It looks easy! Heuristics for combinatorial optimization problems

Human performance on instances of computationally intractable optimization problems, such as the travelling salesperson problem (TSP), can be excellent. We have proposed a boundary-following heuristic to account for this finding. We report three experiments with TSPs where the capacity to employ this heuristic was varied. In Experiment 1, participants free to use the heuristic produced solutions significantly closer to optimal than did those prevented from doing so. Experiments 2 and 3 together replicated this finding in larger problems and demonstrated that a potential confound had no effect. In all three experiments, performance was closely matched by a boundary-following model. The results implicate global rather than purely local processes. Humans may have access to simple, perceptually based, heuristics that are suited to some combinatorial optimization tasks.     

Collaboration Technologies Improve Performance and Communication in Air Battle Management

Team communication is critical for Air Battle Management (ABM). In this study, two communication tools (text chat and electronic whiteboard) and two team resource aids (tabular and graphical displays) were introduced during simulated ABM to supplement radio communication. Results showed that combined chat and virtual whiteboard improved team performance, decreased number and duration of radio transmissions, but had mixed effects on workload. In addition, the graphical resource display improved team performance, decreased number and duration of radio transmissions, and reduced workload compared to the tabular display. These findings indicate that collaboration technologies introduced in this experiment may benefit military operations.     

Word-frequency and phonological-neighborhood effects on verbal short-term memory

Immediate memory span and maximal articulation rate were assessed for word sets differing in frequency, word-neighborhood size, and average word-neighborhood frequency. Memory span was greater for high- than low-frequency words, greater for words from large than small phonological neighborhoods, and greater for words from high- than low-frequency phonological neighborhoods. Maximal articulation rate was also facilitated by word frequency, phonological-neighborhood size, and neighborhood frequency. In a final study all 3 lexical variables were found to influence the recall outcome for individual words. These effects of phonological-word neighborhood on memory performance suggest that phonological information in long-term memory plays an active role in recall in short-term-memory tasks, and they present a challenge to current theories of short-term memory.     

Book reviews

Cult Controversies: The Societal Response to the New Religious Movements James A. Beckford Tavistock Publications, London, 1985

The New Elect: The Church and New Religious Groups. Martin Tierney Veritas, Dublin, 1985

The Occult Roots of Nazism. Nicholas Goodrick‐Clarke. The Aquarian Press. £12.95 pp. 294     

Families' Perceptions of the One-way Screen in the First Meeting

A survey was conducted of family members' perceptions of the initial family interview using a one-way screen with live consultation. There was a high response rate (95%, n = 43 families) and the majority of respondents (80%) perceived the overall experience as useful. Those who read the clinic's information leaflet in advance and felt able to share concerns about the process with the interviewer tended to forget about the screen more quickly. Those who read the leaflet were more likely to find the overall meeting useful. The survey generated a number of suggestions to make this first meeting more 'user friendly'.     

Effects of frustration and magnitude of reward on selective attention, size estimation, and verbal evaluation

A high expectancy of success in playing a “fishing game” was established for all subjects (fourth-grade children) Subjects then played the fishing game for money A nonsense syllable was associated with the money. Half of the subjects were frustrated in their attempts to obtain the money, while the remaining subjects were rewarded in their attempts The dependent measures indicated that, relative to rewarded and control subjects, frustrated subjects (a) looked at pictures of money more often, (b) overestimated the size of money, and (c) attributed more positive statements to the syllable associated with reward Subjects frustrated on a larger reward showed these effects to a greater extent than subjects frustrated on a smaller reward These data support the hypothesis that the incentive value of a reward, and of salient neutral stimuli associated with the reward, is increased by frustration, and that this effect is strengthened by the use of larger rewards.     

Effects of status of attacker and intensity of attack on the intensity of counter-aggression1

Male college students were exposed to a Same, Lower, or Higher status confederate, and to a small or large number of electric shocks from the stooge. Subjects in the Same and High status conditions were more counter-aggressive, both in terms of mean intensity and number of shocks, than subjects exposed to a Low status confederate. These results are in contradiction to the related human and animal data, which have generally indicated that more aggression is directed toward low rather than high status persons The major implications of the present data for other research in this area are (1) the importance of varying status of the attacked as well as status of the attacker, (2) the necessity for systematically varying the different dimensions of “status,” e g, functional (i e, powerful) vs. nonfunctional aspects of status, (3) the importance of looking at different kinds of aggression, e g, physical as well as verbal, (4) the importance of systematically assessing the subject's perceptions of the attacker and the subject's own emotions–arousal, anxiety, guilt, etc at the time of the attack, and (5) the potential for studying variables that determine aggressive and altruistic behavior within the same experimental context.