A revised analysis of the role of efference in motion perception

The analysis of motion perception historically has included efferent as well as afferent mechanisms to account for the perception of motion during eye movement. The application of efferent mechanisms to motion perception has been limited, however, by several illusions which are apparently inconsistent with the notion that oculomotor mechanisms contribute to motion perception. An alternative account is presented of the manner in which efference may contribute to the perception of motion. It is proposed that distinct smooth eye-movement systems contribute differentially to object motion perception. Specifically, activity in the smooth pursuit system gives rise to the perception of object motion, whereas activity in the smooth component of reflexive eye movements does not. Tracking of a moving object results in object motion perception as a result of efference in the pursuit system. However, the pursuit system may be activated to oppose the smooth component of reflexive eye movements in order to preserve fixation on a stationary object. In such cases neither the fixated object nor the eye is moving but illusory movement results from the efference in the pursuit system. A number of illusory movement phenomena are interpreted in terms of this model.     

Single-component microcomputer-driven assessment of attention

The Gordon Diagnostic System (GDS) is a single-component microcomputer-based instrument that can be used to administer 11 psychological tests. The game-like tasks provide objective data for evaluating possible attention-deficit hyperactivity disorder or other conditions that affect a person’s ability to sustain attention and exert self-control. The core of the instrument is an integrated circuit with a microprocessor, a random access memory, and an erasable, programmable read-only memory (EPROM). It can be programmed with an IBM PC and an EPROM programmer. The assembly language source is compiled into machine language, which is used to simulate the GDS on the IBM PC or is “burned” into the ROM. The memory is erasable with ultraviolet light, so revisions can be made easily. The GDS illustrates that “custom” programming a ROM is not limited to large industrial concerns, and that it can be done within small research groups.     

Child care quality and Dutch 2‐ and 3‐year‐olds' socio‐emotional outcomes: Does the amount of care matter?

High amounts of early child care have sometimes been linked to higher levels of behaviour problems, while high‐quality child care has more often been related to fewer behaviour problems and more social competence. The current study investigated whether the level of centre emotional and behavioural support (child care quality) interacted with the amount of child care in predicting children's socio‐emotional behaviour. Participants were 417 children (mean age = 27 months) from 61 Dutch daycare centres. The amount of daycare ranged from 1 to 5 days per week (M = 2.3 days). Multi‐level analyses showed that, independent of the amount of daycare, high levels of centre emotional and behavioural support were related to more caregiver‐rated social competence 1 year later. In addition, children spending 3.5 days or more in highly supportive daycare centres showed the lowest levels of parent‐rated externalizing behaviour 1 year later. The findings emphasize (a) that the combined effects of the amount and quality of child care are important and (b) that high‐quality early child care is related to children's socio‐emotional development. Further policy, practice, and research implications are discussed.

Highlights

• We studied in a Dutch sample how the amount and quality of daycare interacted in relation to children's socio‐emotional outcomes.
• High levels of daycare quality were related to more teacher‐rated social competence.
• Children spending 3.5 days or more in highly supportive daycare centers showed less parent‐rated externalizing behavior.

     

Well-being in major depression and social phobia with and without comorbidity

Background/Objective: Lower levels in well-being have been observed in individuals with Major Depression (MDD) and Social Phobia (SP), but well-planned direct comparisons with control individuals, not suffering from a mental disorder, are lacking. Furthermore, MDD is highly comorbid with anxiety disorders, and SP with depressive disorders. This study is among the first to examine differences in well-being in individuals with a clinical diagnosis of MDD or SP compared to individuals with no such diagnosis and to test differences in well-being within the combined diagnostic categories respective with and without anxiety-depressive comorbidity. Method: Participants were 119 individuals with a diagnosis of MDD, 47 SP and 118 controls. Results: Results revealed that overall well-being as well as emotional, psychological, and social well-being were lower in the MDD and SP group compared to the control group. Individuals with comorbidity reported lower well-being than individuals without comorbidity. Conclusions: These findings have clinical implications as presence of comorbidity may require a different therapeutic approach than with no comorbidity.     

Left-handedness and male-male competition: Insights from fighting and hormonal data

Male-male competition can shape some behavioral or morphological traits of males. Here we investigate if this competition could play a role in the persistence of the polymorphism of handedness in human populations. A negative frequency-dependent selection mechanism has been hypothesized, based on the fact that left-handed men may benefit from a "surprise" advantage during fighting interactions because they are rare in human populations. This advantage may thereby enhance the probability of survival of left- handed men and/or their reproductive success through an increase in social status. In this study, we first explored the association between hand preference and lifetime fighting behavior in a population of 1,161 French men. No effect of hand preference on the probability of fighting was detected, suggesting that the innate propensity to fight does not differ between left- and right-handers. However, among men who had been involved in at least one fight during their lifetime, left-handers reported significantly more fights than right-handers. To explore the biological basis of this behavior, we also investigated the testosterone concentration in saliva samples from 64 French university students. Consistent with frequencies of fights, we found a significantly higher average testosterone concentration in left-handers than in right-handers. We suggest that these behavioral and hormonal differences may be acquired throughout life due to previous experiences in a social context and may favor the persistence of left-handers in humans.     

The effects of self-focused attention, performance demand, and dispositional sexual self-consciousness on sexual arousal of sexually functional and dysfunctional men

Sexually functional (N=26) and sexually dysfunctional heterosexual men with psychogenic erectile disorder (N=23) viewed two sexually explicit videos. Performance demand was manipulated through verbal instruction that a substantial genital response was to be expected from the videos. Self-focused attention was manipulated by introducing a camera pointed at the participant. Dispositional self-consciousness was assessed by questionnaire. Performance demand was found to independently inhibit the genital response. No main effect of self-focus was found. Self-focus inhibited genital response in men scoring high on general and sexual self-consciousness traits, whereas it enhanced penile tumescence in low self-conscious men. Inhibition effects were found in both volunteers and patients. No interaction effects of performance demand and self-focus were found. Subjective sexual arousal in sexually functional men was highest in the self-focus condition. In sexually dysfunctional men, subjective sexual response proved dependent on locus of attention as well as presentation order.     

Relations between Big Five personality characteristics and perceived support in adolescents' families

The authors investigated the longitudinal relations between family members' Big Five personality factors and perceived support. Members of 285 two-parent families with 2 adolescent children judged their own and other family members' Big Five factors and the support perceived from the other members on 3 occasions at 12-month intervals. The Big Five factor Agreeableness was particularly related to perceived support. Changes in individuals' Big Five factors were linked to changes in the support they perceived themselves but even more to changes in the support that other family members perceived from them. Results are consistent with the parallel continuities hypothesis: Individual characteristics will be stable when there is stability in the supportive environment, but when the environment is changing, personality tends to change in the same direction, and vice versa.     

The relationship between perceived length and egocentric location in Müller-Lyer figures with one versus two chevrons

We examined the apparent dissociation of perceived length and perceived position with respect to the Müller-Lyer (M-L) illusion. With the traditional (two-chevron) figure, participants made accurate open-loop pointing responses at the endpoints of the shaft, despite the presence of a strong length illusion. This apparently non-Euclidean outcome replicated that of Mack, Heuer, Villardi, and Chambers (1985) and Gillam and Chambers (1985) and contradicts any theory of the M-L illusion in which mislocalization of shaft endpoints plays a role. However, when one of the chevrons was removed, a constant pointing error occurred in the predicted direction, as well as a strong length illusion. Thus, with one-chevron stimuli, perceived length and location were no longer completely dissociated. We speculated that the presence of two opposing chevrons suppresses the mislocalizing effects of a single chevron, especially for figures with relatively short shafts.     

Ideal mate personality concepts and compatibility in close relationships: a longitudinal analysis

How 2 personalities may be best combined in a couple has often been answered in terms of similarity in partner's personality characteristics. However, results have been inconsistent. The present study proposed that relationship outcomes should depend more on the similarity between individuals' ideal mate personality concepts (IMPCs) and their partner's personality as both perceived by the self and self-reported by the partner. Study 1 introduces a new Q-sort to assess IMPCs and provides evidence for the interindividual variability and the short-term consistency of IMPC. By following nonmarried couples over a 9-month period, Study 2 replicated findings from Study 1 and demonstrated that, overall, the current concept of congruence predicts relationship outcomes better than both personality similarity and the partner's individual personality traits.