Re‐fixation and perseveration patterns in neglect patients during free visual exploration. (6th January 2019)

• Record Type: Journal Article
• Authors: Paladini, Rebecca E.; Wyss, Patric; Kaufmann, Brigitte C.; Urwyler, Prabitha; Nef, Tobias; Cazzoli, Dario; Nyffeler, Thomas; Müri, René M.
• Is Part Of: European journal of neuroscience. Volume 49:Number 10(2019)
• Page Start: 1244
• Page End: 1253
• Publication Date: 2019-01-06
• Subjects: attention -- fixation analysis -- perseverative behavior -- saliency -- stroke; Nervous system -- Periodicals; 612.8
• DOI: 10.1111/ejn.14309
• Languages: English
• ISSNs: 0953-816X

Abstract

Abstract: The literature suggests that neglect patients not only show impairments in directing attention toward the left, contralesional space, but also present with perseverative behavior. Moreover, previous studies described re‐fixations during visual search tasks, and interpreted this finding as an impairment of spatial working memory. The aim of the present study was to study re‐fixations and perseverations (i.e., recurrent re‐fixations to same locations) during free visual exploration, a task with high ecological validity. We hypothesized that: (1) neglect patient would perform re‐fixations more frequently than healthy controls within the right hemispace; and, (2) the re‐fixation behavior of neglect patients would be characterized by perseverative fixations. To test these hypotheses, we assessed 22 neglect patients and 23 healthy controls, measuring their eye movements during free exploration of naturalistic pictures. The results showed that neglect patients tend to re‐fixate locations within the ipsilesional hemispace when they freely explore naturalistic pictures. Importantly, the saliency of discrete locations within the pictures has a stronger influence on fixation behavior within the contralesional than within the ipsilesional hemispace in neglect patients. Finally, the results indicated that, for re‐fixations, saliency plays a more important role within the contralesional than the ipsilesional hemispace. Moreover, we found evidence that re‐fixation behavior of neglect patients is characterized by frequent recurrent re‐fixations back to the same spatial locations which may be interpreted as perseverations. Hence, with the present study, we could better elucidate the mechanism leading to re‐fixations and perseverative behavior during free visual exploration in neglect patients. Abstract : The re‐fixation and perseveration rate in patients with left‐sided visual neglect during a free visual exploration task of naturalistic pictures was investigated. Neglect patients tended to re‐fixate locations within the ipsilesional hemispace, and they showed an overall higher rate of perseverative fixations than healthy controls. The results of this study thus further elucidate the mechanisms leading to perseverative behavior in neglect patients.