Visual asymmetry revisited: Mind wandering preferentially disrupts processing in the left visual field

An emerging theory proposes that visual attention operates in parallel at two distinct time scales – a shorter one (<1 s) associated with moment-to-moment orienting of selective visuospatial attention, and a longer one (>10 s) associated with more global aspects of attention-to-task. Given their parallel nature, here we examined whether these comparatively slower fluctuations in task-related attention show the same visual field asymmetry – namely, a right visual field bias – as often reported for selective visual–spatial attention. Participants performed a target detection task at fixation while event-related potentials (ERP) time-locked to task-irrelevant visual probes presented in the left and right visual fields were recorded. At random intervals, participants were asked to report whether they were “on-task” or “mind wandering”. Our results demonstrated that sensory attenuation during periods of “mind wandering” relative to “on-task”, as measured by the visual P1 ERP component at electrodes sites contralateral to the stimulus, was only observed for probes presented in the left visual field. In contrast, the magnitude of sensory gain in the right visual field was insensitive to whether participants were “on-task” or “mind wandering”. Taken together, our results support the notion that task-related attention at longer time scales and spatial attention at shorter time scales affect the same underlying mechanism in visual cortex.     

The experience of new sensorimotor contingencies by sensory augmentation

Embedded in the paradigm of embodied cognition, the theory of sensorimotor contingencies (SMCs) proposes that motor actions and associated sensory stimulations are tied together by lawful relations termed SMCs. We aimed to investigate whether SMCs can be learned by means of sensory augmentation. Therefore we focused on related perceptual changes. Subjects trained for 7 weeks with the feelSpace belt mapping information of the magnetic north to vibrotactile stimulation around the waist. They experienced substantial changes in their space perception. The belt facilitated navigation and stimulated the usage of new navigation strategies. The belt’s vibrating signal changed to a kind of spatial information over time while the belt’s appeal and perceived usability increased. The belt also induced certain emotional states. Overall, the results show that learning new SMCs with this relatively small and usable device leads to profound perceptual and emotional changes, which are fully compatible with embodied theories of cognition.     

Symptoms of Meares-Irlen/Visual Stress Syndrome in subjects diagnosed with Chronic Fatigue Syndrome

Several diagnostic symptoms of the visual-processing deficit Meares-Irlen/Visual Stress Syndrome are remarkably similar to symptom manifestations reported by individuals with chronic fatigue syndrome (CFS). We surveyed the specific incidences of nine widely-recognised symptoms of visual stress (VS) in a group of subjects (n = 20) previously diagnosed with CFS. The presence of each symptom of VS in the CFS group was compared to its respective presence in both an age and sex matched healthy comparison group (n = 46), and an age and sex matched group comprised of individuals (n = 14) diagnosed with VS. Results showed the frequencies of all nine VS symptoms in the CFS-diagnosed group to be significantly higher (p = .032 – p < .0005) than in the comparison group, with only two symptoms being statistically less frequent in the CFS group than in the VS-diagnosed group. The average number of VS symptoms reported by the CFS group was also significantly higher than the comparison group, yet not significantly different from the VS group. Thus, the occurrence of VS symptoms in subjects diagnosed with CFS appears to be far greater than previously reported, which in turn may indicate the interplay of some yet to be identified underlying factor(s) common to both conditions.     

Evaluation of the attentional capacities and working memory of early and late blind persons

Although attentional processes and working memory seem to be significantly involved in the daily activities (particularly during navigating) of persons who are blind and who use these abilities to compensate for their lack of vision, few studies have investigated these mechanisms in this population. The aim of this study is to evaluate the selective, sustained and divided attention, attentional inhibition and switching and working memory of blind persons. Early blind, late blind and sighted participants completed neuropsychological tests that were designed or adapted to be achievable in the absence of vision. The results revealed that the early blind participants outperformed the sighted ones in selective, sustained and divided attention and working memory tests, and the late blind participants outperformed the sighted participants in selective, sustained and divided attention. However, no differences were found between the blind groups and the sighted group in the attentional inhibition and switching tests. Furthermore, no differences were found between the early and late blind participants in this set of tests. These results suggest that early and late blind persons can compensate for the lack of vision by an enhancement of the attentional and working memory capacities.     

Infant patterns of reactivity to tactile stimulation during parent-child interaction

Touch is the primary modality infants use to engage with the world; atypical responses to tactile stimuli may indicate risk for disordered outcomes. The current study examined infants’ responses to tactile stimulation within parent-child interaction, adding to prior knowledge based on parent report. Nine-month-old infants (N = 497) were observed while parents painted and pressed infants’ hands and feet to paper to make designs. Positive and negative affect and gazing away, exploring, and resistance behaviors were coded. Latent Class Analysis of observed behaviors yielded four tactile response patterns partially consistent with current nosology for sensory processing patterns: Low Reactive, Sensory Overreactive, Sensory Seeking, and Mixed Over/Underreactive. To evaluate whether patterns made valid distinctions among infants, latent classes were examined in relation to parent-reported temperament. Infants in the Mixed Over/Underreactive class were rated higher in distress to limitations and activity level than other infants. Sensory processing patterns observed in parent-child interaction are consistent with those identified by parent-report and may be used in future research to elucidate relations with temperament and typical and atypical development.     

Stance time variability during stair stepping before and after total knee arthroplasty: A pilot study

The main objectives of this pilot study were to: (1) investigate stance time variability (STV) during stair stepping in older adults with osteoarthritis (OA) before and after total knee arthroplasty (TKA), and compare to an age- and sex-matched group of healthy controls with native knees and (2) evaluate the relationship between quadriceps strength and STV during stair stepping before and after TKA. A prospective, observational, pilot study was carried out on 13 individuals (15% male, mean age 62.71 ± 6.84 years) before and after TKA using an instrumented stairway, patient-reported outcomes, timed stair stepping test, and quadriceps strength measures. At 6-months post-operatively, STV during stair descent was significantly greater in the TKA-GROUP compared to the CONTROL-GROUP, but was not significantly different at 12-months compared to controls. There were no significant differences in STV for stair ascent between the pre- and post-operative visits, or compared to controls. There was a trend toward significance for the relationship between quadriceps strength and STV during stair ascent (P = 0.059) and descent (P = 0.073). Variability during stair stepping may provide an important, short-term rehabilitation target for individuals following TKA and may represent another parameter to predict declines in functional mobility.     

视觉单通道还是视听双通道?——通道效应的元分析

多媒体学习中的通道效应认为,学习者对"画面+声音解说"组成的视听双通道材料的识记或理解效果要好于"画面+视觉文本"组成的视觉单通道材料,而逆转通道效应则发现了与之相反的结果。针对以往研究缺陷,重新采用元分析技术,以保持测验和迁移测验作为结果变量,考察通道效应的稳定性。经文献检索、纳入与排除后,共获91篇符合元分析的文献。经数据事先合并处理后,保持测验上生成94个独立效应量(8088人),迁移测验上生成83个独立效应量(6664人)。主效应检验发现:视听双通道在保持测验(d=0.24)和迁移测验(d=0.25)上均显著高于视觉单通道;调节效应检验发现:呈现步调、画面动态性和材料时长在保持测验和迁移测验上均对通道效应起到调节作用,通道效应主要在系统步调(d_(保持)=0.43,d_(迁移)=0.44)、动态画面(d_(保持)=0.50,d_(迁移)=0.59)及短时材料(d_(保持)=0.38,d_(迁移)=0.33)条件下出现;所有结果均未发现逆转通道效应。结论认为:相比视觉单通道,当图文信息以视听双通道呈现时更有利于促进学习者对多媒体学习材料的识记和理解,支持了多媒体学习认知理论;呈现步调、画面动态性以及材料时长是通道效应的重要边界条件。     

The modal view of essence

According to the modal view, essence admits of reductive analysis in exclusively modal terms. Fine (1994) argues that modal view delivers an inadequate analysis of essence. This paper defends the modal view from Fine's challenge. This defense proceeds by examining the disagreement between Finean primitivists and Quinean eliminativists about essence. In order to model this disagreement, a distinction between essence and a separable concept, nature, is required. This distinction is then used to show that Fine's challenge is misdirected and therefore unsuccessful.     

Remarks on Bolzano's Conception of Necessary Truth

This essay presents a new interpretation of Bolzano's account of necessary truth as set out in §182 of the Theory of Science. According to this interpretation, Bolzano's conception is closely related to that of Leibniz, with some important differences. In the first place, Bolzano's conception of necessary truth embraces not only what Leibniz called metaphysical or brute necessities but also moral necessities (truths grounded in God's choice of the best among all metaphysical possibilities). Second, in marked contrast to Leibniz, Bolzano maintains that there is still plenty of room for contingency even on this broader conception of necessity.