Psychological responses to body shape exposure in patients with bulimia nervosa

One of the unresolved issues regarding research on bulimia nervosa concerns the question as to how patients diagnosed with bulimia nervosa respond to body image exposure. In addition, it remains unclear whether there are differential responses associated with different exposure techniques (e.g. in vivo exposure vs. exposure by visualization). The aim of the present study was to investigate psychological responses to body image exposure. Twenty participants diagnosed with bulimia nervosa (DSM IV) and twenty non-eating disordered individuals were exposed to their body image using a video recording (video confrontation). In addition, they were asked to imagine and describe the appearance of their body (imagery task). Results indicate that self-reported negative emotions increased in response to both, video confrontation and imagery task, in the clinical as well as in the control group. Furthermore, video confrontation led to more pronounced group differences than exposure by visualization (imagery task). Participants diagnosed with bulimia nervosa took less time to describe their waist, hips and bottom compared to non-eating disturbed controls. This last result could be interpreted in terms of avoidance behavior and other mechanisms during body image exposure.     

The Meta-Cognitive Beliefs Questionnaire: development of a measure of obsessional beliefs

A 67 item self-report questionnaire called the Meta-Cognitive Beliefs Questionnaire (MCBQ) was developed to assess endorsement of beliefs about the importance of control and negative consequences associated with unwanted, ego-dystonic intrusive thoughts, images and impulses. The MCBQ and a battery of questionnaires that assessed symptoms and cognitions of worry, obsessive-compulsive disorder, anxiety, and depression were administered to large samples of undergraduate students. Beliefs about control of intrusive thoughts and perceived negative consequences due to uncontrolled mental intrusions had a unique significant relationship with obsessions, and to a lesser extent, worry. These findings are consistent with current cognitive behavioral theories that suggest an important role for meta-cognitive beliefs in the pathogenesis of obsessions.     

Assessing the factorial invariance of Harter's self-concept measures: comparing preadolescents with and without spina bifida using child,parent, and teacher report

The purpose of this study was to determine whether the structure of children's self-concept, as rated by children themselves on the Self-Perception Profile for Children (SPPC; Harter, 1985), and the structure of children's competence, as rated by their parents on the Rating Scale of Child's Actual Behavior (PRS) and teachers on the Rating Scale of Child's Actual Behavior (TRS; Harter, 1985), are similar across samples of children with and without spina bifida (children were 8 and 9 years of age; n = 68 in each sample). Using confirmatory factor analyses, results revealed that a multidimensional model for the SPPC and the TRS fit the data well for both samples. On the other hand, the model for both mothers' and fathers' PRS ratings did not fit the data for the spina bifida sample. Further tests of factorial invariance conducted on the SPPC and TRS revealed that the spina bifida and able-bodied samples tended to have the same pattern and magnitude of factor loadings for both instruments. There was some invariance, however, in the amount of unique error variance accounted for across samples. These results bolster our confidence in using the SPPC and TRS to compare children with and without spina bifida.     

Compound self-motion perception induced by two kinds of optical motion

Two kinds of flow patterns consisting of random dots were presented simultaneously to subjects to investigate whether or not two kinds of vection occur simultaneously. One pattern induces vertical linear self-translation, whereas the other induces self-rotation around a vertical axis (when either pattern is presented alone). Three sets of conditions were tested. The first condition was one in which random dots moved in a summed direction of both flow vectors. In the second condition, both flow patterns were simply overlaid, whereas in the third condition, the two kinds of flow patterns were overlaid with a depth separation produced by binocular disparity. The subjects perceived both kinds of vection simultaneously in directions opposite to those of the corresponding flow components under the first condition, whereas either vection occurred mainly under the second condition. Under the third condition, both of the flows induced each kind of vection simultaneously, despite there being no physical vector summation of dot motion. The background flow induced vection in a direction opposite to the flow direction, whereas the foreground flow induced vection in the same direction as the flow direction. These results show that induced self-translation and induced self-rotation can occur simultaneously in two ways.     

Feeling textures through a probe: effects of probe and surface geometry and exploratory factors

Vibratory roughness perception occurs when people feel a surface with a rigid probe. Accordingly, perceived roughness should reflect probe and surface geometry, exploratory speed, and force. Experiments 1 and 2 compared magnitude estimation of roughness with the bare finger and two types of probes, one designed to eliminate force moments, under the subject's active control. Experiments 3 and 4 varied speed under passive control. Log magnitude was consistently a quadratic function of log spacing between elements in the surface. The location of the function's peak was related to the drop point--that is, the spacing at which the probe can just drop between elements--which is affected by probe tip diameter, element height, and speed. Other parameters of the quadratic were affected by probe type and speed.     

Postrecognition of interleaved melodies as an indirect measure of auditory stream formation

Primitive processes involved in auditory stream formation are measured with indirect, objective method. A target melody interleaved with a distractor sequence is followed by a probe melody that was identical to the target or differed by 2 notes. Listeners decided whether the probe melody was present or not in the composite sequence. Interleaved melody recognition is not possible when distractor sequences have the same mean frequency and maximum contour crossover with target melodies. Performance increases with mean frequency separation and timbral dissimilarity and is unaffected by the duration of the silent interval between composite sequence and probe melody. The relation between this indirect task measuring the interleaved melody recognition boundary and direct judgments measuring the fission boundary is discussed.     

Can blindness to response-compatible stimuli be observed in the absence of a response?

Blindness to response-compatible stimuli is the finding that targets are identified less accurately when presented during the planning or execution of a congruent response (e.g., right arrow presented during a right keypress) versus an incongruent response (e.g., right arrow presented during a left keypress). Accounts of this effect suggest the planning and execution of a response are critical to its observation. Five experiments investigated whether a blindness effect would be observed in the absence of a planned response. Results suggest that a planned response is not necessary to observe a content-specific blindness effect and that the blindness effect may actually comprise both an action-related component and a symbolic component that is distinct from the action-planning system.     

The nature and treatment of stuttering as revealed by fMRI A within- and between-group comparison

This article reviews some of our recent functional magnetic resonance imaging (fMRI) studies of stuttering. Using event-related fMRI experiments, we investigated brain activation during speech production. Results of three studies comparing persons who stutter (PWS) and persons who do not stutter (PWNS) are outlined. Their findings point to a region in the right frontal operculum (RFO) that was consistently implicated in stuttering. During overt reading and before fluency shaping therapy, PWS showed higher and more distributed neuronal activation than PWNS. Immediately after therapy differential activations were even more distributed and left sided. They extended to frontal, temporal, and parietal regions, anterior cingulate, insula, and putamen. These over-activations were slightly reduced and again more right sided two years after therapy. Left frontal deactivations remained stable over two years of observation, and therefore possibly indicate a dysfunction. After therapy, we noted higher activations in persons who stutter moderately than in those who stutter severely. These activations might reflect patterns of compensation. We discuss why these findings suggest that fluency-inducing techniques might synchronize a disturbed signal transmission between auditory, speech motor planning, and motor areas.

Educational objectives: The reader will learn about and be able to: (1) identify regions of brain activations and deactivations specific for PWS; (2) describe brain activation changes induced by fluency shaping therapy; and (3) discuss the correlation between stuttering severity and brain activation.