The perception of number from the separability of the stimulus: The Stroop effect revisited

The literature on numerical perception is reviewed from the standpoint of research on selective attention, and predictions are made concerning the dimensional interaction between physical and numerical size of numerals. We manipulated stimulus differences to make the classification of numerical value slightly better (Experiment 1), substantially better (Experiment 2), or worse (Experiments 3–4) than classification of physical size. Garner, Stroop, and redundancy effects were used to gauge the degree of interactive processing. For nearly matched discriminability, both number and size appeared separable when the dimensions were varied orthogonally, but showed Stroop interference and redundancy gain when the dimensions were varied in a correlative fashion. When mismatched, asymmetric Garner and Stroop effects emerged in orthogonal contexts along with Stroop and redundancy gains in correlative contexts. These findings define a unique relation: Numerical value and physical size were optionally separable dimensions. We conclude that a magnitude representation is not mandatory for the perception of numerals. Our conclusions offer a new perspective for understanding both numerical perception and the Stroop phenomenon itself.     

Decisions of timing in bipolarized conflict situations with complete information

Games of timing constitute a sub-class of two-person, constant-sum, infinite games, where the problem facing each player is not what action to take, but rather when he should take action. The theoretical structure of games of timing with complete information and equal accuracy functions is described. An experimental paradigm of such games is presented by a computer-controlled, two-person, infinite game that simulates the Western-style duel.Ten pairs of male subjects participated in three sessions each in a duel experiment. Each pair played 420 duels in which both players had the same accuracy function, but the starting number of bullets available to each player in the dyad was varied systematically. The results of this experiment are analyzed and discussed in terms of variables that relate to predictions arising from the mathematical theory of duels.     

Decisions of timing in experimental probabilistic duels

The paradigm of the 2-person, zerosum, infinite game as a model of bipolarized conflicts in real time is extended to the probabilistic duel, where a player does not know with certainty whether or not this opponent is armed, but only knows the probability of such armament. Twenty dyads participated in a computer-controlled probabilistic duel experiment, ten of them playing a noisy version (where all bullets fired are public knowledge) and ten playing a silent version (where unsuccessful fire is unknown to the opponent). Several game-theoretic implications were tested, some of which demonstrate the efficacy of the theory of games of timing as an explicatory mechanism for decision behavior in experimental duels.     

A PDP-11/45 program for playing n-person characteristic function games

NPER II is an on-line PDP-11/45 computer program for studying bargaining and coalition formation processes within the framework of n-person games in characteristic function form. The extensive vocabulary of the program and its mode of operation are presented nontechnically, followed by an examination of a protocol from a sample four-person game. Improvements over a previous version of the program and applications to other experimental paradigms investigating coalition formation and bargaining are discussed in the last two sections of the paper.     

The effect of contextual factors on the judgement of informal reasoning fallacies

Informal reasoning fallacies are arguments that are psychologically persuasive but not valid. In order to judge the validity of these arguments one has to be sensitive to the context in which they appear. However, there is no empirical study that examines students' sensitivity to contextual factors and whether contextual factors actually influence their ability to identify informal reasoning fallacies. We hypothesized that when explicitly presented with different argumentative contexts, students' performance would reflect their sensitivity to the contextual nature of informal reasoning fallacies. The two experiments that we conducted support this hypothesis and emphasize the mediating role of perspective taking in students' ability to identify fallacious arguments.     

Adolescents' perception of the ideal mate: its relationship to parental characteristics in intact and nonintact families

The relation of adolescents' experiencing parental divorce, their perception of parents' characteristics, and their perception of the ideal mate's characteristics was investigated. One hundred adolescents from intact families and 79 from nonintact families were asked to rank both the degree to which each of 40 personality traits characterized their parents and the degree to which each characterized an ideal partner. The results indicated that there was no significant difference between adolescents from intact and nonintact families in the independence of their characterizations of their ideal mate and of their parents. However, differences were found on some of the personality dimensions that were investigated. These and other findings are discussed within the framework of psychoanalytic theory.     

A discrete time model for detection of randomly presented stimuli

Considered in this paper is a discrete-time Markov decision process with unobservable states, which occurs in equipment checking, medical diagnosis, signal detection, and reaction time studies. The process is characterized by (i) a state S₀ that at some unknown time t, which is determined probabilistically, turns into an absorbing state S₁; (ii) observations that provide fallible information about the true state and which are taken sequentially to determine whether or not the change from S₀ to S₁ has occurred; and (iii) losses for a false alarm and for delays in detecting the change. A response model is proposed, prescribing a terminal decision as soon as the posterior probability that S₁ obtains reaches or exceeds a fixed probability boundary. Predictions are derived concerning the probability of false alarm and several conditional distributions of the number of observations taken.     

Effects of financial incentives on the breakdown of mutual trust

Disagreements between psychologists and economists about the need for and size of financial incentives continue to be hotly discussed. We examine the effects of financial incentives in a class of interactive decision-making situations, called centipede games, in which mutual trust is essential for cooperation. Invoking backward induction, the Nash equilibrium solution for these games is counterintuitive. Our previous research showed that when the number of players in the centipede game is increased from two to three, the game is iterated in time, the players are rematched, and the stakes are unusually high, behavior approaches equilibrium play. Results from the present study show that reducing the size of the stakes elicits dramatically different patterns of behavior. We argue that when mutual trust is involved, the magnitude of financial incentives can induce a considerable difference.     

Bonus and Penalty in Common Pool Resource Dilemmas under Uncertainty

Common pool resource (CPR) dilemmas constitute a class of social dilemmas in which equilibrium behavior results in Pareto deficient outcomes that are not at all desirable by the group. We focus on a class of CPR dilemmas that, in addition to strategic uncertainty about the harvesting behavior of the other group members, include environmental uncertainty about the size of the CPR. In an attempt to decrease the rate of requests from the common pool, and thereby increase individual payoffs, we extend previous research-both theoretically and experimentally-in two different directions. In the bonus treatment, a reward is given to the agent(s) who requests the least, and in the penalty treatment, a charge is imposed on the agent(s) who requests the most. We show that under equilibrium play the bonus treatment decreases total group request, whereas the penalty treatment increases it. Our experimental results do not support this prediction. Rather, both treatments considerably decrease the rate of request and, therefore, increase the rate of provision. The penalty treatment is shown to be more effective in reducing individual requests and enhancing provision rates than the bonus treatment. Copyright 2001 Academic Press.