Inhibition in motor imagery: a novel action mode switching paradigm

Motor imagery requires that actual movements are prevented (i.e., inhibited) from execution. To investigate at what level inhibition takes place in motor imagery, we developed a novel action mode switching paradigm. Participants imagined (indicating only start and end) and executed movements from start buttons to target buttons, and we analyzed trial sequence effects. Trial sequences depended on current action mode (imagination or execution), previous action mode (pure blocks/same mode, mixed blocks/same mode, or mixed blocks/other mode), and movement sequence (action repetition, hand repetition, or hand alternation). Results provided evidence for global inhibition (indicated by switch benefits in execution-imagination (E-I)-sequences in comparison to I-I-sequences), effector-specific inhibition (indicated by hand repetition costs after an imagination trial), and target inhibition (indicated by target repetition benefits in I-I-sequences). No evidence for subthreshold motor activation or action-specific inhibition (inhibition of the movement of an effector to a specific target) was obtained. Two (global inhibition and effector-specific inhibition) of the three observed mechanisms are active inhibition mechanisms. In conclusion, motor imagery is not simply a weaker form of execution, which often is implied in views focusing on similarities between imagination and execution.     

Perfectionism mediated the relationship between brain structure variation and negative emotion in a nonclinical sample

In maladaptive respects, perfectionism reflects an individual’s concern over making mistakes and doubting the quality of his or her own actions excessively, which would affect one’s emotion. However, little is known about the neural mechanisms associated with the perfectionism and negative affect. In this study, voxel-based morphometry was performed to identify the brain regions underlying individual differences in perfectionism, which was measured by the Chinese Frost Multidimensional Perfectionism Scale (CFMPS), in a large sample of nonclinical young adults. Our results showed that the two subdimensions of the perfectionism, concern over mistakes (CM) and doubts about actions (DA), were both positively correlated with the self-reported anxiety and depression as well as the gray matter volume (GMV) in the anterior cingulate cortex (ACC), a pivotal brain region in cognitive control, affective state, and regulation. Moreover, CM, DA, and organization scores were respectively correlated with distributed brain regions involved in multiple cognitive and emotion processes. Our results furthermore revealed that the score of DA acted a mediational mechanism underlying the relationship between the GMV of ACC and self-rating negative affect (anxiety and depression). Taken together, these results might suggest the neuroanatomical basis of perfectionism and the association among the perfectionism, negative emotion, and brain architecture. This study emphasized that perfectionism could play a crucial role in the arousal of negative affect.     

The Variability and Flexibility of Gender-Typed Toy Play: A Close Look at Children's Behavioral Responses to Counterstereotypic Models

Gender differences in play behavior are well documented. However, little work has examined the issue of variability of gender-typed behaviors within individuals or within genders. We investigated whether children's gender-typed toy play behavior is (a) variable across time within individuals, and (b) variable in response to exposure to counterstereotypic models. Extensive observations (N=203) were made of 8 highly gender-typed preschool children over 4 months. Variability was assessed by examining changes in the percentage of masculine and feminine toy play across successive days in which (a) gender neutral stories were read (within-individual variability) and (b) gender counterstereotypic stories were introduced (environmental variability). Variability of gender-typed play within individuals and in response to environmental stimuli was found among girls, but not among boys.     

Impaired awareness of movement disorders in Parkinson’s disease

Background

This study analyzed the presence of awareness of movement disorders (dyskinesias and hypokinesias) in 25 patients with Parkinson’s disease (PD) and motor fluctuations (dyskinesias, wearing off, on–off fluctuations). Of the few studies that have dealt with this topic, none have analyzed the differences in the awareness of motor deficits by comparing the on and off states using motor scales and an extensive battery of tests to assess cognitive and behavioral functioning.

Methods

PD patients were compared on three different scales that we have devised to measure awareness of movement disorders: Global Awareness of Movement (GAM) Disorders, dyskinesia/hypo-bradykinesia rating scales.

Results

Data showed that PD patients had greater awareness and psychological suffering in the off state than in the on state. In particular, they were troubled by motor disabilities related to hypokinesias and had mood-related symptoms and a perception of disability in activities of daily living. Interestingly, patients only showed a selective reduction of awareness of movement disorders associated with executive functions and related to dyskinesias in the on state, compared to a preserved awareness of hypokinesias in the off state. On the contrary, no association with executive functions was found in the off state.

Conclusion

Our findings suggest that the dopaminergic overstimulation of mesocorticolimbic pathways may cause a dysfunction of prefrontal–subcortical connections related to the impaired insight.     

Personality trait similarity between spouses in four cultures

We examined patterns of trait similarity (assortative mating) in married couples in four cultures, using both self-reports and spouse ratings on versions of the Revised NEO Personality Inventory. There was evidence of a subtle but pervasive perceived contrast bias in the spouse-rating data. However, there was strong agreement across methods of assessment and moderate agreement across cultures in the pattern of results. Most assortment effects were small, but correlations exceeding .40 were seen for a subset of traits, chiefly from the Openness and Agreeableness domains. Except in Russia, where more positive assortment was seen for younger couples, comparisons of younger and older cohorts showed little systematic difference. This suggested that mate selection, rather than convergence over time, accounted for similarity. Future research on personality similarity in dyads can utilize different designs but should assess personality at both domain and the facet levels.     

ASTEF: A simple tool for examining fixations

In human factors and ergonomics research, the analysis of eye movements has gained popularity as a method for obtaining information concerning the operator's cognitive strategies and for drawing inferences about the cognitive state of an individual. For example, recent studies have shown that the distribution of eye fixations is sensitive to variations in mental workload---dispersed when workload is high, and clustered when workload is low. Spatial statistics algorithms can be used to obtain information about the type of distribution and can be applied over fixations recorded during small epochs of time to assess online changes in the level of mental load experienced by the individuals. In order to ease the computation of the statistical index and to encourage research on the spatial properties of visual scanning, A Simple Tool for Examining Fixations has been developed. The software application implements functions for fixation visualization, management, and analysis, and includes a tool for fixation identification from raw gaze point data. Updated information can be obtained online at www.astef.info, where the installation package is freely downloadable.     

Ignorance is bliss: the role of observer expectation in dynamic spatial tuning of the attentional focus

When two sequential targets (T1, T2) are inserted in an RSVP stream of distractors, perception of T2 is impaired at intertarget lags shorter than 700 msec. Paradoxically, this deficit disappears when T2 is presented directly after T1 (lag-1 sparing). Visser, Bischof, and Di Lollo (1999) found that lag-1 sparing occurs only when T1 and T2 are presented in the same stream. In contrast, Shih (2000) obtained lag-1 sparing with targets insepa-rate streams. Four experiments addressed this inconsistency and revealed lag-1 sparing with targets in different streams, but only when observers had no foreknowledge of T1's location. We hypothesized that when T1 location is known, attention is focused narrowly on that stream; if T2 then appears in the other stream it is missed, and lag-1 sparing does not occur. When T1 location is not known, attention is focused broadly, encompassing both streams, and lag-1 sparing ensues.     

Parents' representations of their children: an exploratory study using the Osgood Semantic Differential Scales

The results of an exploratory national study carried out in Italy using Osgood's Semantic Differential Scales (Osgood, Suci, & Tannenbaum, 1957) with parents of 100 normal 6- to 11-yr.-old children in mainstream classrooms are reported. The aim was to devise a simple tool to be used to explore parents' perceptions of their children in this age group. Parents were asked to rate "my child" using some of Osgood's Semantic Differential Scales especially adapted for this study. Participants were 97 fathers and 100 mothers. Fathers were 32 to 57 years of age (M = 43.2, SD = 5.4), mothers were 29 to 49 years of age (M = 39.7, SD =4.4). In factor analysis four factors were identified: Activity, Evaluation, Emotions evoked by the child, Personality/Physical contact. Average factor scores were significantly different. There were no significant differences between fathers and mothers on the four factor scores. Children were more positively evaluated the younger they were.     

The time required for perceptual (nonmotoric) processing in IOR

In an inhibition of return (IOR) paradigm, we used a threshold-tracking procedure combined with backward masking to measure the speed of perceptual processing in IOR independent of motoric factors. Instead of the conventional reaction time measure, this procedure yielded the critical exposure duration (DUR_c) that is required in order for a target to be identified reliably before the onset of a trailing mask. In Experiment 1, the facilitation effects conventionally found at short cue—target onset asynchrony (CTOA) were evidenced by shorter values of DUR_c at cued relative to uncued locations. Conversely, the retardation effects conventionally found at long CTOA were evidenced by correspondingly longer values of DUR_c. In Experiment 2, the DUR_c results strongly suggest that the directional reading bias previously observed in IOR studies is due, at least in part, to perceptual rather than motoric factors.