THE INFLUENCE OF INTENSITY AND DURATION OF ELECTRICAL STIMULATION ON SUBJECTIVE VARIABLES

The unpleasantness and subjective duration of an A.C. current of 50 c/sec applied to two fingers was scaled by subjects using the method of magnitude estimation. Stimulation was varied with regard to both intensity and duration. It was found that (1) unpleasantness increased logarithmically with stimulus duration, (2) unpleasantness was a power function, with the exponent 1.5, of stimulus intensity, (3) subjective duration was essentially linearly related to stimulus duration, and (4) subjective duration increased logarithmically with intensity of stimulation.     

Lightness matching for different visual routes through a compound scene

Left and right halves of a visual display were covered with inducing fields (IFs) of different lightnesses. S’s monocular gaze moved over an irreversible route from a neutral Munsell target to a CO series through either the left- or right-side IFs. For the 16 Ss there were 8 different IFs, varying from light to dark. For each of three different gray targets Munsell CO choices varied directly with the lightness of the IFs through which the gaze was routed rather than with the lightness of the total presented display. A replication with modifications is also reported.     

Family preservation using multisystemic treatment: Long-term follow-up to a clinical trial with serious juvenile offenders

In a randomized clinical trial, multisystemic family preservation was shown to significantly reduce rates of criminal activity and incarceration in a sample of 84 serious juvenile offenders and their multi-need families. In the current study, archival records were searched for re-arrest an average of 2.4 years post-referral. Survival analysis showed that youths who received multisystemic family preservation were less likely to be re-arrested than were youths who had received usual services. Such results represent the first controlled demonstration that family preservation, when delivered via a clearly specified treatment model, has lasting effects with serious juvenile offenders. Implications for family preservation and juvenile justice research are discussed.     

The relationship between father absence and children's social problem solving competencies

Predictions of deficits in children's social problem-solving competencies due to early and continuing father absence were investigated. To test these predictions, equal numbers of father-present and father-absent third graders matched on a number of variables were assessed on measures of social problem-solving performance. In Phase 2 of the study, half of the children from the father-absent category received a 15 week intervention programme which was conducted by adult male trainers to provide structured practice in social problem solving. Results demonstrated that father-absent treatment subjects, compared to father-absent control subjects, improved their social problem-solving skills significantly. Despite improvement due to intervention, social problem-solving scores for father-absent treatment subjects were still below those for father-present control subjects. Educational and developmental implications of the findings were discussed.     

Timing the “magical number seven”: Presentation rate and regularity affect verbal working memory performance

The informative value of time and temporal structure often remains neglected in cognitive assessments. However, next to information about stimulus identity we can exploit temporal ordering principles, such as regularity, periodicity, or grouping to generate predictions about the timing of future events. Such predictions may improve cognitive performance by optimising adaptation to dynamic stimuli. Here, we investigated the influence of temporal structure on verbal working memory by assessing immediate recall performance for aurally presented digit sequences (forward digit span) as a function of standard (1000 ms stimulus-onset-asynchronies, SOAs), short (700 ms), long (1300 ms) and mixed (700–1300 ms) stimulus timing during the presentation phase. Participant's digit spans were lower for short and mixed SOA presentation relative to standard SOAs. This confirms an impact of temporal structure on the classic “magical number seven,” suggesting that working memory performance can in part be regulated through the systematic application of temporal ordering principles.     

The utility of ground rule instructions with younger and older adult witnesses

This study examined the effectiveness of ground rules—simple instructions outlining the communication expectations of an investigative interview—with 73 younger (age 18–40) and 57 older (age 60+) adults. Participants watched a film depicting an implied sexual assault and were interviewed after a brief delay. One third received no ground rules, one third received ground rules as statements, and one third received the statements along with practice examples. The interview contained questions that required participants to apply one of the rules. Those who received ground rules were asked their perceptions of the rules. Results demonstrated that practicing ground rules improved response quality to problematic recognition questions, younger adults showed more variability in responses to different ground rules than older adults, and most participants found ground rule instructions useful in investigative interviews. Results provide support for the use of ground rules in interviews with adult witnesses.     

Feeling time in nature: The influence of directed and undirected attention on time awareness

In the present study, we examined the impact of the interaction of environmental and task-induced attentional focus on time perception, specifically awareness of the time flow. We tested 48 participants in either a natural or urban setting over three 25- to 35-min sessions. We manipulated the within-subjects factor task by means of two tasks—one requiring directed attention on the task itself, the other undirected attention on the environment—alongside a control condition with no specific task. We measured time awareness, passage of time judgments, felt time judgments, and estimated time as dependent variables. For time awareness, we found an interaction between environment and task: in the natural environment, only a task requiring directed attention reduced time awareness; whereas, in the urban environment, both tasks reduced time awareness compared to the control condition. The results suggest that natural environments increase time awareness unless we focus our attention on a task.