Does word training increase or decrease interference in a stroop task?

First and second graders (6- and 7-year-olds) practiced reading 20 words. Before and after word training, they named pictures printed with and without these words as distractors. Of interest was whether training would enhance or diminish the interference created by these words in the picture-naming task. Results indicated that children who learned to recognize unfamiliar distractor words more accurately suffered more interference after training. In contrast, children who were already familiar with the words and learned to recognize them faster experienced less interference following training. Results are interpreted as supporting LaBerge and Samuels' model of automatic word processing. Effects of accuracy training are attributed to the elimination of attention as a requirement for processing distractor words. Effects of speed training are attributed to a reduction in the time consumed by distractor words in the central processor.     

Reading between the lines: Event-related brain potentials during natural sentence processing

Event-related potentials (ERPs) were recorded from subjects as they silently read 160 different seven-word sentences, presented one word at a time. Each sentence was in itself a natural, meaningful phrase. Substantial intersubject variability was observed in the ERP waveshapes following the words. More than half of the subjects generated P3 components to word stimuli, but those who did showed similar responses to repeated control presentations of a single word. In addition, it was found that all but the first word in the sentence elicited an ERP with a significant left-greater-than-right asymmetry in the late positivity over temporo-parietal regions. The ERPs to the last words were associated with more late positivity than those to the preceding words. One quarter of the sentences, at random, ended with a word printed in a typeface that was different from that of the preceding words. This infrequent change in typeface elicited a complex ERP having three consistent late positive components.     

A study of the relationship between individual differences in nonverbal expressiveness and factors of personality and social interaction

Some theoretical and applied implications of individual differences in nonverbal expressiveness were investigated in a medical setting. In Study I, the abilities of 21 physicians to express different emotions through voice tone were assessed and related to physician personality and to actual patient ratings of the physician. Study II replicated Study I using visual as well as vocal cues (i.e., videotapes) of a new sample of physicians, and added a study of physician greetings. It was found that: (1) Aspects of expressive ability were reliably correlated with a cluster of personality traits, thus supporting the notion that nonverbal affective style may be a window to inner dispositions; and (2) expressive ability was related to patient satisfaction with the interpersonal manner of their physicians and to the judged likeability of the physician's greeting, thus providing evidence for the importance of this ability for social interaction.     

Social group salience and interethnic cooperation

This research was designed to test the adequacy of H. Tajfel's (1978, Differentiation between social groups: Studies in the social psychology of intergroup relations, New York/London: Academic Press) theory of social identity for predicting cooperative behavior among members of ethnically mixed groups. Equally divided by sex, subjects were 24 Anglo-American and 24 Hispanic undergraduate students attending the University of California, Riverside. Subjects were exposed to cooperative and competitive feedback in four-member, same-sex groups which varied in the ratio of Anglo to Hispanic subjects to create two conditions—a 3 to 1 versus a 1 to 3 in-group to out-group composition. Results showed that members of both ethnic groups were equally cooperative when their own group was in the numerical majority (low-salience condition). In the high-salience condition, however, when their own group was in the numerical minority, Hispanic subjects were significantly more competitive than Anglo subjects. In addition, while Hispanics were significantly more competitive in the minority than in the majority condition, Anglos showed a slight tendency to be less competitive in the minority than in the majority condition. These results are discussed in light of social identity theory and its application to the study of interethnic cooperation/competition in heterogeneous groups.     

Effects of initial success or failure in a stressful or relaxed environment on subsequent task performance

Forty male and 40 female undergraduate subjects worked on anagram problems in either a stressful or a relaxed environment after having experienced either success or failure on a similar task. Internal arousal, which was expected to be minimal following success in a relaxed setting and maximal following failure in the stressful environment, was assumed to bear an inverted U-shaped relation to performance. Consistent with the implications of these assumptions, achievement in a stressful setting was lower following initial failure than following initial success, while initial failure in a relaxed environment facilitated subsequent performance. The interpretation of these results was supported by the effects of the experimental variables on indirect measures of arousal as well as by the relationship between direct measures of arousal and task performance. In addition, the achievement of female subjects tended to be facilitated by failure while the performance of males was consistently debilitated by it.     

The decrement in conditioned fear with increased trials of simultaneous conditioning is not specific to the simultaneous procedure

Three experiments using a conditioned punishment paradigm with rat subjects examined the possibility that the nonmonotonic acquisition function previously found to characterize simultaneous conditioning was due to the noninformative nature of the conditioned stimulus (CS). In Experiment 1 the suppressive effects of a CS previously presented with an unconditioned stimulus (US) in a simultaneous and forward (informative) manner were compared following 20 and an additional 60 conditioning trials. Excitatory conditioning similarly diminished with increased trials for both the simultaneous and forward procedures. Experiment 2 employed a between-groups design. Simultaneous, forward, and trace conditioning procedures were compared following 20 or 100 trials. Each of the three 100-trial groups showed less resistance to extinction than their 20-trial counterparts. Experiment 3 determined that the decrement in excitatory conditioning for the 100-trial groups was not due to the greater number of US presentations, per se, but rather to the number of CS-US pairings. The nonmonotonic acquisition function observed with all three conditioning procedures indicated that informational factors were not responsible for the decrement observed in simultaneous conditioning. The pattern of results suggested that subjects receiving extended conditioning trials were better able to discriminate between training and testing.     

The naive perception of masculinity-femininity on the basis of expressive cues

Groups of naive judges rated 18 videotaped stimulus persons on masculinity, femininity, “dominance, assertiveness,” and “compassion, sensitivity to others.” Stimulus persons were broken down by sex and sex-typing—half were male, half female—and within sexes one third were classified as masculine, feminine, and androgynous on the basis of their scores on the Bem Sex Role Inventory. Two experiments are reported in which groups of judges rate stimulus persons on the basis of such different expressive information as videotaped pictures and recorded voices, videotaped pictures alone, videotaped bodies, videotaped heads, recorded voices, and still photos. The results showed: (1) Judges reliably rated masculinity-femininity from largely expressive cues: (2) judgments of masculinity-femininity were not predominantly determined by judgments of sex role-related traits: (3) the naive judgment of masculinity-femininity significantly corresponded to stimulus subjects' assessed sex roles; (4) stimulus subjects (particulary males) showed a consistent display of masculinity-femininity across expressive channels; and (5) judges used different expressive cues in judging masculinity-femininity in males and females. These results are related to broader questions concerning the relation between expressive behavior and personality.     

Hierarchical structure in perceptual representation

A theoretical framework for perceptual representation is presented which proposes that information is coded in hierarchical networks of nonverbal propositions. The hierarchical structure of the representations implies selective organization: Some subsets of a figure will be encoded as integral, structural units of that figure, while others will not. A context-sensitive metric for the “goodness” of a part within a figure is developed, corresponding to the probability that the subset will be encoded as a structural unit. Converging evidence supporting this position is presented from four different tasks using simple, straight-line figures. The tasks studied are (a) dividing figures into “natural” parts, (b) rating the “goodness” of parts within figures, (c) timed verification of parts within figures, and (d) timed mental synthesis of spatially separated parts into unitary figures. The results are discussed in terms of the proposed theory of representation, the processes that operate on those representations, and the general implications of the data for perceptual theories.     

An experimental analysis of social traps

Social traps, such as the overgrazing of pasturelands, overpopulation, and the extinction of species, are situations where individuals in a group respond for their own advantage in a manner damaging to the group. A laboratory analog was devised to simulate conditions that produce social traps. The traps were constructed by superimposing schedules of reinforcement. Single responses were followed by multiple consequences which were opposite in valence, with the negative consequence delayed. Subjects in groups of three could respond individually for points that applied toward class credit. Each ten presses of a button added one point to the subject's total and subtracted one point from a common pool. The pool was replenished with points at fixed rates. If subjects responded for points faster than the replenishment rates, the pool would empty and the experiment would terminate before subjects could accumulate maximum credit. In addition, the maximum pool size and the ability to communicate were varied. Main effects were found for both, which indicated the least effective resource management occurred when the pool was small and no communication allowed. An analysis of cumulative records showed differing response patterns across conditions.