Aging is often described by changesin the cognitive function which affects the receptive and expressivecapabilities of the language (Riegel and Riegel 1964, Marini et al.2005). Language sample analysis is considered one of the bestpractices for language skills assessment.
In this method, different aspects of thelanguage are analyzed after collecting linguistic sample (Justice et al. 2010). For taking alinguistic sample, various types of discourse, including descriptive,narrative, procedural, persuasive, interpretive, and conversational discoursecan be used (Ball et al.
2009). Narrative discourse mostly elicitedby pictorial stimulus wherein the basic feature is temporal and casual relations between events (Mar 2004) Picture description is one of the dominantmethods in eliciting narrative discourse (Cannizzaroand Coelho 2013), which leads to a better understanding of language skills(Capilouto et al. 2016).
Persuasion is a complex and essential skill, which continues todevelop into early adulthood (Nippold et al.2005). In general, comparing to narrative production, persuasion task isconsidered to be more cognitively demanding (Feltonand Kuhn 2001). Persuasive discourse attempts to express an opinion andgive reasons to support that opinion (Ball,Perkins et al. 2009). This type of discourse may occur in both formalsituations (e.g. school debates, school essays) and informal situations (e.
g.convincing a friend to see a movie or parents to purchase the latest electronicgadget). The ability to persuade and use arguments effectively is considered afundamental social interaction skill (Bartsch etal. 2007). In fact, language is a complex and dynamic cognitive system interms of some important processing dimensions: the micro-linguistic, macrostructure and macro-linguistic.
The micro-linguisticdimension is responsible for inter-sentential functions, macrostructure is responsible for across-sentence analyses and the macro-linguistic dimensionis responsible for intra sentential functioning (Coelho2007, Marini et al. 2011). The micro-linguistic dimension organizes phonological (or graphemic) sequences chains and words (lexical processing), anddetermines the syntax needed for each word to make good-looking sentences(syntactic processing). Macrostructural level of discourse or cohesion is defined asthe set of the possibilities that exist in a sentence for connecting a givenstatement with previous statement. On the other hand, sentences are conjoined by various kinds of meaningrelations described as cohesive ties (Coelho2007). The macro-linguistic dimension determines themeaning of a word or sentence that has a proper context and connects sentencesand statements together by means of cohesion and coherence so as to formulatethe main subject of discourse and integrate cognitive and linguisticcharacteristics (Marini, Andreetta et al. 2011).
In other words, coherence refers to overall stability indiscourse. That is, overall coherence indicates how each sentence in a discourse sample is related to the overall subject of the text (Enos 2011).Studies on age-related differences in adult linguisticabilities yielded different results. Although some studies have been conductedregarding the linguistic changes in the old age, they have had differentresults.
Some scholars believe that the elderly language varies in terms of themicro-structure (Au et al. 1995). However, findings of other researchers show that thisaspect of language does not change in old age (Evanset al. 1993, Marini, Boewe et al. 2005). Although the findings of otherstudies reveal that older adults differ from young adults in terms of somemicrostructural aspects including semantic paraphasia, no difference in sentencecomplexity was found (Marini, Boewe et al.
2005). This inconsistency in the results is less present inmacro structural dimension. Furthermore, according to a study, the correctinformation unit (CIU) (Capilouto et al. 2005)and main events (Capilouto, Wright et al. 2005,Wright et al.
2005) are significantly higher in the young people’sdiscourse than in the elderly. Marini et al. also reported that older peoplesignificantly produce discourses with less thematic informativeness than youngones (Marini, Boewe et al. 2005). Sincelanguage plays a significant role in human life for establishing socialinteractions, and also because speech-language pathologistmake important contributions in maintaining and promoting communication in agingpeople, by awareness of discourse features in the older people, it seems thatit is necessary to examine the language of the older people.
This study seeksto provide a comprehensive and detailed view of adults’ discourse abilities andtheir variations throughout life. By taking into consideration this assumption,this study examined individuals aged 19 to 75 years. Finally,in order to evaluate the existence of age-related differences in macrostructureand macrolinguistic levels of discourse, the narrative and persuasive discourseof different age groups were compared.
