The present experiment developed a methodology for assessing sensitivity of conditional-discrimination performance to within-session variation of reinforcer frequency. Four pigeons responded under a multiple schedule of matching-to-sample components in which the ratio of reinforcers for correct S[subscript 1] and S[subscript 2] responses was…

The interresponse-time structures of pigeon key pecking were examined under variable-ratio, variable-interval, and variable-interval plus linear feedback schedules. Whereas the variable-ratio and variable-interval plus linear feedback schedules generally resulted in a distinct group of short interresponse times and a broad distribution of longer…

This paper is a brief summary of an "open-ended" physics experiment that gave my students a glimpse of what real physics research is like. They found it to be both fun and challenging. The subject of the experiment is the well-known Diet Coke and Mentos reaction. A more detailed description of the experimental results has been published elsewhere.

The authors previously described a procedure that permits rapid, multiple within-participant evaluations of contingency assessment (the "streamed-trial" procedure, M. J. C. Crump, S. D. Hannah, L. G. Allan, & L. K. Hord, 2007). In the present experiments, they used the streamed-trial procedure, combined with the method of constant stimuli and a…

Theories of figure-ground perception entail inhibitory competition between either low-level units (edge or feature units) or high-level shape properties. Extant computational models instantiate the 1st type of theory. The authors investigated a prediction of the 2nd type of theory: that shape properties suggested on the ground side of an edge are…

Conjoint choice experiments are used widely in marketing to study consumer preferences amongst alternative products. We develop a class of choice models, belonging to the class of Poisson race models, that describe a "random utility" which lends itself to a process-based description of choice. The models incorporate a dependence structure which…

Coherence plays a central role when readers construct meaning from a text. Previous research has shown how coherence marking affects text processing and representation. However, this effect seems to depend on reader's prior knowledge of the text content: Low knowledge readers benefit from coherence marking, whereas high knowledge readers benefit…

The working memory model for Ease of Language Understanding (ELU) predicts that processing differences between language modalities emerge when cognitive demands are explicit. This prediction was tested in three working memory experiments with participants who were Deaf Signers (DS), Hearing Signers (HS), or Hearing Nonsigners (HN). Easily nameable…

Reports a retraction of "Hierarchical encoding of behavior: Translating perception into action" by Bridgette Martin Hard, Sandra C. Lozano and Barbara Tversky (Journal of Experimental Psychology: General, 2006[Nov], Vol 135[4], 588-608). All authors retract this article. Co-author Tversky and co-author Hard believe that the research results cannot…

Participants searched a visual display for a target among distractors. Each of 3 experiments tested a condition proposed to require attention and for which certain models propose a serial search. Serial versus parallel processing was tested by examining effects on response time means and cumulative distribution functions. In 2 conditions, the…

In previous work the authors argued that the potential number of effectors in the response set is crucial in discriminating (multiple-effector) keypress from (single-effector) reaching responses. It is not clear, however, what influence the locus of responding (on vs. off the stimulus location for reaching and keypressing, respectively) has on…

This article describes a novel experiment focused on metal ion hydrolysis and the equilibria related to metal ions in aqueous systems. Using [superscript 27]Al NMR, the students become familiar with NMR spectroscopy as a quantitative analytical tool for the determination of aluminum by preparing a standard calibration curve using standard aluminum…

Three experiments investigated whether production of low-frequency spellings could be influenced by other words containing those spellings. Participants saw visually-presented primes (Experiment 1) or heard primes presented auditorily and produced their spelling (Experiments 2 and 3). Primes either shared both orthography and phonology (e.g.,…

To establish a series of derived relations between arbitrary stimuli, 20 subjects were exposed to nonarbitrary and arbitrary relational training and testing procedures. Subjects were then exposed to an avoidance conditioning procedure in which one member from each relation was established as a discriminative stimulus for avoidance and…

This lesson can be used at the beginning of the year to teach students how to conduct inquiries using the essential features described in "Inquiry and the National Science Education Standards" (NRC 1996). The lesson is divided into several activities which may be spread over several days or interspersed with your other beginning-of-the-year…