The missing-fundamental illusion at isoluminance.

The missing-fundamental illusion describes how a square wave with its fundamental Fourier component removed appears as a square wave. This illusion is normally explained with reference to the bandpass nature of the luminance-contrast-sensitivity function, together with a 'default-to-square-wave' rule. Since the chromatic-contrast-sensitivity function is low-pass, we should not expect a missing-fundamental illusion at isoluminance. Using a simultaneous-detection-and-identification paradigm to eliminate contrast as a cue to discrimination, we nevertheless found that chromatic missing fundamentals and square waves could not be separately identified at detection threshold: just under twice the contrast required to detect the stimuli was needed to identify them. To test whether this was due to insufficiently narrow chromatic-channel bandwidths, we measured detection and identification thresholds for chromatic F and 3F sine-wave gratings. In this case identification was possible almost at detection threshold, suggesting that channel bandwidth limitations were not the critical factor. It is suggested that the weak missing-fundamental illusion observed at isoluminance probably reflects the operation of mechanisms similar to those that are responsible for the chromatic Craik-Cornsweet illusion.     

THE ENTANGLED TRINITY,QUANTUM BIOLOGY,AND DEEP INCARNATION

By utilizing the concept of quantum decoherence, augmented by the novel theory of quantum Darwinism, to understand the transition from the quantum to the classical worlds, the scaling up of the concept of quantum entanglement2018 to the biological level offers a fascinating metaphor for the presence of the creative spirit in nature and the “flesh” of Incarnation. This in turn provides helpful theological metaphors for articulating divine presence at the level of life in theistic evolution, partially addressing the issue of evolutionary theodicy by supporting the concept of deep Incarnation. The point of understanding the Incarnation as deeply entangled enfleshment is that it brings the suffering of creation into the life of the Redeemer as well as the Creator, facilitating redemption and hope through the divine life.     

Christianity and Eudaimonia,Luck and Eudaimonism

I argue that Christians have at least two reasons to reject eudaimonism, interpreted as the view that attaining eudaimonia—or happiness—is what fulfills the moral life. First, I contend Christian conceptions of eudaimonia should encompass more than realized moral excellence and its requirements. Second, I claim Christians should construe the love at the heart of their moral life as fully realizable even if it is not evidently reciprocated. Both affirmations contradict eudaimonism by implying that eudaimonia depends on more than fulfilling the moral life—the former by rendering eudaimonia more subject to luck than eudaimonists can allow, the latter by depicting the moral life as less subject to luck than eudaimonists can accept. These affirmations also enable Christians to regard God’s love integral to eudaimonia apart from its role in realizing moral excellence and to deny all inability to attain eudaimonia manifests moral failure.     

The minimum contrast requirements for stereopsis.

A number of researchers have compared the contrast requirements for stereopsis with those for detection of the stereoscopic stimulus, but they have generally failed to allow for the fact that stereopsis requires a detectable stimulus in both eyes at the same time. It is argued that the most appropriate detection threshold for this comparison is that for simultaneous monocular detection (SMD) of the stereoscopic half images. Experiments in which this comparison threshold has been used are summarised and the hypothesis generated that, on using stimuli that are localised in both space and spatial frequency (e.g. Gabor patches or differences of Gaussians), a range of disparities can always be found over which contrast thresholds for depth identification are less than or equal to this SMD threshold (the SMD hypothesis). It is argued that the success of this hypothesis in describing data obtained with these stimuli is consistent with the notions of labelled lines for disparity sign and the size--disparity correlation. Last, experiments are reported in which contrast thresholds for stereoscopic depth identification (front/back) were measured with interocular differences in contrast. The data obtained are consistent with the presence of both inhibitory and excitatory interactions between the eyes when unequal monocular contrasts are presented. The implications of these results and the SMD hypothesis for theories of stereopsis and binocular function are discussed.