Test of models of achromatic transparency

Consider an achromatic disk transparent on an achromatic background formed by two adjoining rectangles, with the common border of the rectangles dividing the disk in half. Current models of achromatic transparency contend that the perceived extent of transparency of the disk depends on the luminance contrast inside the disk and on the luminance contrast in the background outside the disk. Here, a model is proposed which contends that this perceived extent is determined only by the luminance contrasts inherent in the disk: inside the disk and between the disk and the background. Two experiments were designed to determine which luminance contrasts influence transparency. In the first experiment, subjects rated the perceived extent of transparency of the disk for different combinations of the luminances of the disk and of the background. The results strengthen the view that the perceived extent of transparency depends on the luminance contrasts inherent in the disk. In the second experiment, a test was made of the possibility that luminance contrasts between adjoining areas of the background outside the disk are nonessential for transparency. The results show that transparency occurred both when the areas of the background outside the transparent region adjoined one another and when they were separated, confirming that the perceived extent of transparency depended only on luminance contrasts between adjoining areas inherent in the disk.     

Phenomenal transparency in achromatic checkerboards.

The study explored the luminance relations that determine the occurrence of achromatic transparency in phenomenal surfaces on complex backgrounds. Let the luminances of the left and right parts of a transparent surface on a bipartite background and those of the left and right parts of the bipartite background be p and q and m and n, respectively. Metelli proposed that this surface looks transparent when the rule p < q if m < n (or p > q if m > n) is satisfied, and Masin and Fukuda that it looks transparent when the inclusion rule is satisfied, that is, when p epsilon (m, q) or q epsilon (p, n). These rules also apply to achromatic checkerboards formed by one checkerboard enclosed in another checkerboard. This study shows that only the inclusion rule correctly predicted the occurrence of transparency in these checkerboards.     

Biasing the pacemaker in the behavioral theory of timing

In the behavioral theory of timing, pacemaker rate is determined by overall rate of reinforcement. A two-alternative free-operant psychophysical procedure was employed to investigate whether pacemaker period was also sensitive to the differential rate of reinforcement. Responding on a left key during the first 25 s and on a right key during the second 25 s of a 50-s trial was reinforced at variable intervals, and variable-interval schedule values during the two halves of the trials were varied systematically. Responding on the right key during the first 25 s and on the left key during the second 25 s was not reinforced. Estimates of pacemaker period were derived from fits of a function predicted by the behavioral theory of timing to right-key response proportions in consecutive 5-s bins of the 50-s trial. Estimates of pacemaker period were shortest when the differential reinforcer rate most strongly favored right-key responses, and were longest when the differential reinforcer rate most strongly favored left-key responses. The results were consistent with the conclusion that pacemaker rate is influenced by relative reinforcer rate.     

SUSANNA AND THE PRE‐CHRISTIAN BOOK OF DANIEL: STRUCTURE AND MEANING1

The structure of the pre‐Christian book of Daniel as newly edited in Palestine in the first century B.C. is coherent, often symmetrical, and meaningful and was the version used by Jesus and the early Christians. Origen's and Jerome's reordering of the fourteen‐chapter book in conformity with the extant Hebrew, however, vitiated that structure. Susanna's account opened the pre‐Christian Palestinian version. That account inaugurates the themes of wisdom and judgment and provides the restoration of right order within the community in exile, a restoration essential for what transpires thereafter. Her experience is the first of four holy ordeals placed symmetrically in the first half of the book and framing the book as a whole. Significantly, the two chapters of Daniel most quoted in the Gospels are the ones that open the two halves of the book: Susanna, and the first vision of Daniel. Those two chapters are linked thematically and by diction, including the pair of unique phrases ‘[one grown] ancient of evil days' and ‘Ancient of Days’. Susanna exemplifies the experiences of the saints – suffering and then vindicated – and also, for the writers of the synoptic Gospels – the experiences of Jesus in his passion.     

Transient spatial attention and the perceived duration of brief visual events

This study was designed to explore the effects of transient attention—the stimulus-driven component of spatial attention—on the perceived duration of a brief visual event. Observers had to compare the duration of two disks presented successively within a single trial. The disks’ location and duration varied independently. One of these disks, the “attended disk”, was preceded by an attentional cue indicating the disk's location, attracting transient attention in advanced to the disk location. This attentional cue was either a typical onset cue (Experiments 1, 2, and 4) or a singleton cue (Experiment 3) that minimized the differences between the cues. The other disk, the “neutral disk”, was cued with a neutral cue that did not convey information regarding the disk location. We found that the attraction of transient attention to the location of the attended disk prolonged its perceived duration, but only when compared to brief nonattend stimuli.     

Common control by compound samples in conditional discriminations

We tested whether teaching control by single stimulus samples in conditional discriminations would result in common control of two-stimuli compound samples, and vice versa. In Experiment 1, 5 participants were first taught four single-sample conditional discriminations. The first conditional discrimination was as follows: given sample stimulus P1, select comparison stimulus A1 and not A2; given sample P2 select comparison A2 and not A1. The second conditional discrimination was as follows: given sample P1 select comparison B1 and not B2; given sample P2 select B2 and not B1. Different sample stimuli (Q1 and Q2) were used in the third and fourth conditional discriminations. Moreover, A1 and B1 were presented together as comparisons, such that, if Q1 was presented as the sample, A1 was correct and B1 was incorrect; and if Q2 was presented as the sample, B1 was correct and A1 was incorrect. A2 and B2 were also presented as comparisons. When Q1 was presented, A2 was correct and when Q2 was presented B2 was correct. After training with these four single stimulus sample discriminations, participants were tested with compound PQ samples presented with A1, A2, B1, and B2 as comparisons. If common control were established by the PQ stimuli, a participant would select A1 when P1Q1 was presented, A2 when P2Q1 was presented, B1 when P1Q2 was presented, and B2 when P2Q2 was presented. Such common control by PQ samples occurred in 4 of 5 participants. In Experiment 2, 4 participants were given reverse training. They were first taught to select the A1, A2, B1, and B2 stimuli in response to the appropriate PQ combinations and then probed on the single stimulus sample discriminations. All 4 participants were successful on this probe. Experiments 3 and 4 investigated the effects of teaching additional conditional discriminations with novel stimuli on subsequent transfer from the single-sample discriminations to performance on the compound-sample conditional discrimination.     

Further evidence of the invalidity of the magnitude estimation method

IntroductionThe magnitude estimation method is widely applied in diverse areas of psychology. However, Weiss (1972) found that this method may produce judgments that inaccurately represent subjective magnitudes: constructing the stimuli according to a factorial design allowed the bias caused by magnitude estimation to be exposed as a spurious divergence of factorial curves.ObjectiveThe present study experimentally compared magnitude estimation with graphic rating and ratio estimation. The comparison of magnitude estimation with graphic rating retested Weiss's finding. The comparison of magnitude estimation with ratio estimation explored the hypothesis that magnitude estimation may cause a divergence of factorial curves due to the requirement of magnitude estimation to multiply and divide numbers—both ratio estimation and magnitude estimation required participants to judge ratios, but only magnitude estimation required mental multiplication and division.MethodUsing a 3 × 4 factorial experimental design, an achromatic disk was presented concentrically with a larger achromatic square. The brightness of the disk varied with the luminance of the disk and, due to simultaneous contrast, with the luminance of the square. Three different groups of participants judged the brightness of the disk: one group by graphic rating, another by ratio estimation, and the third by magnitude estimation.ResultsIn accord with Weiss's results, graphic rating yielded roughly parallel factorial curves whereas magnitude estimation yielded diverging factorial curves. Ratio estimation also yielded roughly parallel factorial curves, supporting the hypothesis that the magnitude estimation task itself may cause divergence of factorial curves due to the requirement of this method to mentally multiply and divide numbers.ConclusionCaution should be taken in using magnitude estimation, especially in factorial experiments, because this method is likely to cause the researcher to make incorrect inferences about the functional relations between the variables involved in mental information integration. Ratio estimation yields a pattern of factorial curves essentially equivalent to that obtained by graphic rating.     

Left-right holistic integration of human bodies

Holistic integration of faces has been widely studied. More recently, investigations have explored whether similar processing is used for human bodies. Here we show that holistic processing, as measured by the composite task, does occur for bodies but is stronger for left and right halves than for top and bottom halves. We also found composite effects for left-right halves of inverted bodies. Standard composite effects were found for top halves of faces, tested as a control. We argue that our results suggest that holistic processing of faces and bodies might not exclusively occur for identification, but instead may also have evolved to aid communication and/or decisions about mate choice (through judging symmetry).     

The role of contrast in the perception of achromatic transparency: comment on Singh and Anderson (2002) and Anderson (2003)

M. Singh and B. L. Anderson proposed a perceptual theory of achromatic transparency in which the perceived transmittance of a perceived transparent filter is determined by the ratio of the Michelson contrast seen in the region of transparency to that of the background seen directly. Subsequently, B. L. Anderson, M. Singh, and J. Meng proposed that Michelson contrast should be replaced by perceived contrast in this theory. However, their experimental stimuli were nongeneric (i.e., special cases), and their observers had little choice in their matching strategy. Here, the author shows that both of their ratio-of-contrasts theories are incorrect and that problems with their theoretical analyses and experimental designs led them to conclude that mean luminance does not affect perceived transmittance when contrast is held constant. The author also shows that B. L. Anderson's (2003) transmittance anchoring principle is not valid when a transparent surface is perceived to penetrate rather than overlay another surface. Finally, the author shows that M. Singh's (2004) theoretical proof that the ratio-of-Michelson-contrasts theory accurately predicts lightness matching through transparency is incorrect.     

Cultural identity dynamics: Capturing changes in cultural identities over time and their intraindividual organization

Important life transitions – such as migration – have the potential to enrich one's sense of self, but they are also demanding and challenging. The current research investigates how cultural identities change and become configured over time among newly arrived international students and the social factors that predict these longitudinal changes. A four‐wave longitudinal study was conducted during international students' first year in their new country (N = 278). Multivariate hierarchical linear modeling analyses allowed us to unpack both baseline (between‐person) and intraindividual change (within‐person) effects. Whereas increased psychological need satisfaction via both the new and one's heritage cultural group predicted increased identity integration, greater discrimination (i.e., both at baseline and an increase over time) predicted increased compartmentalization and the predominance (categorization) of one identity over the others. Results are discussed in light of novel theoretical developments in the acculturation and identity change literatures.     

SHOULD A B‐THEORETIC ATHEIST FEAR DEATH?

This article discusses Robin Le Poidevin's proposal that a commitment to the B‐theory of time provides atheists with a reason to relinquish the fear of death. For the purposes of the article, I grant Le Poidevin's assertion that the B‐theory gives us a sense in which our lives are ‘eternally real’; but I deny that the B‐theorist is entitled to regard this as sufficient to furnish a reason to cease fearing death. This is because, according to the most prevalent B‐theoretic conception of our emotional attitudes, A‐theoretic (and not B‐theoretic) beliefs are sufficient to ground these attitudes. I discuss this B‐theoretic account of our emotions, which I call the Mellor–MacBeath model, and explain how it relates to the fear of death. I argue that, according to this model, the fear of death – in so far as it is a fear of one's personal annihilation – is warranted, and hence that, if Le Poidevin's proposal is to stand, then we must be given either a new B‐theoretic account of the connection between beliefs and emotions, or an account of why the fear of death is unlike other emotional attitudes.     

On the determinants of surface brightness

The brightness of an achromatic surface with luminance S on an achromatic background with luminance B varies with S, with B, and with the luminance step deltaL at the border of the surface. In agreement with previous findings indicating that the visual system can perform as a photometer, the results of the two experiments reported here show that S and B determined surface brightness independently of deltaL when the surface was adjacent to and when it was separated from the background. This finding suggests that surface brightness depends on the integration of neural signals representing magnitudes of absolute luminance. A weighted-average model of this integration is proposed.     

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.     

Visual impressions of interactions between objects when the causal object does not move

Stimuli were presented that consisted of a stationary row of black-bordered white rectangles. As observers watched, each rectangle in turn from left to right changed from white to black. The final rectangle did not change colour but moved off from left to right. The sequential colour change suggested motion from left to right, and observers reliably reported a visual impression that this illusory motion kicked or bumped the last rectangle, thereby making it move. The impression was stronger when the sequential colour change was faster, but was not significantly affected by the number of the rectangles in the row (ranging from 2 to 8). These results support the conclusion that neither contact nor motion of a causal object is necessary for a visual impression of causality to occur.     

Wittgenstein on Set Theory and the Enormously Big

Wittgenstein's conception of infinity can be seen as continuing the tradition of the potential infinite that begins with Aristotle. Transfinite cardinals in set theory might seem to render the potential infinite defunct with the actual infinite now given mathematical legitimacy. But Wittgenstein's remarks on set theory argue that the philosophical notion of the actual infinite remains philosophical and is not given a mathematical status as a result of set theory. The philosophical notion of the actual infinite is not to be found in the mathematics of set theory, only in a certain associated philosophy – what Wittgenstein calls a certain kind of “prose”.     

Pavlov and the mind-body problem

I. P. Pavlov claimed that the mind-body problem would ultimately be resolved by empirical methods, rather than by rational arguments. A committed monist, Pavlov was confronted by dualism in the case of an hysterical person. Under normal conditions, her body's left side was insensitive to pain, but when she was hypnotized, there was a reversal of her sensitivity to pain, with the right side becoming insensitive. Pavlov acknowledged that the divergence between stimulation and response suggested dualism, yet condemned his disciple G.P. Zelenyî as well as Charles S. Sherrington, for their dualistic tendencies. Pavlov's continuous adherence to monism is attributed to the influence of popular scientific books that he read during his adolescence. The books maintained that science was based upon monism. Pavlov proposed that by introducing the concept of emotions, an hysterical person's condition could be explained within the framework of his theory of higher nervous activity, thereby obviating the need to change his paradigm.     

Aquinas and the Natural Law

Recent decades have seen a shift away from the traditional view that Aquinas's theory of the natural law is meant to supply us with normative guidance grounded in a substantive theory of human nature. In the present essay, I argue that this is a mistake. Expanding on the suggestions of Jean Porter and Ralph McInerny, I defend a derivationist reading of ST I‐II, Q. 94, A. 2 according to which Aquinas takes our knowledge of the genuine goods of human life and their proper ordering to one another to be self‐evident only to the wise who are able to discern the truth about our God‐given human nature. I then show that this reading provides a better account of Aquinas's view than two recent alternatives: John Finnis's brand of inclinationism and Daniel Mark Nelson's virtue‐based interpretation.     

Hume on Mental Transparency

This article investigates Hume's account of mental transparency. In this article, I will endorse Qualitative Transparency – that is, the thesis that we cannot fail to apprehend the qualitative characters of our current perceptions, and these apprehensions cannot fail to be veridical – on the basis that, unlike its competitors, it is both weak enough to accommodate the introspective mistakes that Hume recognises, and yet strong enough to make sense of his positive employments of mental transparency. Moreover, Qualitative Transparency is also philosophically satisfying in providing good philosophical reason for why the mental states that are incorrigible should in fact be so.     

The Legacy of Neoplatonism in F. W. J. Schelling's Thought

F.W.J. Schelling, one of the essential thinkers in the development of German Idealism, formed his own thought not only in a critical dialogue with Kant's and Fichte's transcendentalism and Hegel's earlier conception of thinking, but also in an intensive discussion with Plato and Aristotle. Over and above that, Neoplatonism – especially Plotinus, Proclus and the Christian Dionysius the Areopagite – played a decisive role in Schelling's reception and transformation of ancient philosophy. Selecting the manifold aspects which could be reflected on in this field, I want to make plausible as a transcendental analogy to Plotinus' concept of self-knowledge Schelling's requirement for a raising-up and transformation of the finite 'I' into the form of the Absolute, whose central features converge with the goal of the Plotinian self – transformation of thought into a timeless self-thinking and its ground. A main part of this paper discusses Schelling's and Plotinus' concept of nature as a dynamic process constituted by an immanent 'creating theoria'. Furthermore we find in Schelling's theory of the Absolute as the 'utterly One' a union of Plotinus' notion of a pure One beyond Being with that of the reflexive self-presence of nous, so that this Absolute can be understood as an All-Unity which grounds and embraces all actuality – because it is in itself the most unifying self-affirmation or self-mediation. What follows is a reflection on the anagogical function of art, especially from the viewpoint of Plotinus' non-Platonic rehabilitation of art as an imitation of nature. The last perspectives focus on Schelling's concept of matter and emanation – as different from and at the same time coherent with that of Plotinus – and on Schelling's theory of an absolute self – willing will in connection with Plotinus' Enneads VI.8, 'On free will and the will of the One' as a causa sui.     

Connecting theory to fat talk: Body dissatisfaction mediates the relationships between weight discrepancy,upward comparison,body surveillance,and fat talk

The fat talk literature is meager in terms of offering theoretical explanations for women's self-disparaging communication. The research presented here sought to establish a relationship between three prominent body image theories – self-discrepancy theory, social comparison theory, and objectification theory – and fat talk by proposing body dissatisfaction as a potential mediating mechanism. Young adult women (N = 201) completed an online questionnaire. As predicted, results revealed that body dissatisfaction significantly mediated the relationships between weight discrepancy, upward comparison, body surveillance and fat talk. Effect size estimates indicated that the size of each indirect effect was medium in magnitude.