Education.com
Try
Brainzy
Try
Plus

Understanding Nonverbal Learning Disorders (page 2)

By — MAAP Services for Autism and Asperger Syndrome
Updated on Dec 7, 2010

Nonverbal Affect Lexicon and Emotional Semantics

Bowers and Heilman believe that the damage to the fiber pathways in the right hemisphere caused a roadblock between the nonverbal affect lexicon located in the right hemisphere and the language areas in the left hemisphere that are needed for naming. Thus, although the nonverbal affect lexicon was not inherently damaged, the lesion blocked the access route between that knowledge and the generation of a verbal label for it.

How important is it to be able to identify emotional signals? The significance of these right hemisphere skills is highlighted when we examine the impact of their loss on the quality of a person's life. Right brain damaged patients can be extremely difficult to deal with on a daily basis. They often seem to have lost the most basic social skills--simple things such as knowing when to take turns in a conversation (typically cued by facial expression and voice intonation), or how close to get to someone while engaged in a conversation. They tend to be very talkative but the things they say are often described by listeners as shallow and inconsequential. They laugh during inappropriate moments, or display other emotions that don't seem to fit the context. To the dismay of those around them, they seem to have difficulty putting themselves in someone else's shoes and often alienate their family members and friends. It seems likely that the inability to comprehend nonverbal signals is at the root of many of these problems. Thus, in trying to help these patients and their families adjust, one focus of rehabilitation is to modify these behaviors and to help the brain injured patient to become more sensitive to emotional and social cues.

 Anosognosia and "Plausibility" Assessment

Even more problematic, they often seem to be unaware of their disabilities, a syndrome called anosognosia. Patients with anosognosia don't realize that they aren't thinking clearly, or that they can't do all the things they used to do. For example, an airplane pilot with a right hemisphere stroke and a left hemiparesis talked about going back to work the very next day, ignoring the fact that he was even in the hospital.

This problem may be related to another important specialization of the right hemisphere. The difficulty that right brain damaged patients have in understanding social situations seems to extend to a difficulty in contextualizing all sorts of information. In an interesting study, Howard Gardner and his colleagues had right and left brain damaged patients listen to a series of narratives. The narratives were designed so that each one included something that didn't make sense in the context of the story. When asked to recall the story, the left brain damaged patients and the non brain damaged control subjects either changed the nonsensical detail to fit the story or simply left it out. In contrast, the right brain damaged patients not only remembered the detail but tried to make the rest of the story fit. This process caused them to sacrifice the essence of the narrative and end up with a highly implausible construction. On the basis of these results, Gardner and his colleagues suggested that the right hemisphere houses a system that assesses the 'plausibility' of events. This system, they suggest, is important to the ability to judge the likelihood or probability that an event could actually take place. This notion fits well with some other data showing that right brain damaged patients violate the contextual reality of objects (drawing things like a 'potato bush', for example). These results might be related to the anecdotes about right brain damaged people who seem to be unaware of the magnitude of their deficits--here, they seem "out of touch with reality" in another way.

The fact that the right hemisphere would be in a special position to judge the 'reality' of something seems to be compatible with its other specializations, such as the ability to judge spatial relationships and the ability to distribute attention across both sides of space. The fact that right brain damaged patients have difficulty getting the gist of a narrative suggests that the right hemisphere is also good at judging relationships between other kinds of concepts as well, a skill that would be needed to put things in an appropriate context i.e. to assess how realistic they might be.

Schema Construction

  1. Another way to apply these concepts is in the domain of schema construction. The right hemisphere seems to be specialized to understand how things fit into categories and what the normative schema are for an event or an object. The inability of RBD people to understand jokes and metaphors reflects their difficulty in understanding how things normally fit together, interact, or intersect. They therefore fail to be surprised by an unexpected ending or twist to a story. They also have difficulty seeing how the characteristics of one situation might explain or describe the characteristics of another situation, as happens in metaphor e.g. "my job is a jail". Not surprisingly, RBD people have great difficulty with novelty, and are highly dependent on sameness and routine.

    Studies have shown that no matter how young the child, there is evidence that even at the earliest stages of development the two sides of the brain are different. Since patterns of lateralization are appearing at very early ages, it seems likely that right hemisphere specialization for various aspects of nonverbal function plays an important role in infant development.

    The right hemisphere may thus be of greater importance than the left hemisphere in infant development. Much of the prelinguistic child's learning consists of the perception of visuo-spatial relations, patterns, environmental sounds, etc. The child's perception of the world is organized at this time on the basis of nonverbal information.

     

    Many studies have shown the importance of the attachment between the child and a caregiver for the future social, emotional, and cognitive adjustment of the child. Children who have strong attachments with their caregivers are more likely to explore the environment and develop their cognitive skills accordingly. They are also more likely to have good peer relations in early grades and to be rated as popular children. Other studies have emphasized the importance of the caregivers facial expression and tone of voice in establishing attachment bonds with the child. It is not unreasonable to expect that problems with processing the facial or prosodic information that goes along with parent-child interaction could result in a variety of detrimental outcomes for a child. In fact, we found in a study of brain damaged babies that RBD infants showed less reciprocity in their interactions with their mothers.

    These processes form the foundation for social learning throughout childhood. It is thus likely that a fundamental problem with the right hemisphere may set a child up for being at risk for early difficulties in social functions. These early difficulties are likely to lead to long-lasting problems, since the basic skills are not available to be built upon.

    Some authors have argued that deficits in right hemisphere functions may also interfere with the development of a cohesive sense of self. This could manifest in a variety of ways, depending on the severity of the problem. It is conceivable that some children could be at risk for thought disorder and psychotic disorders. Some children with right hemisphere dysfunction have also been reported to have disruptions in body image.

View Full Article
Add your own comment