The observational study of adolescent gambling in UK amusement arcades

In the UK, excessive fruit machine playing is the most documented form of pathological gambling amongst adolescents. Although there have been a few retrospective questionnaire studies in adolescent fruit machine gambling, there has been very little systematic observational fieldwork into the behaviour. The studies reported explore the social world of fruit machine playing using data collected via the monitoring of 33 UK amusement arcades employing participant and non-participant observation methodologies. The basic aims were to observe the arcade clientele and their behavioural characteristics, and to examine motivations for machine playing. Results suggest that level of adolescent gambling depends upon both time of day and time of year, and regular players conform to rules of etiquette and display stereotypical behaviours when playing fruit machines. The results also suggest that adolescents play fruit machines for a wide range of reasons including fun, to win money, to socialize, to escape and for excitement, and that inland and coastal arcades are frequented by different clienteles, probably as a function of the amusement machine available.     

The fear potentiated startle effect

A differential conditioning study examined whether an acoustic startle probe, presented during extinction of an aversively conditioned visual stimulus, potentiated the reflex eyeblink response in humans and whether this potentiation varied with the change in affective valence of the conditioned stimulus. Sixty college students were randomly assigned to view a series of two slides, depicting either unpleasant/highly arousing, unpleasant/moderate arousing, neutral/calm, pleasant/moderate arousing or pleasant/highly arousing scenes and objects (duration: 8 sec). During preconditioning (8 trials) and extinction (24 trials) acoustic startle probes (white noise bursts [50 ms; 95 dBA] were administered during and between slide presentation). During acquisition (16 trials) CS+ was reinforced by an electric shock. Startle response magnitudes significantly increased from preconditioning to extinction and were substantially larger to CS+. Conditioned startle reflex augmentation linearly increased with the pleasantness of the slides. Furthermore, subjects showed a greater post-conditioning increase of judged aversiveness to slides that they had previously reported to be more pleasant, exactly paralleling the startle reflex results.

     

Poisson signal-detection theory: Link between threshold models and the Gaussian assumption

The Gaussian model of signal detection cannot fit asymmetric data as long as the variances of the distributions are kept equal. It is therefore common practice to assume unequal variances in order to fit these data. But this assumption leads to the well-known crossover problem. The present paper provides new arguments for the abandonment of the Gaussian model with unequal variances. In its stead, this paper reevaluates multiple-parallel-threshold models. In particular, the Poisson model turns out to be very useful: it can handle data with any degree of asymmetry, giving a reasonable interpretation of the two parameters of the receiver-operating characteristic. The three-state-threshold model (Krantz, 1969) is given a new interpretation in light of the Poisson model. The slope of Poisson double-probability plots turns out to be much closer to unity than is predicted by the Gaussian approximation.     

Facilitation and helplessness: The interaction of perceived difficulty and importance of a task

Experimentally induced failure sometimes produces helplessness and sometimes facilitation on subsequent tasks. A model which accounts for this in terms of variations in perceived task difficulty and importance and variations in the cost of effort is proposed. Predictions from the model were confirmed in two experiments using the finger shuttlebox. When subjects expected the test task to be easy, importance of test outcome did not affect performance. However, when they expected the test task to be difficult, low outcome importance led to debilitation, and high importance to facilitation. If, in this condition, subjects experienced initial failure on the task perceived as difficult and important, helplessness rather than facilitation was observed. The model proposed may account for some of the conflicting results obtained in laboratory studies of human helplessness.