Cognitive functions are intermingled and are known to depend upon each other for optimal efficiency. Linguistic performance depends on a series of cognitive domains known as “language supportive functions”. Among these are included attention, working memory, executive functions and visuospatial abilities. Attention plays a major role in several steps of linguistic processing, ranging from lexical selection to the comprehension of complex material (such as sentences and texts) and also writing. The phonological loop (the verbal component of working memory), which accounts for the transient manipulation of verbal material, is critical for adequate syntactic comprehension and vocabulary acquisition. Working memory deficits can interfere with the ability to comprehend texts, as well as discourse and conversation. Executive dysfunction interferes with the subject's ability to access semantic and lexical representations. Executive functions are also involved in sentence and discourse production, as they are necessary for planning how to express an idea. Visuospatial perception abilities may interfere with naming tasks, when subjects are unable to name an object because they cannot recognize it. Finally, it has been demonstrated that aphasia itself may hinder the subject's performance in several cognitive tasks, such as color-picture matching, picture ordering, calculation and drawing from memory. Moreover, the interface between language and other cognitive functions becomes evident in neuropsychological testing, as most tests require input and reasoning for verbally presented material (starting with test instructions), and frequently the output must also be verbal (oral or written), even when non-language functions are being tested.
Keywords: Language, attention, working memory, executive functions, visuospatial abilities
