Friday, May 25, 2018

The Role of Executive Functions in Reading Comprehension - excellent overview of major models of reading comprehension

The Role of Executive Functions in Reading Comprehension. Article or link.

Reese Butterfuss and Panayiota Kendeou

ABSTRACT

Our goal in this paper is to understand the extent to which, and under what conditions, executive functions (EFs) play a role in reading comprehension processes. We begin with a brief review of core components of EF (inhibition, shifting, and updating) and reading comprehension. We then discuss the status of EFs in process models of reading comprehension. Next, we review and synthesize empirical evidence in the extant literature for the involvement of core components of EF in reading comprehension processes under different reading conditions and across different populations. In conclusion, we propose that EFs may help explain complex interactions between the reader, the text, and the discourse situation, and call for both existing and future models of reading comprehension to include EFs as explicit components.

Keywords Executive functions . Reading comprehension . Discourse processes


This article includes an excellent summary of the major models of reading comprehension. This post includes that select material.

The Status of Executive Functions in Models of Reading Comprehension

Reading comprehension is one of the most complex and important cognitive activities humans perform (Kendeou et al. 2016). Given its importance and complexity, researchers have sought to understand reading comprehension via the development and specification of a multitude of models and frameworks that account for various processes and mechanisms of reading.

Generally, reading comprehension refers to the construction of a mental representation of what the text is about (Kintsch and V an Dijk 1978). Although most models of reading comprehension converge on this general idea, the processes and assumptions by which readers construct such representations differ across models and frameworks. It is also important to note that a unified, comprehensive model of reading comprehension has yet to be established. McNamara and Magliano (2009) reviewed and compared one set of models, which are concerned primarily with the construction of the mental representation during reading: The Construction-Integration Model (Kintsch 1988), the Structure-Building Framework (Gernsbacher 1991), the Resonance Model (Albrecht and O'Brien 1993), the Event-Indexing Model (Zwaan et al. 1995), the Causal Network Model (Trabasso et al. 1989), the Constructionist Theory (Graesser et al. 1994), and the Landscape Model (van den Broek et al. 1999). In this review, we investigate the status of EFs in each of these models.

Among this set of models, the Construction-Integration (CI) model (Kintsch 1988) is perhaps the most comprehensive, and it is considered the best approximation to a true theory of reading comprehension (Kendeou and O'Brien 2017). According to the CI model, comprehension is the result of two processes, construction and integration. Construction refers to the activation of information in the text and background knowledge. There are four potential sources of activation: the current text input, the prior sentence, background knowledge, and prior text. As this information is activated, it is connected into a network of concepts. Integration refers to the continuous spread of activation within this network until activation settles. Activation sources from the construction process are iteratively integrated, and only those concepts that are connected to many others are maintained in the network. At the completion of reading, the result is a complete network or a mental representation of what the text is about. This mental representation has been termed the situation model. Even though the initial model makes no explicit reference to EFs, in a subsequent revision, Kintsch (1998) included a suppression mechanism in the CI model by adopting inhibitory links. Specifically, the CI model relies on links between information units to promote an appropriate representation of a text and inhibit inappropriate representations. In this context, facilitatory links connect related information units, and inhibitory (or negative) links connect conflicting or inappropriate information units. Inhibitory links serve to suppress or inhibit inappropriate representations (Kintsch 1998).

The Structure-Building Framework (Gernsbacher 1991) describes comprehension as the result of three processes. The first process, laying a foundation, involves using initial information from a text to lay the groundwork for a mental representation to be constructed. The second process, mapping, involves mapping information from the text onto that foundation to create structures. The third process, shifting, involves a shift to begin building a new structure when readers are unable to map information onto an existing structure. Irrelevant information that does not cohere with a current structure is suppressed. Thus, within the Structure-Building Framework, the suppression mechanism attempts to account for individual differences in comprehension ability. Specifically, the model posits that if incoming information is related to the current structure, then activation of that information is enhanced, resulting in its incorporation into the current structure. When information is not related to the current structure, then activation to that information is suppressed, or, alternatively, readers may shift and use that information to begin building a new structure. The suppression mechanism is the result of readers' ability to inhibit irrelevant information. This ability moderates reading comprehension in that skilled readers have a strong suppression mechanism and can therefore suppress irrelevant information, whereas less-skilled readers lack a strong suppression mechanism. As a result, less-skilled comprehenders' poor suppression ability may lead them to shift too often, which impairs comprehension because more information is competing for limited resources.

The Resonance Model (Myers and O'Brien 1998) attempts to account for factors that influence the activation of information during comprehension, particularly information that is no longer active in working memory. The model emphasizes automatic, memory-based retrieval mechanisms as fundamental assumptions. Specifically, the model assumes that information in working memory serves as a signal to all of memory, which activates information that resonates with the signal. Elements resonate as a function of the number of features that overlap with the contents of working memory. Even though the model has not explicitly incorporated any EFs, O'Brien et al. (1995) found that suppression was involved in processes relevant to the Resonance Model. Specifically, O'Brien et al. found that when an anaphoric phrase reactivated more than one potential antecedent from the text, the selected target antecedent was strengthened in long-term memory, whereas potential, but non-target, antecedents that interfered with the target antecedent were suppressed.

The Event-Indexing Model (Zwaan et al. 1995) was developed as an attempt to account more fully for processes involved with situation model construction of narrative texts. It operates under the assumption that readers monitor and establish coherence along five dimensions of continuity, and thus situation model construction: time, space, causality, motivation, and agents. Thus, within the event-indexing model, EFs such as shifting attention from one dimension to another as well as updating the construction of the situation model account for individual differences in comprehension ability. For example, Bohn-Gettler et al. (2011) found that there are developmental differences in children's ability to monitor the shifts in each of these dimensions.

The Causal Network Model (Trabasso et al. 1989) accounts for how readers generate causal inferences and represent causality during reading. Causal inferences are at the core of building a coherent representation of a story. Narrative elements can be categorized as either settings, events, goals, attempts, outcomes, or reactions. Also, there are assumed to be four types of causal relations: enabling, psychological, motivational, and physical. The model also provided a discourse analysis tool, Causal Network Analysis, to identify the causal structure that underlies story constituents. Overall, the model accounts for the importance of causal relations in memory for the text, but makes no assumptions about specific EFs. The Constructionist theory (Graesser et al. 1994) attempts to account for factors that predict inference generation during reading. The theory emphasizes the role of top-down, strategic processes in the construction of meaning, what has been termed Bsearch after meaning.^ Three assumptions define search after meaning. The first is the reader goal assumption, which suggests that readers construct meaning in accordance with their reading goals. The second is the coherence assumption, which suggests that readers construct meaning at both local and global levels. The third is the explanation assumption, which suggests that readers are driven to construct meaning that explains events they read. Even though the theory makes no concrete assumptions about EFs, it is reasonable to assume that shifting attention likely exerts an influence on the top-down, strategic processes that govern search after meaning.

Lastly, the Landscape Model (van den Broek et al. 1999) simulates the fluctuation of concept activation during reading. The Landscape Model is similar to the CI Model in that it assumes the same four sources of activation. The model also includes two important mechanisms, cohort activation and coherence-based retrieval. Cohort activation assumes that when a concept is activated, all other concepts that are also activated become associated with it (McClelland and Rumelhart 1985). Coherence-based retrieval assumes that the activation of text elements is in accordance with the readers' standards of coherence. In turn, standards of coherence refer to readers' implicit or explicit criteria for comprehension. Even though the Landscape Model makes no concrete assumptions about EFs, it is reasonable to assume that shifting likely exerts an influence on readers' standards of coherence, directing attention to information that aligns with readers' standards.



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