Assessment of Learning Disabilities

Discussing the concept of a learning disability within the context of hearing loss is complex, because the hearing impairment itself can create a specific learning difficulty associated with language and literacy. There are two ways to think about a learning disability. One is from the standpoint of a cognitive assessment. A child with learning disabilities has a specific contrast of strengths and weaknesses in learning, reasoning, and processing abilities. The child should demonstrate near average abilities in some areas of cognition, in contrast to significant deficiencies in other specified areas. This is different from a child with mental retardation, who shows more universal and severe deficiencies in most areas of cognitive functioning.
A second way of defining learning disability is by guidelines, often based on a profile of test scores, and specifically defined by an educational agency, such as a state department of education. In this second definition, a child often has to show a discrepancy between assessed cognitive “ability” (i.e., an IQ test) and assessed educational “achievement” (e.g., achievement tests). Furthermore, the discrepancy cannot be explained by a physical impairment, such as hearing loss. This institutional definition adds complexity to the issue of learning disability and hearing loss.

Hearing loss can cause learning problems associated with language processing that will affect oral communication as well as reading literacy. Many children with hearing loss show reading levels significantly below average for their age and grade placement, even though they have average cognitive (nonverbal) abilities. By educational guidelines, this discrepancy between ability and learning cannot be defined as a learning disability because it is presumably caused by a physical impairment. However, in the context of the first definition of learning disability, such children clearly show a mismatch between nonverbal cognitive functioning and language-based skills. Although these children do not meet school criteria for a learning disability, they function in a similar manner. Most dyslexia is a language-based phenomenon and not a difficulty caused by visual processing problems. Children who are deaf or hard of hearing may have problems with phonetic decoding of words, with comprehension of syntax, and with word recognition and fluency (because of a limited vocabulary base).

To assess literacy problems in children who are deaf or hard of hearing, a psychologist serves the child best by working through a team approach. The psychologist can assess nonverbal cognitive functioning. A teacher of the deaf and hard of hearing or a speech-language pathologist, who is experienced with children with hearing loss, can assess language functioning, including comprehension, syntax, and vocabulary, as well as assessing oral-auditory skills such as phonetic discrimination. A teacher of the deaf and hard of hearing can also provide an assessment of reading skills in the mode of communication most commonly used by the hearing child who is deaf or hard of hearing.

In addition to the standardized intelligence tests, the psychologist can use some specialized tests to assess memory and other processing skills. The visual processing subtests from the Wide Range Assessment of Memory and Learning (WRAML) work quite well with children who are deaf or hard of hearing to assess learning, memory, and processing skills. The nonverbal memory subtests from the K-ABC also prove to be good measures of memory span as well as processing ability. On the K-ABC, children who are deaf or hard of hearing usually perform within an average range on the subtest of spatial memory, which requires them to remember where in 2-dimensional space they observe objects. In contrast, many children who are deaf or hard of hearing have difficulty on a measure of hand movements, in which they have to memorize a sequence of hand gestures. This presumably visual task of sequencing a series of hand gestures is difficult for children who are deaf or hard of hearing, even if their primary mode of communication is sign language. These same children have related difficulties in reading comprehension and writing tasks. The contrast between spatial memory and hand movements may signal difficulties in encoding sequentially-based information.

An exceedingly difficult task is identification of a specific language impairment that co-occurs with the hearing loss. Specific language impairment, also known as a developmental language disorder, occurs in about 6%-8% of children (Leonard, 1998). It usually can be identified in assessment by a significant discrepancy between verbal and nonverbal processing abilities. However, one can expect that children who are deaf or hard of hearing will usually show such a discrepancy by virtue of their auditory processing difficulties. As noted above, their function is if they have an acquired learning disability by virtue of their limitations of auditory learning and resultant language language/literacy delays. Yet, one should expect that if 6%-8% of children show a congenital language disorder, then some children with hearing loss could also have this as a co-occurring condition. Yet our traditional methods of maneuvering the contrasts out are not too helpful in this situation. This presents the difficulty of assessing an “aphasic” condition that is different from the experiential deficits caused by the hearing loss.
When confronted with this daunting task, the psychologist needs to work with the special educators. An experienced teacher of the deaf and hard of hearing or a speech-language pathologist can report if the child’s rate of language learning is typical or atypical for similar children who are deaf or hard hearing. One must control for many features here, including nonverbal cognitive abilities.

Assessment of Children with Hearing Loss and Vision Loss

The Gallaudet survey indicated that 1.6% of children with hearing loss were also classified as legally blind and 2.8% as having low vision (Gallaudet Research Institute, 2003). Although several thousand children across the nation are classified as “deaf-blind,” this term is somewhat misleading in that these children may have a range of both hearing and vision deficits that allows them to use some residual hearing or vision to help function, although at a limited level. This is important, in that assessment of these children can use some auditory and visual stimuli, appropriately adjusted for the individual child’s communication abilities. Furthermore, over half of the children who are deaf-blind have other major developmental disabilities, with mental retardation being the most common (Tedder, Warden, & Sikka, 1993).

The range of visual and auditory deficits, as well as the common presence of mental retardation and other disabilities, indicates that the “deaf-blind” population of children is quite heterogeneous in an assessment context. Mar (2003) has cautioned that most standardized psychological tests are inappropriate in use with this population of children, and one must be cautious in adapting tests that were developed for children who have normal hearing and vision. Therefore, specialized procedures uniquely developed for this population are the most valid and reliable measures of functional ability.

Children who are deaf-blind have significant impairment of two primary sensory modalities used in communication, and many of them are also mentally retarded. Therefore, the majority of these children at a young age are prelinguistic in their communication development. Early assessment should focus on development, learning, and use of functional communication skills. The Callier-Azusa Scale (CAS) is a developmental assessment tool devised for children who are deaf-blind (Mar, 2003). Tedder et al. (1993) described the Communication Observation Schedule (COS) they have designed to assess the functional used of communication by children who are deaf-blind. Finn and Fewell (1994) reported on the efficacy of the Play Assessment Scale (PAS) with children who are deaf-blind. They found that early play behaviors, in the 2-36 month range for children who are developing normally, works well in assessment of children who are deaf-blind. They correlated the play behaviors with three measures specifically used to assess children who are deaf-blind. The measures used were the CAS, the Wisconsin Behavior Rating Scale (developmental skills), and the Gestural Approach to Thought and Expression (nonverbal communication).

As children who are deaf-blind develop communication, they can use a variety of communication modes. These include voice, gestures, sign language, Braille, and augmentative devices such as electronic systems, picture books, communication boards (Mar, 2003; Tedder et al., 1993). The above listed assessment procedures are designed to assess the child’s functional communication capacity with these different modalities. When the children have developed a reliable system of communication, a psychologist can examine cognitive skills by communicating with the child through the preferred mode of communication. Some standard materials can be adapted by using larger visual displays, translating queries or responses, or using some carefully controlled auditory information within the child’s acuity level. A practical approach to meaningful assessment should focus on functional abilities to communicate and learn new information. Working with a team of special educators who are experienced with children who are deaf-blind, a psychologist can develop a valid method of assessment of cognitive abilities. However, as Mar cautions, psychological assessment of such children is difficult. A psychologist who does not routinely work with this population should be well versed on alternative methods for assessment. If not, the children are much better served by referral to specialists who have developed an expertise in assessment of children who are deaf-blind. Many state educational agencies have specialists or referral sources, through programs for the hearing impaired, visually impaired, or severely mentally retarded.

Assessment of Attention-Deficit/Hyperactivity Disorder

Attention deficit hyperactivity disorder (ADHD) occurs in 3% to 5% of the general childhood population (Barkley, 1998) and in 6.6% of children with hearing loss. ADHD is diagnosed by behavioral assessment, and DSM-IV criteria (Diagnostic and Statistical Manual of Mental Disorders--4th Edition, American Psychiatric Association, 1994) serve as the gold standard for defining this disorder. ADHD is defined by symptoms of either inattention or hyperactivity-impulsivity that are present before 7 years of age and persist for at least 6 months. These behaviors must be severe enough to impair social or academic functioning. Furthermore, symptoms need to be present in two or more different settings.

Common settings for assessment of ADHD include the child’s home, the school, and an examination by a psychologist. To objectively assess the behaviors in different settings, most psychologists use standardized behavior rating scales completed by an adult familiar with the child in that particular setting. Typically, parents will report on the home setting and the classroom teacher will report on classroom behavior. The usual standard is that on scales of inattention or hyperactivity, the child’s rated score should be within a clinical significant range (> 95-98th percentile).
In diagnosing ADHD in children who are deaf or hard of hearing with multiple handicaps, one must consider two important variations. First, it is essential that the psychologist know the child’s level of cognitive functioning in order to accurately interpret behaviors. For example, the child may appear impulsive or inattentive during the psychological examination, but these behaviors may be consistent with the child’s overall developmental level. Similarly, if parents or teachers overestimate the child’s cognitive level, they may interpret physical activity or attention span in the context of the child’s chronological age, rather than in the context of the child’s mental age. With this overestimate, they may inflate their concerns about problem behaviors.

Second, many children who are deaf or hard of hearing are integrated into regular education classrooms. Within these settings, the regular education teacher often reports on the child’s behavior, either informally or by a behavior rating scale. In this context, the teacher may compare the behavior of the child who is deaf or hard of hearing to standards for children with normal hearing. For example, a child who is hard of hearing may be described as inattentive in a regular education classroom, but the problem of sustaining attention is not due to an inherent attention disorder, but rather to the difficulty attending to auditory cues in a classroom. The child may not sustain attention because of difficulty processing language information that is too complex for the child, or difficulty discerning the auditory signal in the noisy environment.

Given these two variations with children who are deaf or hard of hearing, the psychologist should develop a clear profile of the child’s disabilities, and how they may affect behaviors associated with attention and activity level. When there is such misinterpretation of a child’s behaviors, usually there are significant differences in rating behaviors among the home ratings, classroom ratings, and direct observations by the psychologist in an individual examination. Wide variation of behavior ratings for children with multiple disabilities is often a clue to misinterpretation of the behaviors based on various norms. If the variation includes ratings by a regular education teacher, the psychologist should seek additional ratings from specialists who work with children who are deaf or hard of hearing and children with other physical handicaps. This can include ratings from teachers of the deaf and hard of hearing, educational audiologists, and speech-language pathologists.

In the assessment of possible ADHD in a child who is deaf or hard of hearing with multiple handicaps, one should not be bound to a one-time assessment procedure. If ADHD is suspected by the psychologist, then assessment of the child can be ongoing with treatment serving a diagnostic purpose. Standard treatment protocol for ADHD is tripartite -- behavior interventions at home and school, counseling for parents and teachers, and a medication trial. If ADHD is suspected as a component problem for the child, all three treatment strategies can be implemented and monitored. There are specific behavior techniques that are helpful in modifying the problems associated with ADHD within the home and at school (Barkley, 1998). Associated with these are counseling for parents and teachers, so that they can understand the nature of ADHD, and develop a positive and effective attitude toward working with a child who has ADHD. If ADHD is suspected, the counseling and behavior training should be implemented to determine if the child’s behavior is responsive to these standard methods. In addition, a medication trial can often be arranged with a physician. Barkley reported that 50%-95% of ADHD children respond positively to stimulant medication. This medication is safe when appropriately prescribed and supervised by a physician. If the child’s suspected ADHD behaviors improve while on medication, and regress when the trial is suspended, this supports an ADHD diagnosis.

Assessment of Autistic Spectrum Disorders

Autistic spectrum disorders include autism, pervasive development disorder—not otherwise specified (PDD-NOS), Asperger syndrome, Rett syndrome, and Childhood Disintegrative Disorder. Autistic spectrum disorders have a prevalence rate in children of about 0.5% (Simms & Schum, 2000). The most common forms are autism and PDD-NOS. There are three core criteria for the diagnosis of autism:

severe deficits in communication;

severe deficits in social interaction;

restricted and stereotyped patterns of behavior, interests, and activities.

In PDD-NOS, a combination of two or more of these categories is present, but do not meet the threshold for severity or breadth required for the diagnosis of autism (American Psychiatric Association, 1994).

Autism is diagnosed by behavioral assessment. DSM-IV lists a specific set of behavioral criteria, and there are checklists and rating scales for autistic behaviors. However, there is no rote formula for tallying behaviors and deriving a diagnosis of autism. Rather, one must interpret behaviors in the total context of the child’s experience and abilities. For example, approximately two-thirds of children with autism are also mentally retarded. Some people assume that behaviors, which are often manifested by children who are severely retarded, are unique to autism. A child who is severely retarded will have a limited repertoire of play behaviors. This limited repertoire of behaviors, such as repetitive manipulation of objects in sensorimotor play, can be misinterpreted as the restricted and repetitive behaviors of autism. In fact, compulsive behaviors are common in young children and are not unique to autism, with 40%-60% of young children who are normally developing demonstrating compulsive routines (Evans, Leckman, Carter, Reznick, Henshaw, and King, et al., 1997). Lord, Rutter, and LeCouteur (1994) have pointed out that compulsions and rituals that involve an end point are not autistic.

Because a key criterion of autism is a communication disorder, diagnosing this disorder in children with hearing loss must be done carefully. It is difficult to determine if the child is not communicating well because of the autistic disorder, or because of the experiential deficit due to the hearing loss. Furthermore, in the context of children who have multiple handicaps who are deaf or hard of hearing, many of them will be cognitively impaired. With this cognitive impairment, they will function at a below average developmental level, and therefore may show features of restricted and repetitive behaviors due to developmental delays rather than autistic preoccupation.

Assessment of social behaviors is a dependable method for differentiating autism from other disorders. All forms of autistic spectrum disorders, including PDD-NOS and Asperger syndrome, show disordered social interaction as a component of the disorder. Recent research has shown four key social behaviors that differentiate autistic spectrum children from other groups of children, including children who are developing normally, children with specific language impairment, and children who are mentally retarded:

direct imitation

joint attention

representational and pretend play

affective reciprocity

These four behavior features can all be demonstrated non-verbally by children who are deaf or hard of hearing with limited communication. One must interpret the child’s social behaviors in the context of their cognitive abilities. For example, a child with a mental age of 12 months will not show pretend or representational play. However, by 18 months the child may show early domestic mimicry. The doll task from the Bayley Mental Scale can assess this. The standardized version of this task is for a child to follow a verbal directive to use a spoon, comb, and tissue with the doll. However, in a non-standardized probe to screen for social behaviors in young, nonverbal children, one can give the child each of the three implements in the presence of the doll to see if the child uses these implements in a representational scheme. This is a quick and reasonably reliable method for assessing such social behavior and awareness in young children.
If a child who is deaf or hard of hearing demonstrates many or all of the four key social behaviors, it is unlikely that he or she has an autistic spectrum disorder.

Sensory Integration Dysfunction

With differential diagnosis of autism, the issue of sensory integration dysfunction often arises. Sensory integration (SI) is a theoretical model developed in the field of occupational therapy. Occupational therapists and other special educators often use this model to describe difficulties observed with children who have atypical development. SI problems are sometimes described as hyper- or hypo-sensitivity to stimuli. Some children are described as “craving” certain physical activities such as swinging, rocking, or deep pressure. Proponents of SI therapy claim that the therapeutic techniques are effective in treating behaviors associated with autism, mental retardation, and learning disabilities. Despite these claims, there is much scientific evidence indicating that SI therapy is of limited or no efficacy in these treatments, and, furthermore, that the hypothetical SI model is not validated (Cummins, 1991; Humphries, Wright, Snider, & McDougall, 1992; Wilson, Kaplan, Fellowes, Gruchy, & Faris, 1992; Hoehn & Baumeister, 1994; Siegel, 1996; Dawson & Watling, 2000; ASAT, 2003; Shaw, 2003).

In this context, one should not rely upon SI “behaviors” to substantiate a diagnosis of autism in children who are deaf or hard of hearing with multiple handicaps. Proponents of SI apply the model to a variety of developmental disorders, and therefore the SI behaviors are not considered unique to autism even among such proponents. Furthermore, there is no other credible evidence that indicates that SI-like behaviors are unique to autistic spectrum disorders. The core features for a diagnosis of autism are social and communication disorders, as well as restricted and repetitive behaviors. Formal diagnosis does not rely upon sensory processing difficulties.

Despite this warning about the questionable validity of the SI model, many clinicians recognize that young children with atypical development often show a cluster of behaviors that have sometimes been labeled as SI dysfunction. These behaviors include inconsistent hypersensitivity to external stimuli (e.g., sound, touch, movement, positioning), and sometimes a preference for active stimulation, usually involving movement (e.g., bouncing, swinging, brushing, deep pressure). There are alternative models to explain these behaviors that are more firmly grounded upon scientific examination.

Kagan’s research on temperament has shown that from infancy onward, there are certain children who have a low threshold of arousal to unfamiliar situations, which is manifested by distress, arousal, and anxiety symptoms (Kagan, 1997; Kagan, Snidman, & Arcus, et al., 1998). His research group has demonstrated that these infants who are highly reactive even show faster latency in evoked auditory responses, which suggests that this reaction may be related to the hypersensitivity to sound stimuli (Woodward, McManis, Kagan, Deldin, Snidman, Lewis, et al., 2001). Kagan has speculated that the infants who are highly reactive may develop symptoms of anxiety over time. It may be that the hypersensitivity described in SI dysfunction is actually a manifestation of this low threshold for arousal. These hypersensitive behaviors may be a manifestation of anxiety and high arousal. However, because these children cannot articulate their internal distress (i.e., anxiety), their behaviors are misidentified.

In a similar vein, the feature of “craving” motor activity may actually represent early manifestation of hyperactivity. Children with a diagnosis of ADHD show a pattern of sensory behaviors similar to those described by the SI dysfunction model (Dunn & Bennet, 2002). Pre-school-aged children with ADHD show a pattern of symptom behaviors similar to those shown by older ADHD children (Wilens et al., 2002). ADHD children often crave physical activity and motion, as well as novel stimuli. It may be that these incipient signs of ADHD in children with atypical development have been misinterpreted as SI phenomena.

In short, the model of SI dysfunction is of questionable validity. However, the behavioral phenomena recognized by many clinicians, and probably misattributed to SI dysfunction, actually exist. It may be that these behavioral displays suggest alternative problems of either anxiety or ADHD. A psychologist evaluating young children with multiple handicaps should keep these hypotheses in mind. Whether or not one accepts the hypothetical model of SI dysfunction, there is clear evidence that these behaviors are not unique or specific to autistic spectrum disorders, but rather may be manifested by children with a variety of disabilities.

Assessment of Emotional and Behavioral Problems

Many years ago, Meadow (1976) reported a cluster of behavior problems shown by children with hearing loss that occur at a higher rate than by children in the general population. They include impulsiveness, immaturity, egocentricity, and absence of inner controls. It may be that such behavioral problems do not represent that presence of pathology, but rather represent a delay in positive development caused by limitations in communication (Schum, 1991). In this context, when evaluating children who are deaf or hard of hearing for behavioral and emotional problems, it is essential that a psychologist have a thorough understand of the child’s communication history and current level of communication functioning.

It is helpful to have a thorough language evaluation from a speech-language pathologist to describe the child’s level of language functioning. As a rough measure, one can use an age-equivalent score for communication as an index for social behavior. Many times, the child’s social behavior will be commensurate with their level of communication ability, rather than with their level of nonverbal cognitive ability (Schum, 2000). Furthermore, a good communication history can determine how functional the child’s communication has been with significant persons, particularly parents. This is important in understanding how effective communication has been in transmitting behavioral expectations and social knowledge (Schum, 1991).

In assessing emotional adjustment, a useful distinction can be made between children who have congenital hearing loss and those who have post-lingual acquired hearing losses. The congenital group of children usually does not show signs of depression or anger associated with the hearing loss. These children typically define their hearing loss as a “difference” from children with normal hearing levels. In contrast, children with acquired hearing loss are more likely to manifest depression or anger, because they truly have had a recognizable change in their physical abilities. This group is more likely to define their hearing impairment as a “loss.”

In assessing emotions problems, clinicians should be cautious using any type of self-reports or projective techniques that depend upon language facility to diagnose emotional problems (e.g., questionnaires, Thematic Apperception Test (TAT), Rorschach). Because of communication difficulties, including frequent delays and disorders of language, responses from children who are deaf or hard of hearing cannot be reliably compared to norms developed for children. Self-report inventories are often written at a reading level too high for many children who are deaf or hard of hearing to reliably comprehend. Reponses to projective techniques may often seem impoverished and stilted, but this may reflect communication difficulties rather than internally mediated pathology. Given this confounding problem of communication, it is more reasonable to focus assessment upon observable behaviors, as well as on informal self-reports from children who use their preferred mode of communication.

Cognitive Assessment and Significant Motor Impairment

Cognitive assessment of children who are deaf or hard of hearing with significant motor problems creates particular problems. As noted above, a valid cognitive assessment with children who are deaf or hard of hearing should emphasize use of nonverbal measures. However, many such measures require some hand dexterity to solve problems, such as block construction tasks or drawing figures. For most children at or above 3 years of age, the Leiter-R is the preferred method for cognitive assessment. It has been designed to minimize responses that depend upon hand dexterity. The standard response format is to place picture cards in a tray. However, the test has valid alternative procedures that include pointing to pictures or signaling a choice with an eye gaze. It can also be modified by having the child indicate “yes/no” as the examiner points to each picture choice. The response options for the Leiter-R are quite robust and have successfully been used with children who are quadriplegic.