Political ideology, exploration of novel stimuli, and attitude formation

In this study, the relations among political ideology, exploratory behavior, and the formation of attitudes toward novel stimuli were explored. Participants played a computer game that required learning whether these stimuli produced positive or negative outcomes. Learning was dependent on participants’ decisions to sample novel stimuli and discover the associated valence. Political ideology correlated with exploration during the game, with conservatives sampling fewer targets than liberals. Moreover, more conservative individuals exhibited a stronger learning asymmetry, such that they learned negative stimuli better than positive. Mediational analyses revealed that the differences in learning were due to the extent of exploratory behavior during the game. Relative to liberals, politically conservative individuals pursued a more avoidant strategy to the game, which led to their development of a more pronounced valence asymmetry in learning and attitude formation.     

TV commercials as achievement scripts for women

This study suggests that sex stereotypes implicitly enacted, but never explicitly articulated, in TV commercials may inhibit women's achievement aspirations. Men and women (N=180) viewed locally produced replicas of four current, sex-stereotyped commercials, or four replicas that were identical except that the sex roles were reversed, or (control) named their favorite TV programs. All subjects then wrote an essay imagining their lives “10 years from now.” The essays were coded for achievement and homemaking themes. Women who viewed traditional commercials deemphasized achievement in favor of homemaking, compared to men and compared to women who had seen reversed role commercials. The reversed role commercials eliminated the sex difference in net achievement focus. Control subjects were indistinguishable from their same-sex counterparts in the traditional condition. The results identified some social changes needed to make “equality of opportunity” a social reality for women as well as men.     

Multiple semantic encoding of homophones and homographs in contexts biasing dominant or subordinate meanings

The resolution of lexical ambiguity was studied in two experiments. While subsequent selection would appear to limit longer term storage to one meaning of an ambiguous word, multiple initial encoding of homophones and homographs was indicated by the intrusion of their alternative meanings across trials in a Brown-Peterson paradigm. In Experiment 1 subjects heard four words and then engaged in a 10osec distractor task. Written recall was then demanded. On context trials a homophone with two distinct alternative meanings was presented with other words biasing either a dominant or subordinate meaning, for example, look, stare,peer, glance. On the next trial words related to an alternative meaning were presented, for example, dock, wharf, quay, jetty. Intrusions of the graphic forms of alternative meanings le.g.,PIER) into critical trial recall occurred whether the dominant or subordinate meaning of the homophone had been biased by context. Experiment 2 employed visual presentation of homographs, for example, GOLD, IRON,LEAD, and oral recall, but was logically similar to Experiment 1. Intrusions of the alternative codings of homographs across trials again occurred, for example, GUIDE, DIRECT,lead, regardless of the meaning originally biased by context.     

Effects of stimulus variation on the reinforcing capability of nonpreferred stimuli

We examined the effects of stimulus (reinforcer) variation in several different contexts. In Study 1, we identified high-quality (HQ) and low-quality (LQ) stimuli based on results of a paired-stimulus assessment and examined their effects when available under concurrent-reinforcement schedules for 8 participants. No participants showed preference for the LQ stimuli when compared singly or in a varied arrangement to the HQ stimulus. In Study 2, we identified nonpreferred (NP) stimuli based on results of a single-stimulus assessment and examined their effects when available under single-reinforcement schedules for 3 participants. Results of Study 2 were mixed. One participant's data indicated that the varied presentation of NP stimuli produced a modest improvement in performance over that observed when the stimuli were presented singly. By contrast, a second participant's data showed no facilitative effect for the varied delivery of NP stimuli and that the inclusion of an HQ stimulus in the varied arrangement obscured the reinforcing effects of the HQ stimulus. The 3rd participant's data showed no effect for the varied delivery of NP stimuli but an apparent facilitative effect when an HQ stimulus was included in the varied arrangement, which was attributable solely to the presence of the HQ stimulus.     

Behavioral and electrical brain measures of semantic priming in patients with Alzheimer's disease: implications for access failure versus deterioration hypotheses

This study investigated the nature of anomia and semantic memory deficits in patients with Alzheimer's disease (DAT). We measured reaction time (RT) and the N400 event-related brain potential (ERP) in a word-picture semantic priming paradigm for DAT patients and elderly controls. For patients, pictures were classified as a function of the individual's naming ability to determine whether naming deficits reflected a failure to access a picture's name or reflected a deterioration of its semantic representation. As expected, DAT patients had significantly poorer naming performance than controls. For successfully named pictures, robust RT and ERP priming effects were obtained in both groups. In DAT patients, priming for unnamed pictures was heterogeneous. The results are discussed in terms of current hypotheses of semantic memory deficits in DAT.     

Action planning in the presence of distracting stimuli: an investigation into the time course of distractor effects

Humans have a remarkable capability to respond efficiently to a stimulus of interest despite other stimuli competing for neural resources. The current study investigated how the human system copes with distracting stimuli. During each trial, participants viewed 2 sequential stimuli that were each associated with a specific action based on an arbitrary mapping. The 1st stimulus served as a distractor, and the 2nd stimulus required a response (target). When the distractor preceded the target by more than a few hundred milliseconds, response latencies were slower when the 2 stimuli were associated with the same response. The authors propose that this negative compatibility effect stemmed from an inhibitory mechanism that the human system utilizes to prevent the distractor from eliciting an unwanted response.     

The Effects of Instructions on Mothers’ Ratings of Attention-Deficit/Hyperactivity Disorder Symptoms in Referred Children

Tested whether instructions for how to rate child attention-deficit/hyperactivity disorder (ADHD) symptoms would improve the agreement between mothers’ ratings of symptoms in their children and ratings provided by teachers and objective observers. Sixty-eight mothers of 5 to 12 year old children (53 boys and 15 girls) referred for ADHD assessment were randomly assigned to receive or not receive the instructions. Mothers and teachers rated the children on the SNAP-IV Rating Scale and objective observers rated the children’s behavior during structured tasks. Relations between mother and teacher, and mother and observer ratings were generally stronger for mothers in the Instruction group compared to mothers in the No Instruction group, in some cases significantly stronger. The instructional materials also improved mothers’ knowledge of how to rate ADHD symptoms and reduced some associations between mothers’ ratings and family socioeconomic status. These instructions have the potential to improve clinical assessments of child ADHD symptoms.