Utrocular discrimination is not sufficient for utrocular identification.

Area of Science:

• Vision science
• Ophthalmology
• Psychophysics

Background:

• Reliability and validity are crucial concepts in understanding visual perception.
• Utrocular identification, the process of determining which eye is stimulated, is complex.
• Previous research has not fully elucidated the factors influencing accurate utrocular identification.

Purpose of the Study:

• To investigate the distinction between reliable discrimination and valid identification in vision.
• To examine how luminance changes and feedback affect utrocular identification accuracy.
• To explore the role of perceived eye stimulation in visual direction.

Main Methods:

• Four experiments were conducted using varying visual stimulation conditions.
• Participants performed utrocular identification tasks with and without feedback.
• Luminance changes in target and non-target eyes were manipulated.
• Binocularly deficient subjects were included in one experiment.

Main Results:

• Conditions yielding reliable discrimination did not guarantee valid identification.
• Feedback reduced the covariation of responses with visual direction as subjects sought alternative cues.
• A "feeling-in-the-eye" sensation correlated with luminance change, not necessarily the target stimulus.
• Responses ranged from reliably incorrect to reliably correct based on luminance changes in the non-target eye.

Conclusions:

• Visual perception's reliability does not equate to its validity.
• Luminance changes significantly influence utrocular identification accuracy.
• The findings support the projection of monocular stimulation to a cyclopean eye.