Neglect Alexia: A Literature Review of Cognitive Mechanisms, Assessment, and Rehabilitation

Spatial neglect is a neuropsychological disorder of contralesional spatial awareness that most commonly occurs following right hemisphere stroke. This disorder is characterized by a reduced ability of the affected patients to attend, respond, or orient to contralesional stimuli (Parton et al., 2004). Spatial neglect can affect different sensory modalities, spatial sectors, and reference frames, leading to significant impairments in everyday activities, such as reading, navigation, and interaction with objects (Adair & Barrett, 2008; Pitteri et al., 2018). Among the cognitive deficits associated with spatial neglect, neglect alexia is a reading disorder in which individuals may add, omit, substitute, or misread words/letters on the contralesional side of page/words, despite the presence of preserved other language abilities (Lee et al., 2009). Although neglect alexia frequently co-occurs with spatial neglect, the two conditions can dissociate, thereby indicating the existence of partially independent underlying mechanisms (Lee et al., 2009; Ronchi et al., 2016; Vallar et al., 2010). The present thesis consists of a literature review concerning neglect alexia within the broader context of spatial neglect. In Chapter 1, an overview of spatial neglect is provided, including its definition, symptoms, prevalence, major subtypes, neuroanatomy, and contemporary theoretical models. Current methods for assessing and rehabilitating spatial neglect are also reviewed. In Chapter 2, the focus is on neglect alexia by discussing its definition, clinical features, subtypes, dissociations from spatial neglect, neuroanatomical correlates, explanatory cognitive models, current assessment approaches, and rehabilitation strategies. In the final chapter (i.e., Chapter 3), the main limitations regarding the existing studies are discussed. Moreover, a tentative comprehensive battery for assessing neglect alexia is proposed. Finally, research areas that require further investigation are identified.