On the Phylogenesis of Executive Functions and Their Connection with Language Evolution.

Abstract

T term Executive Functions (EFs; also executive control or cognitive control) refers to the higher order cognitive processes involved in the regulation of goal-oriented actions in complex contexts and non-routine situations (Gilbert and Burgess, 2008). EFs are crucial for the temporal organization of purposive behaviors, language and reasoning (Fuster, 2008). There is no single taxonomy of EFs that scholars generally agree upon (Jurado and Rosselli, 2007). The various models proposed in the literature suggest that EFs capacities entail several key components, including flexibility, planning, monitoring, working memory, and inhibition (Ardila, 2008). Although a dynamic and flexible network involving several cortical and subcortical brain regions mediates EFs, there is a consensus that their main neural substrate is the prefrontal cortex (PFC) (Fuster, 2008). Specifically, the dorsolateral region of PFC is generally involved in classic EFs such as planning, problem-solving and some working memory operations, whereas the orbitofrontal region is more closely associated with the regulation of emotions and social behavior. Neuroscientific (Barkley, 2001) and comparative (Hills, 2011; Volter and Call, 2014) studies have dealt with the issue of the evolution of EFs. The evolution of EFs for the later PFC regions and their connections with language origins has been the subject of particular interest (Risberg, 2006). Some studies have suggested that the emergence of EFs occurred recently in the evolution of Homo sapiens (Ardila, 2008; Coolidge and Wynn, 2009). According to Coolidge and Wynn (2009) and Wynn and Coolidge (2007), modern humans evolved an enhanced working memory capacity that fostered EFs 32,000 years ago, enabling complex contingency planning, abstract reasoning and innovation. Ardila (2008) has proposed that EFs appeared 150,000 years ago in connection with the advent of language grammar. According to Ardila (2016), the temporal organization of behavior (the core function of EFs) comes from the perception of actions that is correlated with the grammatical ability to use verbs and represent these actions: Temporality means “before” and “after,” that is, something that changes, or develops or moves, that is, an action. (…) the “perception of actions” would represent a single preadaptation both for grammatical language and for meta-cognitive executive functions (Ardila, 2016, p. 2). In this paper, I advocate a different scenario for the phylogenesis of EFs and their connection with language evolution. By reviewing studies coming from Evolutionary Cognitive Archaeology (ECA), I suggest that EFs evolved in the context of toolmaking before the appearance of Homo sapiens. By virtue of this, I treat the issue of the relationship between EFs and language evolution in a different manner to the models that assigned a prominent role to grammar. I hypothesize that language could have had a narrative origin and that the study of the evolution of EFs together with the investigation of the role of EFs in language processing can corroborate this hypothesis.