephalon (anterograde & retrograde; eg Korsakoff’s)
- Medial temporal lobe & hippocampus (anterograde; eg
Alzhiemer’s)
73.
74. EBP, Systematic r/v by Cicerone et al., 2000
“…the evidence for the effectiveness of compensatory memory
training for subjects with mild memory impairments is
compelling enough to recommend it as a practice standard.”
However it was conceded that memory rehabilitation is most
effective when clients:
- Are reasonably independent in daily function
- Have insight and self awareness of their memory deficits
- Are capable and motivated to continue active, independent
strategy use once therapy has finished.