Although the diagnoses of Asperger's syndrome (AS) and autism were first described more than 60 years ago, our knowledge about the nature of these disorders remains in its youth. There is ongoing debate and uncertainty about the differences between these disorders. In particular, the validity of AS as a unique diagnostic category continues to be called into question. Some consider AS to be a "milder" form of autism, while others feel that it is merely an equivalent label for autism in the absence of significant language and cognitive delays, namely high-functioning autism (HFA).

If we claim that there are no clear distinctions between these disorders, we may neglect to provide supports that are consistent with a child's unique cognitive strengths. In addition, if the term "mild" is used to differentiate AS from HFA, it perpetuates a myth that is inconsistent with current outcome studies of this population (Tsatsanis, 2003), while creating barriers to accessing intervention services that may be reserved for individuals with more "severe" disabilities. When meeting the daily demands of social life is a constant challenge, when achieving vocational goals is a statistical long shot, and when living a life free of mental health challenges is unlikely, we cannot consider the disorder of AS to be a "milder" form of anything.

One of the primary principles of evidence-based clinical practice in the field of speech-language pathology is to recognize the needs of the individuals we serve. There is a clear need to consider that these diagnoses may represent distinct challenges that affect social and communication skills. In addition, there is a need to consider that individuals with either HFA or AS warrant our services as speech-language pathologists, as one may not be truly milder than the other.

The answers to the following questions may clarify the distinctions between HFA and AS and serve as a guide in planning interventions.

Q: I've always been told that distinguishing between Asperger's syndrome and high-functioning autism is irrelevant, since intervention planning is the same. Is this true?

There is disagreement on this issue. Although the argument has been made that there are no relevant distinctions among individuals on the autism spectrum with high IQ, several contemporary neuropsychological studies have led to greater recognition of the potential differences in learning styles (Tsatsanis, 2004). In fact, there appear to be different learning pathways for different social learning disabilities. Individuals with AS often present with a verbal IQ that is higher than performance or nonverbal IQ, while individuals with HFA often present with the opposite pattern. In other words, an individual with AS may show strengths in verbal language and verbal memory, while an individual with HFA may show strengths in visual-spatial perception and visual memory. Additionally, an individual with AS may show weaknesses in visual-spatial perception and visual memory, while an individual with HFA may show weaknesses in verbal language and verbal memory. These distinctions will have implications for determining appropriate educational goals and learning supports; therefore, considering diagnosis as irrelevant may be problematic.

Q: Is there a diagnostic tool that SLPs can use to formally distinguish AS from HFA?

Although there are a number of observation instruments that are helpful for diagnosing autism spectrum disorders, a formal measure that reliably differentiates HFA from AS is not yet available. In fact, the current controversies regarding these distinctions have led to a variety of published definitions of AS, resulting in individuals with significant differences in learning style being identified with the same label. Therefore, every individual should be carefully assessed to determine his or her unique learning strengths and challenges, regardless of diagnosis.

Q: What are the implications of these learning distinctions on social communication?

Unique minds and learning style differences contribute to unique social and communicative profiles. Strengths in visual-spatial reasoning lead individuals with HFA to prefer more solitary play and leisure activities involving drawing, computers, and puzzles; conversely, given their strengths in verbal language and verbal memory, individuals with AS may prefer initiating verbal monologues with others. Likewise, the passive conversational style of an individual with HFA may stand in contrast to the verbose conversational style of an individual with AS. These distinctions, as well as others, are summarized in Table 1 above. Note that these distinctions represent prototypical examples of HFA and AS and may not be relevant to a particular individual.

Q: What are the implications of these learning distinctions on intervention planning?

The neuropsychological studies mentioned previously have important implications for intervention and designing appropriate learning and educational supports. Individuals with AS may prefer verbally mediated strategies, while children with HFA may prefer visual supports. If we are aware that an individual with AS demonstrates strong verbal abilities, this cognitive strength provides an ideal modality for intervention. Verbal mediation can be incorporated throughout daily routines and activities to facilitate awareness of the subtleties of social communication typically conveyed through nonverbal social cues. This "verbal decoding of nonverbal behaviors" might, for example, involve helping individuals develop verbal definitions for specific facial expressions, gestures, and body postures, so they may talk themselves through nonverbal social problem solving.

In contrast, providing static visual information is more appropriate in supporting individuals with HFA to understand social cues, language, and social conventions. For example, facilitating an understanding of the internal states of others may be accomplished with Comic Strip Conversations, a type of support in which another's thoughts are captured through pictorial representations within a "thought bubble" (Gray, 1994). Through this visual information, a concrete support is provided for considering the emotional consequences of one's actions on others. For individuals with HFA, verbal mediation may be less effective, if not disruptive, given their relatively weak language comprehension.

Interestingly, written language is a common modality for supporting social and communicative skills in individuals with either HFA or AS. While visual-spatial perception can be challenging for individuals with AS, strengths in word prediction and language can support written language skills. Individuals with HFA also may develop the ability to process the written word, as their relative strengths in visual-spatial skills and rote auditory memory contribute to phonetic decoding. Thus, a written cue card may convey information more effectively than raising one's eyebrows and gesturing toward a student's desk. Similarly, the use of a written map to illustrate information about one's conversational partners—such as what they like to talk about, what experiences they have had, and their favorite activities—could be provided (Winner, 2002).

Q: Since individuals with AS and HFA are "high-functioning," is there a role for an SLP on an educational team?

Recently, ASHA published several documents related to the roles and responsibilities of the SLP serving individuals with autism spectrum disorders, including those with HFA and AS (see sidebar, p. 21). These documents highlight a number of critical roles that we serve, including—but not limited to—screening, diagnosis, assessment, and intervention (ASHA, 2005). Nevertheless, it is not uncommon for school-aged students with AS and HFA to be denied an Individualized Education Plan (IEP) or speech-language pathology services because of their cognitive abilities, academic proficiencies, and relatively sophisticated language skills.

A student's eligibility for support services should be made as part of an educational team process as designated by the Individuals with Disabilities Education Act of 2004 (IDEA, 2004). Full consideration of the available evidence for this determination is essential. Although "high-functioning" is often ascribed to these disorders, this description is typically made on the basis of a full-scale IQ score, rather than on an individual's ability to actively engage in everyday activities. Outcome studies on these populations demonstrate that cognitive, academic, and language abilities do not ensure an individual's ability to establish and maintain satisfying relationships that foster success at school, at home, and in the community. In fact, challenges in social communication significantly compromise the ability to adjust to new social demands in academic settings and to achieve vocational goals after high school. Additionally, social communication challenges heighten risk for anxiety and depression.

These findings suggest that one of our roles as SLPs is to advocate for intervention to address the gap between the relative strengths in cognitive, academic, and language abilities and the relative weaknesses in social-communicative functioning. Areas of support to improve social communicative competence might include fostering:

• Verbal and nonverbal communication—develop awareness of how to initiate and shift conversational topics and how to provide an adequate amount of background information.
• Social awareness and social problem—solving skills-increase awareness of how to select appropriate topics, read and perceive nonverbal social cues, make inferences, and use language to negotiate with peers.
• Emotional regulation—improve ability to use language to self-organize behavior across social settings, express emotional states, and develop conventional social coping strategies.

Although uncertainty may always be present during discussions related to the nature of HFA and AS, there is no uncertainty when it comes to recognizing that we, as SLPs, need to accommodate and modify intervention plans for our clients' unique minds. The greater our knowledge of how to tailor an approach to an individual, the more likely we can use this knowledge to enhance social and communicative growth in our clients.