Cueing the location of a distractor: an inhibitory mechanism of spatial attention?

Presenting an irrelevant distractor increases reaction times to a target. The current study shows that cueing the location of an upcoming 'distractor' can help to reduce the effects the distractor has on target processing. It is hypothesized that this reduction is due to the active inhibition of the cued location. In two experiments in which the location of the distractor was cued in advance, a reduced effect of the distractor on target-processing was observed. Analyses indicated that this effect was most likely caused by inhibition of the distractor location. The present findings suggest that inhibition plays an important role in visual-spatial selection processes and that this inhibitory mechanism can be controlled in a top-down fashion.     

The effects of weather on daily mood: a multilevel approach

The present study examines the effects of six weather parameters (temperature, wind power, sunlight, precipitation, air pressure, and photoperiod) on mood (positive affect, negative affect, and tiredness). Data were gathered from an online diary study (N = 1,233), linked to weather station data, and analyzed by means of multilevel analysis. Multivariate and univariate analyses enabled distinction between unique and shared effects. The results revealed main effects of temperature, wind power, and sunlight on negative affect. Sunlight had a main effect on tiredness and mediated the effects of precipitation and air pressure on tiredness. In terms of explained variance, however, the average effect of weather on mood was only small, though significant random variation was found across individuals, especially regarding the effect of photoperiod. However, these individual differences in weather sensitivity could not be explained by the Five Factor Model personality traits, gender, or age.     

Spatial working memory effects in early visual cortex

The present study investigated how spatial working memory recruits early visual cortex. Participants were required to maintain a location in working memory while changes in blood oxygen level dependent (BOLD) signals were measured during the retention interval in which no visual stimulation was present. We show working memory effects during the retention period in early visual cortex which were retinotopically organized in the sense that evoked BOLD responses were specific to the position of the remembered location on an imaginary clock. We demonstrate that this activity is similar to activity observed in conditions in which participants have to direct spatial attention to the same location. We suggest that during the retention interval modulation of neurons coding the remembered location evoke a baseline shift, providing converging evidence for the notion that spatial working memory may use spatial attention as a rehearsal mechanism.     

Studies on wild house mice VI: Differential effects of the Y chromosome on intermale aggression

The aim of this study is to determine the effects of different parts of the Y chromosome of wild house mice on aggression. To reach this goal, intercrosses were made between two selection lines for attack latency (SAL and LAL) and their congenic strains (SAL. LY and LAL. SY). This procedure resulted in F₁ hybrids that carried the same autosomes, but differed in their X chromosome and the two different parts of their Y chromosomes, the different parts of the Y chromosome being a recombining part called the pseudoautosomal region (PAR) and a non-recombining part (non-PAR). We conclude that both parts of the Y chromosome contribute slightly but significantly to variation in aggression. The major effect is accomplished by the PAR of the aggressive parent; a mirror effect is achieved by the non-PAR of the aggressive parent in interaction with the PAR. © 1994 Wiley-Liss, Inc.     

A divided attention experiment with pervasively hyperactive children

Task performance of 12 pervasive hyperactives and controls was studied in a divided attention reaction time experiment. The two groups differed with respect to task efficiency. The hyperactives were slower than controls, had more variable reaction times, and made more frequent errors. Task inefficiency could not be explained by a deficiency in divided attention or impulsive responding in the hyperactive group. Further, the observed differences in IQ between the groups could not account for the differential performance finding. It is concluded that input and/or output processes, probably in combination with energetical factors, might be disturbed in hyperactive children.The authors wish to thank L. Leertouwer for making the drawings, and the students Ellie Wekking and Sipke Boorsma for their selection procedure work. This research was supported by a grant from the Netherlands Foundation for the Advancement of Pure Research (ZWO) and by the Professor Duijker Fund.     

Controlled processing and vigilance in hyperactivity: Time will tell

This paper reviews the concept of sustained attention, placing it within a theoretical framework in which deficits of attention are conceived of as deficits of controlled information processing. Two types of deficit of sustained attention are distinguished: perceptual sensitivity and perceptual criterion. These two deficits are linked to a model of human performance that links controlled processes to the energetic pools: arousal and activation. Perceptual sensitivity (d) deficits are said to reflect arousal deficiencies, especially when observed in the early period of a vigil. Perceptual criterion deficits are associated with the activation pool and the response criterion measure . Despite clear evidence of perceptual deficiency in the hyperactive children to a greater extent than in the control group, and that performance in d declined with time on task, a significant interaction failed to occur between group classification and time on task. Thus, the results failed to support the hypothesis of a sustained attention deficit in hyperactives, since if hyperactives have a sustained attention deficit, both d and should have shown a significantly greater decline in the hyperactive group than in the controls with time on task.The authors wish to thank L. Leertouwer for making the drawings. This research was supported by grants from the Netherlands Foundation for the Advancement of Pure Research (ZWO) and the Professor Duijker Fund.     

Nonregulation of food intake in restrained,emotional, and external eaters

In the present study, regulation of ice cream intake after a preload was examined in 20 high and 20 low scorers (median split) on subscales of the Restraint Scale (RS) (Herman, Polivy, Pliner, Threshold, & Munic, 1978) and the Dutch Eating Behavior Questionnaire (DEBQ) (van Strien, 1986). For each subscale it was hypothesized that low scorers would regulate their ice cream intake. High scorers on disinhibitive scales (i.e., the RS and the DEBQ-emotional and -external subscales) were expected to counterregulate after a preload. In contrast, high scorers on the inhibitive DEBQ-restraint scale were expected to regulate their ice cream intake. A robust effect was found: high scorers never regulated ice cream intake after a preload on either the disinhibitive or the inhibitive scales, while low scorers always did. For the RS a significant interaction effect was found [F(1,39)=4.97, p=.03]. None of the other subscales showed interaction effects. The t tests showed that low scorers on all subscales ate significantly less after a preload than without one, while high scorers on all subscales did not differ in intake after a preload or without one. This nonregulation appears to be characteristic of people preoccupied with caloric intake, regardless of the content of the preoccupation.