注意和工作记忆提取对变化盲视的影响

变化盲视是指观察者不能探测到视觉情境中明显的变化。本研究采用线索提示范式考察了注意和工作记忆提取对变化盲视的影响。结果发现,前置有效线索虽然不能缩短变化探测的时间,但可以降低变化盲视发生的概率,而后置有效线索既不能缩短变化探测的时间,也不能降低变化盲视的发生概率。结论表明,注意对变化盲视有显著影响,但工作记忆提取对变化盲视的影响不显著。     

The relationship between fluid intelligence and sustained inattentional blindness in 7-to-14-year-old children

Previous researches have shown that people with higher fluid intelligence are more likely to detect the unexpected stimuli. The current study systematically explored the relationship between fluid intelligence and sustained inattentional blindness in children. In Experiment 1, we measured one hundred and seventy-nine 7-to-14-year-old children’s fluid intelligence and sustained inattentional blindness. The results showed that fluid intelligence was negatively related to sustained inattentional blindness only in 7-to-8-year-old children. In Experiment 2, we explored sustained inattentional blindness in sixty children with high Raven’s scores. We found that compared with children who have average Raven’s scores aged 11-to-12 years old, children with high Raven’s scores were unable to better avoid sustained inattentional blindness. In general, this research implies that the relation between fluid intelligence and sustained inattentional blindness is weak. Fluid intelligence could predict sustained inattentional blindness only when children do not have enough perceptual capacities to complete the primary task.     

Manipulations of distractor frequency do not mitigate emotion-induced blindness

Emotional distractors can impair perception of subsequently presented targets, a phenomenon called emotion-induced blindness. Do emotional distractors lose their power to disrupt perception when appearing with increased frequency, perhaps due to desensitisation or enhanced recruitment of proactive control? Non-emotional tasks, such as the Stroop, have revealed that high frequency distractors or conflict lead to reduced interference, and distractor frequency appears to modulate attentional capture by emotional distractors in spatial attention tasks. But emotion-induced blindness is thought to reflect perceptual competition between targets and emotional distractors, and it is unclear whether high frequency emotional stimuli cause less disruption at this relatively early stage of processing. In four experiments, participants searched streams of images for a rotated target image. A negative or neutral distractor appeared before the target, and their relative frequency was manipulated. Across all experiments, the frequency of emotional distractors did not modulate emotion-induced blindness even when participants were explicitly informed that they would appear often or seldom. Thus, increased distractor frequency does not appear to mitigate the priority allotted to emotional distractors during perceptual competition.     

The Occipital Cortex in the Blind

ABSTRACT— Studying the brains of blind individuals provides a unique opportunity to investigate how the brain changes and adapts in response to afferent (input) and efferent (output) demands. We discuss evidence suggesting that regions of the brain normally associated with the processing of visual information undergo remarkable dynamic change in response to blindness. These neuroplastic changes implicate not only processing carried out by the remaining senses but also higher cognitive functions such as language and memory. A strong emphasis is placed on evidence obtained from advanced neuroimaging techniques that allow researchers to identify areas of human brain activity, as well as from lesion approaches (both reversible and irreversible) to address the functional relevance and role of these activated areas. A possible mechanism and conceptual framework for these physiological and behavioral changes is proposed.     

On the role of attention in generating explicit awareness of contingent relations: evidence from spatial priming

In a series of four experiments, we examine the hypothesis that selective attention is crucial for the generation of conscious knowledge of contingency information. We investigated this question using a spatial priming task in which participants were required to localize a target letter in a probe display. In Experiment 1, participants kept track of the frequency with which the predictive letter in the prime appeared in various locations. This manipulation had a negligible impact on contingency awareness. Subsequent experiments requiring participants to attend to features (color, location) of the predictive letter increased contingency awareness somewhat, but there remained a large proportion of individuals who remained unaware of the strong contingency. Together the results of our experiments suggest that the construct of attention does not fully capture the processes that lead to contingency awareness, and suggest a critical role for bottom-up feature integration in explicit contingency learning.     

Attentional processes and meditation

Visual attentional processing was examined in adult meditators and non-meditators on behavioral measures of change blindness, concentration, perspective-shifting, selective attention, and sustained inattentional blindness. Results showed that meditators (1) noticed more changes in flickering scenes and noticed them more quickly, (2) counted more accurately in a challenging concentration task, (3) identified a greater number of alternative perspectives in multiple perspectives images, and (4) showed less interference from invalid cues in a visual selective attention task, but (5) did not differ on a measure of sustained inattentional blindness. Together, results show that regular meditation is associated with more accurate, efficient, and flexible visual attentional processing across diverse tasks that have high face validity outside of the laboratory. Furthermore, effects were assessed in a context separate from actual meditation practice, suggesting that meditators’ better visual attention is not just immediate, but extends to contexts separate from meditation practice.     

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.     

重复刺激的末位优势效应

探讨在RSVP任务中重复刺激的呈现位置和报告方式对重复知盲效应的影响, 检验该研究提出的注意资源最优化假设和末位优势效应。实验1操作了刺激性质和重复刺激位置, 得出了刺激性质和重复刺激位置的交互效应; 实验2操作了刺激性质和情景信息, 结果是交互效应不显著; 实验3操作了刺激性质和报告方式, 出现了刺激性质和报告方式的交互效应。该结果表明: (1)由于注意资源分配的优化, 重复刺激有末位优势效应。(2)重复知盲的产生不是发生在知觉阶段, 而是发生在报告阶段。(3)注意资源分配最优化理论比建构/归因理论能更合理地解释重复知盲的发生。     

Intentionalism and Change Blindness

According to reductive intentionalism, the phenomenal character of a conscious experience is constituted by the experience's intentional (or representational) content. In this article I attempt to show that a phenomenon in visual perception called change blindness poses a problem for this doctrine. Specifically, I argue that phenomenal character is not sensitive, as it should be if reductive intentionalism is correct, to fine-grained variations in content. The standard anti-intentionalist strategy is to adduce putative cases in which phenomenal character varies despite sameness of content. This paper explores an alternative antiintentionalist tack, arguing, by way of a specific example involving change blindness, that content can vary despite sameness of phenomenal character.

The role of perceptual load in inattentional blindness

Perceptual load theory offers a resolution to the long-standing early vs. late selection debate over whether task-irrelevant stimuli are perceived, suggesting that irrelevant perception depends upon the perceptual load of task-relevant processing. However, previous evidence for this theory has relied on RTs and neuroimaging. Here we tested the effects of load on conscious perception using the "inattentional blindness" paradigm. As predicted by load theory, awareness of a task-irrelevant stimulus was significantly reduced by higher perceptual load (with increased numbers of search items, or a harder discrimination vs. detection task). These results demonstrate that conscious perception of task-irrelevant stimuli critically depends upon the level of task-relevant perceptual load rather than intentions or expectations, thus enhancing the resolution to the early vs. late selection debate offered by the perceptual load theory.