On the scaling of visual space from motion—in response to Pizlo and Salacfa-Golyska

Pizlo and Salack-Golyska (1994) have raised an important question about the validity of the interpretation of experiments reported by Lappin and Love (1992)—based on the fact that alternative cues in the image plane might have supported the shape discriminations in those experiments. The meaning of the hypothesis that visual space may be scaled by congruence under motion is clarified, pertinent evidence is reviewed, and new experimental evidence is reported We conclude that visual space can be metrically scaled by congruence of moving shapes.     

Classical geometric illusion effects with nonclassical stimuli: Angular induction from decomposing lines into point arrays

Angular induction is the process by which one line segment can bias judgment of orientation and/or collinearity of another segment, and it has been established that the magnitude of error is a determinate function of the relative angle between the two. We examined how these known relationships are affected by decomposing the induction segment into an array of scattered points. The bias that was produced by such arrays was found to be consistent with a formal model of angular induction, with the strength of the effect decreasing as the scatter among the points was increased. This decline in strength was almost linear with a logarithmic transform of the dimensions of the stimulus array. We also evaluated the hypothesis that the induction stimulus is detected by one or more channels—for example, neurons—for which the sensitivity profiles are modeled as Gabor wavelets. The change in induction strength with increasing point scatter was not predicted by a single width of channel. However, the combined activity of an ensemble of channels that differed in width did match the perceptual effects if one also stipulated that each channel would respond maximally to a fine-line stimulus.     

Detachment and defeasibility in deontic logic

The purpose of the paper is to present a logical framework that allow to formalize a kind of prima facie duties, defeasible conditional duties, indefeasible conditional duties and actual (indefeasible) duties, as well as to show their logical interconnections.     

Reaction-anticipation transitions in human perception-action patterns

We investigated the hypothesis that reaction and anticipation in human perceptual-motor performance are two coordinative modes of a single pattern-forming dynamical system, rather than separate behaviors. Subjects coordinated the onset of finger flexions with visual metronome flashes in each of three patterns: reactive, synchronized, or syncopated. The stimulus frequency was progressively increased (0.125–1.375 Hz) or decreased (1.375-0.125 Hz) in small steps (0.125 Hz) every 10 cycles. We observed qualitative transitions in both the time interval between stimulus and corresponding action (Δt) and their relative phase (ø) at critical values of the stimulus frequency, corresponding to changes from ‘reactive-to-anticipatory’ and ‘anticipatory-to-reactive’ performance. Such transitions provide evidence of a single, multifunctional system, which can be adequately described by the dynamics of collective variables characterizing the respective perception-action patterns.     

Sentence processing: Evidence against the serial,independent stage assumption

The assumption that the processing stages involved in sentence comprehension are serially and independently executed was tested in two separate experiments using two new sentence types. One experiment was a sentence-picture verification task, the other was not. In Experiment I, subjects viewed sentences such as It's false that the dots are red and indicated, by pressing the appropriate response key, which of two colors would make the sentence true. In Experiment II, subjects verified sentences such as It isn't true that the dots aren't red against pictures of colored dots. On the strength of Sternberg's additive factor method, present findings challenge the validity of the serial, independent stage assumption, and results are alternatively discussed in terms of a capacity sharing model.This research was supported by PHS research grant MH 23401 to Sam Glucksberg, principal investigator.     

Forest lights: Notes on the conceptualization of the unconscious

Using the metaphor of lights appearing unexplained in the night, the author argues for a conceptualization of the unconscious based on a posture of trust and acceptance rather than one of fear and explanation.His last book,Idea and Experience, dealt with Husserl's project of phenomenology inIdeas I. He has recently completed another book,The Embers and the Stars: A Philosophical Inquiry into the Moral Sense of Nature.     

Zur Geschichte und gegenwärtigen Lage der Philosophie in der ČSR

Official Czech philosophy has been dominated by a mix of Engelsian philosophy of science and positivism, a combination explained in part by the survival of positivism in Czechoslovakia and the failure of analytic philosophy to make inroads into Czech thinking. However, due to Jan Patoka's influence in espousing the works of Husserl and Heidegger, there was an anthropologically oriented Marxism (K. Kosik) although its successes were greater abroad than in Czechoslovakia. A more neopositivistic variant (L. Tondl) of Marxism also appeared, but it was a short-lived phenomenon without purchase on mainstream philosophy.A certain renewal of Czech philosophy was evident before 1968, once again largely due to Patoka's influence. Foreign guests who took part in informally organized, often secret, seminars and discussion groups were very instrumental in spreading new ideas. Despite these positive occurrences, Czech philosophy is experiencing a crisis at the level of the middle generation of non-academic, philosophically competent intellectuals among whom sceptical and nihilist attitudes prevail. A rebirth of spirit may be in the offing if the recovery of the specific sense of the Czech Reformation's idea of truth is pursued.