Social Interaction During Computer-based Activities: Comparisons by Number of Sessions, Gender, School-level, Gender Composition of the Group, and Computer-child Ratio

This study assessed the quality of social interactions that occur in group-based computer learning contexts. Gender comparisons of interactions were examined across 3 sessions with 116 preschoolers (M age?=?4.9 years) and 108 fifth and sixth-grade (M age?=?11.7 years) Canadian children from southwestern Ontario, when children had access to one computer per child (parallel computer) or one computer per group (integrated computer), and when they worked with same-gender or mixed-gender peers. Preschoolers engaged in more collaborative behaviors in mixed-gender than same-gender groups, while elementary children engaged in collaborative behaviors more often in integrated than parallel computer conditions. In mixed-gender groups, boys were more likely than girls to dominate the computer in elementary school while girls were more likely than boys to dominate the computer in preschool.     

Assessing ADHD-related Family Stressors with the Disruptive Behavior Stress Inventory (DBSI): A Replication and Extension

The Disruptive Behavior Stress Inventory (DBSI) was developed to provide information related to the occurrence and severity of stressors that result from having a child with ADHD. Data provided in the initial 2002 study by Johnson and Reader (Journal of Clinical Psychology in Medical Settings, 9, 51–62) provided good preliminary support for the reliability of the DBSI, as well the ability of the scale scores to differentiate primary caregivers of children with and without a history of ADHD. The present study was an attempt to replicate major findings of the 2002 study using an additional larger sample and extend it by conducting item-level analyses to determine the degree to which individual DBSI items differentiate primary caregivers of children with and without a history of ADHD. Results provided additional support for the reliability and validity of the DBSI by replicating major findings from the 2002 study and further suggesting that a large majority of the 40 items individually differentiate between primary caregivers of children with and without a history of ADHD.     

Women's body satisfaction at midlife and lifetime body size: a prospective study.

The relationship between past body size and current body dissatisfaction among 933 middle-aged women from a prospective birth cohort study was examined. Women provided self-report data on weight esteem at age 54. Height and weight data were collected at ages 7, 11, 15, 20, 26, 36, 43, and 54. Data on reproductive variables were also collected prospectively. Hierarchical linear modeling and multiple regression analyses were used. Women who were dissatisfied at midlife were heavier at age 7 and showed a more rapid increase in body mass index with age. A late menarche, being postmenopausal, and having started hormone replacement therapy before menopause were associated with less dissatisfaction. Attention to these factors across the life span is necessary to understand body dissatisfaction in women at midlife.     

Assimilative hue shifts in color depend on bar width

Hue shifts were measured in isoluminant color gratings whose bar width was varied from 2′ to 20′ of visual angle. Subjects matched the hues in each grating with individual Munsell swatches. Hue shifts were largest for bar widths of 2′; however, they depended on the color combination used. Green and red shifted toward (i.e., assimilated with) whatever second grating color they were paired with. Blue, on the other hand, assimilated with red and with yellow, but remained relatively unchanged when combined with green. Yellow shifted only minimally, regardless of the second grating color. Hue shifts decreased with increasing stripe width and disappeared between 4.5′ and 7.5′. Compared with the assimilative hue shifts, color contrast effects were slight or absent. These results cannot be attributed merely to chromatic aberration, macular pigment, eye movements, or field size.     

Transfer of a response controlling stimulus duration across discrimination problems

In the acquisition phase, pigeons learned to peck at a changeover key to shorten the duration of S? but not of S+ presented on the food key in a discrimination problem. In the transfer phase, the significance of S+ and S? was changed through extinction of both, equal reinforcement, or discrimination reversal, while the changeover key was not available. Transfer tests then showed appropriate modification of the changeover response. Similar transfer was demonstrated across orthogonal stimulus dimensions. Further analytic studies showed that this transfer of the changeover response did not depend upon mediation due to differential response rates to the food key. This research strategy enriches the study of the “second learning process” by providing an indicator of stimulus control in all phases of the procedure. Direct transfer between different problems also indicates that discriminative stimuli, although physically dissimilar, have the same “psychological value” for the subject.     

Computer signal detection by monitoring auditory evoked potentials

A digital computer, using a simple decision algorithm, attempted to determine when an acoustical signal had been presented to a cat by monitoring the amplitude of the evoked potentials (EP) at brainstem auditory nuclei. The signal-to-noise level at threshold and the shape and range of the decision model “psychometric functions” were similar to those obtained from humans in the same task. In addition, the detection performance obeys Weber’s law, the mean amplitude of the EP increases monotmonically with signal level, the variance of the amplitude is independent of both signal and noise level, and both the mean latency and the variance of the latency of the peaks decrease with increasing signal level. These findings suggest that the synchronization in firing of a population of single units plays a part in determining the amplitude of the EP. Interaural effects in detection performance were found at the inferior colliculus and, to a lesser extent, at the superior olive.     

Attention and multidimensional discrimination1

Observers’ ability to perform several discrimination tasks at the same time was tested using a two-alternative temporal forced-choice procedure. Discrimination of two auditory dimensions (pitch and intensity) and two visual dimensions (horizontal position and vertical position) was measured under conditions where one, two or all four dimensions required attention. Three signal durations were used: 67, 133, and 200 msec. Increasing the number of dimensions requiring attention systematically reduces the precisions of discrimination for each dimension. Auditory and visual discrimination is affected similarly. The amount of reduction in discrimination is independent of whether the dimensions requiring attention involve the same or different sensory modalities. The data are analyzed for evidence of a constant processing capacity employed in both single and multidimensional discrimination. The possibility that the observed performance levels could be achieved by sequentially processing the simultaneous inputs is also considered.     

Space and movement in working memory

Encoding seen movement of another human body requires visuo-spatial processing, and recall involves motor activity. However, encoding whole body movement patterns is affected differently by patterned and spatial secondary tasks, and this difference is reversed for encoding of spatial targets for movement (Smyth, Pearson, & Pendleton, 1988). The experiments reported here investigate the rehearsal of such movement patterns and their recall over unfilled and filled intervals. Performing, watching, or encoding a sequence of spatial positions while carrying a memory load of movement patterns did not affect recall of those movements, whereas performing, watching, or encoding a further set of patterned movements reduced the number recalled from the original set. However, memory for a series of locations in space was not affected by watching patterned movements during the interval, and only order information was affected by watching movement to a series of spatial locations during the interval. The results are discussed in terms of the independence of rehearsal mechanisms for spatial sequencing and movement patterns.