Presence and television.

Film and a number of emerging entertainment technologies offer media consumers an illusion of nonmediation known as presence. To investigate the possibility that television can evoke presence, 65 undergraduate students were shown brief examples of rapid point‐of‐view movement from commercially available videotapes on a television with either a small screen (12 inches [30.5 cm], measured diagonally) or a large screen (46 inches [116.8 cm]). Participants' responses were measured via a questionnaire and a computer‐based recording of arousal (electrodermal activity). Viewers of both televisions reported an enjoyable sense of physical movement, excitement, involvement, and a sense of participation. Furthermore, as predicted, participants who watched the large screen television thought the movement in the scenes was faster, experienced a greater sense of physical movement, enjoyed the movement to a greater extent, found the viewing experience more exciting, and were more physiologically aroused. Practical and theoretical implications are discussed.     

The relation between the generalized matching law and signal-detection theory

The generalized matching law can be applied to a signal-detection matrix to give two equations. The first relates responding in the presence of the stimulus to the reinforcements for the responses, and the second relates responding in the absence of the stimulus to the reinforcements for the responses. Evidence for stimulus discrimination is given by biases that are opposite in sign in the two equations. As the logarithmic ratio and z proportion transformations are similar, the combination of the absolute values of the two logarithmic biases gives a measure equivalent to the signal-detection measures d′ and η. The two equations can also be combined to eliminate the biases caused by the signalling stimuli and to produce a generalized matching-law statement relating overall performance to the obtained reinforcements.     

Forms, uses and functions of children's favourite objects

In this study, the notion of a favourite object is used as a heuristic concept for things that children are occupied with and absorbed by. According to earlier studies, favourite objects can be grouped into four categories: forerunners of transitional objects, primary and secondary transitional objects, and favourite toys. This initial classification was compared to results of cluster analyses of characteristics of favourite objects among 32 preschool and 30 primary school children, corroborating the initial classification and specifying the typology. The distribution of types of objects was different for the two groups of children, but was not dependent on age within groups or, for the preschool children, on mental development. These results indicate that changes of favourite objects with mental maturation are slow.
The softness of the material of primary and secondary transitional objects and the preference for objects that could be kept close to the body suggest that the comforting character of these favourite objects has its root in the child's self-soothing actions with the object.     

Self-harming behavior of a parent with borderline personality disorder assessed using revealed preference and attributional approaches: a case study

This article discusses a case study involving a parent with Borderline Personality Disorder who exhibited self-harming behaviors. Assessment and intervention were based both on a review of the client's attributions about causes of her own behavior as being either internalizing or externalizing, and on a review of motivation of the behaviors using functional analysis. Antecedent situations for self-harming behaviors were identified to provide a basis for reviewing the client's attributions of reasons for disordered behavior. A new technique of functional analysis was applied using the principle of revealed preference arising from behavioral economics. Revealed preference identified outcomes that were valued by the client, enabling new responses to be identified to attain these reinforcers. Attribution re-training was provided. Significant reductions in self-harming behaviors were achieved during brief therapy and were maintained during follow-up.     

Preference for reinforcers under varying schedule arrangements: A behavioral economic analysis

The field of behavioral economics combines concepts from economics and operant conditioning to examine the influence of schedules or price on preference for reinforcers. Three case studies are reported in which behavioral economic analyses were used to assess relative preference for reinforcers shown by people with intellectual disabilities when schedule requirements varied. The studies examined (a) preference for different reinforcers, (b) substitutability of reinforcers, and (c) changes in preference as a function of schedule requirements.     

Choice: Effects of changeover schedules on concurrent performance

The components of concurrent schedules were separated temporally by placing interval schedules on the changeover key. The rates of responding on both the main and changeover keys were examined as a function of the reinforcement rates. In the first experiment, the sensitivity of main-key performance to changing reinforcement rates was inversely related to the temporal separation of components, and changeover performance was monotonically related to the ratio of the reinforcement rates. In the second experiment, when the ratio of the reinforcement rates was scheduled to remain constant while the frequency of reinforcement was varied, changeover performance did not remain constant. A “sampling” interpretation of changeover responding was proposed and subsequently tested in a third experiment where extinction was always scheduled in one component and the frequency of reinforcement was varied in the second component. It was concluded that changeover performance can be interpreted using molar measures of reinforcement and that animals sample activities available to them at rates which are controlled by relative reinforcement rates.     

Assessing preference for reinforcers using demand curves, work-rate functions, and expansion paths

Much research has focused on the effects of environmental variability on foraging decisions. However, the general pattern of preference for variability in delay to reward and aversion to variability in amount of reward remains unexplained a either a mechanistic or a functional level. Starlings' preferences between a fixed and a variable option were studied in two treatments, A and D. The fixed option was the same in both treatments (20-s fixed-interval delay, five units food). In Treatment A the variable option gave two equiprobable amounts of food (20-s delay, three or seven units) and in D it gave two equiprobable delays to food (2.5-s or 60.5-s delays, five units). In both treatments the programmed ratio [amount/(intertrial interval+latency+delay)] in the fixed option equaled the arithmetic mean of the two possible ratios in the variable option (ITI = 40 s, latency = 1 s). The variable option was strongly preferred in Treatment D and was weakly avoided in Treatment A. These results are discussed in the light of two theoretical models, a form of constrained rate maximization and a version of scalar expectancy theory. The latter accommodates more of the data and is based on independently verifiable assumptions, including Weber's law.