Types of work-family interface: well-being correlates of negative and positive spillover between work and family

The aim of the present study was to test the structure of the work-family interface measure, which was intended to take into account both the positive and negative spillover between work and family demands in both directions. In addition, the links among the types of work-family spillover and the subjects' general and domain-specific well-being were examined. The sample (n = 202) consisted of Finnish employees, aged 42, who had a spouse/partner. Confirmatory factor analyses indicated that a four-factor model, including negative work-to-family spillover, negative family-to-work spillover, positive work-to-family spillover, and positive family-to-work spillover, was superior compared to the other factor models examined. Path analysis showed, as hypothesized, that the negative work-to-family spillover was most strongly related to low well-being at work (job exhaustion) and next strongly to low general well-being (psychological distress), whereas the negative family-to-work spillover was associated with low well-being in the domain of family (marital dissatisfaction). Positive work-to-family spillover was positively related both to well-being at work and general well-being. Inconsistent with our expectations, positive family-to-work spillover was not directly related to any of the well-being indicators examined.     

Why are artificial polymorphous concepts so hard for birds to learn?

Stimulus sets defined in terms of artificial polymorphous concepts have frequently been used in experiments to investigate the mechanisms of discrimination of natural concepts, both in humans and in other animals. However, such stimulus sets are frequently difficult for either animals or humans to discriminate. Properties of artificial polymorphous stimulus sets that might explain this difficulty include the complexity of the individual stimuli, the unreliable reinforcement of individual positive features, attentional load, difficulties in discriminating some stimulus dimensions, memory load, and a lack of the correlation between features that characterizes natural concepts. An experiment using chickens as subjects and complex artificial visual stimulus sets investigated these hypotheses by training the birds in discriminations that were not polymorphous but did have some of the properties listed above. Discriminations that involved unreliable reinforcement or high attentional load were found to approach the difficulty of polymorphous concept discriminations, and these two factors together were sufficient to account for the entire difficulty. The usual kind of artificial polymorphous concept may not be a good model for natural concepts as they are perceived and discriminated by birds. A RULEX account of natural concept learning may be preferable.     

EEG theta and gamma responses to semantic violations in online sentence processing

We explore the nature of the oscillatory dynamics in the EEG of subjects reading sentences that contain a semantic violation. More specifically, we examine whether increases in theta ( approximately 3-7 Hz) and gamma (around 40 Hz) band power occur in response to sentences that were either semantically correct or contained a semantically incongruent word (semantic violation). ERP results indicated a classical N400 effect. A wavelet-based time-frequency analysis revealed a theta band power increase during an interval of 300-800 ms after critical word onset, at temporal electrodes bilaterally for both sentence conditions, and over midfrontal areas for the semantic violations only. In the gamma frequency band, a predominantly frontal power increase was observed during the processing of correct sentences. This effect was absent following semantic violations. These results provide a characterization of the oscillatory brain dynamics, and notably of both theta and gamma oscillations, that occur during language comprehension.     

The antecedents and correlates of agreeableness in adulthood

Data from a 25-year prospective study of 194 individuals indicated that teacher and peer reports of aggression, compliance, and self-control at age 8 distinguished high-agreeable from low-agreeable adults at age 33. Profile analyses revealed two behavioral types in childhood and two personality types in adulthood, with considerable continuity in the composition of these high- and low-agreeable types over time. High-agreeable childhood types had fewer disobedience and concentration problems than low-agreeable childhood types, and among boys, high-agreeable childhood types had better school grades and fewer behavior problems than their low-agreeable counterparts. High-agreeable adulthood types reported less alcoholism and depression, fewer arrests, and more career stability than did low-agreeable adulthood types.     

Discrimination of intentional and random motion paths by pigeons

Twelve pigeons (Columba livia) were trained on a go/no-go schedule to discriminate between two kinds of movement patterns of dots, which to human observers appear to be "intentional" and "non-intentional" movements. In experiment 1, the intentional motion stimulus contained one dot (a "wolf") that moved systematically towards another dot as though stalking it, and three distractors ("sheep"). The non-intentional motion stimulus consisted of four distractors but no stalker. Birds showed some improvement of discrimination as the sessions progressed, but high levels of discrimination were not reached. In experiment 2, the same birds were tested with different stimuli. The same parameters were used but the number of intentionally moving dots in the intentional motion stimulus was altered, so that three wolves stalked one sheep. Despite the enhanced difference of movement patterns, the birds did not show any further improvement in discrimination. However, birds for which the non-intentional stimulus was associated with reward showed a decline in discrimination. These results indicated that pigeons can discriminate between stimuli that do and do not contain an element that human observer see as moving intentionally. However, as no feature-positive effect was found in experiment 1, it is assumed that pigeons did not perceive or discriminate these stimuli on the basis that the intentional stimuli contained a feature that the non-intentional stimuli lacked, though the convergence seen in experiment 2 may have been an effective feature for the pigeons. Pigeons seem to be able to recognise some form of multiple simultaneously goal-directed motions, compared to random motions, as a distinctive feature, but do not seem to use simple "intentional" motion paths of two geometrical figures, embedded in random motions, as a feature whose presence or absence differentiates motion displays. Electronic Publication     

Innovations in Assessing ADHD: Development, Psychometric Properties, and Factor Structure of the ADHD Symptoms Rating Scale (ADHD-SRS)

This research involved the development of a behavior rating scale designed to measure ADHD and the investigation of the scale's psychometric properties and factor structure. This scale, the ADHD Symptoms Rating Scale (ADHD-SRS), was developed for the assessment of ADHD in the school-age (K–12) population. Participants were 1006 children and adolescents (in grades K–12) who were rated by their parents and/or teachers. The results indicate that the ADHD-SRS possesses strong internal consistency reliability and test–retest reliability and moderate cross-informant reliability. The data also suggest that the ADHD-SRS has strong content validity. Convergent validity of this instrument was also high, as demonstrated by correlations with three previously validated behavior rating scales. Significant age and gender differences in ADHD symptoms were found with both the parent and teacher respondent populations. Finally, the factor analysis of the ADHD-SRS suggested a two factor oblique rotation as the best fit for both the parent and the teacher data. After a visual inspection of the items which loaded on each factor, Factor 1 was named Hyperactive-Impulsive and Factor 2 was named Inattention. These two factors, along with the items which loaded on each factor, appear to be remarkably similar to the two categories listed in the DSM-IV for ADHD. Directions for future research, as well as clinical implications and limitations of the research are discussed.     

The development of adaptive choice in a self-control paradigm

Sixteen girls (ages 4, 6, 9, and 12) performed on concurrent-chain schedules of reinforcement. The initial links were variable-interval 10-s schedules, and the terminal links offered a long delay (20, 30, 40, or 50 s) followed by two tokens or a short delay (10 s) followed by one token. Tokens were used to buy toys and sweets. The effect of increasing the delay to the large reward differed significantly across age groups. Whereas 6- and 9-year-olds maintained a strong preference for the larger, more delayed reward under all delay conditions, half of the 4-year-olds and all the 12-year-olds showed increasing preference for the small reward as the delay to the large reward increased. The results suggest a two-stage account of the development of self-control. In the first stage, behavior is increasingly controlled by reward size, as children learn how to wait for delayed rewards, and in the second phase behavior is increasingly controlled by reward rate, as children learn when it is in fact profitable to wait.     

Perception of object unity in chicks: A comparison with the human infant

Newly hatched chicks (Gallus gallus) were imprinted on a display consisting of two rod pieces that moved above and below a central occluder. On test trials, the chicks approached a complete rod in preference to two rod pieces. This finding, supported by those from control coditions, suggests that chicks, soon after hatching, perceive object unity. The results are compared with those from human infants.     

Minimal spectral contrast of formant peaks for vowel recognition as a function of spectral slope

In four experiments we investigated whether listeners can locate the formants of vowels not only from peaks, but also from spectral “shoulders”—features that give rise to zero crossings in the third, but not the first, differential of the excitation pattern—as hypothesized by Assmann and Summerfield (1989). Stimuli were steady-state approximations to the vowels [a, i, з, u, ?] created by summing the first 45 harmonics of a fundamental of 100 Hz. Thirty-nine harmonics had equal amplitudes; the other 6 formed three pairs that were raised in level to define three “formants.” An adaptive psychophysical procedure determined the minimal difference in level between the 6 harmonics and the remaining 39 at which the vowels were identifiably different from one another. These thresholds were measured through simulated communication channels, giving overall slopes to the excitation patterns of the five vowels that ranged from ?1 dB/erb to +2 dB/erb. Excitation patterns of the threshold stimuli were computed, and the locations of formants were estimated from zero crossings in the first and third differentials. With the more steeply sloping communication channels, some formants of some vowels were represented as shoulders rather than peaks, confirming the predictions of Assmann and Summerfield’s models. We discuss the limitations of the excitation pattern model and the related issue of whether the location of formants can be computed from spectral shoulders in auditory analysis.