Sensory Modulation Functions
Chung-Hui Lin
OT3 of CSMU
2 categories of terminology
• Neurophysiological • Behavior
– Sensory processing – Sensory registration
– Stimulus detection – Sensory
– Integration of responsiveness
sensation – Sensory integration
– neuromodulation
Sensory processing
Neurophysiologic
Terms
(not directly observable) synthesis
Reception…..detection
neuromodulation
Behavioral terms
(observable) Sensory integration
modulation praxis
Terminology
• Sensory processing
– Reception, modulation, integration, and
organization of sensory stimuli
• Sensory registration(sensory detection)
– The behavior of noticing sensory sti. In the
environment
• Synthesis(integration)
– Interaction with other CNS activities after
detecting the sensory information
Sensory integration (1)
• The neurological process that organizes
sensation from one’s body and the
environment and makes it possible to use the
body effectively within the environment
• Behavior shows adequate sensory reception,
registration, and synthesis
• Integration of sensory information leading to
the production of adaptive environmental
interactions
Sensory integration (2)
• At cellular level
– Occurs within the CNS as inputs
(excitatory/inhibitory) from external and
internal environment of the body
– Neuromodulation: balancing inputs
(exc./inh.) and adapting to environmental
changes
Balance sensory input
Sensory integration (3)
• At behavior level
– To responses that match the demands and
expectations to the environment
– Sensory seeking and sensory avoiding
– Distractibility, impulsiveness, increased
activity level, disorganization, anxiety, and
poor self-regulation
Modulation (1)
• Filtering of sensations
• attending to tasks that are relevant
• maintaining an optimal level of arousal
• maintaining to task till the end
Modulation (2)
• Ayres
– Allows a person to respond to relevant input,
to not respond to what is irrelevant
– Promotes adaptive environmental interactions
• Parham
– Facilitates engagement in satisfying and
meaningful occupations (self-care, play and
work)
Sensory modulation
dysfunction(SMD)
• Imbalance between inhibition and excitation
within CNS
• Over-responsive(too little inhibition)
– sensory defensiveness
– Olfactory (O), tactile(T), auditory(A)
– Over active, hyperverbal, distractible, disorganized
• Under-responsive(too much inhibition)
– sensory dormancy
– No response to OTA, low arousal level
• Fluctuating in between
Over-responsive
Under-responsive
under-responsiveness
• High neurological threshold to input
• Seeking stronger sensation
• No aware inputs
• Prone to danger or injury
• Need intensive vestibular and
proprioceptive sensations to allow for
appropriate environmental interaction
Over-responsiveness (1)
• Low neurological threshold to input
• Strong react to input
• Sensory defensiveness 🡪 avoidance and
withdrawal
• May reflect activation of the sympathetic
nervous system (EDR)
• May overload than shut down the
processing of sensory input
Over-responsiveness (2)
• Is multidimentional, rather than
representing a continuum
• Responsiveness shifts
– Difficult to moderate the sensory input in an
appropriate level to adapting the
environmental changes
– Affect attention, emotional stability and
cognitive processing
Neurotransmission
• Reticular system: arousal
• Limbic system: emotional tone
• Hypothalamus: autonomic regulation
Subcategories of disorders
• Aversive response
• Gravitational insecurity
• Arousal level
• Tactile defensiveness
• Sensory defensiveness
– Smell, taste, sound, and light
Symptoms of modulation difficulties
• Attention:
-easily distractable, has fleeting attention
-tunes out from activity, difficult to engage
-cannot focus easily from one object or
activity to another
• Sensory defensiveness
– A fight or flight reaction to sensation that others
would consider non-noxious
– Occurs in all sensory systems
Other classification
• Low registration
– 低登錄量(與高閾值相一致的行為反應)—遺漏週遭的感
覺刺激或較少做出反應。
• Sensation seeking
– 感覺尋求(與高閾值相抗衡的行為反應)—追求感覺經驗
且對此感到愉快
• Sensory sensitivity
– 感覺敏感(與低閾值相一致的行為反應) —容易分心對一
般感覺刺激常感到易怒或不舒服。
• Sensory avoiding
– 感覺逃避(與低閾值相抗衡的行為反應)—刻意逃避感
Averse responses
• Characterized by autonomic nervous system
reactions such as dizziness & nausea
• Associated w/ poor vestibular processing (poor
processing of semicricular canal-mediated info)
• Intervention:
– activities that provide enhacned proprioceptive &
linear vestibular stimulation
– geared to desensitizing responses to vestibular
stimulation
gravitational insecurity
• Symptoms:
– described as a "primal fear" response to changes in
head position or disturbances to the base of support
– difficulty processing sensation received by the otolith
organs of the vestibular system
• Intervention:
– activities that provide enhanced proprioceptive &
linear vestibular stimulation such as: jumping, pushing
heavy objects, wearing a weighted vest, swinging,
walking on uneven surfaces
Tactile
• Tactile (avoidance of touching certain textures)
defensiveness is the most common sensory
defensiveness
• Tactile System: processes info through 2
channels:
– protective system - light touch
– discriminative system - quality of tactile input
– Must work together for child to react appropriately to
touch sensations
Tactile defensiveness
• Symptoms:
– over-reaction to touch (won't touch stuffed animals,
cotton balls, clay, finger paint, foot, etc.)
– avoids touch from others (prefers firm touch over light
touch)
– frequently dislikes crowds
– avoids having hair washed/cut; nails clipped;
baths/showers
– avoid certain textures of clothing (will only war sweats; will
not wear jeans; clothing that is tight or touches certain
areas bothers them; changes clothes frequently)
– trouble maintaining grasp of certain objects
– avoids going barefoot
• Performance areas likely to be disrupted:
– Social interaction
– Grooming/hygiene
– Dressing
– Play
– Object manipulation
– Household/chores
– Environmental exploration & access
Vestibular
• Interprets sensations from the pull of gravity
Forms a basic reference for other sensory
systems
• To be interpreted for adaptive function,
vestibular input must interact with
proprioceptive input from muscles & joints
• Symptoms:
– avoids backward movement of body or head
– avoids upside down head position
– avoids challenges to balance or center of gravity
– avoids movement through space (cars/vehicles;
play ground equipment; swings; climbing
structures; elevators; escalators, etc.)
– seeks movements (whirling, jumping, swinging) or
hesitant to take risks
• Poorly modulated vestibular system:
– Vertigo
– feeling of rocking (like on a boat)
– sensation of falling rapidly
– grogginess, disorientation
• Vestibular System - not active enough to generate
adequate muscle tone:
– tires easily
– exhibits clumsiness or falls frequently during play
– has difficulty holding his head up when sitting at his desk
• Vestibular is responsible for modulating the
arousal of the nervous system for maintaining a
calm, alert orientation
• Performance areas likely to be affected:
– Environmental access & exploration
– Play
– Mobility & postural development
– Transportation
– Grooming (hair washing/cutting)
Proprioceptive
• Proprioceptive system
– works w/ the brain to modulate the vestibular
system
– input from joints & muscles enables the brain to
correctly interpret vestibular input
– proprioceptive input (pushing, pulling, carrying
heavy objects, joint compression, etc.) is used in
conjunction w/ vestibular input to help integrate
the effects of sensory overload such as dizziness
• Proprioceptive symptoms:
– pulls, twists, chews on things (shirt, pencil)
– breaks toys or hurts classmates when did not mean to
– leans, bumps, trips, or crashes into objects
– walks along touching walls
– too much pressure when writing
– deliberately falls & crashes into things
– constantly "physically tackles" everything
– stands too close when talking to others
– walk is stiff & uncoordinated
– pulls on fingers or cracks knuckles
Oral
• Oral symptoms:
– avoidance of certain food textures or things that touch
the mouth
– avoids tooth brushing
– avoidance of certain temps of food
– may have smooth, slimy foods
– may dislike grainy textures
– may seek oral stimulation by sucking or chewing on
objects or clothing
– does not articulate sounds such as fricatives (f, s, sh,
th)
• Performance areas likely to be disrupted
– Eating
– oral hygiene
– dental care
– Speech
– Play
– non-nutritional oral activity
Taste
• Taste Symptoms:
– picky; dislikes or avoids certain foods
– eats restricted range
– dislikes toothpaste
– seeks intense tastes like spicy or sour foods
• Performance areas likely to be affected:
– Eating
– oral hygiene
Temperature
• Temperature Symptoms:
– reacts to temps that are above or below neutral body
temp
– easily bothered by heat or cold; oblivious to heat or cold
– over/under dressing or for the temp
– extremely sensitive to food temps
• Performance areas likely to be affected:
– grooming & hygiene
– Eating
– environmental access & exploration
– dressing
Auditory
• Auditory Symptoms:
– over-sensitivity to certain sounds (hands over ears)
– radio may irritate hem
– white noise may seem load
– vacuum cleaner or hair dryer may cause a startle reaction
– may be distracted by sounds that are usually not noticed by other
people (i.e. environmental sounds such as: clock ticking, refrigerators,
air conditioning, or heating units; toilets; water running)
• Performance areas likely to be disrupted:
– environmental access & exploration
– on task behavior/attention
– social interaction
Visual
• Visual symptoms:
– oversensitivity to light (florescent lights; outside light)
– stares at spinning objects
– avoid visual gaze (no eye contact)
– become over-stimulated by bright colors & busy patterns
– visual cliffs (i.e. stairs or curbs)
– visual distractibility
• Performance areas likely to be affected:
– environmental access & exploration
– on task behavior/attention
– social interaction
olfactory
• Olfactory symptoms:
– over-sensitivity to the smell of non-noxious odors (i.e. food
smells - those disliked)
– may detect odors long before others
– may gag, nausea/vomit, when smelling such things as
soap/perfume/cleaning products
• Performance areas likely to be affected
– environmental access & exploration
– Eating
– Grooming
– household care
Other Non-specific Sensations
• Symptoms:
– fearful of new situations, places, or people
– fearful of unusual events, high activity events
– trouble sleeping or getting to sleep
– attention
• Performances areas likely to affected:
– emotional stability
– environmental access & exploration
– regulatory/arousal behaviors
underresponsiveness
• React in a way that suggests that they do not notice
sensation
• Appear lethargic or apathetic
• May fail to become alert even w/ intense sensation
• Intervention:
– activities should be aimed at providing movement &
resistance to movement such as swinging in a variety of
positions (prone/sitting), jumping on trampolines, &
propelling on scooter boards
• pain Symptoms:
– decreased awareness: under-reacts or lacks
awareness; seems to seek out intense stimulus;
hurts self; seeks dangerous situations
– over sensitivity: over reacts to non-noxious stimuli
• Performance area likely to be affected
– health & safety
https://momentousinstitute.org/blog/making-sense-of-sensory-processing
• Sensory Input Techniques to Calm and Focus
your Child
• https://www.youtube.com/watch?v=4i258YX-
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