Krista M. Wilkinson

Contributions of Principles of Visual Cognitive Science to AAC System Display Design

Beukelman (1991) introduced the concept of the magic versus the cost of communicative competence in AAC. Fundamentally, this refers to the relative effort that must be exerted (the cost) in order for AAC to be a viable communication mode (the magic). Many clinicians have seen the magic for clients who are truly successful in using AAC; such successes have also been documented in the literature. Yet until AAC is successful with each and every client for whom it is implemented, it is necessary to continue to identify barriers to its effective use. In the same year, Light and Lindsay (1991) argued for consideration of principles of cognitive science in constructing maximally useful AAC symbol arrays. In the current paper, we consider how knowledge from one area of cognitive science, that of visual cognition, might be integrated into AAC symbol array construction. We review four areas of visual cognition that might relate to the construction of AAC displays:(a) organization of stimulus arrays within either grids (row-column configuration) or integrated within natural scenes, (b) symbol location, (c) color and contrast, and (d) symmetry and axial orientation.

Roles of graphic symbols in the language acquisition process for persons with severe cognitive disabilities

Symbols play dual roles for nonspeaking persons learning language via instruction. They are the medium by which internal representations of the world are expressed and they provide an inference about how individuals perceive their world. This paper reviews and synthesizes the current empirical literature on symbols and suggests future research directions.

Profiles of language and communication skills in autism

Language in autism appears to be best characterized by a selective deficit in applying language forms for purposes of functional communication. This pattern of selective deficit has been called the ‘‘form/function dissociation.’’ This article outlines the language characteristics most often associated with autism and considers whether the observed patterns are specific to autism as a syndrome. Those characteristics that appear to be syndrome-specific are analyzed from the perspective of the form/function dissociation. Intervention considerations are briefly reviewed.

Considerations for the Composition of Visual Scene Displays: Potential Contributions of Information from Visual and Cognitive Sciences

Aided augmentative and alternative (AAC) interventions have been demonstrated to facilitate a variety of communication outcomes in persons with intellectual disabilities. Most aided AAC systems rely on a visual modality. When the medium for communication is visual, it seems likely that the effectiveness of intervention depends in part on the effectiveness and efficiency with which the information presented in the display can be perceived, identified, and extracted by communicators and their partners. Understanding of visual-cognitive processing – that is, how a user attends, perceives, and makes sense of the visual information on the display – therefore seems critical to designing effective aided AAC interventions. In this Forum Note, we discuss characteristics of one particular type of aided AAC display, that is, Visual Scene Displays (VSDs) as they may relate to user visual and cognitive processing. We consider three specific ways in which bodies of knowledge drawn from the visual cognitive sciences may be relevant to the composition of VSDs, with the understanding the direct research with children with complex communication needs is necessary to verify or refute our speculations.

Preschoolers' speed of locating a target symbol under different color conditions

A pressing decision in AAC concerns the organization of aided visual symbols. One recent proposal suggested that basic principles of visual processing may be important determinants of how easily a symbol is found in an array, and that this, in turn will influence more functional outcomes like symbol identification or use. This study examined the role of color on accuracy and speed of symbol location by 16 preschool children without disabilities. Participants searched for a target stimulus in an array of eight stimuli. In the same-color condition, the eight stimuli were all red; in the guided search condition, four of the stimuli were red and four were yellow; in the unique-color condition, all stimuli were unique colors. Accuracy was higher and reaction time was faster when stimuli were unique colors than when they were all one color. Reaction time and accuracy did not differ under the guided search and the color-unique conditions. The implications for AAC are discussed.

Fast Mapping and Exclusion (Emergent Matching) in Developmental Language, Behavior Analysis, and Animal Cognition Research

Researchers from behavior analytic, developmental, and comparative perspectives have all investigated the conditions under which new arbitrary (symbolic) stimulus-stimulus relations are acquired. For example, young children, people with severe mental retardation, and several species of nonhuman mammals all exhibit emergent matching (EM) in the context of a wellestablished matching-to-sample baseline: When presented with an undefined sample stimulus and a comparison array that includes one undefined comparison and one or more baseline comparisons, participants select the undefined comparison. Further, subsequent testing may show a learning outcome: Exposure to EM trials may result in a new defined relation involving the formerly undefined stimuli. Between 1974 and the late 1980s, emergent matching and learning outcomes were described independently by behavior analytic, child language, and animal cognition researchers. Cross-literature citations were virtually absent, however. More recently, crossdisciplinary citations have begun to appear. This article briefly reviews the history of EM research, emphasizing the independent development of research programs, methods, and terminology in the three disciplines. We then identify several research areas where a multidisciplinary approach may benefit all concerned.

EMERGENT WORD-OBJECT MAPPING BY CHILDREN: FURTHER STUDIES USING THE BLANK COMPARISON TECHNIQUE

Two experiments examined the emergent mapping phenomenon in Portuguese-speaking children aged 3–13, This phenomenon is relevant to developmental psychologists’ interest in ‘last mapping” of new word-referent relations and also to behavior analysts’ interest in behavior that emerges without explicit conditioning. We studied 52 children, using the “blank comparison” matching-to-sample technique described by Wilkinson and McIlvane (1997), The technique allows direct measurement of the stimulus control bases of emergent mapping, for example, to determine whether new words and their referents are related directly or via rejection (i.e., exclusion) of previously defined referents. Children demonstrated both types of controlling relations. These studies systematically replicate prior emergent mapping research in a large cohort of non-English-speaking children. Also found were apparent developmental differences between older and younger children. Although all children tended to relate novel stimuli, the tendency appeared to decline as children aged. This study confirms the utility of the blank comparison technique in emergent mapping research and also provides the first data set from school-aged children.

Working Memory Demands of Aided Augmentative and Alternative Communication for Individuals with Developmental Disabilities

Abstract When speech is not functional to meet some or all of an individuals communication needs, aided augmentative and alternative communication (AAC) systems are often implemented. Although aided AAC systems offer some advantages over speech, they also impose some unique demands, especially on working memory, which is commonly defined as the cognitive system by which individuals maintain and manipulate information while completing tasks. For instance, the presence of an external aided AAC device containing arrays of symbols, not all of which are visible simultaneously, presents multiple working memory demands: individuals must maintain the target concepts in mind, all the while (a) navigating through multiple pages, (b) remembering the appropriate or most efficient navigation path, (c) locating the target symbols within the array once the host page has been located, and (d) inhibiting responses to potentially interesting distracters throughout the process. Each of these task demands involves one or more working memory operations that have been identified and studied extensively in research in the cognitive sciences. Failure to acknowledge or understand how working memory might interact with AAC use may place unintentional barriers to effective AAC interventions. This paper explores current information about working memory operations and highlights some of the most relevant issues that warrant further direct study.

EXCLUSION LEARNING AND EMERGENT SYMBOLIC CATEGORY FORMATION IN INDIVIDUALS WITH SEVERE LANGUAGE IMPAIRMENTS AND INTELLECTUAL DISABILITIES

We evaluated formation of simple symbolic categories from initial learning of specific dictated word-picture relations through emergence of untaught or derived relations. Participants were 10 individuals with severe intellectual and language limitations. Three experimental categories were constructed, each containing 1 spoken word (Set A), 1 photograph (Set B), and 1 visual-graphic “lexigram” (Set C). Exclusion-based learning procedures were used to teach first the 3 auditory-visual relations (A-B relations) and then the 3 visual-visual relations (B-C relations) for each category. Seven participants acquired these initial relations. The untaught relations C-B and A-C were then assessed to evaluate the emergence of symbolic categories. Participants demonstrated virtually errorfree performances on C-B and A-C derived relations. The study helps to define operationally a highly useful procedural path for systematic instruction in symbolic functioning for persons with intellectual and language disabilities associated with autism and other neurodevelopmental disorders.

Further considerations of visual cognitive neuroscience in aided AAC: the potential role of motion perception systems in maximizing design display.

Current augmentative and alternative communication technologies allow animation within visual symbol displays. Clinicians therefore have the option of incorporating motion-based effects into AAC displays. Yet there is no research in the field of AAC to guide this clinical decision-making, in terms of the number or types of animated symbols that would best suit specific communication needs. A great deal is known within the discipline of cognitive neuroscience about how humans perceive motion, however. In this paper we propose that the field of AAC might exploit these known principles of motion perception, and we identify some potential uses of different types of motion. The discussion is presented within the context of neuro-cognitive theory concerning the neurological bases for motion perception.