Late‐ but not early‐onset blindness impairs the development of audio‐haptic multisensory integration

Integrating different senses to reduce sensory uncertainty and increase perceptual precision can have an important compensatory function for individuals with visual impairment and blindness. However, how visual impairment and blindness impact the development of optimal multisensory integration in the remaining senses is currently unknown. Here we first examined how audio‐haptic integration develops and changes across the life span in 92 sighted (blindfolded) individuals between 7 and 70 years of age. We used a child‐friendly task in which participants had to discriminate different object sizes by touching them and/or listening to them. We assessed whether audio‐haptic performance resulted in a reduction of perceptual uncertainty compared to auditory‐only and haptic‐only performance as predicted by maximum‐likelihood estimation model. We then compared how this ability develops in 28 children and adults with different levels of visual experience, focussing on low‐vision individuals and blind individuals that lost their sight at different ages during development. Our results show that in sighted individuals, adult‐like audio‐haptic integration develops around 13–15 years of age, and remains stable until late adulthood. While early‐blind individuals, even at the youngest ages, integrate audio‐haptic information in an optimal fashion, late‐blind individuals do not. Optimal integration in low‐vision individuals follows a similar developmental trajectory as that of sighted individuals. These findings demonstrate that visual experience is not necessary for optimal audio‐haptic integration to emerge, but that consistency of sensory information across development is key for the functional outcome of optimal multisensory integration.     

感知运动经验在心理时间线形成中的作用—来自盲生的证据

本研究考察视觉和读写习惯有关的感知运动经验是如何影响心理时间形成的。实验1和实验2分别采用一天内和一生中的词语或短句,以小学三年级的普生和盲生为被试,结果发现不论是短的还是长的时间,普生对早的刺激按左键,晚的刺激按右键反应更快,而盲生未出现早左晚右的心理时间线。实验3和实验4分别以短时间和长时间范围的时间词为材料,以初一盲生和普生为被试,结果发现普生和盲生都是对过去的时间按左键,未来的时间按右键反应快;而且在长的时间范围内,盲生的反应时长于普生。结果表明视觉是心理时间线的基础,阅读经验在盲生心理时间线的形成中起着关键作用。     

Reinstating effortful encoding operations at test enhances episodic remembering

Two experiments investigated the effects of reinstating encoding operations on remember and know responses in recognition memory. Experiment 1 showed that reinstating an effortful encoding task (generating words from fragments) increased remember responses at test but reinstating an automatic encoding task (reading intact words) did not. This pattern was confirmed in Experiment 2 in which words were either read intact or generated from anagrams. These findings show that repeating effortful (but not automatic) encoding operations at test cues not only the recognition of the information that was acquired via those operations but also the conscious recollection of the encoding episode.     

Epistemic Contextualism,Semantic Blindness and Content Unawareness

It is held by many philosophers that it is a consequence of epistemic contextualism that speakers are typically semantically blind, that is, typically unaware of the propositions semantically expressed by knowledge attributions. In his ‘Contextualism, Invariantism and Semantic Blindness’ (this journal, 2009), Martin Montminy argues that semantic blindness is widespread in language, and not restricted to knowledge attributions, so it should not be considered problematic. I will argue that Montminy might be right about this, but that contextualists still face a serious and related problem: that it is a consequence of epistemic contextualism that subjects are typically unaware of contents conveyed by knowledge attributions, independently of whether these are semantic or non-semantic contents. Even if semantic blindness is widespread in language, it does not seem that content unawareness of this sort is.     

Cutaneous Pattern Perception on Foreheads in 3- and 4-Year-Old Children

In the present study, we investigated how 3- and 4-year-old children perceived mirror-image stimuli traced on their foreheads. First, the subjects were taught matching-to-sample tasks with symmetrically shaped and asymmetrically shaped figures (called mirror-image stimuli) on cards. Then the subjects were taught cutaneous perception of a figure traced by the experimenter's finger on the forehead. Last, the subjects were tested with mirror-image stimuli in cutaneous perception tasks. The results of these experiments indicated that the subjects who could discriminate the mirror-image stimuli could also perceive asymmetrical stimuli as mirror reversals.     

Motion-induced blindness is influenced by global properties of the moving mask

Perceptual fluctuations experienced during motion-induced blindness (MIB) have been characterized as the result of a competition between representations of the moving mask and stationary (or slowly moving) targets (Bonneh, Cooperman, & Sagi, 2001). While there is evidence to support a local influence of the mask on target disappearance, what is not yet clear is whether the global properties of the mask can likewise impact disappearance. In the present study, we investigated the presence of a global effect of the mask on MIB by manipulating global motion properties of the mask while controlling its local motion properties surrounding the target. Results showed a significant impact of the global mask properties on the observed degree of disappearance. We also tested for a complementary local effect by comparing conditions in which we manipulated local mask properties while controlling global properties. This analysis did not yield evidence for a local effect, although this may have been due to our weaker manipulation of local mask properties compared to previous studies. Overall, the present results highlight a key role of global stimulus representations in producing the perceptual disappearances observed in MIB.     

Misdirected by the gap: the relationship between inattentional blindness and attentional misdirection

In several of our articles we have drawn analogies between inattentional blindness paradigms and misdirection. Memmert (2010) however, has criticized this analogy and urged for caution in assuming too much of a close relationship between these two phenomena. Here we consider the points raised by Memmert and highlight some misunderstandings and omissions in his interpretation of our work, which substantially undermine his argument. Debating the similarities and differences between aspects of misdirection and inattentional blindness is valuable and has the potential to highlight the utility of these two phenomena. However, it is important not to be misdirected by subtle differences between particular instances of each phenomenon, at the expense of failing to detect the opportunities that these phenomena present for extending our understanding of attention and awareness.     

Did I read or did I name? Diminished awareness of processes yielding identical 'outputs'

It has been proposed that incompatible intentions (e.g., to inhale and not inhale while holding one’s breath while underwater) are an essential ingredient of conscious conflict. Laboratory tasks such as the Stroop color naming task can instantiate conscious conflict innocuously. However, little research has explored what occurs subjectively at the other end of conflict, when intentions are harmonious. The hypothesis of synchrony blindness proposes that, during harmonious processing, not only may one not experience any conflict, but one may also be unaware that more than one process yielded the same intention/action plan. Accordingly, in the Stroop task, participants reported less of an urge to err (by reading) when words were presented in the congruent condition (e.g., RED presented in red) than when the very same words were presented in standard font color, suggesting that awareness of word-reading was diminished experimentally. The implications of this finding for theories about consciousness are discussed.     

Implicit processing of tactile information: evidence from the tactile change detection paradigm

People can maintain accurate representations of visual changes without necessarily being aware of them. Here, we investigate whether a similar phenomenon (implicit change detection) also exists in touch. In Experiments 1 and 2, participants detected the presence of a change between two consecutively-presented tactile displays. Tactile change blindness was observed, with participants failing to report the presence of tactile change. Critically, however, when participants had to make a forced choice response regarding the number of stimuli presented in the two displays, their performance was significantly better than chance (i.e., implicit change detection was observed). Experiment 3 demonstrated that tactile change detection does not necessarily involve a shift of spatial attention toward the location of change, regardless of whether the change is explicitly detected. We conclude that tactile change detection likely results from comparing representations of the two displays, rather than by directing spatial attention to the location of the change.     

Understanding the Moral Phenomenology of the Third Reich

This paper discusses the issue of German moral responsibility for the Holocaust in the light of the thesis of Daniel Goldhagen and others that inherited negative stereotypes of Jews and Jewishness were prime causal factors contributing to the genocide. It is argued that in so far as the Germans of the Third Reich were dupes of an 'hallucinatory ideology,' they strikingly exemplify the 'paradox of moral luck' outlined by Thomas Nagel, that people are not morally responsible for what they are and are not responsible for. The implications of this paradox for the appraisal of German guilt are explored in relation to the views of a number of recent writers on the Holocaust.