Are visual features of a looming or receding object processed in a capacity-free manner?

Numerous experiments have examined whether moving stimuli capture spatial attention but none have sought to determine whether visual features of looming and receding objects are extracted in a capacity-free manner. The current experiment (N = 28) used the task-choice procedure originated by Besner and Care (2003) to examine this possibility. Stimuli were presented in 3D space by manipulating retinal disparity. Results indicate that features of an object are extracted in a capacity-free manner for both looming and receding objects for participants who consciously perceive motion but not for participants who do not consciously perceive motion. These results suggest that the cognitive system is biased to process potentially animate objects, perhaps because of the evolutionary advantage this cognitive ability may provide.     

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.     

Negative priming from masked words: retrospective prime clarification of center-surround inhibition?

Masked repetition and semantic priming effects were examined in 2 experiments. In Experiment 1, a masked-prime lexical decision task followed a phase of detection, semantic, or repetition judgments about masked words. In Experiment 2 participants made speeded pronunciations to target words after they tried to identify masked primes, and the proportion of semantically and identically related prime-target pairs was varied. Center-surround theory CT. H. Carr & D. Dagenbach, 1990; D. Dagenbach, T. H. Carr, & A. Wilhelmsen, 1989) predicts positive repetition priming but negative semantic priming when people attempt, but fail, to extract the meanings of masked words. A retrospective prime-clarification account, in contrast, predicts that semantic and repetition priming effects will vary (being positive or negative) as a function of expectations about the prime-target relation. The data support a retrospective prime-clarification account, which, unlike center-surround theory, correctly predicted negative repetition priming effects.     

Response conflict reverses priming: a replication

Subjects named target words that followed a masked prime word of 33-msec (Experiments 1A and 1B) or 200-msec (Experiment 2) duration. The target word was either presented alone or accompanied by an interleaved distractor word. Targets presented alone were named more quickly following an identical prime than following an unrelated prime (repetition priming). In Experiment 1A, targets with distractors were named more slowly following an identical prime than following an unrelated prime (negative priming), replicating Milliken, Joordens, Merikle, and Seiffert (Psychological Review, 1998). In Experiments 1B and 2, repetition priming was reduced, although not reversed, for targets with distractors. The results of all three experiments are opposite to the usual finding of enhanced priming for perceptually degraded targets and suggest that response conflict engages retrospective mechanisms that counteract the facilitatory effects of priming.     

Reading “glasses” will prime “vision,” but reading a pair of “glasses” will not

In a lexical decision task with two primes and a target, the target was preceded 300 msec by the second prime (P2) which in turn was preceded by a brief forward and backward masked first prime (P1). When P1 and P2 were unrelated, reaction times were faster when the target was related to P2 (e.g.,wave SALT ... pepper) than when the target was unrelated to P2 (and P1—e.g.,wave LOAN ... pepper). However, this semantic priming effect was reduced to statistically nonsignificant levels when P1 and P2 were repetitions of the same word. That is, priming did not occur forsalt SALT ... pepper relative toloan LOAN ... pepper. This reduction in priming was observed whether P2 and the target were strongly or weakly related. These findings raise problems for current accounts of semantic priming.     

An empirical comparison of natural-father and stepfather family systems.

This study examined the family system differences between 40 volunteer natural-father and stepfather families. Family triads consisting of the husband, the wife, and a child whose age ranged from 12 to 15 years were studied. Four instruments were used: (a) the Family Concept Q-Sort; (b) a Semantic Differential; (c) a demographic questionnaire; and (d) an interaction-reaction questionnaire. Analyses of variance on the data obtained from the Q-sorts and the Semantic Differentials indicated that stepfather family systems are different from natural-father family systems along several salient dimensions including psychological adjustment, satisfaction with family, reciprocal understanding, and perceived goodness and potency. It was concluded that the differences between the family systems in terms of their interpersonal relations and perceptions affect the entire stepparent family system and its ability to function adequately.     

Munchausen syndrome by proxy: Clinical review and legal issues

Well-established policies and procedures govern the identification, management, and treatment of most variations of child abuse. For many therapists, such cases have become “routine”. Munchausen syndrome by proxy is an under-recognized form of child abuse in which a parent feigns or creates illness in a child specifically to have the child subjected to unnecessary diagnostic tests and treatments by medical practitioners. Variations range from false reports of fevers or allergies, to life-threatening abuse, such as surreptitious poisonings or injections with toxic substances. This article reports a case example of Munchausen syndrome by proxy, provides a review of historical, diagnostic and management issues, and discusses legal issues relevant to detection of the perpetrator and protection of the child victim.