**4. Restricted, repetitive and stereotyped patterns of behaviour**

As the last of three important characteristics, the DSM-IV-TR mentions restricted, repetitive and stereotyped patterns of behaviour, interests and activities. This can refer to motoric ster‐ eotypies or mannerisms, preoccupations with objects, parts of objects or interests, or their inflexibility in deviating from routines [2].

#### **4.1. Stereotyped use of objects**

Uta Frith confirms that autistic people are often very interested in details, which may ap‐ pear as restricted interests to others [3] and that routines and repetitions are also of im‐ portance for them [19].These behaviour can be explained by the central coherence theory. This theory poses that autistic people have a weak central coherence, meaning that they have the tendency perceive objects and situations in parts rather than perceiving the whole picture or combine information to holistic patterns [3]. As a consequence informa‐ tion is often processed out of context [31]. This theory explains the focus on details, but possibly also the need for repetition and routines shown by people with ASD. The abili‐ ty to generalize parts to the whole keeps situations similar and predictable, and there‐ fore less frightening. If one misses this ability then a coping mechanism is to stick to routines in order to keep situations predictable and safe. If preformed to the extreme these routines become stereotyped behaviours.

Repetitive and stereotyped use of objects is not only seen in autistic people but also in peo‐ ple with intellectual disabilities. In a study where 108 children with severe and profound mental disabilities were included less than two percent suffered from ASD. However, repet‐ itive routines and stereotyped play were found in 60 percent of this group with a mental age below 20 months [52]. Also in children who are blind strong interest in parts of objects and repetitive use of objects can be seen. Mainly this is the result of the blindness-specific con‐ straints on the use of play material that require visual-manual skills. Blind children, when playing alone, prefer toys and materials that produce distinctive tactile or auditory effects [53]. Toys are often articles of daily living and objects in their surroundings such as spoons, walls and furniture. Activities are often aimed at making noise [53, 54].This behaviour is thought to be a way of getting hold on the function of an object and in contrast to children with ASD this behaviour can be relatively easily stopped or interrupted.

#### **4.2. Self Stimulation**

When these people with intellectual disabilities have an additional sensory impairment, problems in symbolic play and imitation can become more evident. It is reasonable to think that people with impaired vision or hearing have more difficulties in imitating because they are less able to perceive actions of others, than people without these impairments. Similarly, symbolic play can be affected. People have less modalities to perceive a toy with, and there‐ fore also see less ways in which they may use it. Combined with an intellectual impairment they can also have troubles in understanding the function the object is intended to have.

Lack of symbolic play was demonstrated to be related to abnormalities in language develop‐ ment that are typical of ASD, such as repetitive speech [52]. Similar to many of the impair‐ ments in ASD that were discussed, this too can be attributed to a lack of ToM. According to Brown et al. [12] ASD is characterized by problems in ToM, symbolic play, and context de‐ pendent language. Shared features of these three skills in childhood are: 1) there has to be a communication pattern between parent and child regarding feelings and thoughts; 2) one has to see and understand the direction of someone else's attitudes towards a shared world; and 3) feel inclined to identify oneself with this shared world. People with ASD have prob‐ lems with all three features. Children who are deaf encounter problems with the first fea‐ ture. They are offered less ToM related language. Children who are blind have trouble with the second feature and subsequently children who are deafblind have trouble with the first

**4. Restricted, repetitive and stereotyped patterns of behaviour**

As the last of three important characteristics, the DSM-IV-TR mentions restricted, repetitive and stereotyped patterns of behaviour, interests and activities. This can refer to motoric ster‐ eotypies or mannerisms, preoccupations with objects, parts of objects or interests, or their

Uta Frith confirms that autistic people are often very interested in details, which may ap‐ pear as restricted interests to others [3] and that routines and repetitions are also of im‐ portance for them [19].These behaviour can be explained by the central coherence theory. This theory poses that autistic people have a weak central coherence, meaning that they have the tendency perceive objects and situations in parts rather than perceiving the whole picture or combine information to holistic patterns [3]. As a consequence informa‐ tion is often processed out of context [31]. This theory explains the focus on details, but possibly also the need for repetition and routines shown by people with ASD. The abili‐ ty to generalize parts to the whole keeps situations similar and predictable, and there‐ fore less frightening. If one misses this ability then a coping mechanism is to stick to routines in order to keep situations predictable and safe. If preformed to the extreme

and second feature.

inflexibility in deviating from routines [2].

490 Recent Advances in Autism Spectrum Disorders - Volume I

these routines become stereotyped behaviours.

**4.1. Stereotyped use of objects**

Finally, autistic people show stereotyped movements with their own bodies or parts of their body. These are often thought to be self-stimulatory. Stereotyped movements can be per‐ formed with every body part but often involve the hands or walking [55, 56] and sometimes become self-injurious [57, 58]. These movements occur in other developmental disorders as well [55, 56], but are especially common in ASD. According to Kraijer self-stimulatory be‐ haviours are often caused by lack of stimulation from the environment [44]. In these situa‐ tions people use their own bodies to provide themselves with the stimulation they need at that moment. He adds to this that the amount of self-stimulatory behaviour and also intensi‐ ty and severity, that is whether it is self-injurious, is related to the level of functioning. The lower the functional level of the person, the more the self-stimulatory behaviour increases in amount and severity [44].

Stereotyped behaviours occur in people with visual impairments as well. Typical stereotyped behaviours in people who are blind are body rocking, head shaking, eye poking and hand flap‐ ping Because these behaviours often occur in the blind, they are sometimes referred to as blind‐ isms, [18, 20]. Actually this term is not entirely correct, because these stereotyped behaviours are not unique for people who are blind; mannerisms would be a better term. Body rocking and head movements, for instance, are typical examples of behaviours that can be seen in people with visual impairment, intellectual disabilities and ASD [18, 20, 24]. Stereotyped behaviours were seen in nearly all [59] and in all [60] blind children, but in children with visual impairment the prevalence is still 10-45% [59]. There also seems to be an age dependency in stereotyped be‐ haviours in blind children. In the first two years stereotyped behaviours increase in frequency to decline thereafter [61]. Stereotyped movements are also found in people with multiple disa‐ bilities. Heather Murdoch [62] suggests that stereotyped behaviours may be a part of normal motor development but that in people with multiple disabilities, these behaviours do not de‐ velop further. In a typically developing child, repetitive behaviours appear as well but develop into conscious movements later on, whereas in people with multiple disabilities they may re‐ main repetitive movements. Trying to stop these behaviours may hamper the development of other motor activities or communicative signs [62].

Whereas stereotyped movements in people without ASD are part of a normal develop‐ ment, in people with ASD they are part of their syndrome. Gense and Gense [20] believe that the differences between these behaviours in visually impaired people with or with‐ out ASD can be found in the severity and perseverance of this behaviour. People with ASD show higher intensities and stronger persistence in stereotypical behaviours [20, 57]. Similar to the behaviours in the intellectually disabled, this could be due to a lack of ex‐ ternal stimulation. Especially in the blind, where stimulation from visual input is miss‐ ing, self-stimulatory stereotyped movements could provide the necessary sensory stimulation [18]. Another difference between people with ASD and people without, is that stereotyped behaviour can more easily be interrupted or stopped in people with vis‐ ual impairments alone [20]. Sometimes not much more has to be undertaken than mak‐ ing the blind person conscious of these unconsciously executed stereotyped behaviour patterns.

Despite the obvious similarities between autistic and non-autistic people with sensory and intellectual disabilities, this chapter also outlines that even though the symptoms ap‐ pear the same, sometimes subtle difference can still be found. This may be due to the possibility that underlying processes of the behaviours are different for autistic and nonautistic individuals [4, 5, 15]. If attempted, a differentiation can thus be made by study‐ ing the subtle differences and underlying causes. A couple of years ago, this was done by making a valid instrument to diagnose ASD in people one of the most challenging combination of disabilities, namely deafblindness and profound intellectual disabilities. Hoevenaars-van den Boom and colleagues were able to confirm the huge overlap in be‐ havioural symptoms between autistic and non-autistic people, but were also able to suc‐ cessfully distinguish the autistic from non-autistic people with their approach that was suited to the developmental level of the participants. They found that differences in this group can be found in the social communicative field, mostly in openness for contact, reciprocity and joint attention and communicative functions [7]. It is clear that when us‐ ing a careful and sophisticated approach, a distinction can be made between autistic and

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A fair diagnosis of ASD, or no ASD, is very important for the treatment and interaction with people with sensory and intellectual disabilities. An ASD diagnosis or a lack thereof will af‐ fect how a person will be treated, as autistic or not. If a child with ASD is placed in a setting where his or her ASD goes unrecognized, the clinicians and care takers might fail to respond to the needs of this person [65]. An important example of why recognition of ASD is so im‐ portant is the treatment of stereotyped behaviour. Stereotyped movements can be a way to reduce stress [19, 20]. In someone with no ASD but with blindness or deafblindness, this be‐ haviour is usually caused when the person does not get enough stimulation from their envi‐ ronment [17, 18], whereas in persons with ASD stereotyped behaviours can be a way to escape from overstimulation or as a way to ensure the optimal level of arousal. In both cases the way to treat stereotyped behaviour will be different, give extra stimulation or reduce overstimulation, respectively. A valid diagnosis would be very helpful in cases where clini‐ cians or parents have to decide what kind of intervention to give. If it is clear whether some‐ one has ASD or not treatment and interaction can be adjusted. Someone with ASD needs a more structured environment, and needs clear instructions when something needs to be done. In someone with ASD, things need to be re-explained in new situations, because of their difficulties in generalizing [6]. It also seems that the sooner we are aware of ASD the better. People with ASD need to be approached in way that is accommodated to their needs [65], and for the wellbeing of the child, it is best if this is done as soon as possible. A recent meta-analysis on intensive early intervention programs for ASD shows that programs that intervene early are most effective and can produce changes in the area of language and adaptive behaviour [67]. Adaptive behaviour was also found to increase as well when addi‐ tional behavioural treatments were given to children with ASD and intellectual disabilities

[68]. These studies showed that if ASD is treated, successful results can be achieved.

non-autistic people with sensory and intellectual disabilities

**5.2. Interaction, treatment and teaching**
