Mood, personality disorder symptoms and disability in obsessive compulsive hoarders: a comparison with clinical and nonclinical controls

Hoarding is a symptom of obsessive compulsive disorder (OCD), as well as a diagnostic criterion for obsessive compulsive personality disorder (OCPD). One recent study suggests that people who suffer from compulsive hoarding report more general psychopathology than people who do not [Frost, R.O., Krause, M.S., & Steketee, G. (1996). Hoarding and obsessive compulsive symptoms. Behavior Modification, 20, 116-132]. The present study addressed whether persons with OCD hoarding exhibit more depression, anxiety, OCD and personality disorders symptoms than community controls, OCD nonhoarders, or other anxiety disorder patients. Disability was also examined. Hoarding subjects were older than the other three groups, but age did not account for any of the differences observed among the groups. Compared to controls, OCD hoarding, nonhoarding OCD and anxiety disorder patients showed elevated YBOCS scores, as well as higher scores on depression, anxiety, family and social disability. Compared to nonhoarding OCD and anxiety disorder patients, OCD hoarding patients scored higher on anxiety, depression, family and social disability. Hoarding subjects had greater personality disorder symptoms than controls. However, OCD hoarding subjects differed from OCD nonhoarding and anxiety disorder subjects only on dependent and schizotypal personality disorder symptoms. The findings suggest that hoarding is associated with significant comorbidity and impairment compared to nonhoarding OCD and other anxiety disorders.     

Effects of directionality in deductive reasoning: I. The comprehension of single relational premises

Four experiments involving 123 university students tested directionality effects in the comprehension of spatial relations, quantified statements, and propositional connectives with a sentence-picture verification task. Presentation of the referents of terms in the statements was separated by 1 s, and presentation order was congruent or incongruent with the order of terms in the statement. Some relations showed faster verification times for congruent display order, others for incongruent display order, and still others showed no directionality effect. The authors proposed a 2-step process model for the construction of semantic representations of relational statements, in which a reference object is established first, and then the second object is attached in relation to it. This theory explains the various directionality effects as a general preference to process information about the reference object before information about the target object.     

Form and movement in stereokinetic cycloids: motion lost and found

In exploring stereokinesis, we devised flat cycloidal display figures which, when rotated on a disc in the frontal plane, are perceived as illusory three-dimensional forms with movement in depth; the dominant percepts were of twisted loops with an internal writhing motion. These dominant forms could be convincingly represented by stereo pairs derived from the flat display; related forms, not seen in the illusion, could also be constructed, seeming to show a selectivity for preferred stereokinetic forms by the perceptual system. Models were made of the stereo forms; when rotated, they showed similar illusions and selectivity. We suggest that the illusions arise because some components of the real motion do not appear in the sensory field. The perceptual system accommodates for this by constructing percepts which are not necessarily veridical but do reconcile form and motion into a coherent unity. The results are discussed in relation to concepts of invariance and rigidity, and with regard to the creative response to sensory data by the perceptual system.     

Development of object permanence in food-storing magpies (Pica pica)

The development of object permanence was investigated in black-billed magpies (Pica pica), a food-storing passerine bird. The authors tested the hypothesis that food-storing development should be correlated with object-permanence development and that specific stages of object permanence should be achieved before magpies become independent. As predicted, Piagetian Stages 4 and 5 were reached before independence was achieved, and the ability to represent a fully hidden object (Piagetian Stage 4) emerged by the age when magpies begin to retrieve food. Contrary to psittacine birds and humans, but as in dogs and cats, no "A-not-B error" occurred. Although magpies also mastered 5 of 6 invisible displacement tasks, evidence of Piagetian Stage 6 competence was ambiguous.