Biased temporal order judgments in chronic neglect influenced by trunk position

Area of Science:

• Neuroscience
• Cognitive Psychology
• Perception

Background:

• Patients with neglect and extinction exhibit altered temporal order perception.
• They often misjudge the timing of simultaneous stimuli, perceiving ipsilesional stimuli as earlier.
• This leads to a biased point of subjective simultaneity (PSS).

Purpose of the Study:

• To investigate if the egocentric position of stimuli relative to the trunk influences temporal order perception biases in neglect patients.
• To determine if this modulation is specific to active neglect symptoms.

Main Methods:

• Utilized a controlled experimental design keeping retinal and head-centered stimulus coordinates constant.
• Assessed temporal order perception in patients with neglect, recovered neglect patients, and healthy controls.
• Manipulated the egocentric position of stimuli relative to the participant's trunk.

Main Results:

• The magnitude of the temporal order perception bias (PSS) was significantly modulated by stimulus position relative to the trunk.
• This modulation was only present in patients actively experiencing neglect symptoms.
• Recovered patients, those without neglect history, and healthy controls did not show this pathological bias or modulation.

Conclusions:

• Egocentric spatial position, specifically trunk-relative location, significantly impacts temporal order perception in neglect.
• The findings underscore the crucial interaction between spatial representation and temporal processing in neglect.
• This suggests that trunk-centered spatial frames are vital for understanding temporal deficits in neurological conditions.