Reactivity and response to pain

Male and female volunteers (N = 144) answered the Reactivity Scale (RS) and underwent testing for their perceived intensity and tolerance for finger-pressure pain. Half the Ss were randomly assigned to a low-intensity treatment (1150 g) and half to a high-intensity treatment (2300 g). Pain was rated at 30 and 60 sec., and Ss were asked to endure it as long as possible up to 5 min. The major findings were as follows: (1) women outscored men on reactivity; (2) the three pain measures intercorrelated highly; (3) high-intensity stimulation produced higher pain ratings and shorter tolerance than did low-intensity stimulation; (4) men gave lower intensity ratings than women and tolerated the pain longer; (5) reactivity related positively to judged pain at 30 and 60 sec, and negatively to pain tolerance; (6) there were no significant interaction effects among stimulus intensity, sex and reactivity for any pain measure; (7) the variance in the pain measures accounted for by stimulus intensity, sex and reactivity ranged from 26 to 32%. The implications were briefly discussed for the validity of the RS and factors explaining responses to experimentally-induced pain.     

Visual context processing and its development in gamers and non-gamers

Visual context processing was investigated in both action video game players and nonplayers using the Ebbinghaus illusion task (N = 312, 39.4% female) in a cross-sectional study design. When presented in context, players showed markedly poorer target size discrimination accuracy compared with nonplayers in the 6-, 7-, 8-, and 9-years old age groups, but this difference was reduced in 10-years old group and diminished in adults. When presented in isolation (no-context), the two groups displayed similar performance in all age groups. Furthermore, nonplayers (linear) and players (bell curve) showed profoundly different age-related differences in context processing. These findings provide evidence that players might have enhanced perceptual bias to process visual context in the transition from early childhood to early adolescence, and the differences between the two groups start at early ages and continue with distinct developmental profiles.     

Some properties of estimated scale invariant covariance structures

Scale invariance is a property shared by many covariance structure models employed in practice. An example is provided by the well-known LISREL model subject only to classical normalizations and zero constraints on the parameters. It is shown that scale invariance implies that the estimated covariannce matrix must satisfy certain equations, and the nature of these equations depends on the fitting function used. In this context, the paper considers two classes of fitting functions: weighted least squares and the class of functions proposed by Swain.Constructive comments by the referees are greatly appreciated. The author gratefully acknowledges Michael Browne's interest in his work.     

Frame multiplicity and policy fiascoes: Limits to explanation

The dynamics of intractability, frame multiplicity and intense controversy not only characterize policy formation struggles, as described by Schön and Rein, but also affect the evaluation of policies and government action. Policy analysts play an important part in the politics of policy evaluation. This article demonstrates that they tend to produce very different explanations for controversial, failing policies. Such differing explanations imply different causal attributions, different allocations of blame, and different lessons for future policy-making. Such differences are not random occurrences; they are embedded in the analytical frames that evaluators use to reconstruct policy processes and to explain their outcomes. It is shown that at least three deep-rooted frames can be reconstructed: fiascoes as failures of public problem solving, fiascoes as institutional imbalances, and fiascoes as system artefacts. One of the great epistemological challenges is how to deal with multiple analytical frames. The final part of the article discusses various strategies.     

Early selective-attention effect on evoked potential reinterpreted

In a dichotic listening situation stimuli were presented one at a time and at random to either ear of the subject at constant inter-stimulus intervals of 800 msec. The subject's task was to detect and count occasional slightly different stimuli in one ear. In Experiment 1, these ‘signal’ stimuli were slightly louder, and in Experiment 2 they had a slightly higher pitch, than the much more frequent, ‘standard’, stimuli. In both experiments signals occured randomly at either ear. Separate evoked potentials from three different locations were recorded for each of the four kinds of stimuli (attended signals, unattended signals, attended standards, unattended standards). Contrary to Hillyard et al. (1973), no early (N₁ component) evoked-potential enhancement was observed to stimuli to the attended ear as compared with those to the unattended ear, but there was a later negative shift superimposed on potentials elicited by the former stimuli. This negative shift was considered identical to the N₁ enhancement of Hillyard and his colleagues which in the present study was forced, by the longer inter-stimulus interval used, to demonstrate temporal dissociation with the N₁ component. The ‘Hillyard effect’ was, consequently, explained as being caused by a superimposition of a CNV kind of negative shift on the evoked potential to the attended stimuli rather than by a growth of the ‘real’ N₁ component of the evoked potential.     

Motivation as a function of success frequency

Motivation and Emotion - It is well-established that intermediate challenge is optimally motivating. We tested whether this can be quantified into an inverted-U relationship between motivation and...     

Effects of ritanserin on offense and defense in male mice

Effects of ritanserin on agonistic behavior of isolated mice exhibiting aggressive or nonaggressive behavioral strategies were studied in pair-wise encounters with group-housed opponents. An ethological approach to behavioral scoring is adopted, which allows for examination of the profiles of individual subjects. Although the data generally support the view that ritanser in has little effect on offense or defense in male mice, the stimulation of pre-aggressive behavior (threats, alerts, tail rattles) was detected in some nonaggressive mice. © 1995 Wiley-Liss, Inc.     

Representational momentum and related displacements in spatial memory: A review of the findings

Memory for the final location of a moving target is often displaced in the direction of target motion, and this has been referred to asrepresentational momentum. Characteristics of the target (e.g., velocity, size, direction, and identity), display (e.g., target format, retention interval, and response method), context (landmarks, expectations, and attribution of motion source), and observer (e.g., allocation of attention, eye movements, and psychopathology) that influence the direction and magnitude of displacement are reviewed. Specific conclusions regarding numerous variables that influence displacement (e.g., presence of landmarks or surrounding context), as well as broad-based conclusions regarding displacement in general (e.g., displacement does not reflect objective physical principles, may reflect aspects of naive physics, does not solely reflect eye movements, may involve some modular processing, and reflects high-level processes) are drawn. A possible computational theory of displacement is suggested in which displacement (1) helps bridge the gap between perception and action and (2) plays a critical part in localizing stimuli in the environment.     

Locomotion,incidental learning,and the selection

In three experiments, we examined the effects of locomotion and incidental learning on the formation of spatial memories. Participants learned the locations of objects in a room and then made judgments of relative direction, using their memories (e.g., "Imagine you are standing at the clock, facing the jar. Point to the book"). The experiments manipulated the number of headings experienced, the amount of interaction with the objects, and whether the participants were informed that their memories of the layout would be tested. When participants were required to maintain a constant body orientation during learning (Experiment 1), they represented the layout in terms of a single reference direction parallel to that orientation. When they were allowed to move freely in the room (Experiment 2), they seemed to use two orthogonal reference axes aligned with the walls of the enclosing room. Extensive movement under incidental learning conditions (Experiment 3) yielded a mixture of these two encoding strategies across participants. There was no evidence that locomotion, interaction with objects, or incidental learning led to the formation of spatial memories that differed from those formed from static viewing.