Combining language and space: sentence bisection in unilateral spatial neglect

Area of Science:

• Neuroscience
• Cognitive Psychology
• Linguistics

Background:

• Right-brain-damaged patients with left spatial neglect display a rightward deviation in line bisection tasks.
• Orthographic features of word stimuli influence performance in word bisection for both patients and healthy individuals.
• Previous research highlights the impact of stimulus properties on spatial attention and bisection tasks.

Purpose of the Study:

• To investigate the influence of linguistic factors on sentence bisection performance.
• To compare sentence bisection in patients with and without spatial neglect, and in control participants.
• To determine if linguistic processing, such as readability and violations, modulates spatial bias in neglect.

Main Methods:

• Experiment 1 assessed the effect of information in the right-sided part of sentences.
• Experiment 2 evaluated the impact of lexical and syntactic violations within sentences.
• Participants included right-brain-damaged patients with and without neglect, and healthy controls, performing visuo-manual bisection tasks.

Main Results:

• Neglect patients demonstrated a significant overall rightward bias, exceeding that of non-neglect patients and controls.
• The rightward bias in neglect patients varied by stimulus type, being largest for lines, smaller for letter strings, and smallest for sentences.
• Sentence readability and linguistic integrity reduced the rightward bias in neglect patients.

Conclusions:

• Linguistic processing, specifically sentence readability, can mitigate the rightward bias observed in spatial neglect during bisection tasks.
• Visuo-manual sentence bisection is influenced by fundamental linguistic mechanisms, promoting a more leftward appreciation of the stimulus.
• These findings suggest that engaging higher-level cognitive functions like language processing can modulate spatial attention deficits in neglect.