Embodied Cognition: A Challenging Road for Clinical Neuropsychology

Clinical neuropsychology (CN) has clearly emerged as a diagnostic discipline, influenced by disembodied and localizationist-connectionist approaches. In this sense, cognition has been understood as a relatively isolated link of perception and movement. The classic model “perception → cognition→ action” has guided the design of instruments and the interpretation of the results in pathological conditions of the central nervous system. This trend has been maintained over time thanks to the convergence of the localizationist approach and computational models of information processing adopted by CN (Shallice, 1988). Recently, embodied cognition (EC) has put the sensory-motor system on the stage of human cognitive neuroscience (Willems and Francken, 2012; Freund et al., 2016). EC proposes that the brain systems underlying perception and action are integrated with cognition in bidirectional pathways (Borghi and Pecher, 2011; Ibáñez et al., 2013; Cardona et al., 2014), highlighting their connection with bodily (Gallese and Lakoff, 2005; Gallese and Sinigaglia, 2011) and emotional (Niedenthal, 2007; De Jaegher et al., 2010) experiences, leading to research programs aimed at demonstrating the influence of action on perception (Proffitt, 2006; Creem-Regehr and Kunz, 2010; Witt, 2011) and high-level cognition (Barrett et al., 2007; Goldin-Meadow and Beilock, 2010; Ibáñez and Manes, 2012). Embodied cognition (EC) findings are gradually leading to an integrative view of mental functions and their interdependence with the context, questioning the validity of the computational paradigm and the localizationalist doctrine in explaining brain functioning and its correspondence with complex behavior. These findings have also given a scientific character to the study of bodily experience in the analysis of brain function. The continuous accumulation of evidence from EC has had both theoretical and experimental influence and is expected to ultimately impact the clinical field. This article presents some of the main challenges that neuropsychology faces in integrating EC in its clinical assessment and diagnosis processes.

Clinical neuropsychology (CN) has clearly emerged as a diagnostic discipline, influenced by disembodied and localizationist-connectionist approaches. In this sense, cognition has been understood as a relatively isolated link of perception and movement. The classic model "perception → cognition → action" has guided the design of instruments and the interpretation of the results in pathological conditions of the central nervous system. This trend has been maintained over time thanks to the convergence of the localizationist approach and computational models of information processing adopted by CN (Shallice, 1988).
Embodied cognition (EC) findings are gradually leading to an integrative view of mental functions and their interdependence with the context, questioning the validity of the computational paradigm and the localizationalist doctrine in explaining brain functioning and its correspondence with complex behavior. These findings have also given a scientific character to the study of bodily experience in the analysis of brain function. The continuous accumulation of evidence from EC has had both theoretical and experimental influence and is expected to ultimately impact the clinical field. This article presents some of the main challenges that neuropsychology faces in integrating EC in its clinical assessment and diagnosis processes.

CEREBRAL BOUNDARIES: ROOTS OF NEUROPSYCHOLOGICAL ASSESSMENT
Historically, perception and movement have been separated from cognition. The events that occurred in the nineteenth century are a turning point in the parsed study of the functions of the nervous system. The neurophysiology of the motor and sensory processes was consolidated from the pioneering findings of Bell (1811) and Magendie (1822). With the same importance in CN, Dax (1836) (See, Cubelli and Montagna, 1994;Manning and Thomas-Anterion, 2011) and Broca (1861) reported the correspondence between alterations in language production and damage to the left frontal zone of the brain, consolidating the localizationist approach in the explanation of cognitive organization.
Although alternative proposals such as the equipotential theory (Lashley, 1929) that emphasized the interactivity of the whole brain (holism) emerged, localizationalist doctrine and its methods were extended at an accelerated rate to the study of various cognitive functions, making it impossible to trace a single line of scientific development from that period.
In this way, the diagnostic procedures and methods of investigation in CN were directly influenced by localizationist theory. Pioneering neuropsychologists, including Henry Hecaen, Oliver Zangwill, Hans-Lukas Teuber and Brenda Milner, worked together with neurosurgeons to develop reliable tools that would discriminate patients with brain lesions from normal controls (Halstead, 1947;Hartlage, 1966). The approach between behavioral neurology and psychometrics led to the selection of sensitive tests to find anatomic-clinical correspondences contained in classical neuropsychological batteries, such as the Halstead-Reitan (Halstead, 1947;Wolfson, 1985, 1993) Luria-Nebraska (Golden et al., 1980) and other instruments used in clinical practice (Strauss et al., 2006).
A methodology associated with strict localizationism has been the double dissociation (Teuber, 1955;Weiskrantz, 1968Weiskrantz, , 1991, which is shown when lesions in area A affect function X more than function Y, while lesions in area B affect function Y more than function X. This type of approach responds to a logic of "effect = structure" and suggests that performance in a given task depends on a specialized area of the cerebral cortex (Pribram, 1971).
The convergence between the modular theory of Fodor (1983) and the advent of neuroimaging techniques gave credence to this fragmented brain organization, leading to the overvaluation of strong dissociations between brain functions such as hearing (Peretz et al., 1994;Peretz and Coltheart, 2003), memory (Moscovitch, 1995;Moscovitch and Nachson, 1995) and language (Warrington and Shallice, 1984;Warrington and McCarthy, 1987;Pinker and Ullman, 2002;Crutch and Warrington, 2003) and to the selection of numerous tasks aimed at inferring the delimited location of brain damage that still have clinical utility in the recognition of cognitive alterations (Strauss et al., 2006;Lezak, 2012). Although the development of measuring instruments represented an advance in the CN, many tasks cannot easily be extrapolated to activities of daily living. To overcome this problem, important advances have been made in the development of tests that have greater ecological validity, establishing a better relationship between the evaluation and the interpretation of the results, taking into account the impact that cognitive alterations have in the everyday activities of patients (Wilson et al., 1985(Wilson et al., , 1987McDonald et al., 2003;Torralva et al., 2009). However, perception and action are still isolated from cognitive domains.

AN INTEGRATIVE VIEW OF BRAIN-CONTEXT INTERACTION
The idea of coupling between mental processes is not new in CN. In fact, clinical evidence from the pioneering work of Gonzalo (1950) (see Gonzalo-Fonrodona, 2009) and Goldberg (1989Goldberg ( , 1995 suggested a dynamic organization of the cerebral cortex underlying sensory, cognitive and motor integration. These findings have been supported by cross-modal studies (Fuster et al., 2000;Ghazanfar and Schroeder, 2006;Driver and Noesselt, 2008;Spence and Parise, 2012) that show interactivity and coupling in processes such as vision (Klapetek et al., 2012), hearing , somato-perception and the chemical senses (Hanson-Vaux et al., 2013).
However, it was the discovery of mirror neuron system (MNS) in the human brain (Rizzolatti and Craighero, 2004) that facilitated EC to show the interaction of language and motor system (Rizzolatti and Arbib, 1998;Pulvermuller, 2005;Arévalo et al., 2015). In light of these findings, neuropsychological exploration in diseases traditionally classified as movement disorders has uncovered a compromise in action language processing (Bak, 2013), such as corticobasal degeneration (Cotelli et al., 2006;Silveri and Ciccarelli, 2007), Huntington's disease (Peran et al., 2004;Kargieman et al., 2014), progressive supranuclear palsy (Bak et al., 2006;Cotelli et al., 2006), amyotrophic lateral sclerosis (Neary et al., 2000;Bak et al., 2001;Bak and Hodges, 2004) and Parkinson's disease (Boulenger et al., 2008;Cardona et al., 2013Cardona et al., , 2014, revealing the compromise of language even at an early stage of pathology and becoming a potential early marker in the specific case of Parkinson's disease. Additionally, under the EC framework, the study of emotional processing, understood as a multilevel and context-dependent domain (Barrett et al., 2007), has been given a prominent place, making it clear how neurodegenerative pathologies (Ibáñez and Manes, 2012) and neuropsychiatric disorders (Ibáñez et al., 2011) present notorious difficulties when integrating contextual cues into ecological cognitive tasks.

CONCLUSION
Embodied cognition (EC) findings in the area of neuropsychology demonstrate that interactivity and multimodality are fundamental features of brain functioning and that contextual interdependence can be a crucial factor in regard to bringing about effective interventions, opening the door to new research in various clinical conditions. This premise reflects a methodological imperative for CN. First, the model of cerebral functioning that guides neuropsychological intervention should be strengthened in consensus. In this sense, EC invites an integrative vision of mental processes and encourages the development of new methods that complement the approaches of cognitive functions. Although current assessment tools are sensitive and reliable in detecting cognitive deficits associated with central nervous system disorders, the design and integration of multimodal, emotional and contextual processing measures may have more ecological validity than other measures (Franzen and Wilhelm, 1996;Chaytor and Schmitter-Edgecombe, 2003;Rabin et al., 2007).
Second, the findings of linkages between the language and motor systems could guide the establishment of clinical guidelines that include the evaluation of the language of action in neurodegenerative motor pathologies and could also provide new perspectives and intervention strategies that may delay cognitive impairment in these clinical pictures. This suggestion is based on the positive results of cognitive stimulation in reducing executive and functional deficits in patients with Parkinson's disease (Sinforiani et al., 2004;Sammer et al., 2006). In this way, it is necessary to clarify the different deficits in language processing to propose cross-modal treatments that facilitate the attenuation of motor deficits. Likewise, the establishment of the relationship between the language and motor systems leads to the need to verify the presence of other couplings between the sensory-motor system and other domains of cognition to enable the establishment of rehabilitation programs.
Embodied cognition (EC) also provides new perspectives and intervention strategies in other areas of mental health. Some proposals have emerged in clinical psychology (Zatti and Zarbo, 2015) and psychiatry (Fuchs, 2009;Fuchs and Schlimme, 2009) in which classical theories of cognition presented serious limitations in explaining the appearance of nonunderlying behavioral alterations to specific brain injuries and in which experience and environmental factors play fundamental roles.
The integration of experience and context into the triad "perception, cognition and action" has been previously accepted in the understanding of brain development in childhood. However, EC findings show that the adult brain remains context-dependent and that experience directly impacts both structural and brain functioning throughout life. Although localizational and computational models have made numerous contributions to the development of clinical practice, EC highlights the role of the body and the sensory-motor experience, allowing a broader vision and a better understanding of cognitive processes under both normal and pathological conditions.

AUTHOR CONTRIBUTIONS
The author confirms being the sole contributor of this work and approved it for publication.