A discrimination analysis of training-structure effects on stimulus equivalence outcomes.

Experiments designed to establish stimulus equivalence classes frequently produce differential outcomes that may be attributable to training structure, defined as the order and arrangement of baseline conditional discrimination training trials. Several possible explanations for these differences have been suggested. Here we develop a hypothesis based on an analysis of the simple simultaneous and successive discriminations embedded in conditional discrimination training and testing within each of the training structures that are typically used in stimulus equivalence experiments. Our analysis shows that only the comparison-as-node (many-to-one) structure presents all the simple discriminations in training that are subsequently required for consistently positive outcomes on all tests for the properties of equivalence. The sample-as-node (one-to-many) training structure does not present all the simple discriminations required for positive outcomes on either the symmetry or combined transitivity and symmetry (equivalence) tests. The linear-series training structure presents all the simple discriminations required for consistently positive outcomes on tests for symmetry, but not for symmetry and transitivity combined (equivalence) or transitivity alone. Further, the difference in the number of simple discriminations presented in comparison-as-node training versus the other training structures is larger when the intended class size is greater than three or the number of classes is larger than two. We discuss the relevance of this analysis to interpretations of stimulus equivalence research, as well as some methodological and theoretical implications.     

An examination of the effects of adult age on explicit and implicit learning of figural sequences

Memory for previously learned figural sequences and item-to-item covariations within figural sequences was examined under explicit and implicit instructional conditions in three age groups: young adults (17-23 years); middle-aged adults (35-45 years); and older adults (55-65 years). In Phase 1 of the experiment, the acquisition phase, half the subjects in each age group learned sequences of three to eight items in which the item-to-item changes conformed to an artificial grammar, and the other half of the subjects in each age group learned strings in which the item-to-item changes were nongrammatical. In Phase 2, the implicit/explicit test phase, subjects made forced-choice judgments about parts of the strings that they learned in Phase 1, under either explicit or implicit instructions. Analyses of Phase 2 data revealed that subjects in both instructional conditions used item-to-item covariations in making decisions about grammatical strings. However, use of previously learned covariations as well as the number of correct judgments about previously learned strings was greater in the explicit condition than in the implicit condition. An age-related deficit was found for explicit recognition of grammar-following sequences.     

Conflict Aversion: Preference for Ambiguity vs Conflict in Sources and Evidence

This research investigates preferences and judgments under ambiguous vs conflicting information. Three studies provided evidence for two major hypotheses: (1) Conflicting messages from two equally believable sources are dispreferred in general to two informatively equivalent, ambiguous, but agreeing messages from the same sources (i.e., conflict aversion); and (2) conflicting sources are perceived as less credible than ambiguous sources. Studies 2 and 3 yielded evidence for two framing effects. First, when the outcome was negative, subjects' preferences were nearly evenly split between conflict and ambiguity, whereas a positive outcome produced marked conflict aversion. Second, a high probability of a negative outcome or a low probability of a positive one induced conflict preference. However, no framing effects were found for source credibility judgments. Study 3 also investigated whether subject identification with a source might affect preferences or credibility judgments, but found no evi dence for such an effect. The findings suggest cognitive and moti vational explanations for conflict aversion as distinct from ambi guity aversion. The cognitive heuristic is that conflict raises suspicions about whether the sources are trustworthy or credi ble. The motivational explanation stems from that idea that if sources disagree, then the judge not only becomes uncertain but also must disagree with at least one of the sources, whereas if the sources agree then the judge may agree with them and only has to bear the uncertainty.     

One extreme or the other or perhaps the golden mean? Issues of spatial resolution in face processing

The findings of some of the key studies that have examined the contribution of different bands of spatial information, specified in terms of cycles per face, to face recognition, and identification are reviewed. Based on findings from studies of low-, high-, and band-pass filtering, it is concluded that neither low facial scales nor high facial scales are optimal. Instead, a center range of facial scales, approximately 8-16 cycles per face, appears to make the greatest contribution to the recognition process. A study of identification of band-pass filtered faces is reported that reinforces the view derived from the literature. This indicated that a band with a harmonic mean of 11.1 cycles per face provided the most efficient recognition, with speed and accuracy declining at lower and higher bands.     

Predictors of Self-Reported Anxiety and Panic Symptoms: An Evaluation of Anxiety Sensitivity, Suffocation Fear, Heart-Focused Anxiety, and Breath-Holding Duration

The purpose of this study was to examine the extent to which anxiety-related individual difference variables predict anxious responding when individuals experience aversive bodily sensations. Thus, we explore several psychological and behavioral predictors of response to a single 25-sec inhalation of 20% carbon dioxide-enriched air in 70 nonclinical participants. Predictor variables included anxiety sensitivity, suffocation fear, heart-focused anxiety, and breath-holding duration. Multiple regression analyses indicated that only anxiety sensitivity significantly predicted postchallenge panic symptoms, whereas both anxiety sensitivity and suffocation fear predicted postchallenge anxiety. These data are in accord with current models of panic disorder that emphasize the role of fear of fear in producing heightened anxiety and panic symptoms and help clarify specific predictors of anxiety-related responding to biological challenge.     

Counter-stereotypical impulsivity and violence among African American college men

The study examined the relationship between impulse control and violence in terms of past feelings and acts among African American males enrolled in Historically Black Colleges and Universities. Data were gathered from a sample of 1,874 male undergraduates in eleven colleges and universities with predominantly African-American students. Less than six percent were classified as impulsive, and even less than half of the impulsive males had past feelings and acts of violence. The study offers strategies for impulse control which may help to further minimize incidents of violence on the college campus.     

Moral Incapacity and Deliberation

Was Luther avowing a genuine moral incapacity when he claimed that he could do no other? Bernard Williams has distinguished moral from psychological incapacity in terms of deliberation. There are three particular difficulties for the notion: in addition to (1) scepticism about whether the agent is genuinely incapable, there are (2) the possibility of conflicting moral incapacities, and (3) apparent cases where there is no actual or possible deliberation. If (1) can be countered, (2) can be met by ceteris paribus clauses, and it is shown that these do not remove the element of necessity. And (3) can be met by showing how possible deliberation is involved in putative counter-examples. Williams' account needs to be augmented to deal with cases of the morally unthinkable, and refined to allow for incipient attempts to do the morally impossible     

Effects of Directed Thinking on Intentions to Engage in Beneficial Activities: Actions Versus Reasons1

An important application of psychological principles involves increasing intentions to engage in activities that, although admittedly beneficial, are often not initially appealing (e.g., studying, quitting smoking, dieting). The present study tests the utility of directed thinking as a tool for eliciting intentions to engage in such activities. Undergraduate students were directed to think either about the reasons why people should find studying enjoyable or about the actions that people might take to make studying enjoyable. Regardless of whether they thought as individuals or in cooperating dyads, students who thought about actions later reported greater intentions to spend time studying than did students who thought about reasons. The results have both theoretical and practical significance.     

Vienna Indeterminism: Mach,Boltzmann, Exner

The present paper studies a specific way of addressing the question whether the laws involving the basic constituents of nature are statistical. While most German physicists, above all Planck, treated the issues of determinism and causality within a Kantian framework, the tradition which I call Vienna Indeterminism began from Mach’s reinterpretation of causality as functional dependence. This severed the bond between causality and realism because one could no longer avail oneself of a priori categories as a criterion for empirical reality. Hence, an independent reality criterion had to be sought, a problem which all three physicists to be studied solved in different ways that were mainly conditioned by their different concepts of probability. In order to prevent a dissipation of intuited facts, Mach had to resort to a principle of unique determination as his reality criterion, especially when discussing the Principle of Least Action. Giving theories more independence, Boltzmann understood atomism as property reduction to precisely defined theoretical entities and their interactions. While this served as a relative reality criterion, he also advocated a constructivist one because atomism was already implied by our finitary reasoning power. Finally, Exner contemplated the idea that all apparently deterministic laws are only a macroscopic limit of an irreducible indeterminism, because by adopting the frequency interpretation, observable collectives could be considered as the real basic entities. This revised version was published online in June 2006 with corrections to the Cover Date.