Simultaneity constancy

Sound and light take different amounts of time to reach their respective receptors, to be transduced, and to be transmitted to the cortex. Their processing times also vary with factors such as intensity and retinal eccentricity. We assessed the capability of subjects to perceive simultaneity correctly despite these variations. Temporal asynchronies of up to 200 ms were introduced between the components of sound/light pairs. Using the method of constant stimuli, seven subjects judged which came first. Distance, and hence the times of arrival of paired visual and auditory targets, was varied from 1 to 32 m. Visual intensity was varied by viewing the target through 1.8 dB attenuating glasses, and a retinal eccentricity of 20 degrees was compared to central presentation. Despite large differences in reaction times, which varied in a predictable way with the stimulus parameters, the timing of sound/light pairings judged as simultaneous corresponded to when the light and sound left the source simultaneously. Almost complete compensation was found in all conditions tested, showing that these substantial but predictable variations in timing can be taken into account in creating simultaneity constancy.     

Simultaneity and sequence in the perception of apparent motion

Motion perception usually is accompanied by the phenomenological impression of sequence as objects move through successions of locations. Nonetheless, there is accumulating evidence that sequential information is neither necessary nor sufficient for perceiving motion. It is shown here that apparent motion is specified by counterchange rather than sequence—that is, by co-occurring toward- and away-from-background changes at two spatial locations, regardless of whether the changes are simultaneous or sequential. Motion is perceived from the location of the toward to the location of the away change, even when the changes occur in reverse temporal order. It is not perceived for sequences of away or toward changes, as would be expected if motion were specified by onset or offset asynchronicity. Results previously attributed to onset and offset asynchrony are instead attributable to onsets and offsets occurring in close temporal proximity at the same location. This was consistent with units for detecting away and toward changes that are temporally biphasic; that is, they are excited by changes in one direction and inhibited by immediately preceding or immediately following changes in the opposite direction. These results are accounted for by a model for counterchange-specified motion entailing the biphasic detection of toward and away changes.     

康德与根本恶

康德在18世纪80年代把自由意志视为一种善的意志,认为自由的同时又是恶的意志是不存在的。后来康德在《单纯理性限度内的宗教》中拒绝了这种看法,认为人身上有一种内在于自己Willkür的对恶的普遍倾向,即根本恶。这种根本恶从动机二元论角度也可以表述为人在采纳道德法则和幸福作为准则的动机时颠倒了它们之间的道德次序,禀赋在动机二元论中体现为道德法则和幸福,而倾向是对这两个动机之间的等级关系的表达。所有特殊的恶的准则都有一个最高的准则即Gesinnung,这个概念使根本恶成为既是与生俱有的,又是自由选择的结果,从而使根本恶可以被归责。     

Kant and the determinacy of intuition

A central issue in debates about Kant and nonconceptualism concerns the nature of intuition. There is sharp disagreement among Kant scholars about both whether, prior to conceptualization, mere intuition can be considered conscious and, if so, how determinate this consciousness is. In this article, I argue that Kant regards pre-synthesized intuition as conscious but indeterminate. To make this case, I contextualize Kant's position through the work of H.S. Reimarus, a predecessor of Kant who influenced his views on animals, infants, and the role of attention. I use Reimarus to clarify Kant's otherwise ambiguous commitments on the determinacy of intuition in animals and newborns, and the role attention, concepts, and judgment play in making intuited contents determinate. This contextualization helps to shed light on Kant's discussion of pre-synthesized intuition in the threefold synthesis of the A-Deduction by demonstrating that Kant's theory of mind in the deduction offers transcendental grounding for empirical accounts of infant development like Kant and Reimarus's. The upshot is a Kant at odds with many recent interpretations of his theory of mind: pre-synthesized intuition is conscious but indeterminate.     

Culture: Copying,Compression, and Conventionality

Through cultural transmission, repeated learning by new individuals transforms cultural information, which tends to become increasingly compressible (Kirby, Cornish, & Smith, 2008 ; Smith, Tamariz, & Kirby, 2013 ). Existing diffusion chain studies include in their design two processes that could be responsible for this tendency: learning (storing patterns in memory) and reproducing (producing the patterns again). This paper manipulates the presence of learning in a simple iterated drawing design experiment. We find that learning seems to be the causal factor behind the increase in compressibility observed in the transmitted information, while reproducing is a source of random heritable innovations. Only a theory invoking these two aspects of cultural learning will be able to explain human culture's fundamental balance between stability and innovation.     

Kant and Husserl

This paper was presented at the Kant-Congress held in Memphis, Tennessee in March, 1995.     

Kant and the Discipline of Reason

Kant's notion of ‘discipline’ has received considerable attention from scholars of his philosophy of education, but its role in his theoretical philosophy has been largely ignored. This omission is surprising since his discussion of discipline in the first Critique is not only more extensive and expansive in scope than his other discussions but also predates them. The goal of this essay is to provide a comprehensive reading of the Discipline that emphasizes its systematic importance in the first Critique. I argue that its goal is to establish a set of rules for the use of pure reason that, if followed, will mitigate and perhaps even eliminate our tendency to make judgments about supersensible objects. Since Kant's justification for these rules relies crucially on claims he has defended in the Doctrine of Elements, I argue further that, far from being a dispensable part of the Critique as commentators have tended to claim, the Discipline is, in fact, the culmination of Kant's critique of metaphysics.