Abstract:

Is visual consciousness a discrete or continuous pattern? Although previous research has established the existence of two distinct patterns of visual awareness within perceptual blindness paradigms, subjects often encounter challenges in distinguishing missed stimuli from correct rejections, both in terms of subjective judgments and objective tasks associated with these paradigms. The challenges arise from the mechanisms that restrict consciousness in perceptual blindness paradigms. In contrast, the attentional blindness paradigms offer a better exploration of the visual awareness patterns by circumventing this problem.

In attentional blindness paradigms, the attentional blink paradigm rapidly and sequentially presents multiple stimuli (about 10 stimuli per second) in a fixed spatial position. Subjects are required to identify one or more targets among several distractors. The high-speed presentation of stimuli and the interference from non-target stimuli significantly constrain information processing. Consequently, understanding whether subjects represent the second target in their consciousness as discrete or continuous proves valuable for researchers analyzing the patterns of consciousness. Compared to other paradigms, attentional blink effectively modulates consciousness to varying degrees by controlling the lags, it can not only avert potential confusion in subjects' subjective judgments but also minimizes errors resulting from exogenous attention.

Nevertheless, research using the attentional blink paradigm to investigate visual consciousness patterns have yielded conflicting evidence in both behavioral data and event-related potentials. According to the summary of previous studies, factors influencing visual awareness patterns in the attentional blink can be categorized into the following groups: firstly, measurement methods, with the properties of the scales used in subjective measurements potentially influencing subjects' judgments and leading to impure results. When it comes to objective measurements, the objective index is not equivalent to the complete subjective experience and may only represent a certain dimension of the stimulus experience (such as the duration or intensity of perception). Secondly, stimulating materials, which means stimuli that can change continuously, such as line segments, tend to favor the continuous pattern more than stimuli that are dichotomous, such as words. Furthermore, the response modalities constrained by experimental tasks can influence subjects' judgments. For instance, an orientation discrimination task using gratings, which can be continuously adjusted, may reveal a continuous pattern, while a face gender judgment task may favor a discrete pattern. Therefore, future studies could consider weakening or altering the continuous (discrete) properties of stimuli using technical means (e.g., morphing) and it is essential to distinguish between the level of material processing and subjects' response modalities. In addition, the processing level factor refers to the theory that different processing levels of stimuli lead to distinct visual consciousness patterns. Specifically, subjects tend to perceive low-level stimuli continuously and high-level stimuli dichotomously. Subsequent studies may require subjects to respond to different levels of features of the same stimulus to maintain stricter control over additional variables. Besides, according to the adaptive gating hypothesis based on spatial attention and the attentional set theory based on target feature switching, it can be generalized that as attentional load increases, results tend to shift from discrete to continuous patterns. Therefore, future studies can finely manipulate experimental variables like spatial distance and further investigate attentional load using similar stimuli in high-level dimensions (e.g., semantic). Future research can refine experimental methods and operations based on the aforementioned factors and suggestions. This will enable a more comprehensive empirical exploration of the visual awareness patterns based on attentional blink.

From a neuroscience perspective, due to the diverse interpretation of data resulting from different neural theories, more empirical research evidence is needed to elucidate the relationship between these various theories. Importantly, researchers should empirically differentiate and test these theories a priori rather than attempting to explain results post hoc and in a data-driven manner.

Key words: visual consciousness patterns, dichotomous visual consciousness, continuous visual consciousness, attentional blink