The picture exchange communication system (PECS) is a form of augmentative and alternative communication produced by Pyramid Educational Consultants, Inc. While the system is commonly used as a communication aid for children with autism spectrum disorder (ASD), it has been used with a wide variety of learners, from preschoolers to adults, who have various communicative, cognitive, and physical impairments, including cerebral palsy, blindness, and deafness. PECS has been the subject of much academic research, with currently over 85 PECS-related publications.
PECS was developed in 1985 at the Delaware Autism Program by Lori Frost and Andy Bondy. They noted that traditional communication techniques, including speech imitation, sign language, and picture point systems, relied on the teacher to initiate social interactions and none focused on teaching students to initiate interactions. Based on these observations, Frost and Bondy created a functional means of communication for individuals with a variety of communication challenges.
PECS is designed to teach functional communication skills with an initial focus on spontaneous communication. It has been and continues to be implemented in a variety of settings and contexts (home, school, community) so users have the skills to communicate their wants and needs. PECS does not require complex or expensive materials since it uses picture symbols as the modality. PECS is a method to teach young children or any individual with a communication impairment a way to communicate within a social context. Research has shown that many preschoolers using PECS also begin developing speech. Based on the current evidence base, PECS has been described as an emerging treatment shown to increase communication skills for individuals with ASD.
Video Picture exchange communication system
Philosophy
The training protocol is based on the principles of applied behavior analysis. The goal of PECS is spontaneous and functional communication. Verbal prompts are not used during the early phases, thus building immediate initiation and avoiding prompt dependency. PECS begins with teaching a student to exchange a picture of a desired item with a teacher/communicative partner, who immediately honors the request. After the student learns to spontaneously request for a desired item, the system goes on to teach discrimination among symbols and then how to construct a simple sentence. In the most advanced phases, individuals are taught to respond to questions and to comment. Additionally, descriptive language concepts such as size, shape, color, number, etc. are also taught so the student can make their message more specific. For example, I want big yellow ball.
Maps Picture exchange communication system
PECS Protocol
After a preparation, the PECS Protocol occurs in six phases:
- Reinforcer Inventory: Before implementing the PECS protocol, the teacher develops an inventory of which items the learner likes. This way, no verbal prompting is needed to ask the child what they want. The chosen reinforcers should be consistently motivating to the user.
- Phase 1: How to Communicate During Phase I, the focus is on teaching the student to initiate social communication. The student is taught to approach the communicative partner with a picture of a desired object or food item and place the picture in the trainer's hand, in order to receive the desired reward. This exchange is taught using one picture, selected by the trainer. Within Phase I, two trainers are utilized. One trainer acts as the student's communicative partner, and the other trainer acts as the physical prompter, who prompts the student to reach towards the communicative partner with the picture in exchange for the student's reward.
- Phase 2: Distance and Persistence During Phase 2, the student is taught to initiate social interaction when the communicative partner is not nearby and waiting. The student is taught to persevere if the reward is not immediately provided, to communicate over longer distances whether it be across a larger table or walking farther distances to reach his/her communicative partner, and initiate spontaneous communication. Teaching the child persistence is comparable to a typically developing child raising his/her voice to gain attention when initial attempts are not recognized by the communication partner. Training should progress across different settings, with different communicative partners, and different types of reinforcing items to assist in the generalization of PECS usage.
- Phase 3: Discrimination Between Symbols During this phase, the student is taught discrimination of symbols and how to select the symbol which depicts a desired item.
Once the student demonstrates mastery with pairings of preferred and non-preferred pictures, discrimination between two preferred pictures is introduced.The picture array is increased until the child can discriminate among all the pictures in the picture book. Frost and Bondy's 4-Step Error Correction Procedure is used to correct mistakes. For children who have difficulty with picture discrimination, mini objects can be used followed by a gradual shift to pictures. Students progress to this step after they can reliably request their favorite items from a variety of people. Pyramid Educational Consultants markets an app designed to reinforce Phase 3 instruction. - Phase 4: Using Phrases During Phase 4, the student is taught sentence structure in order to make requests by using expressions such as "I want ____ ".
Another skill targeted in this phase is commenting as it is learned at the same time as requesting among typically developing children. The requests consist of a sentence starter and a picture of the desired activity or item on a sentence strip. The communicative partner reads back the sentence after it has been exchanged by the student. A delay between the sentence starter and the activity/reward is often used to encourage speech and/or vocalizations. Speech/vocalizations are rewarded by providing the student with a greater amount of the reinforcer to encourage the student to use a picture and speech rather than a picture exchange alone to request activities and items. Teaching children using PECS to create a sentence using expressions such as "I want ___" is a way to increase the complexity of their communicative exchanges. - Phase 5: Answering a Direct Question During Phase 5, the student is taught to respond to the prompt, "What do you want?"
The goal of this phase is for the child to respond "I want ___ " regardless of whether the item is present. This phase adds upon already established skills and a desired item is still used to motivate the user to respond. A delayed prompting procedure is used in which the question and prompt are initially presented at the same time and later a delay is established between the question and gestural prompt. Ultimately, the student should answer the question before additional prompts are provided. According to Bondy and Frost, skills developed in Phase 5 are acquired quickly because sentence construction is familiar to the student and they are motivated to answer. In this phase, the student is also taught descriptives (i.e. colors, size) so that he or she can indicate preferences within desired reinforcers (e.g. I want the red ball). - Phase 6: Commenting During this phase, the student is taught to respond to questions as well as to spontaneously comment on items, people, or activities present in his or her environment. The student can now respond to the question "What do you want?" with "I want ___" In this phase, the student is also taught to differentiate between appropriate responses to the questions "What do you see?" and "What do you want?" The teacher should structure the environment to give the student plenty of opportunities to make spontaneous comments. The teacher can sabotage the environment to elicit comments from the student. Functional communication skills the student should now have developed include being able to make spontaneous requests, responsive requests, and responsive and spontaneous comments.
Depending on the age and cognitive level of the user, the time to master PECS will vary. One study found that it takes an average of 246 trials for users to master all six phases of PECS.
Effectiveness
There is evidence that PECS is easily learned by most students, with its primary benefit being a means of communication for children and adults who have limited or no speech due to autism or other communication disorders. With regard to the intervention setting for AAC training, there is evidence that PECS is most readily learned when instruction takes place in a general education setting. Evidence also indicated that learners initiate a higher number of picture exchanges when PECS is taught in a single setting versus multiple settings.
The consensus among most researchers is that "PECS is recommended as an evidence-based intervention for enhancing functional communication skills of individuals with ASD." On the other hand, the 2009 National Standards Report from the National Autism Center lists PECs among emerging treatments that not (yet) have sufficient evidence of effectiveness.
An initial concern was that PECS might delay or inhibit speech development. However, a recent review of several peer-reviewed studies found that "there is no evidence within the reviewed studies to suggest that PECS inhibited speech; to the contrary, if any effect was observed, it was facilitative rather than inhibitory." When difficulties do arise, it is often due to a lack of powerful reinforcers and/or trainer error. A systematic review of interventions for children with autism spectrum disorder reported that use of PECS resulted in short-term improvement in word acquisition, but the effects were not maintained over time.
However, evidence from meta-analyses indicate that PECS does not result in equal communicative outcomes for all children with ASD. PECS training appears to have the most beneficial effects for younger learners. In addition, evidence of maintenance and generalization effects of functional communication gains achieved through PECs training has been mixed. Research indicates that "PECS is probably best used as an initial intervention to teach manding and the basic elements of what is a communicative exchange," and is not the best selection "for a long-term intervention as it does not address question asking and may be better implemented as part of a multimodal system for when picture communications are more socially appropriate."
Additional applications
There is emerging research that suggests adults with developmental disabilities and severe communication deficits may benefit from the implementation of PECS as well. Others tried to combine PECS training with video modeling.
References
Bibliography
- Bondy, A.S. 2001. "PECS: Potential benefits and risks." The Behavior Analyst Today 2:127-132.
- Mirenda, P. 2001. "Autism, Augmentative Communication, and Assistive Technology: What Do We Really Know?" Focus on Autism and Other Developmental Disabilities 16(3):141-151.
- Hart, S., and Banda, D.R. 2010. "Picture Exchange Communication System With Individuals With Developmental Disabilities: A Meta-Analysis of Single Subject Studies." Remedial and Special Education. 31(6) 476-488.
- Vicker, B. 2011. "What is the "Picture Exchange Communication System" or PECS?" Autism Support Network. Retrieved from: http://www.autismsupportnetwork.com/resources/autism-what-picture-exchange-communication-system-or-pecs-223321
External links
- What is PECS? from the Official PECS USA website
Source of the article : Wikipedia
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