Adaptive decision processes in perceptual comparisons: effects of changes in the global difficulty context

Adaptive decision processes were investigated in experiments involving an unexpected change in the global ease or difficulty of the task. Under accuracy stress, a shift from an easy to a difficult context induced a marked increase in decision time, but a shift from a difficult to an easy context did not. Under speed stress, a shift to a more difficult context induced lower accuracy and rated confidence, depending on the difficulty of the decisions. A view of caution developed in D. Vickers's (1979) accumulator theory--whereby one seeks to base decisions on more information--is compared with a view based on slow and fast guessing theory (W. M. Petrusic, 1992; W. M. Petrusic & J. V. Baranski, 1989a)--whereby one seeks to base decisions on more diagnostic information. On balance, the findings support the latter view.     

T-junctions,apparent depth,and perceived lightness contrast

Observers performed lightness matches for physically equivalent gray targets of a simultaneous lightness contrast display and displays in which both targets were on the same background. Targets either shared a common line-texture pattern with their respective backgrounds or did not. Results indicate that when targets share a line-texture pattern with their respective backgrounds, a contrast effect is obtained. However, when the target's pattern is different than the background's pattern, perceived contrast is significantly reduced and the target appears as a separate 3-D entity. This result applies to both vertically and horizontally oriented displays, to targets that are increments or decrements, and to line-texture patterns that are black or white. Line patterns that are shared by targets and backgrounds result in T-junctions that provide occlusion information. We conclude that targets and backgrounds perceived to be on separate planes because of T-junctions are less likely to be perceptually grouped together and that their luminance values are less likely to be compared with one another.     

Who are the comorbid adolescents? Agreement between psychiatric diagnosis,youth, parent,and teacher report

The investigators examined the rates of psychiatric comorbidity for externalizing and internalizing behavior problems, using semistructured diagnostic interview and parent, teacher, and youth report on the Achenbach checklists. The study also evaluated the effects of conjunctive, compensatory, and disjunctive data combination strategies. Using the same data and identical diagnostic thresholds, between 5 and 74% of 189 youths presenting to an outpatient clinic were identified as having comorbid internalizing and externalizing problems. Parent report and semistructured interview indicated the highest comorbidity rates. Despite good cross-source agreement (rs .29–.58), there was very little agreement about which specific youths presented with comorbid internalizing and externalizing problems (kappas .14–.40). Results also indicate that single DSM-IV disorders, such as bipolar disorder, can manifest comorbid patterns of behavior problems on checklists.     

Effects of Defendant Ethnicity on Juries' Dispositions of Felony Cases1

This research examined jury decisions in 317 noncapital felony cases in El Paso, Texas, and assessed the impact of juror ethnicity on jury trial outcomes. Results revealed that there was no relation between defendant ethnicity and the probability of conviction. Anglo American defendants, however, received sentences that were approximately twice as severe as Hispanic defendants. Sentences imposed by juries were significantly related to defendant ethnicity and type of crime for which they were tried. Sentences were also influenced by defendant ethnicity in interaction with jury ethnic composition. Important differences appeared when there was a critical mass of 6 or more Hispanics on juries. This study, using criminal court data, provides a unique opportunity to examine the utility of social psychological theories for understanding actual trial outcomes.     

Propositions,Numbers, And The Problem Of Arbitrary Identification

Those inclined to believe in the existence of propositions as traditionally conceived might seek to reduce them to some other type of entity. However, parsimonious propositionalists of this type are confronted with a choice of competing candidates – for example, sets of possible worlds, and various neo-Russellian and neo-Fregean constructions. It is argued that this choice is an arbitrary one, and that it closely resembles the type of problematic choice that, as Benacerraf pointed out, bedevils the attempt to reduce numbers to sets – should the number 2 be identified with the set Ø or with the set Ø, Ø? An “argument from arbitrary identification” is formulated with the conclusion that propositions (and perhaps numbers) cannot be reduced away. Various responses to this argument are considered, but ultimately rejected. The paper concludes that the argument is sound: propositions, at least, are sui generis entities.

     

Perception of the Mccolloch Effect Correlates with Activity in Extrastriate Cortex: A Functional MagneticResonance Imaging Study

The McCollough effect is a striking color aftereffect that is linked to the orientation of the patterns used to induce it. To produce the McCollough effect, two differently oriented grating patterns, such as a red-and-black vertical grating and a green-and-black horizontal grating, are viewed alternately for a few minutes. After such colored gratings are viewed, the white sections of avertical black-and-white test grating appear to be tinged with green, and the white sections of a horizontal grating appear to be tinged with pink. We present evidence from a functional magnetic resonance imaging study that the perception of the McCollough effect correlates with increased activation in the lingual and fusiform gyriùextrastriate visual areas that have been implicated in color perception in humans.     

Measuring counsellor theoretical orientation

Previous studies of counsellors' and psychotherapists' theoretical orientations have suggested the importance of two superordinate dimensions of beliefs about therapeutic practice: an analytical-experiential dimension and an objective-subjective dimension. A 40-item measure was developed which tapped both these. A study involving 132 counsellors found evidence that the Counsellor Theoretical Position Scale is a reliable and valid measure of important aspects of theoretical orientation to counselling practice.     

A Renewed Interest in Human Classical Eyeblink Conditioning

Abstract—Over the past few years, a number of publications have reported the results of a variety of human classical eyeblink conditioning experiments. This renewed interest in human classical eyeblink conditioning appears to be caused by several factors, including the preference by some researchers to observe and report on behavior directly, the discovery that eyeblink conditioning can be used to assess basic biological and psychological processes, recent success in using eyeblink conditioning to determine the cause and expression of brain pathologies, and the successful use of this simple behavioral procedure in human imaging and electrophysiological experiments.