Simultaneous Discrimination Learning in Pigeons: Value of S - Affects the Relative Value of its Associated S+

In a simple simultaneous discrimination involving a positive stimulus (S+) and a negative stimulus (S-), it has been hypothesized that positive value can transfer from the S+ to the S- (thus increasing the relative value of the S-) and also that negative value can transfer from the S- to the S+ (thus diminishing the relative value of the S+; Fersen, Wynne, Delius, & Staddon, 1991). Evidence for positive value transfer has been reported in pigeons (e.g. Zentall & Sherburne, 1994). The purpose of the present experiments was to determine, in a simultaneous discrimination, whether the S- diminishes the value of the S+ or the Sis contrasted with the S+ (thus enhancing the value of the S+). In twoexperiments, we found evidence for contrast, rather than value transfer, attributable to simultaneous discrimination training. Thus, not only does the S+ appear to enhance the value of the S-, but the S appears to enhance rather than reduce the value of the S+.     

Report on work in progress: “Towards a new science of the human”

A multidisciplinary and global study of the evolutionary process of the universe in general and mankind in particular is proposed, drawing from both modern science, approached by taking into consideration its various interdependent aspects; and the study of western and eastern ancient traditions, which prove to have a common foundation that is the comprehension and the control of the evolutionary process itself.

Such a study will lead to the compilation of a “Corpus Unus” of the new science of the human, a science which does not belong to a race, a culture or an age, but is specific to the human being as such.

Such a science will imply the exploration of mankind and of the evolutionary process, and applying the results in a pragmatic way to the betterment of human beings, society, and universe.     

An Eye-tracking Analysis of the Effect of Prior Comparison on Analogical Mapping

The present research examined the effect of prior experience on the distribution of attention during judgments of analogical similarity. Identifying analogical similarity requires mapping a set of relations in one situation onto a matching set of relations in an analogous situation. Analogical mapping is difficult when the common relational structure is embedded in contexts with dissimilar surface features and irrelevant surface similarities. Prior comparison of analogs may help subjects find future relational correspondences and ignore surface similarity (Markman and Gentner 1993). In the present study, attention was measured with eye tracking, which was monitored while subjects rated the similarity of analogous scenes. Experimental but not control subjects had previously compared scenes with the same structure. Eye fixation data indicated that prior comparison did not affect attention to structure-relevant objects, but significantly reduced attention to irrelevant surface-similar objects. Scanning data showing that both groups scanned within scenes more than between scenes were consistent with structure-mapping models of analogy.     

“Hey,let me hold your guns for a while”: A qualitative study of messaging for firearm suicide prevention

A recommended component of suicide prevention is encouraging at‐risk individuals to voluntarily and temporarily reduce access to firearms and other lethal methods. Yet delivering counseling on the topic can be difficult, given the political sensitivity of firearm discussions. To support such counseling, we sought to identify recommended framing and content of messages about reducing firearm access for suicide prevention. Through qualitative interviews with firearm owners and enthusiasts, we identified key points for use in framing (identity as a gun owner, trust, voluntary and temporary storage, and context and motivation) and specific content (preference for “firearm” over “gun,” and legal issues such as background checks for transfers). These findings build on prior work and should enhance efforts to develop and deliver effective, acceptable counseling and—ultimately—prevent firearm suicide.     

Development of a single-code/default coding strategy in pigeons

We tested the hypothesis that pigeons could use a cognitively efficient coding strategy by training them on a conditional discrimination (delayed symbolic matching) in which one alternative was correct following the presentation of one sample (one-to-one), whereas the other alternative was correct following the presentation of any one of four other samples (many-to-one). When retention intervals of different durations were inserted between the offset of the sample and the onset of the choice stimuli, divergent retention functions were found. With increasing retention interval, matching accuracy on trials involving any of the many-to-one samples was increasingly better than matching accuracy on trials involving the one-to-one sample. Furthermore, following this test, pigeons treated a novel sample as if it had been one of the many-to-one samples. The data suggest that rather than learning each of the five sample-comparison associations independently, the pigeons developed a cognitively efficient single-code/default coding strategy.     

“work ethic” in pigeons: Reward value is directly related to the effort or time required to obtain the reward

Stimuli associated with less effort or with shorter delays to reinforcement are generally preferred over those associated with greater effort or longer delays to reinforcement. However, the opposite appears to be true of stimuli thatfollow greater effort or longer delays. In training, a simple simultaneous discrimination followed a single peck to an initial stimulus (S+_FR1 S−_FR1) and a different simple simultaneous discrimination followed 20 pecks to the initial stimulus (S+_FR20 S−_FR20). On test trials, pigeons preferred S+_FR20 over S+_FR1 and S−_FR20 over S−_FR1. These data support the view that the state of the animal immediately prior to presentation of the discrimination affects the value of the reinforcement that follows it. This contrast effect is analogous to effects that when they occur in humans have been attributed to more complex cognitive and social factors.     

The robustness of estimates of total indirect effects in covariance structure models estimated by maximum

The large sample distribution of total indirect effects in covariance structure models in well known. Using Monte Carlo methods, this study examines the applicability of the large sample theory to maximum likelihood estimates oftotal indirect effects in sample sizes of 50, 100, 200, 400, and 800. Two models are studied. Model 1 is a recursive model with observable variables and Model 2 is a nonrecursive model with latent variables. For the large sample theory to apply, the results suggest that sample szes of 200 or more and 400 or more are required for models such as Model 1 and Model 2, respectively.For helpful comments on a previous draft of this paper, we are grateful to Gerhard Arminger, Clifford C. Clogg, and several anonymous reviewers.     

Logical reasoning,world knowledge,and mental imagery: Interconnections in cognitive processes

To better understand the role of problem content in verbal reasoning, the effect of two aspects of problem representation on conditional reasoning was examined. Specifically, this study focused on the effect of availability of knowledge schemata and mental imagery on recognition of indeterminacy. Four groups of 20 adults solved syllogisms that varied in imagery value and in tendency to access knowledge schemata (assessed by ratings of the relatedness of antecedent and consequent clauses of premises). When problems both were high in imagery value and had related clauses, performance was significantly better on indeterminate syllogisms. Access to schemata may permit elaborative processing and the generation of counterexamples to invalid inferences; imagery may support representation of problems and generation of elaborative information in memory.