Bootstrap Confirmation Made Quantitative

Glymour’s theory of bootstrap confirmation is a purely qualitative account of confirmation; it allows us to say that the evidence confirms a given theory, but not that it confirms the theory to a certain degree. The present paper extends Glymour’s theory to a quantitative account and investigates the resulting theory in some detail. It also considers the question how bootstrap confirmation relates to justification.     

Rational emotive behavior therapy successes and failures: Eight personal perspectives

Eight experts in Rational Emotive Behavior Therapy (REBT) provided personal examples of their own successes and failures in applying REBT to themselves. The experts actively talked to themselves both rationally and irrationally. Understandably, there were far more shoulds, oughts, musts, and have to’s in the narratives in which the experts described when they failed to use REBT than when they succeeded in using REBT. Rational self-talk was more prevalent in the examples of how REBT was successfully used by the experts. Reprinted from Journal of Counseling & Development, Summer 2001, Volume 79. ACA. Reprinted with permission. No further reproduction authorized without written permission from the American Counseling Association.     

Joint attention,shared goals,and social bonding

There has recently been interest in the ways in which coordinated movements encourage coactors to feel socially closer to one another, but this has generally overlooked the importance of necessary precursors to this joint action. Here we target two low‐level behaviours involved in social coordination that may mediate a relationship between joint actions and social bonding, namely joint attention and shared goals. Participants engaged in a simple reaction time task while sitting next to a partner performing the same task. In a joint attention condition, both participants attended to stimuli presented on the same half of a computer screen, while in a control condition, they attended to opposite sides of the computer screen. Shared goals were manipulated by giving participants the instruction to keep below a threshold score for both individual response times and accuracy (individual goal), or their joint mean response time and accuracy (i.e., averaging their mean response time and accuracy with that of their partner: shared goal). Attending to the same side of the screen led to higher ratings on a composite social bonding index directed towards a partner, while shared goals did not cause any effects on partner ratings. Joint attention was sufficient to encourage social closeness with an interaction partner, which suggests that any activities which encourage attending to the same point in space could have some influence on how connected coactors feel about one another.     

Time and defeasibility in FIPA ACL semantics

Inferences about speech acts are often conditional, non-monotonic, and involve the issue of time. Most agent communication languages, however, ignore these issues, due to the difficulty to combine them in a single formalism. This paper addresses such issues in defeasible logic, and shows how to express a semantics for ACLs in order to make non-monotonic inferences on the basis of speech acts.     

Feedback type as a moderator of the relationship between achievement goals and feedback reactions

The aim of the current study is to shed new light on the inconsistent relationship between performance‐approach (PAp) goals and feedback reactions by examining feedback type as a moderator. Results of a field experiment (N = 939) using a web‐based work simulation task showed that the effect of achievement‐approach goals was moderated by feedback type. Relative to individuals pursuing mastery‐approach goals, individuals pursuing PAp goals responded more negatively to comparative feedback but not to task‐referenced feedback. In line with the hypothesized mediated moderation model, the interaction between achievement goals and feedback type also indirectly affected task performance through feedback reactions. Providing employees with feedback is a key psychological principle used in a wide range of human resource and performance management instruments (e.g., developmental assessment centres, multi‐source/360° feedback, training, selection, performance appraisal, management education, computer‐adaptive testing, and coaching). The current study suggests that organizations need to strike a balance between encouraging learning and encouraging performance, as too much emphasis on comparative performance (both in goal inducement and in feedback style) may be detrimental to employees' reactions and rate of performance improvement.     

Specifying theories of developmental dyslexia: a diffusion model analysis of word recognition

The nature of word recognition difficulties in developmental dyslexia is still a topic of controversy. We investigated the contribution of phonological processing deficits and uncertainty to the word recognition difficulties of dyslexic children by mathematical diffusion modeling of visual and auditory lexical decision data. The first study showed that poor visual lexical decision performance of reading disabled children was mainly due to a delay in the evaluation of word characteristics, suggesting impaired phonological processing. The adoption of elevated certainty criteria by the disabled readers suggests that uncertainty contributed to the visual word recognition impairments as well. The second study replicated the outcomes for visual lexical decision with formally diagnosed dyslexic children. In addition, during auditory lexical decision, dyslexics presented with reduced accuracy, which also resulted from delayed evaluation of word characteristics. Since orthographic influences are diminished during auditory lexical decision, this strengthens the phonological processing deficit account. Dyslexic children did not adopt heightened certainty criteria during auditory lexical decision, indicating that uncertainty solely impairs reading and not listening.     

Contrast effects in typicality judgements: A hierarchical Bayesian approach

We examine the influence of contrast categories on the internal graded membership structure of everyday concepts using computational models proposed in the artificial category learning tradition. In particular, the generalized context model (Nosofsky, 1986), which assumes that only members of a given category contribute to the typicality of a category member, is contrasted to the similarity-dissimilarity generalized context model (SD-GCM; Stewart & Brown, 2005), which assumes that members of other categories are also influential in determining typicality. The models are compared in a hierarchical Bayesian framework in their account of the typicality gradient of five animal categories and six artefact categories. For each target category, we consider all possible relevant contrast categories. Three separate issue are examined: (a) whether contrast effects can be found, (b) which categories are responsible for these effects, and (c) whether more than one category influences the typicality. Results indicate that the internal category structure is codetermined by dissimilarity towards potential contrast categories. In most cases, only a single contrast category contributed to the typicality. The present findings suggest that contrast effects might be more widespread than has previously been assumed. Further, they stress the importance of characteristics particular of everyday concepts, which require careful consideration when applying computational models of representation of the artificial category learning tradition to everyday concepts.     

Salient material properties and haptic volume perception: The influences of surface texture, thermal conductivity, and compliance

We investigated the influences of surface texture, thermal conductivity, and compliance on the haptic perception of the volume of small cubes. It was hypothesized that an object containing highly salient material properties would be perceived as larger in volume than the same object without these properties. Blindfolded subjects were asked to explore pairs of cubes differing in their material properties and to select the one with the larger volume. The results showed that, counterintuitively, a smooth cube was perceived as being significantly larger than a rough cube of the same physical volume, with average biases of about 19 %. Furthermore, cubes with a higher thermal conductivity were perceived as significantly larger than cubes with a lower thermal conductivity (average bias of about 7 %). In addition, the magnitude of the bias in this condition was not changed by increasing or decreasing the temperature of the test objects, suggesting that the effect of thermal conductivity could not be attributed directly to the heat flow. Finally, a hard cube was perceived as significantly larger than a soft cube of equal physical volume, with an average bias of about 25 %. These results reveal that the studied material properties have significant and consistent influences on the haptic perception of volume. The observed biases provide an indication of the levels at which the processing of haptic information on volume and material properties occurs.     

The speed and accuracy of perceptual decisions in a random-tone pitch task

Research in perceptual decision making is dominated by paradigms that tap the visual system, such as the random-dot motion (RDM) paradigm. In this study, we investigated whether the behavioral signature of perceptual decisions in the auditory domain is similar to those observed in the visual domain. We developed an auditory version of the RDM task, in which tones correspond to dots and pitch corresponds to motion (the random-tone pitch task, RTP). In this task, participants have to decide quickly whether the pitch of a “sound cloud” of tones is moving up or down. Stimulus strength and speed–accuracy trade-off were manipulated. To describe the relationship between stimulus strength and performance, we fitted the proportional-rate diffusion model to the data. The results showed a close coupling between stimulus strength and the speed and accuracy of perceptual decisions in both tasks. Additionally, we fitted the full drift diffusion model (DDM) to the data and showed that three of the four participants had similar speed–accuracy trade-offs in both tasks. However, for the RTP task, drift rates were larger and nondecision times slower, suggesting that some DDM parameters might be dependent on stimulus modality (drift rate and nondecision time), whereas others might not be (decision bound). The results illustrate that the RTP task is suitable for investigating the dynamics of auditory perceptual choices. Future studies using the task might help to investigate modality-specific effects on decision making at both the behavioral and neuronal levels.