The natural appearance of unnatural incline speed

In three experiments, college students provided judgments about a marble's speed along a nonlinear incline. Each experiment revealed widespread support for the slope-speed belief, a mistaken belief holding that an object's speed at any point depends on the slope at that point. In truth, an object's incline speed varies with its elevation. In Experiment 1, participants relied solely on a diagram. In Experiments 2 and 3, participants observed computer animations depicting the descent of a marble at speeds conforming to either the slope-speed belief or Newtonian theory, and they rated the slope-speed version as more "natural" than the correct version. The task in Experiment 1 gauged participants' consciously available knowledge, but the perceptual realism of the slope-speed animations suggests that the slope-speed belief is also held outside awareness. By contrast, virtually all previously identified false beliefs about motion appear unnatural once animated.     

Multiple-interval timing in rats: Performance on two-valued mixed fixed-interval schedules

Three experiments studied timing in rats on 2-valued mixed-fixed-interval schedules, with equally probable components, Fixed-Interval S and Fixed-Interval L (FI S and FI L, respectively). When the L:S ratio was greater than 4, 2 distinct response peaks appeared close to FI S and FI L, and data could be well fitted by the sum of 2 Gaussian curves. When the L:S ratio was less than 4, only 1 response peak was usually visible, but nonlinear regression often identified separate sources of behavioral control, by FI S and FI L, although control by FI L dominated. Data were used to test ideas derived from scalar expectancy theory, the behavioral theory of timing, and learning to time.     

Concurrent task effects on memory retrieval

Previous studies combining continuous free recall with a concurrent task have generally shown that concurrent tasks impose fairly negligible effects on memory retrieval. By contrast, dual-task studies employing either cued recall or semantic retrieval reveal gross memory impairment and suggest that retrieval is delayed by the centrally demanding phase of the concurrent tasks (i.e., response selection). To explore this conflict, subjects performed continuous free recall while carrying out a serial-choice#x2014; response time (RT) task, as in the previous free recall studies. Unlike these previous studies, however, the choice#x2014;RT task utilized arbitrary stimulus#x2014;response mappings in order to increase the proportion of time devoted to the centrally demanding response selection phase. Recall total was reduced significantly, and recall latency was slowed substantially.     

Pleasure, guilt and secretory immunoglobulin A

Before producing saliva samples for Immunoglobulin A assay, 30 subjects listed their pleasurable activities and rated them in terms of pleasure and guilt. Levels of Immunoglobulin A were higher in those subjects with high ratios of pleasure-guilt scores.     

Form Without Matter

Three different concepts of matter are identified: matter as what a thing is immediately made of, matter as stuff of a certain kind, and matter in the (dubious) sense of material 'substratum'. The doctrine of hylomorphism, which regards every individual concrete thing as being 'combination' of matter and form, is challenged. Instead it is urged that we do well to identify an individual concrete thing with its own particular 'substantial form'. The notions of form and matter, far from being correlative, are relatively independent. There is nothing absurd in the notion of form without matter . Matter provides neither a principle of individuation nor a criterion of identity for individual concrete things: their form alone provides both. Finally, a substance ontology which admits also the existence of particular qualities, or tropes, is to be preferred both to a substance ontology which denies the existence of tropes and to a pure trope ontology.     

Long-term positive and negative identity priming: Evidence for episodic retrieval

An episodic retrieval account of negative priming (Neill, 1997; Neill & Valdes, 1992) was evaluated in three experiments. Duringpractice, regular word pairs were presented to subjects differing numbers of times. The subjects named specific target words while they ignored specific distractor words. Following a 5-min retention interval, memory for practice was revealed:Test responses for target words exhibited positive priming that increased with increases in the number of times that the words had been attended. Test responses for distractor words exhibited either positive priming (Experiment 1) or negative priming (Experiments 2–3) that also increased with increases in the number of times that the words had been ignored. The type of priming that abstractors exhibited was determined by several contextual similarities between the practice environment, in which distractors were ignored initially, and the test environments, in which they were processed subsequently. Negative priming that spanned a 5-min interval, increased with increases in the number of times that a distractor was ignored, and was sensitive to contextual changes indicated that the direction of the effect was temporally backward because the test probe cued memory for earlier processing of the priming stimulus when the distractor had been ignored.     

When two memories can and cannot be retrieved concurrently

We examined whether two memories can be retrieved concurrently from long-term memory. In Experiment 1, the subjects recalled words, either from two categories—alternating between the two—or from just one category. In Experiment 2, the subjects recalled two words belonging to either the same category or different categories, and the category prompts for these two responses appeared either simultaneously or successively. The results of both studies are consistent with the view that two items from different categories must be retrieved serially, whereas two items from the same category can be retrieved in parallel.     

Entity, Identity and Unity

I propose a fourfold categorisation of entities according to whether or not they possess determinate identity-conditions and whether or not they are determinately countable. Some entities – which I call ‘individual objects’ – have both determinate identity and determinate countability: for example, persons and animals. In the case of entities of a kind K belonging to this category, we are in principle always entitled to expect there to be determinate answers to such questions as ‘Is x the same K as y?’ and ’How many Ks are there satisfying condition C?’, even if we may sometimes be unable in practice to discover what these answers are. But other entities apparently lack either determinate identity, or determinate countability, or both. In these terms I try to explain certain important ontological differences between familiar macroscopic objects and various rather more esoteric entities, such as the ‘particles’ of quantum physics, quantities of material stuff, and tropes or property instances. This revised version was published online in August 2006 with corrections to the Cover Date.