A linear optical trajectory informs the fielder where to run to the side to catch fly balls

P. McLeod, N. Reed, and Z. Dienes (2002) argued that the linear optical trajectory (LOT) strategy incorrectly cues fielders to run forward for balls headed beyond them. The authors of this article explain that the downward optical curvature found for balls landing beyond the fielder's initial position occurs because the balls reorient the direction the fielder is facing during pursuit. Thus, when downward optical curvature begins, the ball is headed to land in front of where the fielder is facing and running. This investigation of open-loop failure conditions has led to new insights such as the reorientation of the fielder, and it supports the use of maintaining matching rates of vertical and lateral optical ball movement consistent with primacy of the LOT control mechanism even when interception is unachievable.     

Time-to-contact estimation of accelerated stimuli is based on first-order information

The goal of this study was to test whether 1st-order information, which does not account for acceleration, is used (a) to estimate the time to contact (TTC) of an accelerated stimulus after the occlusion of a final part of its trajectory and (b) to indirectly intercept an accelerated stimulus with a thrown projectile. Both tasks require the production of an action on the basis of predictive information acquired before the arrival of the stimulus at the target and allow the experimenter to make quantitative predictions about the participants' use (or nonuse) of 1st-order information. The results show that participants do not use information about acceleration and that they commit errors that rely quantitatively on 1st-order information even when acceleration is psychophysically detectable. In the indirect interceptive task, action is planned about 200 ms before the initiation of the movement, at which time the 1st-order TTC attains a critical value.     

Cultural meanings of nature: an analysis of contemporary motion pictures

To evaluate current cultural meanings of nature, the authors asked 65 undergraduate students to "list 3 movies in which nature was an important aspect of the film." They also were asked to specify the natural element that stood out to them and describe "how it related to the overall theme of the movie." Two independent groups of raters skilled in interpretive analysis developed thematic meanings from these responses. Following this, in a 2nd study, a different group of participants rated the 18 most frequently mentioned natural elements on thematic scales derived from the initial interpretive analysis. Participants in the 1st study mentioned 33 different movies at least twice and 5 themes that captured the meaning of nature in these films. Correlational results derived from the 2nd study indicated that rating scales reflecting these 5 themes formed 2 distinct groups; the first group described settings in which nature is experienced as adversarial and plays a significant role in dramatic action, and the second group defined settings in which nature is viewed either as a place of refuge or simply as a locale in which ongoing narrative action occurs. The general conclusion reached in both studies concerns the often noted but not always appreciated fact that movies--similar to everyday events and actions--always take place in specific settings and that neither life events nor dramatic narratives can be understood apart from specific settings.     

Effects of alternative reinforcement on human behavior: the source does matter

Competing theories regarding the effects of delivering periodic response-independent reinforcement (more accurately, response-independent points exchanged for money) on a baseline rate of behavior were evaluated in human subjects. Contiguity theory holds that these events decrease target responding because incompatible behavior is adventitiously strengthened when the point deliveries follow target behavior closely in time. Matching theory holds that response-independent points, like any other alternative reinforcer, should reduce target responding. On this view, temporal contiguity between target responding and response-independent point delivery is unimportant. In our experiment, four different responses (moving a joystick in four different directions) were reinforced with points exchangeable for money according to four independent variable-interval schedules. Different schedules of point delivery were then superimposed on these baselines. When all superimposed point deliveries occurred immediately after one of the four responses (the target response), time allocated to target responding increased. When the superimposed point deliveries could be delivered at any time, time allocated to target responding declined and other behavior increased. When superimposed points could never immediately follow target responses, time allocated to target responding decreased further and other behavior or pausing predominated. The findings underscore the contribution of temporal contiguity in the effects of response-independent deliveries of food, money, points, etc.     

Science and Human Behavior: a tutorial in behavior analysis

B. F. Skinner's Science and Human Behavior (1953) became the main source of my understanding of behavior during my first semester as a college professor in 1955 at Kansas University. It has continued to exert a major influence throughout my career as the basis for a completely deterministic science of behavior, as a handbook to be consulted as a first step in dealing with any issue in behavior analysis, and as a tutorial in behavioral interpretive analysis--in the use of a small number of behavioral concepts and principles to understand behavior of all degrees of complexity. I describe four general interpretive orientations or maxims that are of broad significance for behavior analysis, and also two underappreciated major theoretical contributions.     

Perceptual judgements of others' tasting experiences: are they enjoying their food?

Motivated by previous work suggesting that infants make stereotypic facial reactions to different tastes, we assessed communicative signals that might enable an adult to interpret the strength, taste, and hedonic value of a liquid flavour another adult is consuming. Four subjects (tasters) were overtly videoed consuming drinks that varied in strength (low, medium, and high concentrations), taste (sweet, sour, bitter, and salty), and hedonic value (taster-rated enjoyment). 26 observers assessed the strength, taste, and taster's enjoyment of the drink from video clips of the tasters. Observers perceived the hedonic value of the drinks to the taster and the drinks' strength based on the tasters' reactions but were generally poor at assessing the specific taste of the drink. For all tastes except the bitter ones, observers might have based their judgements of taste on how much the taster appeared to enjoy the drink. These findings are discussed in terms of communication of food's value.     

A cognitive-behavioural analysis of mental toughness in national rugby league football teams

This study examined the relations between demographic characteristics of rugby players and selected aspects of psychological performance in rugby league football. Mental toughness was assessed using Psychological Performance Inventory and Hardiness on the Personal Views Survey III-R. Participants (N=70) were international rugby league footballers representing four teams (Wales, France, Ireland, England) in the 2000 Rugby League World Cup. Participants completed the questionnaires in training camp. Welsh-nationality players had a significantly higher mean score on two of the hardiness subscales. Hardiness measures displayed the greatest and most frequently statistically significant differences. The findings concur with previous work indicating superior hardiness is related to improved performance in sports.     

Contents Volume 112 2003

Volume Contents

Contents Volume 112 2003     

Author index 115 2003

Authors Index

Author index 115 2003