By adapting and modifying the environment, children and adults with significant disabilities are enabled and empowered, thus fostering equality, independence, self-choice, and inclusion. This overview provides a description and brief history of MSE, and goes on to discuss its importance and benefits.
Multi Sensory Environment Defined
In general, a multi sensory environment is a safe, non-threatening, dedicated space (or room) designed to promote intellectual activity, heighten awareness and brain arousal, and encourage relaxation or direct neural pathways. MSE is engineered to bring together multi sensory equipment to stimulate the sensory pathways of touch, taste, sight, sound, smell, and movement without the need for intellectual reasoning or direct neural pathways. MSE either produces a calming effect on individuals prone to frustration or stimulates passive individuals who appear withdrawn (Mertens, 1999). In an MSE, stimulation can be intensified, reduced, presented in isolation or combination, packaged for active or passive interaction, and matched to fit the motivation, interests, recreation, and educational needs of the user (Pagliano, 1999)
An MSE should be a demand-free environment where individuals can select and experience sensory stimulation in their own right, with respect and dignity. Experience is limited when it is not completely controlled by the individual. Only the individual knows internally (and unconsciously) what makes them feel good. The MSE needs to provide opportunities for the person to experience the room on his or her own terms.
Three groups benefit from the use of multi sensory stimulation: (a) those with profound disabilities who, because of a disability, have limited opportunity to access multi sensory stimulation on their own; (b) those who may have sensory processing challenges and need varying sensory simulation in order to process self-regulation; and (c) those without disabilities where multi sensory stimulation and experiencing the environment is a basis for learning and relaxation.
Because an MSE must fit the user’s needs and interest, an MSE can be a recreation activity, an educational tool, and/or a therapy. Comparing an MSE to a fitness center, a visit to the gym may simply be for enjoyment and pleasure (recreation), or a visit to the gym may be used to build muscle or lose weight and considered to be more therapeutic. The same environment, the fitness center, is used for both applications but different methods are used based on the objective. Similarly, an MSE is a multidimensional platform that can be used in different applications.
A universal definition of MSE was developed from a meeting of experts in 2009 (Fornes, Messbauer, Pagliano, & Verheul, 2009). This definition states that MSE is a dynamic pool of intellectual property (IP) developed over 35 years. The MSE IP is a medium for communication that centers around a natural process of multi sensory stimulation that is accessible, demand-free, choice-driven, empowering, meaningful, and pleasurable, based on the need and interest of the person with respect, equality, and human dignity. This MSE multidimensional IP platform can be used in different applications including recreation and leisure, education, and treatment (Fornes et al., 2009). MSE can be used as recreational activity, promoting relaxation, pleasure, and enjoyment. MSE can also be used as an educational tool promoting exploration and interaction with the environment, allowing learn to occur. Finally, an MSE can be utilized with various treatment techniques to encourage a therapeutic outcome. See Figure 1 for a visual representation of the MSE IP platform.
The goal, in all applications, is for multi sensory stimulation to change the participant’s brain arousal to improve neurological physiology and functional ability, leading to improved communication, quality of life, and well-being. The multi sensory stimulation approach can be tailored in intensity and frequency of stimulation to an individual’s threshold (consisting of auditory, visual, tactile, gustatory, olfactory, and kinetic modes) in an attempt to increase arousal and awareness and elicit meaningful, behavioral response (Fornes, Messbauer, Pagliano, & Verheul, 2009).
MSE provides a feedback loop that includes a facilitator to make observations and keep the individual engaged in the MSE experience. The feedback loop allows for each MSE experience to be different and suited to the individual.
A multi sensory environment represents an enriched environment that (a) provides a pleasurable experience of a variety of sensory motor activities (Messbauer, 2006), (b) produces an atmosphere of trust and relaxation or heightened awareness, and (c) promotes self-choice opportunities with the ability to control and interact with one’s environment (Lancioni, Cuvo, & O’Reilly, 2002). This enriched environment encourages learning and improves the participant’s quality of life.
It is important to note that sensory stimulation and multi sensory enrichment are very different from sensory integration, but the terms are often used interchangeably. Sensory integration is a treatment approach that demands active participation and is not choice-driven. It is focused on the remediation of an assessed sensory deficit. A therapist guides children to develop adaptive responses to sensory-based activities. Sensory integration is very physically demanding and is not stress-free or relaxing, although some children do find enjoyment from the treatment. Sensory stimulation, or MSE, on the other hand, is a demand-free environment that allows participants to explore and interact with the environment and the various sensory stimuli at their free will. The facilitator is there only to support and guide the individual, but not to interfere. The person may show enjoyment in response and be more aware and adapt to his or her environment, but the goal is not specifically to promote adaptive responses.
A Brief History of MSE
Sensory learning is not a new topic. Aristotle believed that knowledge was acquired through sensory experiences from the environment and that sensory information was the basis of all knowledge. Historically, MSE has been readily placed in a long tradition of sensory work with people with intellectual disabilities (ID). The Swiss physician, Johann Jakob Guggenbühl (1816–1863) employed sensory training in his ill-fated Abendberg institution, while both Jean-Marc-Gaspard Itard (1774–1838) and Edouard Seguin (1812–1880) working in France explicitly incorporated sensory training into their educational methods (Scheerenberger, 1983). Maria Montessori (1870–1952) argued that intellectual disability was, in part, a result of impoverished institutional environments that provided no sensory stimulation and, therefore, intellectual disabilities should be treated as an educational rather than a medical issue. The development of MSE may be viewed in part as a reaction against institutional settings with their concomitant sensory deprivation (Hogg, Lambe, & Smeddle, 2001).
The first recognized form of multi sensory stimulation for people with severe cognitive disabilities was the sensory cafeteria employed by Cleland and Clark (1966). These researchers reported that well-chosen sensory stimuli for children with developmental delays, withdrawn from their environment, mental retardation, and autism could promote their development, improve their capability to communicate, and positively affect their behavior.
In the mid-70s, the term snoezelen was coined by staff working at the recreation departments of two centers in the Netherlands (Haarendael and De Hartenberg) as a leisure activity for people with severe/profound developmental disabilities (Hulsegge & Verheul, 1987). The snoezelen philosophy was founded on the premise that for an individual with severe/profound disability, an appeal to primary sensations was a more immediately powerful means of contact than any initial appeal to intellectual capabilities. Learning was regarded as secondary or incidental. Learning is not a must, but the individual with severe/profound disabilities should be given the opportunity to gain experiences. If allowed this opportunity, learning will occur. The snoezelen philosophy viewed MSE as an environment where the person with a disability was in control and where the professional, parent, or caregiver was a facilitator who ensured that the environment matched the mood of the individual user (Hulsegge & Verheul, 1987).
By the mid-80s, the snoezelen philosophy found its way into other European countries and has been used for the past 25 years throughout Europe as a popular educational and leisure activity for individuals with various challenges, mainly those with severe cognitive and intellectual challenges. More recently, MSE has been used for a wide spectrum of people, including those with intellectual, physical, and emotional disabilities, autism, severe/profound mental retardation, learning disabilities, emotional disturbances, visual impairments, mental illness, and individuals with dementia and Alzheimer’s (Cuvo, May, & Post, 2001; Hope, 1998).
Benefits of MSE
MSE promotes therapeutic effects by positively affecting both behavioral and physiological measures. MSE has been shown to facilitate sensory development, motor and cognitive development (Lotan, Burshtein, Calhana, & Shapiro, 2003), language development, and hand/eye coordination. In addition, it can promote an understanding of cause-and-effect relationships. MSE encourages exploration and creativity, higher responsiveness to others (Carlotti, 2005; Kwok, To, & Sung, 2003), self determination (Champagne & Stromberg, 2004), and both mental and physical relaxation (Cuvo, May, & Post, 2001). MSE has been shown to improve one’s awareness, concentration, focus, attention, and social skills (Long & Haig, 1992; Verheul, 2008). A multi sensory approach decreases aggressive, self-stimulatory and self-injurious behaviors; decreases agitation (Carlotti, 2005; Shapiro, Parush, Green, & Roth, 1997); and can result in a reduction in the use of psychotropic medications (Kaplan, Clopton, Kaplan, Messbauer, & McPherson, 2006). These positive effects transfer to other settings where individuals exhibit fewer challenging behaviors long after experiencing an MSE (Kaplan et al., 2006; Singh et al., 2004). Even children with the severest cognitive impairments seem to benefit from time spent in a multi sensory environment (Cuvo et al., 2001). They appear happier while in a sensory room and tend to vocalize more, stay on task, and be more alert (Cuvo et al., 2001; Lancioni, Singh, O’Reilly, & Oliva, 2005). MSE stimulation facilitates recovery of the nervous system so that people in comas are able to process information of increasing variety and complexity (Hotz et al., 2006). MSE can also relieve severe pain (Schofield & Davis, 2000). Most of all, MSE produces pleasure and a sense of well-being. Able-bodied children can run and interact with their environment in meaningful ways. MSE provides an opportunity for children with severe disabilities to play, learn, and interact with the environment in their own way.
Overview of Neuroanatomy and the Senses
The brain is the most complex part of the human body and the seat of intelligence. It interprets the senses, initiates movement, and controls behavior. The nervous system consists of the central nervous system (CNS – brain stem and spinal cord) and the peripheral nervous system (PNS – motor and sensory neurons) and is made up of billions of neurons (Waxman, 2003). The brain is divided into three basic units: (a) the forebrain is the largest, most highly developed, consists mainly of the cerebrum, and serves as the source of intellectual activities; (b) the midbrain is the uppermost part of the brain stem and controls reflex action, eye movement, and other voluntary movements; (c) the hindbrain includes the upper part of the spinal cord (brain stem) and the cerebellum, controls involuntary vital functions such as heart rate and respiration, and coordinates movement (Waxman, 2003).
MSE researchers and practitioners are mostly concerned with the neuron, the synapse, and firing of the nerves. The neuron is the functional unit of the brain. All sensations, movements, thoughts, memories, and feelings are a result of signals that pass through neurons. Neurons consist of three parts: the cell body, the dendrites, and the axon. The dendrites extend out from the cell body like branches and receive messages from other nerve cells. Signals then pass from the dendrites through the cell body and travel away from the cell body down an axon to another neuron. The sheath includes a fatty molecule called myelin, which provides insulation for the axon and helps nerve signals travel faster and farther (Waxman, 2003).
Connections between neuronsare almost always synaptic. There are 10 to a 100 trillion synaptic connections at any given time. These networks and connections fire in unison and are the heart of how well the brain functions. A synapse is a very small space separating two nerve cells of an effectors system, such as muscle. A bioelectrical impulse is transmitted across the synapse through neurotransmitters released from the bouton, an enlargement at the end of the axon. The bouton contains catalytic proteins called enzymes. Some of these enzymes are capable of destroying the neurotransmitter, thus inhibiting the nerve transmission (Waxman, 2003). Other enzymes are capable of manufacturing the neurotransmitter (Pfaff, 2006).
The major neurotransmitters are acetylcholine, norepinephrine, dopamine, serotonin, and histamine. These neurotransmitters serve in systems that heighten arousal. Other neurotransmitters that serve in systems that reduce arousal are adenosine, opioids, and Gamma-aminobutyric acid (GABA). Gamma-aminobutyric acid is an inhibitory neurotransmitter because it tends to make cells less excitable. The neurotransmitters depolarize or hyperpolarize (i.e., excite or inhibit) the receiving neuron. The effects are determined by the nature of the receptors. For example, acetylcholine excites motor-voluntary muscles but inhibits the heart muscle (Pfaff, 2006). If the chemicals in the neurotransmitters facilitate depolarization, they excite the nerve cell and produce excitatory postsynaptic potential (EPSP). If the chemicals in the neurotransmitters inhibit depolarization, they reduce the action potential and produce inhibitory postsynaptic potential (IPSP) (Waxman, 2003; Pfaff, 2006).
The motor neurons include the autonomic nervous system (ANS) and the somatic nervous system. ANS consists of two divisions: the sympathetic and parasympathetic systems. The sympathetic system controls the mobilization of body resources for emergencies. When an organism gets excited, the heart rate increases, pupils dilate, and glands secrete (Waxman, 2003). Everything tends to act as a unit with the effect of preparing the organism for fight or flight. The parasympathetic system is complementary to the sympathetic system. It quiets down an organ, which the sympathetic system has activated.
Sensory Processing and the Senses
Sensory processing allows one to take in and make sense of many different kinds of sensations coming into the brain through different sensory receptors and pathways at the same time. Our ability to respond and function depends upon adequate and accurate sensory processing (Ayres, 1982). The sensations ultimately are responsible for how we learn and how we function.
MSE primarily utilizes auditory, visual, tactile, olfactory, gustatory, and kinesthetic sensory input to help individuals self-select the needed sensory stimulation in order to achieve brain arousal or relaxation. Kinetic modes consist of the vestibular (sense of movement and one’s body in space) and proprioceptive (sense of joint and muscle use). Vestibular, proprioceptive, and tactile sensations produce automatic response (Waxman, 2003).
Auditory Stimulation
Auditory stimulations, the stimuli for hearing, are vibrations (sound waves) transmitted through the air. The vibrations stimulate nerve fibers in the ear, which generate impulses. The nerve impulses terminate in the auditory area of the temporal lobes of the brain and sound is thus perceived.
Visual Stimulation
Visual stimuli are created by fibers in the eye responding to direct stimulation as well as to stimulation of neighboring fibers. If a receptor is responding to a weak stimulus but a nearby receptor is responding to a stronger stimulus, the weaker response will be inhibited by the stronger. The effect of this is to accentuate borders and contours (i.e., differences) and to obscure uniform fields (i.e., habituation). Lateral inhibition functions for the cutaneous, auditory, and gustatory modalities. There are environmental cues to which the organism is prewired to respond, presumably those cues that are most necessary for survival (Kaufman, 1987).
Olfactory Stimulation
The sense of smell is the olfactory sense. The olfactory receptors are cells on hairs extending from the ends of the olfactory bulbs. The smell receptors are stimulated by gaseous molecules, although the exact mechanism is unknown. The afferent pathways for smell funnel directly to the brain through the limbic system, displaying the primitiveness of this sense organ. Thus, smell has a more direct route to the brain than other senses.
Gustatory Stimulation
The perception of taste is augmented by smell and touch. To a person whose nostrils are shut tight, a raw apple tastes the same as a raw potato. There are four primary tastes – sweet, sour, salt, and bitter. The taste receptors are in taste buds distributed around the tongue. The number of taste buds decreases with age.
Tactile Stimulation
Touch is crucial to human survival, and plays an important role in our emotional development, creation of memories, and connecting with our environment. The sense of touch is the ability to distinguish various objects through touch and pressure. Some people will crave tactile activities, some show no reaction, while others may display adverse reactions to touch (Ayres, 1972). Tactile sensations arise from receptors located in the skin that fire when touching or being touched. Touch is the mother of all sensory systems. The human finger is so sensitive it can detect a surface bump just one micron high, while the human eye can’t resolve anything much smaller than 100 microns. Touch is an ancient sense in evolution: even the simplest single-celled organisms can feel when something brushes up against them and will respond by nudging closer or pulling away. While we can perceive something visually or acoustically from a distance and without really trying, if we want to learn about something tactilely, we must make a move, we must rub the fabric. But many individuals with disabilities are unable to make this move on their own. While the sensory receptors for sight, vision, smell, and taste are clustered together in the head, conveniently close to the brain, touch receptors are scattered throughout the skin and muscle tissue and must convey their signals by way of the spinal cord.
Tactile sensations are processed in two separate and distinct touch systems: light touch and deep pressure touch. The light touch system, a primitive system and dominant sensation, carries pain, temperature, tickle, itch, and scratch. The sensations tend to spread rapidly, making it difficult to tell precisely where the original contact was made. The pressure touch system carries vibration and joint and muscle sensations. It is a newer and discrete system; the sensations tend to be precise. One can tell where contact is made, when it started and stopped, and how hard it is. This sensation is a subordinate sensation and pathways go to the area of the brain that gives us a vague sense of what it is and then to the cortex for precise identification (Messbauer, 2006).
Vestibular Stimulation
Vestibular sensations arise from firing of the vestibular apparatus in the inner ear and influence one’s movement and motion. The vestibular system talks to and influences every other system. Vestibular perception or sense of gravity provides input to the middle ear and its balance mechanism, including activity such as rolling, swinging, seesaw, merry-go-round, and other rocking activities. Some people will become dizzy and nauseous; others will show no reaction (Messbauer, 1999).
Proprioception Stimulation
Proprioceptive sensation is tied to receptors embedded in muscles, tendons, and ligaments that help us identify where body parts are in space. Proprioceptive sensations help us feel grounded, secure, organized, settled, and calm. The best proprioceptive sensory feedback is active movement of the muscles and joints and when the muscles contract against resistance (Messbauer, 2006). Some children will crave these activities and others will show no reaction. Activities that encourage proprioception are jumping, hopping, or tumbling. Every effort of voluntarily walking, standing, or running gives motion to the body and is directed by a sense of the condition of the muscles. Without this sense we could not regulate the actions of the muscles.