Using the analysis of covariance to increase the power of priming experiments.

Although priming paradigms are widely used in cognitive psychology, the statistical analyses typically applied to priming data may not be optimal. Conceiving of priming paradigms as change-from-baseline designs suggests that the analysis of covariance (ANCOVA), using baseline performance as the covariate, is a more efficient (i.e., powerful) analysis. Specifically, ANCOVA provides more powerful tests of 1) the presence of priming and 2) between-group differences in priming. In addition, for within-subject designs with multiple baseline conditions, ANCOVA may increase the power of within-subjects effects. Efficiency gains are demonstrated with a re-analysis of priming datasets from implicit memory research. It is suggested that similar gains may be realized in other areas of priming research. Important assumptions of this procedure, which must be evaluated for the appropriate application of ANCOVA, are discussed.     

An Inconsistency in the Knowledge Argument

I argue that Frank Jackson's knowledge argument cannot succeedin showing that qualia are epiphenomenal. The reason for this is that there is, given thestructure of the argument, an irreconcilable tension between his support for the claim thatqualia are non-physical and his conclusion that they are epiphenomenal. The source of the tensionis that his argument for the non-physical character of qualia is plausible only on theassumption that they have causal efficacy, while his argument for the epiphenomenal characterof qualia is plausible only on the assumption that they are non-physical. Since these two argumentscannot be combined coherently, the most Jackson's argument can establish is thatqualia are non-physical.     

Making Sense of Spin

‘Spin’ is a pejorative term for a ubiquitous form of communication. Spin is viewed by many as deceptive, and by others as bending or twisting the truth. But spin need not be deceptive and the metaphors are less than clear. The aim here is to clarify what spin is: spin is identified as a form of selective claim‐making, where the process of selection is governed by an intention to bring about promotional perlocutionary effects. The process of selection may pertain to aspects of some situation or phenomenon; or to the lexis used in making the claims. Not all selective promotional communication is spin. Spin involves a distinctive kind of dissociation between the speaker's first‐order interpretation and the constructed interpretation or claim offered to others. With these clarifications in place the discussion turns to the complex connections between spin, truthfulness and deception. Aspect‐selective spin can be truthful, and it need not be deceptive in its intentions or effects, but may risk deceiving audiences. Lexical spin is less readily truthful, and both forms of spin prudentially require a distinctive kind of concealment of the speaker's intentions. The account developed here does not address normative questions about whether, or how, spin might be wrong, but aims to provide a clear and adequate account of spin as a basis for addressing normative questions about spin.     

A specific calculating ability

We report two experiments that investigate the calculating strategy used by a low IQ savant to identify prime numbers. Hermelin and O'Connor (1990) had suggested previously that this subject may use a procedure first described by Eratosthenes to detect a prime number, namely, dividing a target number by all primes up to the square root of the target number and testing for a remainder. In the first experiment, we compare the reaction times of the savant to decide whether a number is prime with those of a control subject proficient in mathematical calculation. In addition, we measured the savant's speed of information processing using an inspection time task. We found that the reaction times of the savant, although generally faster, followed the same pattern of the control subject who reported using the Eratosthenes procedure. The savant's inspection time indicated that his speed of processing was far superior to that expected from someone of his IQ. In the second experiment, we measured the time it takes mathematics students to divide by different prime numbers and we also tested them on the prime identification task. We used their division times to simulate their performance on the prime number identification task under the assumption that they used the Eratosthenes procedure. We also simulated the reaction times that would result from a simple memory-based procedure for identifying primes. We found that the Eratosthenes simulation, in contrast to the memory simulation, provided a good fit to both the students' and the savant's reaction times. We conclude that the savant is using a complex computational algorithm to identify primes and suggest two explanations of how the apparent contradiction between his low general intelligence and his superior numerical ability might be resolved.