Space-time mapping on the sagittal axis in congenital blindness

Area of Science:

• Cognitive Psychology
• Neuroscience
• Sensory Perception

Background:

• Evolutionary theories suggest sagittal space-time mapping arises from visuo-locomotion coupling during forward movement.
• This perspective implies congenitally blind individuals may lack a sagittal mental timeline due to the absence of visual input.
• Prior research supporting this was limited and its theoretical basis questioned, as auditory-visual locomotion coupling is preserved in blindness.

Purpose of the Study:

• To systematically investigate whether congenitally blind individuals exhibit space-time mappings on the sagittal axis.
• To explore the role of sensory-locomotion coupling in the development of a sagittal mental timeline.
• To clarify the origins of sagittal mental timelines.

Main Methods:

• Three experiments were conducted using diverse paradigms, including reaction time (RT) tasks, naming tasks, and explicit space-time mapping tasks.
• Participants included individuals with congenital blindness and normally sighted controls.
• Tasks assessed implicit and explicit space-time associations and the use of spatial metaphors.

Main Results:

• Congenitally blind participants demonstrated preferred space-time mappings in the sagittal dimension, similar to sighted individuals, in an implicit RT task.
• This mapping occurred automatically even when temporal relations were task-irrelevant, as shown in a naming task.
• In an explicit task, blind participants tended to position the past behind and the future in front, often using spatial metaphors.

Conclusions:

• Congenitally blind individuals possess a sagittal mental timeline.
• Sensory-locomotion coupling experience in blind individuals is either similar to sighted individuals or not critical for sagittal space-time mapping.
• The findings challenge the necessity of visuo-locomotion coupling for developing a sagittal mental timeline, suggesting alternative origins.