Perceptual grouping in haptic search: The influence of proximity, similarity, and good continuation

We conducted a haptic search experiment to investigate the influence of the Gestalt principles of proximity, similarity, and good continuation. We expected faster search when the distractors could be grouped. We chose edges at different orientations as stimuli because they are processed similarly in the haptic and visual modality. We therefore expected the principles of similarity and good continuation to be operational in haptics as they are in vision. In contrast, because of differences in spatial processing between vision and haptics, we expected differences for the principle of proximity. In haptics, the Gestalt principle of proximity could operate at two distinct levels-somatotopic proximity or spatial proximity-and we assessed both possibilities in our experiments. The results show that the principles of similarity and good continuation indeed operate in this haptic search task. Neither of our proximity manipulations yielded effects, which may suggest that grouping by proximity must take place before an invariant representation of the object has formed. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Discriminating famous from fictional names based on lifetime experience: evidence in support of a signal-detection model based on finite mixture distributions

It is widely accepted that signal-detection mechanisms contribute to item-recognition memory decisions that involve discriminations between targets and lures based on a controlled laboratory study episode. Here, the authors employed mathematical modeling of receiver operating characteristics (ROC) to determine whether and how a signal-detection mechanism contributes to discriminations between moderately famous and fictional names based on lifetime experience. Unique to fame judgments is a lack of control over participants' previous exposure to the stimuli deemed "targets" by the experimenter; specifically, if they pertain to moderately famous individuals, participants may have had no prior exposure to a substantial proportion of the famous names presented. The authors adopted established models from the recognition-memory literature to examine the quantitative fit that could be obtained through the inclusion of signal-detection and threshold mechanisms for two data sets. They first established that a signal-detection process operating on graded evidence is critical to account for the fame judgment data they collected. They then determined whether the graded memory evidence for famous names would best be described with one distribution with greater variance than that for the fictional names, or with two finite mixture distributions for famous names that correspond to items with or without prior exposure, respectively. Analyses revealed that a model that included a d' parameter, as well as a mixture parameter, provided the best compromise between number of parameters and quantitative fit. Additional comparisons between this equal-variance signal-detection mixture model and a dual-process model, which included a high-threshold process in addition to a signal-detection process, also favored the former model. In support of the conjecture that the mixture parameter captures participants' prior experience, the authors found that it was increased when the analysis was restricted to names in occupational categories for which participants indicated high exposure.     

Description of an Intensive Dialectical Behavior Therapy Program for Multidiagnostic Clients With Eating Disorders

The authors describe an intensive outpatient dialectical behavior therapy (DBT) program for multidiagnostic clients with eating disorders who had not responded adequately to standard, empirically supported treatments for eating disorders. The program integrates DBT with empirically supported cognitive behavior therapy approaches that are well established for the treatment of eating disorders. Attention is given to inclusion and exclusion criteria, how the program differs from standard treatments for eating disorders, and the application of specific DBT treatment components for multidiagnostic clients with eating disorders.     

Knowledge and use of memory strategies in amnestic mild cognitive impairment

Despite the inclusion of memory strategy training in many interventions for amnestic mild cognitive impairment (aMCI), little research has directly examined knowledge and use of memory strategies in aMCI and their relationship to memory performance in order to guide the development of targeted interventions. The present study aimed to compare strategy knowledge and use between an aMCI and a healthy older adult (HOA) sample, and to determine the contribution of strategy knowledge and use to memory performance in each of these groups. The sample comprised 37 aMCI and 52 HOA participants aged over 60 years. All participants completed questionnaires to assess strategy knowledge and self-reported use of internal and external strategies in everyday life. In addition, strategy use was observed on the measures of retrospective and prospective memory performance (the CVLT-II and the CAMPROMPT). The aMCI group demonstrated decreased strategy knowledge and observed use of internal strategies, although equivalent observed use of external strategies compared with the HOA group. Furthermore, they reported equivalent use of both internal and external strategies. Observed use of strategies was significantly associated with retrospective memory performance for both groups and prospective memory performance for the aMCI group, supporting the inclusion of strategy training in interventions.     

Visual object categorisation at distinct levels of abstraction: a new stimulus set.

We designed a new stimulus set with 269 line drawings of everyday artifacts and animals. The stimulus set contains several typical exemplars from a sample of 25 basic-level categories. We determined to what extent these stimuli were named at the basic level and at a more subordinate level. An additional experiment showed the validity of this calibration: typicality ratings were correlated significantly with the level of naming. In a final experiment we found that this effect depends largely on the global configuration of a stimulus as it was still apparent with degraded images obtained by locally shifting small fragments of the drawings.