Cognitive Treatments for Aphasia: Should We and Can We Help Attention and Working Memory Problems?

Article excerpt

Findings from a growing number of studies indicate that patients with aphasia frequently have concomitant impairments of working memory, attention, or both that may negatively affect their language comprehension and production skills (e.g., Caspari, Parkinson, LaPointe, & Katz 1998; Murray, 2002). In contrast, how these cognitive deficits might be remediated or accommodated for has been the subject of relatively few investigations. The purpose of this article is to review critically initial research findings pertaining to treating working memory and attention in patients with aphasia. First, evidence supporting the coexistence of attention and working memory problems in aphasia is reviewed briefly. Next, previous results pertaining to the direct behavioral treatment of attention and working memory impairments in patients with aphasia are described and evaluated. Finally, suggestions are provided to spur further empirical investigation of behavioral and pharmacologic treatments for nonlinguistic deficits associated with aphasia.

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Over the past few decades, there has been increasing interest in examining the integrity of nonlinguistic, cognitive processes such as attention and working memory in aphasia and in understanding the relationship between these cognitive functions and the communicative impairments and outcomes of patients with aphasia. Findings from numerous studies indicate that attention, working memory, or both are frequently compromised in patients with aphasia, and that these concomitant impairments may underlie or contribute to a variety of aphasic symptoms (Caspari et al., 1998; Connor, Helm-Estabrooks, & Palumbo, 2001; King & Hux, 1996; Kreindler & Fradis, 1968; Yasuda, Nakamura, & Beckman, 2000). Accordingly, clinicians and researchers have been advised to take these coexisting cognitive deficits into consideration when planning assessment and treatment of aphasia (Helm-Estabrooks, 2002; Murray, 1999, 2002; Van Mourik, Verschaeve, Boon, Paquier, & Van Harskamp, 1992). To date, however, there has been limited empirical investigation of how to accommodate for or directly remediate the attention and working memory problems of patients with aphasia.

This article critically reviews preliminary findings pertaining to whether we should or can treat attention and working memory in patients with aphasia. First, to establish that speech-language clinicians should extend aphasia treatments to include consideration of nonlinguistic deficits, a brief review of the concepts and neural correlates of attention and working memory as well as evidence supporting the coexistence of attention and working memory problems in aphasia is provided. Next, previous results pertaining to the direct behavioral treatment of attention and working memory impairments in patients with aphasia are described and evaluated. Finally, suggestions are offered to spur further empirical investigation of direct and indirect behavioral treatments and pharmacotherapies for nonlinguistic deficits associated with aphasia.

ATTENTION AND WORKING MEMORY: CONCEPTS AND NEURAL CORRELATES

Both attention and working memory represent multidimensional cognitive constructs dependent on neural architectures that involve several cortical and subcortical structures and pathways. With respect to attention, debate persists regarding whether attention is best conceptualized as a capacity-limited system or rather a cognitive bottleneck (Murray & Kean, in press; Shuster, in press). Capacity or resource models specify that attention consists of one or more finite pools of attentional or processing resources and a governing system that manages the flexible deployment of these attentional resources to one or more activities (Kahneman, 1973; Norman & Shallice, 1986). Performance falters when the resource demands of a given task or tasks are not met because of a capacity limitation (i.e. …