Embryo vaccination of chickens with infectious bronchitis virus: histologic and ultrastructural lesion response and immunologic response to vaccination

The present study examined the effects of instruction type and boredom proneness (BP) on vigilance performance, workload, and boredom. Subjects completed the Boredom Proneness Scale and were assigned to high and low groups based on their scores. They then monitored a VDT for critical signals. Half the subjects were instructed to detect "critical" flickers (detection emphasis), and the remaining subjects were instructed to relax but to respond to any flickers observed (relaxation emphasis). Subjects also provided pre- and postvigil ratings of workload, stress, and boredom. A performance decrement was observed for all conditions. Low-BP subjects outperformed high-BP subjects and reported less boredom. Thus the results from the present study provide evidence for the long-sought, elusive link between trait boredom and performance in vigilance. In addition, subjects who received relaxation-emphasis instructions reported lower workload, frustration, and stress for the vigil than did those receiving detection-emphasis instructions. These results are discussed in terms of a recent dynamic model of stress as it relates to sustained attention.     

Auditory registration without learning.

In 3 studies, the authors explore how repeated exposure to a spoken word affects memory for perceptual attributes associated with the word (such as a talker's voice or a word's plurality). Subjects heard a list of words; particular words were repeated differing numbers of times. At test, subjects estimated the frequency of each word, with instructions to give frequency judgments of "zero" to words with changed attributes. The experiments demonstrate that memory for perceptual attributes improves very little after the first few repetitions, although word memory continues to improve. The experiments extend the registration without learning effect (D. L. Hintzman, T. Curran, and B. Oppy, 1992) to auditory words, to complex attributes (voice), and to conditions of low and high stimulus variability (two or many voices). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Double-blind versus deceptive administration of a placebo.

Subjects were given varying doses of a placebo, consisting of decaffeinated coffee, with double-blind or deceptive instructions. Deceptive administration simulated clinical situations in that subjects were led to believe that they were receiving an active drug. In contrast, subjects in double-blind conditions were aware that they might receive a placebo. Double-blind and deceptive administration of the placebo produced different, and in some instances, opposite effects on pulse rate, systolic blood pressure, and subjective mood. Deceptive administration produced an increase in pulse rate, whereas double-blind administration did not. A theoretically predicted curvilinear effect on systolic blood pressure, alertness, tension, and certainty of having consumed caffeine was confirmed with deceptive administration, but not with double-blind administration. Double-blind administration produced curves in the opposite direction on each of these variables. The effects of the placebo on motor performance varied as a function of subjects' beliefs about the effects of caffeine. These data challenge the validity of double-blind experimental designs and suggest that this common method of drug assessment may lead to spurious conclusions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence evaluation in complex decision making.

Investigated the role of representation of evidence in the decision processes of 26 21–73 yr old experienced jurors to test a 3-stage story model of juror decision making. The 3 stages are evidence evaluation through story construction, decision alternative representation (verdict category establishment for the juror task), and story classification (selecting the verdict category that best fits the story based on the evidence). Ss made individual decisions on the verdicts for a filmed murder trial. Extensive interviews were conducted to determine Ss' cognitive representations of the evidence in the case, the verdict categories presented in the trial judge's instructions, and the procedures they were to follow according to law to reach a verdict. Results indicate, as hypothesized, that the trial evidence was represented in a story form. Differences among Ss in cognitive representations of evidence were correlated with their verdicts, although other aspects of the decision process (verdict category representations, application of the standard of proof procedural instruction) were not. It is concluded that adequate theories of decision making must emphasize cognitive aspects of performance, such as the representation of evidence. (64 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Ethnic diversity and distributed information in group decision making: The importance of information elaboration.

Ethnic diversity may impede groups' use of distributed information in decision making. This is not so much because diversity interferes with groups' ability to reach agreement, but because ethnic diversity may disrupt the elaboration (exchange and integration) of distributed information. The authors find evidence for this proposition in an experiment (N = 63 groups) in which ethnically diverse groups are shown to benefit more from instructions emphasizing information integration than ethnically homogeneous groups when dealing with distributed information, whereas neither ethnic diversity nor information integration instruction affected decision making performance in groups with fully shared information. These effects were mediated by a behavioral measure of group information elaboration. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Teaching adults new words: The role of practice and consolidation.

Semantic and orthographic learning of new words was investigated with the help of the picture-word interference (PWI) task. In this version of the Stroop task, picture naming is delayed by the simultaneous presentation of a semantically related as opposed to an unrelated distractor word (a specific PWI effect), as well as by an unrelated word compared with a nonword (a general PWI effect). This interference is taken to reflect automatic orthographic and semantic processing. The authors observed that participants showed both types of PWI effects for newly learned words following a single study session. Interestingly, specific PWI effects were not obtained immediately after testing but did emerge a week later without additional practice. This suggests that a period of consolidation is involved in the establishment of word representations. In addition, identical PWI effects were obtained when the study and test words were presented in either the same or different letter case. This provides evidence that the newly acquired orthographic representations are coded in an abstract format. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Interpersonal decision making: The resolution of a dyadic conflict.

"The cooperative resolution of a dyadic conflict was studied as a special case of decision making. Two subjects were required to select a joint decision. The instructions and the task were designed to induce a reasoning set and achievement orientation. The efficiency of the joint decisions was related to the type of choice situation (conflict), the magnitude of individual differences, and the nature and amount of interpersonal influence (interaction). Latency and rationality of choice were the measures of efficiency. Maximal inefficiency was associated with the possibility of gambling, outcomes of loss rather than of gain, moderate individual differences, increasing degrees of verbal interaction, and a weak leader-follower relationship. The dyadic resolution of a decision conflict was conservative in strategy." From Psyc Abstracts 36:01:3GE14A. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's and adults' long-term memory for spatial locations over an extended time period.

Eight-, 11-, and 19-year-olds' memory for spatial locations over an extended time period was assessed. Subjects participated in two experimental sessions that were separated by an average of 5 months. All subjects walked through the environment during the fall session, but only half of the subjects at each age level made bearing and distance estimates to target locations. During the subsequent spring session, all subjects made bearing and distance estimates to the same targets. Accuracy at all age levels in the spring was unaffected by (a) the opportunity to recall locations in the fall and (b) the number of walks through the environment in the fall. However, the bearing accuracy of 8- and 11-year-olds declined significantly from fall to spring, whereas the accuracy of 19-year-olds remained stable. It was suggested that adults remember spatial location information better than children over an extended time period because they code location information in more organized representations and/or more effectively use environmental stimuli as retrieval cues. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Use of hypnosis as an aid to eyewitness memory.

72 hypnotically susceptible undergraduates observed a videotape of a simulated bank robbery. One week later, Ss were interviewed in 1 of 3 conditions: hypnotized, relaxed, or waking. Half of the Ss in each of these groups received imagery instructions; the remainder were given guided memory instructions. Each S answered 47 questions, including 5 misleading ones, about both the video event and the context of the viewing room. Ss also were offered a photo identification task. Results show that overall recall accuracy for both the video and live events was high. Hypnosis had no positive effect on recall, nor were hypnotized witnesses more susceptible to misleading information. The type of memory instruction interacted with recall condition. This interaction differed for the video and live aspects of the event. Rated confidence on photo choice was positively related to both accuracy of choice and amount recalled. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The limitations of decision trees and automatic learning in real world medical decision making

The decision tree approach is one of the most common approaches in automatic learning and decision making. The automatic learning of decision trees and their use usually show very good results in various "theoretical" environments. But in real life it is often impossible to find the desired number of representative training objects for various reasons. The lack of possibilities to measure attribute values, high cost and complexity of such measurements, and unavailability of all attributes at the same time are the typical representatives. For this reason we decided to use the decision trees not for their primary task--the decision making--but for outlining the most important attributes. This was possible by using a well-known property of the decision trees--their knowledge representation, which can be easily understood by humans. In a delicate field of medical decision making, we cannot allow ourselves to make any inaccurate decisions and the "tips," provided by the decision trees, can be of a great assistance. Our main interest was to discover a predisposition to two forms of acidosis: the metabolic acidosis and respiratory acidosis, which can both have serious effects on child's health. We decided to construct different decision trees from a set of training objects. Instead of using a test set for evaluation of a decision tree, we asked medical experts to take a closer look at the generated trees. They examined and evaluated the decision trees branch by branch. Their comments show that trees generated from the available training set mainly have surprisingly good branches, but on the other hand, for some, no medical explanation could be found.     

Problem-reformulation training and visualization training with insight problems.

Two studies investigated effects of training on solution of insight problems. Two kinds of instruction were emphasized: Subjects were directed to (a) work on reformulating their initial view of the problem in order to avoid unnecessary assumptions about it, or (b) carefully visualize problem components. Training Ss received one or both of these types of instruction repeatedly in combination with practice on insight problems. Results indicate that reformulation instructions contributed to performance, but visualization instructions did not. It is suggested that a program that integrates instruction and practice can improve student proficiency with insight problems. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Communication in severe aphasia: effectiveness of three instruction modalities

In this study to determine which modality of instruction (verbal, pantomine, or combined verbal and pantomine) was the most effective in eliciting accurate and prompt responses from severely aphasic persons, subjects completed tasks involving body movements and object manipulation in response to each of the 3 modalities of instruction. Results showed that severely aphasic persons completed single-stage commands at least as accurately and, depending on the task type, more accurately when given combined instructions than they did when given verbal or pantomined instructions only. The combined instructions also resulted in a greater mean response promptness score (correct responses only) than either verbal or pantomined instruction.     

Form and objective of the decision rule in absolute identification

In several conditions of a line length identification experiment, the subjects' decision making strategies were systematically biased against the responses on the edges of the stimulus range. When the range and number of the stimuli were small, the bias caused the percentage of correct responses to be highest in the center and lowest on the extremes of the range. Two general classes of decision rules that would explain these results are considered. The first class assumes that subjects intend to adopt an optimal decision rule, but systematically misrepresent one or more parameters of the decision making context. The second class assumes that subjects use a different measure of performance than the one assumed by the experimenter: instead of maximizing the chances of a correct response, the subject attempts to minimize the expected size of the response error (a "fidelity criterion"). In a second experiment, extended experience and feedback did not diminish the bias effect, but explicitly penalizing all response errors equally, regardless of their size, did reduce or eliminate it in some subjects. Both results favor the fidelity criterion over the optimal rule.     

The serologic detection of virus-induced infections in the domestic goose (Anser anser dom.)

The purpose of this paper is to introduce a multimedia computer software package that has been developed for the Federal Armed Forces of Germany to train military physicians in trauma management. The program presents different groups of casualties with characteristic wounds and multiple injuries on a CD-ROM and provides many clinical options at each decision point. Automatically evaluating the decisions for accuracy, the objective of the program is to train for triage, resuscitation, and evacuation of wounded in combat under pressure of time. The computer-assisted instruction program is inexpensive and allows easily accessible self-instruction as a supplement to formal classroom training. Using this teaching software, it may be possible to teach a standardized emergency case-management algorithm for battlefield trauma. There was a high level of acceptance for this type of instruction. This is encouraging for medical educators involved in producing multimedia packages for teaching emergency medicine.     

Some social psychological effects of group decision rules.

This study examined the effects of group decision rules and decision outcomes on satisfaction with the outcomes, perceived fairness of the rules, and amount of rejection between majority members and deviates. Two hundred and seventy male subjects were led to believe that they belonged to groups, each of which consisted of a four-person majority and a lone deviate. The groups ostensibly made decisions by using a majority, dictatorial, or unanimity rule. Principal findings of the study were as follows: Subjects were more satisfied with decisions with which they agreed than with decisions with which they disagreed. The perceived fairness of the decision rules was primarily a function of the representativeness of the decision. Subjects felt the rule was fairer when it resulted in a decision that was representative of the preferences of most group members than when it resulted in a decision that was unrepresentative. Finally, mutual rejection occurred between majority members and the lone deviate. The strongest rejection, however, was by majority members toward the deviate in instances when, under the dictatorship and unanimity rules, the deviate was able to impose an unrepresentative decision on the majority. Findings are discussed partly in terms of the effects of outcomes on the perceived legitimacy of decision rules and the resulting feelings toward group members held to be responsible for implementation of the rules. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A mathematical analysis on the biological zero problem in laser Doppler flowmetry

Whilst neurons within the lateral hypothalamus are well known to be responsive to the presentation of previously learned associative stimuli, the consolidation of a Pavlovian association is thought to depend in large part upon other brain regions, including the amygdala. The present study addressed this assumption directly, by examining the effect of post-session infusions of sulpiride within the lateral hypothalamus upon the acquisition of a conditioned approach response in an appetitive differential conditioning task. Subjects were exposed to an initially neutral stimulus (CS+), which immediately preceded the availability of a 10% sucrose reward (US). A second, control stimulus (CS ) was also presented. but never in close temporal proximity to the US. The number and duration of alcove approaches were recorded. Immediately following each training session, subjects were infused bilaterally with sulpiride (0, 0.5, 5 microg) in the vicinity of the perifornical region of the lateral hypothalamus. Sulpiride dose-dependently enhanced the rate of acquisition of a conditioned approach response to presentation of the CS+, but was without affect upon approach behaviour during CS(-) or US presentations. Thus, 0.5 microg sulpiride facilitated at an early stage (session 2 onwards) the number of alcove approaches to the CS+, while 5 microg sulpiride enhanced to a greater extent the duration of conditioned approach, particularly during later sessions. A subsequent locomotor test using 0.5 mg/kg d-amphetamine indicated that repeated infusions of the higher dose sulpiride (5 microg), but not the lower dose (0.5 microg), resulted in behavioural sensitisation to administration of the psychomotor stimulant. Acquisition of a novel conditioned instrumental response was not affected by previous exposure to sulpiride. These data suggest that dopamine-sensitive neurons within the lateral hypothalamus may play a significant role in the acquisition of appetitive Pavlovian associations.     

Effect of instructional set on responses to the Geriatric Depression Scale.

A community sample of elderly subjects (M age?=?74 years) was randomly assigned to four variations in reference group instructions on the Geriatric Depression Scale (GDS). In one condition, subjects received no instructions as to reference group, which is the standard instructional format of the test. In the other three conditions, subjects were asked to compare themselves with one of three reference groups: age group peers, adults in general, or themselves at a younger age. Results indicated that the GDS is robust with respect to variation in reference group instruction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of instructional set on attributions of nonvolition during hypnotic and nonhypnotic analgesia.

Fifty highly hypnotizable subjects were assigned to four treatment groups or a no-treatment control group and then underwent two pain stimulation trials. Half the treated subjects were administered hypnotic analgesia, half waking analgesia. Within hypnotic and nonhypnotic treatments, half the subjects were given actively worded analgesia instructions, half passively worded instructions. Subjects in the four treated groups reported equivalent pain reduction and equivalent use of coping imagery, although hypnotic subjects rated themselves as more deeply hypnotized than did nonhypnotized subjects. Both hypnotic and nonhypnotic subjects given passive instructions rated their pain reduction as occurring involuntarily, whereas those given active instructions reported that their pain was reduced through their active use of coping strategies. These findings support sociocognitive formulations of hypnotic responding that view ratings of involuntariness as reflecting contextually guided interpretations of behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increasing contextual pressures to breach posthypnotic amnesia.

The study investigated conditions that produce strong social pressures on posthypnotically amnesic Ss to remember more before being given the cue to remove amnesia. Highly susceptible Ss who passed posthypnotic amnesia were classified as voluntary or involuntary (having high or low control over recall). Test Ss were serially subjected to 3 pressure situations before being given the cue to lift amnesia: (a) instructions to be honest, (b) lie detection, and (c) a replay of a video of the session. Control Ss sat for the same amount of time and were only asked if they could remember anything else while the experimental Ss received pressure recalls. All but 1 S breached in the experimental condition. Only the voluntary Ss breached in the control condition. Results are discussed as they relate to breaching amnesia and the voluntary dimension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)