Time gaps in mental imagery introduced by competing saccadic tasks

Area of Science:

• Cognitive Neuroscience
• Ophthalmology
• Psychology

Background:

• Saccades, rapid eye movements, are known to suppress visual processing.
• Emerging research suggests saccades may also interrupt other cognitive processes, like mental imagery.
• Spontaneous eye movements can reflect ongoing cognitive activity.

Purpose of the Study:

• To investigate whether voluntary saccades and attention shifts impact concurrent mental imagery.
• To determine if spontaneous saccades affect mental imagery.
• To understand the role of attentional resource competition in cognitive task interference.

Main Methods:

• Participants performed a motion imagery task concurrently with secondary tasks.
• Secondary tasks included voluntary saccades, anti-saccades, and attention shifts without saccades.
• Imagery performance was compared across different secondary task conditions and a fixation control.

Main Results:

• Voluntary saccades and anti-saccades significantly delayed motion imagery.
• Attention-shifting tasks also delayed imagery, but to a lesser extent than saccades.
• Spontaneous saccades accompanying imagery did not cause delays compared to fixation.

Conclusions:

• Dual-tasking with voluntary saccades or attention shifts creates significant time gaps in cognitive activity.
• Cognitive interference arises from competition for shared attentional resources.
• Saccades and attention shifts, when voluntary, disrupt ongoing mental processes.