Conscious access in the near absence of attention: Critical extensions on the dual-task paradigm

Abstract

Whether conscious perception requires attention remains a topic of intense debate. While certain complex stimuli such as faces and animals can be discriminated outside the focus of spatial attention, many simpler stimuli cannot. Because such evidence was obtained in dual-task paradigms involving no measure of subjective insight, it remains unclear whether accurate discrimination of unattended complex stimuli is the product of automatic, unconscious processing, as in blindsight, or is accessible to consciousness. Furthermore, these paradigms typically require extensive training over many hours, bringing into question whether this phenomenon can be achieved in naive subjects. We developed a novel dual-task paradigm incorporating confidence ratings to calculate metacognition and adaptive staircase procedures to reduce training. With minimal training, subjects were able to discriminate face-gender despite little or no top-down attentional amplification, while also displaying above-chance metacognitive accuracy. In contrast, the discrimination of simple coloured disks was significantly impaired and metacognitive accuracy collapsed, even in a partial-report condition. In a final experiment we used blended face/disk stimuli and confirmed that face-gender but not colour orientation can be discriminated in the dual-task. Our results show direct evidence for metacognitive conscious access in the near absence of attention for complex, but not simple, stimuli.

Waving goodbye to contrast: Self-generated hand movements attenuate visual sensitivity

“…Prospective investigations are also required to examine more precisely how our findings generalise over different categories of stimuli or stimulus feature differentiation. It has been shown that these aspects can interact with attention and metacognition (Stein & Peelen, 2017;Matthews et al, 2018). In addition, the precise influence of evidence-reliability remains to be elucidated in more extensive work as it has also been shown to affect confidence judgments and metacognition (Boldt, De Gardelle & Yeung, 2017;Bang & Fleming, 2018;Denison & al., 2018).…”

Conscious perception of flickering stimuli in binocular rivalry and continuous flash suppression is not affected by tACS-induced SSR modulation

“…Alternatively, it may be that tACS had a cumulative negative effect on cognitive performance, however, this is unlikely given the positive time-on-task effect observed in the first CFS experiment. Instead, our participant instructions did not emphasise the equal distribution of confidence for a given block, meaning that what we measured may not actually have reflect trial-by-trial fluctuation of confidence, but instead meta awareness of fatigue, attentional drift or mindwandering over blocks (Matthews et al, 2018).…”

“…The advantage of this non-parametric method is its robustness against violations of Gaussian equal variance. The area under this curve now represents metacognitive sensitivity (Matthews et al, 2018;Matthews et al, 2019).…”

Conscious perception of flickering stimuli in binocular rivalry and continuous flash suppression is not affected by tACS-induced SSR modulation

“…The advantage of this non-parametric method is its robustness against violations of Gaussian equal variance. The area under this curve now represents metacognitive sensitivity (Matthews et al, 2018;Matthews et al, 2019).…”