Haptic perception of wetness

In daily life, people interact with textiles of different degrees of wetness, but little is known about the mechanics of wetness perception. This paper describes an experiment with six conditions regarding haptic discrimination of the wetness of fabrics. Three materials were used: cotton wool, sponge-structured viscose and thin viscose. Two ways of touching were investigated: static touching, in which only thermal cues were available, and dynamic touching, in which additional mechanical cues were available. For dynamic touching, average Weber fractions for discrimination were around 0.3, whereas for static touching, they ranged from 0.34 to 0.63. The results show that people can make use of the additional mechanical cues to significantly improve their discrimination performance. There was no significant difference between Weber fractions for the three materials, showing that wetness can be judged as a separate perceptual quantity, independent of the material.     

Designs for studying the effectiveness of long-term psychoanalytic treatments: balancing level of evidence and acceptability to patients

Long-Term Psychoanalytic Treatments (LTPT) include both long-term psychoanalytic psychotherapy (LTPP) and psychoanalysis (PsAn). Current opinion seems to be that there is some evidence for the effectiveness of LTPP, but none for that of PsAn. This may be due in part to researchers not balancing the level of evidence of randomized controlled studies (RCTs), cohort studies, and pre-post studies with patients' acceptance of these various research designs used in studying the effectiveness of LTPT. After a review of the merits of eight possible control conditions for LTPT in RCTs and cohort studies, and a consideration of the limitations and merits of pre-post studies, it was found that RCTs pair high levels of evidence with limited degrees of patient acceptance, especially where PsAn is concerned. Cohort studies appear to provide at most a moderate level of evidence. Their acceptability is hardly better than that of RCTs, as it depends on the acceptability of control conditions similar to those of RCTs. The acceptability of pre-post studies is much better, but they can provide, at most, a moderate level of evidence. Apart from randomization, they can meet all methodological criteria for high-quality research (often they do not, but there are ways to correct this). In summary, in the long-term treatment of complex mental disorders with LTPT, RCTs often pair a high level of evidence with limited patient acceptance of the method. Compared to RCTs, cohort studies show a lower level of evidence without much gain in acceptability. Pre-post studies pair the highest level of acceptability with the lowest level of evidence of the three designs. Limited acceptability is not to be confused with no acceptability, nor moderate level of evidence with none.     

Walter the banker: the conjunction fallacy reconsidered

In a famous experiment by Tversky and Kahneman (Psychol Rev 90:293–315, 1983), featuring Linda the bank teller, the participants assign a higher probability to a conjunction of propositions than to one of the conjuncts, thereby seemingly committing a probabilistic fallacy. In this paper, we discuss a slightly different example featuring someone named Walter, who also happens to work at a bank, and argue that, in this example, it is rational to assign a higher probability to the conjunction of suitably chosen propositions than to one of the conjuncts. By pointing out the similarities between Tversky and Kahneman’s experiment and our example, we argue that the participants in the experiment may assign probabilities to the propositions in question in such a way that it is also rational for them to give the conjunction a higher probability than one of the conjuncts.     

The Distinction Between Quantitative and Qualitative Dimensions of Emotions: Clinical Implications

REBT theoreticians and practitioners describe two sets of emotions (and behaviors) as a reaction to adversity, whether these are functional or dysfunctional. This article deals with the ways in which REBT practitioners and theoreticians interpret these two sets of reactions, using either a quantitative or qualitative method. It favors the qualitative approach and illustrates it with a graphical representation of the two sets. The use of graphs turns out to be particularly useful for explaining certain phenomena to clients and for teaching novice practitioners. It also provides a framework for establishing an effective new thought or rational belief.     

Haptic pop-out of movable stimuli

When, in visual and haptic search, a target is easily found among distractors, this is called a pop-out effect. The target feature is then believed to be salient, and the search is performed in a parallel way. We investigated this effect with movable stimuli in a haptic search task. The task was to find a movable ball among anchored distractors or the other way round. Results show that reaction times were independent of the number of distractors if the movable ball was the target but increased with the number of items if the anchored ball was the target. Analysis of hand movements revealed a parallel search strategy, shorter movement paths, a higher average movement speed, and a narrower direction distribution with the movable target, as compared with a more detailed search for an anchored target. Taken together, these results show that a movable object pops out between anchored objects and this indicates that movability is a salient object feature. Vibratory signals resulting from the movable ball were found to be a reasonable explanation regarding the sensation responsible for the pop-out of movability.     

Prior Attitudes,Salient Value Similarity,and Dimensionality: Toward an Integrative Model of Trust in Risk Regulation1

Although it is widely recognized that trust plays an important role in people's responses to various risks, there is still considerable conceptual disagreement about the different aspects of trust. There are at least 3 different approaches to trust: (a) dimensional, (b) salient value similarity, and (c) associationist. Three British datasets on genetically modified food were used to test the plausibility of a causal model that integrates these approaches. It appears that value similarity can be predicted by a combination of prior attitudes and perceived attitudes of the other, and that value similarity precedes other important trust judgments. The study suggests that various risk‐relevant judgments are expressions of a more general attitude toward genetically modified food, and raises questions about the usefulness of detailed modelling.     

Delayed sensory feedback in the learning of a novel motor task

Summary Generally the therapeutical effect of EMG feedback is viewed in terms of the immediate contiguity between response and information. According to this view any feedback delay would deteriorate the result. In this article the validity of this notion has been investigated. Three groups of normal subjects were required to perform a difficult movement under three feedback conditions: immediate EMG feedback, delayed EMG feedback, and a control (no EMG feedback) condition. The results indicated a significant difference between the EMG feedback groups and the control condition. However, no such difference was found between the immediate and delayed feedback conditions. The results suggested that the immediacy of the feedback is not the main factor in EMG feedback, but the specificity of the information.This study was supported by Grant no. 15-35-03 from the Netherlands Organization for the Advancement of Pure Research     

Stuttering and anxiety: The difference between stutterers and nonstutterers in verbal apprehension and physiologic arousal during the anticipation of speech and non-speech tasks

To test if stressful anticipation of speech situations is a factor in eliciting stuttering behavior, the difference between 24 stutterers and 24 nonstutterers in verbal apprehension and physiologic activity was studied before and during speech tasks (reading and conversation), and nonspeech tasks (motor and intelligence task).Results indicate that the difference between stutterers and nonstutterers mainly were restricted to anxiety ratings assessed after each task. Heart rate, vasomotor responses, and electrodermal activity recorded before and during speech tasks were higher compared with the physiologic activity before and during nonspeech tasks but, unexpectedly, this was also the case for nonstutterers. It is concluded that stuttering is not elicited by anxiety.     

The orienting reaction during human eyelid conditioning following preconditioning exposures to the CS

Summary Two experiments on latent inhibition are described in which the electrodermal and alpha blocking components of the orienting reaction (OR) were measured during human eyelid conditioning. In the first experiment the 16 Ss in the experimental group received 20 CS pre-exposure trials. The OR habituated on those trials but reappeared fully after the first conditioning trial. Therefore, after that trial there was no difference in OR amplitude with a no pre-exposure control group. The two groups did not differ in conditioning performance either. In the second experiment two groups of 25 Ss received an equal number of CS pre-exposures but one group was conditioned during the performance of a masking task. This time the reappearance of the OR was only observed in the no-task group. The results of both experiments are discussed in relation to Sokolov's theory on the facilitative effect of the OR on conditioning.The author wishes to thank Ernest van Lieshout and Ad van Oirschot for running the experiments and for help in the data analysis