Subjective discriminability of invisibility: a framework for distinguishing perceptual and attentional failures of awareness.
Conscious visual perception can fail in many circumstances. However, little is known about the causes and processes leading to failures of visual awareness. In this study, we introduce a new signal detection measure termed subjective discriminability of invisibility (SDI) that allows one to distinguish between subjective blindness due to reduction of sensory signals or to lack of attentional access to sensory signals. The SDI is computed based upon subjective confidence in reporting the absence of a target (i.e., miss and correct rejection trials). Using this new measure, we found that target misses were subjectively indistinguishable from physical absence when contrast reduction, backward masking and flash suppression were used, whereas confidence was appropriately modulated when dual task, attentional blink and spatial uncertainty methods were employed. These results show that failure of visual perception can be identified as either a result of perceptual or attentional blindness depending on the circumstances under which visual awareness was impaired.
Kanai
Ryota
R
Institute of Cognitive Neuroscience & Dept. of Psychology, University College London, 17 Queen Square, WC1N 3AR London, United Kingdom. r.kanai@ucl.ac.uk, kanair@gmail.com
Walsh
Vincent
V
Tseng
Chia-huei
CH
D054518:Attentional Blink; D001364:Awareness; D015350:Contrast Sensitivity; D004192:Discrimination, Psychological; D006801:Humans; D009949:Orientation; D010364:Pattern Recognition, Visual; D010470:Perceptual Masking; D010775:Photic Stimulation; D011601:Psychophysics; D012684:Sensory Thresholds; D017603:Signal Detection, Psychological; D014796:Visual Perception