SENSORY PERCEPTION

SENSORY PERCEPTION
LEARNING OUTCOMES:

After completing this topic, students will be able to:

1. Discuss the components of the sensory-perception process.
2. Describe factors that influence sensory function
3. Identify clinical signs and symptoms of sensory deprivation and
overload.
4. Describe essential components in assessing a client’s sensory-
perception function
5. Discuss factors that place a client at risk for sensory disturbance.
INTRODUCTION
 An individual’s senses are essential
for growth, development, and
survival. Sensory stimuli give
meaning to events in the
environment. Any alteration in
people’s sensory functions can
affect their ability to function within
the environment.
Components of the sensory
experience
The sensory process involves two
components:
Reception
Perception.
Sensory reception- is the process of receiving stimuli or
data. These stimuli are either external or internal to the
body.
 External stimuli are visual (sight), auditory (hearing),
olfactory (smell), tactile (touch), and gustatory(taste).
 Internal stimuli are kinesthetic or visceral.
Kinesthetic- refers to awareness of the position and
movement of body parts
Stereognosis- the ability to perceive and
understand an object through touch by its shape, size,
and texture
Visceral- refers to any large organ within the body. Visceral organs
may produce stimuli that make a person aware of them.

For an individual to be aware of the surroundings, four aspects of the

sensory process must be present:
 Stimulus – this is an agent or act that stimulates a nerve receptor.
 Receptor- a nerve cell acts as a receptor by converting the stimulus
to a nerve impulse.
 Impulse conduction- the impulse travels along the nerve pathways
either to the spinal cord or directly to the brain
 Perception- or awareness and interpretation of stimuli, takes place in
the brain, where specialized brain cells interpret the nature and
quality of the sensory stimuli.
Arousal
Mechanism
For the person to
receive and
interpret stimuli, the
brain must be alert.
The reticular activating system (RAS) in the
brainstem is thought to mediate the arousal
mechanism. The RAS has two components:
1. reticular excitatory area (REA)
- is responsible for arousal and wakefulness.
2. reticular inhibitory area (RIA)
 Sensoristasis
is the term used to describe the state
in which a person is in optimal arousal.

 Awareness is the ability to perceive internal and

external stimuli, and to respond appropriately
through thought and action.
FACTORS AFFECTING SENSORY
FUNCTION
1. Developmental stage
Perception of sensation is critical to the intellectual, social, and
physical development of infants and children. Adults have many learned
responses to sensory stimuli. The sudden loss or impairment of any sense,
therefore, has a profound effect on a person of any age.
Normal physiological changes in older adults put them at higher risk for
altered sensory function. Hearing loss is common in older adults.
2. Culture
An individual’s culture often determines the amount of stimulation that
a person considers usual or “normal.” Cultural deprivation, or cultural care
deprivation, is a lack of culturally assistive, supportive, or facilitative acts
3. Stress
During times of increased stress, people may find their senses
already overloaded and thus seek to decrease sensory stimulation.
4. Medication and Illness
Certain medications can alter an individual’s awareness of
environmental stimuli. Narcotics, antiepileptic agents, and sedatives,
for example, can decrease awareness of stimuli.
5. Lifestyle and personality
Lifestyle influences the quality and quantity of stimulation to
which an individual is accustomed. People’s personalities also differ
in terms of the quantity and quality of stimuli with w/c they are
comfortable.
 Sensory alterations
 People become accustomed to
certain sensory stimuli, and when
these change markedly an individual
may experience discomfort. For
example, when clients enter a
hospital they usually experience
stimuli that differ in quantity and
quality from those to which they are
accustomed. These changes may
cause clients to become confused
and disoriented.
 1. Sensory
deprivation
is generally thought of as a decrease in
or lack of meaningful stimuli. The RAS is
unable to maintain normal stimulation
to the cerebral cortex. Because of this
reduced stimulation, a person becomes
more acutely aware of the remaining
stimuli and often perceives these in a
distorted manner. The person often
experiences alterations in perception,
cognition, and emotion.
 Excessive yawning, drowsiness, sleeping

Decreased attention span, difficulty concentrating,

decreased problem solving
Impaired memory
Clinical
Periodic disorientation, general confusion, or nocturnal
manifestations confusion

Sensory
Pre-occupation with somatic complaints, such as
palpitations

deprivation Hallucinations or delusions

Crying, annoyance over small matters, depression

Apathy, emotional lability

2. Sensory overload
 Sensory overload generally occurs when a person is unable to
process or manage the amount or intensity of sensory stimuli.
 Contributing factors to sensory overload:
a) Increased quantity or quality of internal stimuli, such as pain,
dyspnea, or anxiety.
b) Increased quantity or quality of external stimuli such as a noisy
health care setting, intrusive diagnostic studies, or contacts with
many strangers
c) Inability to disregard stimuli selectively
d) The person usually feels overwhelmed and does not feel in control.
CLINICAL MANIFESTATIONS Sensory CLINICAL MANIFESTATIONS
Deprivation Sensory Overload
• Excessive yawning drowsiness • Complaints of fatigue
sleeping • sleeplessness
• Decreased attention span
• Irritability
difficulty concentrating
• Anxiety
• decreased problem solving
• Impaired memory • restlessness
• Periodic disorientation general • Periodic or general disorientation
confusion • Reduced problem-solving ability
• nocturnal confusion and task performance
• Preoccupation with somatic • Increased muscle tension
complaints, such as palpitations • Scattered attention and racing
• Hallucinations or delusions thought
• Crying, annoyance over small
matters
• depression
• Apathy
emotional liability
3. Sensory deficit

 A sensory deficit is impaired

reception, perception or both, of
one or more of the senses.
Blindness and deafness are sensory
deficit. When the loss of sensory
function is gradual, individuals
often develop behaviors to
compensate for the loss;
sometimes these behaviors are
unconscious.
Nursing
Management
Assessing
1. Nursing History
2. Mental status examination
3. Physical examination
4. Clients at risk for sensory
deprivation or overload
5. Client environment
6. Social support network
 Visual acuity, using a Snellen chart or other reading material
such as a newspaper, and visual fields •
 Hearing acuity, by observing the client’s conversation with
others and by performing the whisper test and the Weber and
Rinne tuning fork tests
 Olfactory sense, by asking the client to identify specific aromas
 Gustatory sense, by asking the client to identify three tastes
such as lemon, salt, and sugar
 Tactile sense, by testing light touch, sharp and dull sensation,
two point discrimination, hot and cold sensation, vibration
sense, position sense, and stereognosis.
 Diagnosing
 Acute confusion: abrupt onset of reversible
disturbances of consciousness, attention, cognition,
and perception that develop over a short period of
time.

 Chronic confusion: irreversible, long-standing, and/or

progressive deterioration of intellect and personality
characterized by decreased ability to interpret
environmental stimuli.

 Impaired memory- inability to remember or recall bits of

information.

 Risk for acute confusion: at risk for alterations in

consciousness, attention, cognition, and perception
that develops over a short time period.
Planning
Planning includes goals associated with the
care of clients independent of setting and
those specific to the home environment.
The overall outcome criteria for clients with
sensory-perception alterations are to:
 Prevent injury
 Maintain the function of existing senses
 Develop an effective communication
mechanism
 Prevent sensory overload or deprivation
 Reduce social isolation
 Perform activities of daily living
independently and safely.
 Implementing
1. Promoting healthy
sensory function: Detecting
sensory problems early is
one step toward
preventing serious
problems.
The Early Hearing
Detection and Prevention
(EHDI) Tracking and
Surveillance System goals
have been established by
the Centers for Disease
Control and
Prevention(CDC)
2. Managing Acute Sensory Impairments
When assisting clients who have a
sensory impairment, a nurse needs to:
a) Encourage the use of sensory aids
b) Promote the use of other senses
c) Communicate effectively
d) Ensure client safety
3. Adjusting Environmental stimuli
A hospitalized client functions best when the
environment is somewhat similar to that of the
individual’s ordinary daily life.
a) Preventing sensory overload
b) Preventing sensory deprivation
4. The confused client
Confusion can occur in clients of all ages, but it is
most commonly seen in older adults. Confusion often
presents with subtle symptoms, but it is important for
the nurse to differentiate between acute (delirium)
and chronic confusion (dementia)
EVALUATING

 Using the measurable and

desired outcomes
developed during the
planning stage as a guide,
the nurse collects the data
needed to judge whether
client goals and outcomes
have been achieved.
THANK YOU!