Article

Context-specific adaptation of saccade gain in parabolic flight.

Department of Otolaryngology-Head & Neck Surgery, Biomedical Engineering, The Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
Journal of Vestibular Research (impact factor: 1.35). 12(5-6):211-21.
Source: PubMed

ABSTRACT Previous studies established that vestibular reflexes can have two adapted states (e.g., gains) simultaneously, and that a context cue (e.g., vertical eye position) can switch between the two states. Our earlier work demonstrated this phenomenon of context-specific adaptation for saccadic eye movements: we asked for gain decrease in one context state and gain increase in another context state, and then determined if a change in the context state would invoke switching between the adapted states. Horizontal and vertical eye position and head orientation could serve, to varying degrees, as cues for switching between two different saccade gains. In the present study, we asked whether gravity magnitude could serve as a context cue: saccade adaptation was performed during parabolic flight, which provides alternating levels of gravitoinertial force (0 g and 1.8 g). Results were less robust than those from ground experiments, but established that different saccade magnitudes could be associated with different gravity levels.

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Keywords

adapted states
 
context cue
 
context state
 
context-specific adaptation
 
different gravity levels
 
different saccade gains
 
different saccade magnitudes
 
gains
 
ground experiments
 
head orientation
 
Horizontal
 
Previous studies
 
provides alternating levels
 
saccadic eye movements
 
two states
 
varying degrees
 
vertical eye position