9.3 Naturalistic Developmental Behavioral Interventions (NDBIs) and Augmentative Communication (PECS, AAC)

9.3 Naturalistic Developmental Behavioral Interventions (NDBIs) and Augmentative Communication (PECS, AAC)

Naturalistic Developmental Behavioral Interventions (NDBIs)

Naturalistic Developmental Behavioral Interventions (NDBIs) represent an integration of behavioral science (ABA principles) and developmental science. Unlike traditional, highly structured Discrete Trial Teaching (DTT) conducted at a table, NDBIs occur in natural routines, emphasize child initiation, incorporate shared control, and use natural reinforcers related to the child's ongoing activities.

Core Defining Characteristics of NDBIs

1. Natural Play and Routine Contexts: Learning trials are embedded within child-led play, daily care routines, and social interactions.
2. Child-Led Initiations and Shared Control: Practitioners follow the child's focus of attention and motivation rather than dictating target items.
3. Natural Reinforcement Contingencies: Reinforcers are directly and functionally linked to the child's communicative attempt (e.g., requesting a car results in getting to roll that car, rather than receiving an unrelated edible).
4. Balanced Turn-Taking and Affective Engagement: Interventions prioritize warm, reciprocal social interactions, joint engagement, and positive emotional tone.
5. Prompting and Fading Embedded in Interaction: Prompts (e.g., wait time, modeling, physical guidance) are delivered naturally during play and systematically faded.

Comparison of Major NDBI Frameworks

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Picture Exchange Communication System (PECS)

The Picture Exchange Communication System (PECS), developed by Frost and Bondy, is a low-tech augmentative communication protocol grounded in Skinner's analysis of verbal behavior. PECS explicitly teaches functional manding (requesting) through physical exchange before addressing tacting (commenting).

The Six Phases of PECS Training

1. Phase I: How to Communicate

   • Goal: Initiate communication by picking up a picture, reaching toward a partner, and releasing the icon into the partner's hand.
   • Protocol: Requires two trainers (Communicative Partner and Physical Prompter). No verbal prompts (e.g., "Give me the picture") are used. The Physical Prompter physically guides the learner from behind to pick up and release the icon upon showing interest in a preferred item.

2. Phase II: Distance and Persistence

   • Goal: Generalize the exchange across distance and persistence.
   • Protocol: The learner travels to their communication book, removes the icon, travels to the Communicative Partner, and delivers the icon across varied environments and people.

3. Phase III: Picture Discrimination

   • Phase IIIA: Discrimination between a highly preferred item icon and a non-preferred item icon. Error correction (4-step error correction procedure) is implemented if incorrect.
   • Phase IIIB: Discrimination between two or more preferred icons, verified by a correspondence check (learner must take the item corresponding to the icon exchanged).

4. Phase IV: Sentence Structure

   • Goal: Build multi-word requests using a Sentence Strip.
   • Protocol: The learner attaches an "I want" icon onto a sentence strip, followed by the picture of the desired item, removes the strip, and hands it to the partner. Learners are taught to point to the icons while the partner reads the strip back.

5. Phase V: Answering "What do you want?"

   • Goal: Respond to a direct question while maintaining spontaneous requesting.
   • Protocol: The partner points to the "I want" icon while asking "What do you want?", gradually fading the point prompt until the learner answers the question spontaneously.

6. Phase VI: Responsive and Spontaneous Commenting

   • Goal: Comment on the environment in response to questions like "What do you see?" or "What do you hear?" using icons like "I see", "I hear", "It is".
   • Protocol: Expands the verbal repertoire beyond mands to tacts and social conversation.

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Augmentative and Alternative Communication (AAC) and Speech-Generating Devices (SGDs)

AAC includes all forms of communication (other than oral speech) used to express thoughts, needs, wants, and ideas.

• Unaided AAC: Relies on body movements, manual sign language, gestures, and facial expressions without external tools.
• Aided Low-Tech AAC: Communication boards, PECS books, symbol wallets, point grids.
• Aided High-Tech AAC / SGDs: Speech-Generating Devices (e.g., iPad apps such as Proloquo2Go, TouchChat, LAMP Words for Life; dedicated tobii dynavox devices) that produce synthesized or digitized speech output when icons are selected.

Behavior-Analytic AAC Integration Standards

1. Multimodal Communication: QBA practitioners support any functional communication mode used by the learner (vocalizations, SGD, signs, gestures). AAC does not impede or suppress vocal speech development; empirical research demonstrates it frequently facilitates vocal speech acquisition.
2. Motor Planning & Core Vocabulary: High-tech AAC layouts should maintain consistent spatial locations for core vocabulary words to build automatic motor planning.
3. FCT and Prompting: Functional Communication Training (FCT) principles guide AAC instruction, utilizing systematic least-to-most or most-to-least prompting, differential reinforcement, and immediate access to requested outcomes.

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Peer-Mediated Social Skills Interventions

Peer-mediated interventions (PMI) involve training neurotypical or socially proficient peers to act as intervention agents, facilitating social interactions, play, and communication for individuals with ASD in inclusive educational or community settings.

Key Implementation Components

• Peer Training: Teaching peers specific strategies such as gaining attention, offering choices, sharing materials, prompting responses, giving compliments, and persisting through communication breakdowns.
• Adult Facilitation: The behavior analyst or educator provides subtle prompting, feedback, and reinforcement to the peer-target child dyad rather than leading the social interaction directly.
• Benefits over Adult-Mediated Prompting: PMI reduces prompt dependency on adults, promotes natural peer social rewards, increases generalization across settings, and fosters authentic inclusive social networks.