Defining Compulsive Behavior

Neuropsychology Review - Compulsive tendencies are a central feature of problematic human behavior and thereby are of great interest to the scientific and clinical community. However, no consensus...     

An fMRI investigation on image generation in different sensory modalities: The influence of vividness

In the present fMRI study the issue of the specific cortices activation during imagery generation in different sensory modalities is addressed. In particular, we tested whether the vividness variability of imagery was reflected in the BOLD signal within specific sensory cortices. Subjects were asked to generate a mental image for each auditory presented sentence. Each imagery modality was contrasted with an abstract sentence condition. In addition, subjects were asked to fill the Italian version of the Questionnaire Upon Mental Imagery (QMI) prior to each neuroimaging session. In general, greater involvement of sensory specific cortices in high-vivid versus low-vivid subjects was found for visual (occipital), gustatory (anterior insula), kinaesthetic (pre-motor), and tactile and for somatic (post-central parietal) imagery modalities. These results support the hypothesis that vividness is related to image format: high-vivid subjects would create more analogical representations relying on the same specific neural substrates active during perception with respect to low-vivid subjects. Results are also discussed according to the simulation perspective.     

Heart rate variability in the human transplanted heart: Nonlinear dynamics and QT vs RR-QT alterations during exercise suggest a return of neurocardiac regulation in long-term recovery

Rationale. Functional reinnervation of the transplanted human heart by the autonomic nervous system has not been demonstrated. A lack of autonomic control of the transplanted allograft is reflected by an increased resting heart rate, a sluggish heart rate response to dynamical exercise and a reduced heart rate variability. Recent evidence suggests that a measure of deterministic chaos in the heartbeat interval series (point correlation dimension, PD2i) is superior to the conventional power spectrum or other stochastic measures in detecting changes in the mechanism underlying heartbeat generation.Methods. The PD2i is based on the presumption that the variability is determined and patterned, whereas the stochastic measures all assume that the variability is around a stationary mean and is noise. The PD2i reconstructs the degrees of freedom (number of independent variables) in the system that generates the time series examined, and does this irrespective of whether the system is stochastic or deterministic and is stationary in time.Results. PD2i was determined for heartbeat intervals (RR, ECG digitized at 1200 Hz; supine posture) of 23 heart transplant recipients (HTR: 9 adults, 14 children; 0.04-7.7 years after transplantation) and 21 healthy control subjects (CTL; 13 adults, 8 children). The PD2i (+/? SD) averaged 5.4 +/? 0.7 for the CTL adults and 5.4 +/? 0.6 for the CTL children. Mean PD2i was reduced after transplantation to 1.1 +/? 0.1 in 6 HTRs recorded within 1 year after surgery; in one HTR recorded 2 weeks after surgery the mean PD2i was 3.7. Between 1 to 2 years PD2i was found increased in 2 of 3 subjects and between 2 to 8 years it was increased in 13 of 13, but not to control levels. In normal hearts the QT subinterval of each heartbeat cycle is associated with inotropy and the RR-QT remainder with chronotropy (i.e., the dyastolic interval during which RR is primarily regulated). To examine more closely the residual and returning heartbeat dynamics of the HTR subjects, these subinterval series were examined during mild exercise (40 to 90 Watts) and its recovery. In recent HTRs, resting QT and RR-QT were moderately reduced and modulated by exercise and recovery, but with an approximate 100 beat latency. In long-term (7-8 years) HTR subjects there was a rapid and larger response to exercise/recovery, but compared to normal the range was smaller and the complexity of the subinterval trajectories in time was simpler.Conclusions. Recurrence of low-dimensional deterministic dynamics after transplantation suggests recovery of neurocardiac control attributable to 1) reorganization of the viable intrinsic cardiac nervous system, 2) reinnervation by the extrinsic autonomic nervous system, or 3) both.     

The classification of children's knowledge: development on the balance-scale and inclined-plane tasks

R.S. Siegler (1981, Monographs of the Society for Research in Child Development, 46 C2, Serial No. 189) has shown that performance on several Piagetian tasks is governed by similar rule structures. The purpose of the first study was to extend his analysis to the inclined-plane task, replicate his original observations about development on the balance-scale task, and determine the consistency in children's rule usage across tasks. We found that Siegler's (1981) binary decision representations adequately characterized development on these tasks, and there was fair correspondence of rule classifications across tasks. An alternative classification procedure, used to diagnose the rules of children who failed our original classification criteria, showed that most of these children's performance patterns were very similar to Siegler's rule patterns. In the second experiment, we improved the diagnosticity of our rule-assessment protocol in light of F. Wilkening and N. H. Anderson's (1982, Psychological Bulletin, 92, 215-237) criticisms, and observed that many Rule III children's predictions were associated with those of integration rules on both tasks. Despite these methodological improvements, many children, especially 5- to 7-year-olds, evidenced use of centration and lexicographic strategies, suggesting that these classifications are not simply an artifact of problem sampling. Some of the problems associated with the classification of children's knowledge are discussed.     

Synaesthetic perception of colour and visual space in a blind subject: an fMRI case study

In spatial sequence synaesthesia (SSS) ordinal stimuli are perceived as arranged in peripersonal space. Using fMRI, we examined the neural bases of SSS and colour synaesthesia for spoken words in a late-blind synaesthete, JF. He reported days of the week and months of the year as both coloured and spatially ordered in peripersonal space; parts of the days and festivities of the year were spatially ordered but uncoloured. Words that denote time-units and triggered no concurrents were used in a control condition. Both conditions inducing SSS activated the occipito-parietal, infero-frontal and insular cortex. The colour area hOC4v was engaged when the synaesthetic experience included colour. These results confirm the continued recruitment of visual colour cortex in this late-blind synaesthetes. Synaesthesia also involved activation in inferior frontal cortex, which may be related to spatial memory and detection, and in the insula, which might contribute to audiovisual integration related to the processing of inducers and concurrents.     

Gender Hierarchy in the Space: The Role of Gender Status in Shaping the Spatial Agency Bias

According to the Spatial Agency Bias (SAB), more agentic groups (men) are envisioned to the left of less agentic groups (women). This research investigated the role of social status in shaping the spatial representation of gender couples. Participants were presented pairs consisting of one male and one female target who confirmed gender stereotypes. The status of the targets in each pair was systematically varied (high-status vs. low-status job). Participants chose the target order (female/male vs. male/female) they preferred. In line with gender-status expectations (male: high-status, female: low-status), a male in a high-status job led to a spatial arrangement that favored the male/female order, regardless of the status of the female target. The female/male order was favored only when the female had a high-status job and the male a low-status job. No SAB occurred for pairs in which both targets displayed low-status jobs. The implications of status for the SAB are discussed.     

Pet Loss and Human Emotion: Romanian Students' Reflections on Pet Loss

Thirty-five graduate and undergraduate students, owners of dogs and cats, were asked to respond in writing to a several questions regarding their relationship with their pet. In this retrospective analysis, we discuss aspects that describe the pet-owner relationship, including attachment and the role played by the pet in the owner's life (e.g., emotional support, the pet being seen as a family member). Most of the participants felt that their pet's loss caused great pain; some considered that even if they had suffered greatly, the death of their pet was not felt more intensely and severely than the death of any other family member or a friend.     

The Role of Vividness of Visual Mental Imagery on Different Dimensions of Creativity

Although research demonstrated that people can mentally manipulate and synthesize visual elements into a creative object, the role that vividness of visual imagery plays on creative imagery is still unclear. This study explored the relationships between vividness of visual imagery and 3 dimensions of creative imagery: originality, practicality, and mental spatial transformations of visual elements. Fifty-three participants performed the creative mental synthesis task and completed the Vividness of Visual Imagery Questionnaire (VVIQ). Results revealed a positive relationship between vividness and the practicality dimension of objects. No relationship was found either between vividness and originality or between vividness and transformational complexity. The association vividness–practicality seems to reflect the ability to use pictorial information of imagery when people generate functional objects that belong to specific categories. Future research directions are discussed.