Re-evaluation of choice alternatives as a function of their number and qualitative similarity.

6th-grade school children were given systematically varied choices from among several toys in order to test 2 derivations from Festinger's theory of psychological dissonance (see 32: 347). This theory states: "the magnitude of dissonance and consequent amount of increased liking for the chosen alternative and decreased liking for the unchosen alternative increases with (a) the qualitative dissimilarity of alternatives, and (b) the number of alternatives." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Bargaining strength as a function of coalition alternatives.

Previous research has shown that a person's bargaining strength in a coalition situation is a function of the number and size of alternative coalitions available to the bargainer and the value (expected profit) of these alternatives. The present study examined the effects of number and size of the alternatives on bargaining strength and tested the weighted probability and equal excess theories of coalition formation. The number and size of alternative coalitions were varied independently, and the value of each member in alternative coalitions was kept constant. 168 undergraduates were asked to bargain in 1 of 3 coalition games over a sequence of 6 trials. Results indicate that both number and size affected coalition outcomes: The number of alternatives primarily affected the payoff shares of the coalition members, whereas the size of alternatives primarily affected the frequencies of coalitions. Tests of the predictions of the weighted probability and equal excess models showed little support for either theory. Some restrictions on the generality of these models are suggested. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response strength as a function of stimulus novelty: Concept formation in the pigeon.

Cites a previous study which showed that a distinctive CS presented on the 1st trial of acquisition generated more responses after extinction than another CS presented regularly during acquisition. In the present study 140 pigeons were presented with a different distinctive CS on each 1st trial of 5 acquisition sessions. Ss were then broken down into 7 groups which were tested, following extinction, for residual response strength of (a) Day 1 novel CS, (b) Day 2 novel CS, (c) Day 3 novel CS, (d) Day 4 novel CS, (e) Day 5 novel CS, (f) the regular CS, and (g) a novel CS never presented before. Contrary to the previous study where a novel CS inhibited responding, Group 7 exhibited the most responding in this study. Results support a concept formation interpretation of the previous study and are difficult to explain from a "stimulus trace" or "identical elements" position. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age differences in retention as a function of learning.

The hypothesis that observed age-related decrements in recall scores derive primarily from degree of acquisition rather than from retention deficits per se was investigated. 40 elderly and 30 young Ss learned 9 paired associates under equal learning opportunity, learning to criterion or overlearning conditions. Retention was measured at 20 min. and 1 wk. Elderly Ss learned less on equal exposure and required more trials to criterion, but once having learned the material retained it as well as young Ss. Trials beyond criterion did not enhance the retention scores of elderly Ss and may have introduced negative motivational factors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Hippocampal lesions and associated learning in the pigeon.

The performance of pigeons with hippocampal lesions was compared with that of unoperated and neostriatal-lesioned control Ss in 3 experiments. In Experiment 1, hippocampal-lesioned birds were retarded in the acquisition and the maintenance levels of autoshaped responding. However, the deficit was attenuated following the addition of a response contingency to the autoshaping schedule. In Experiment 2, the hippocampal-lesioned birds showed impaired performance on a differential reinforcement of low rates of responding schedule. From the high levels of responding in Experiment 2, underresponding was observed in hippocampal-lesioned birds relative to control Ss on return to the autoshaping schedule in Experiment 3. Results are interpreted in terms of impaired classical conditioning in hippocampal-lesioned birds. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spatial learning and memory as a function of age in the dog.

Spatial learning and memory were studied in dogs of varying ages and sources. Compared to young dogs, a significantly higher proportion of aged dogs could not acquire a spatial delayed nonmatching-to-sample task. A regression analysis revealed a significant age effect during acquisition. Spatial memory was studied by comparing performance at delay intervals of 20, 70, and 110 s. At short delays aged and young dogs were similar; at longer delays, errors increased to a greater extent in old than in young dogs; however, this was not statistically significant. It was possible to identify 2 groups of aged animals, age-impaired and age-unimpaired. Several of the dogs were also tested on an object recognition memory task, which was more difficult to learn than the spatial task. The possibility that these findings are confounded by breed differences is considered. Overall, the present results provide further evidence of the value of a canine model of aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The pigeon as a quality-control inspector.

"Many of the operations involved in the quality-control inspection of commercial products consist of monotonous checking jobs performed by human operators." They require little manual skill or dexterity, good visual acuity, color vision, and are difficult to automate. A device was built to permit inspection of pharmaceutical capsules by pigeons; pigeons "inspected on a 99% correct basis within 1 wk. of daily discrimination training." A technique for using 2 birds—double inspectors—was suggested with reward for defective capsules detected only when they both agreed for the purpose of further reducing error probability. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Vicarious learning as a function of five increasing levels observed in a model.

Tested the hypothesis of a synchronous evolution between vicarious learning and nonvicarious learning of a random color sequence. 60 female 18-30 yr. Old ss were assigned to 6 groups. A control group learned the sequence without any prior observation of a model (m); the average performance of this group was determined and filmed. For each of the 5 experimental groups, the observation period was interrupted after the filmed m had reached learning levels of 25, 50, 75, 92, and 100% respectively. Each o then continued with the learning of the sequence until the 100% learning criterion was achieved. O's initial performance demonstrated a learning level equal to that reached by m on the trial (series of 12 answers) following the end of the observation period; furthermore, during the observation period, o learned the elements of the sequence learned by M. There was an overall decrease in the number of trials required by o to master the final learning criterion as a function of the increasing learning levels observed. Results are discussed within the mediation hypothesis framework. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Extent of drug use as a function of number of risk factors.

Tested the hypothesis that extent of drug use is an increasing function of the number of etiological variables rather than any particular set of them. 1,960 high school students completed a questionnaire that included the Johns Hopkins Symptom Checklist and a drug and alcohol use survey. A highly significant linear relation was found between usage and number of risk factors. 24 combinations of risk factors were represented in the sample, but none accounted for more than 21% of Ss with multiple risk factors. Ss who exhibited 4 risk factors proved to be 4? times more likely to report heavy drug use than would be expected from the base rate of heavy drug use. These findings support a general rather than a specific coping model of drug abuse. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential learning and forgetting as a function of the social frame of reference.

"The present study was aimed at demonstrating how learning and recall become selective because of the relevant frames of reference… . Brahmins and Karana… were required to learn and recall… favorable and… unfavorable familiar stereotypes concerning themselves." Effectiveness of learning was seen to be dependent upon whether the stereotypes were identified with a caste different from one's own and whether they reflected favorable or unfavorable attitudes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Lyme arthritis as the incorrect diagnosis in pediatric and adolescent fibromyalgia

In areas endemic for Lyme disease there is increasing concern and anxiety about possible chronic and untreatable manifestations of the disease. The authors have diagnosed fibromyalgia in many patients with chronic musculoskeletal complaints in whom chronic Lyme arthritis had previously been diagnosed as the cause of their joint pains. Fibromyalgia is a common disorder, causing arthralgia (not true arthritis), fatigue, and debility. The repeated and/or long-term antibiotic therapy prescribed for "chronic Lyme disease" is not successful in curing the symptoms of fibromyalgia. Especially in areas where anxiety about Lyme disease is great, it is important to be careful in diagnosing chronic Lyme disease. Fibromyalgia is a potentially treatable and curable cause of chronic complaints and should be considered in the differential diagnosis of "refractory Lyme arthritis."     

Transfer of serial learning as a function of interlist positional relations.

Transfer from one serial list to another was analyzed in terms of the degree of correspondence of interlist positional associations. This analysis implies that transfer of serial learning is inversely related to the number of positions that the items are displaced in the transfer list relative to their 1st-list locations. 3 experiments were conducted with a total of 168 undergraduates and 120 4th and 5th graders. 2 of these studies involved a serial-serial transfer design, while a serial-spatial discrimination transfer paradigm was used in the 3rd. Results of each study are consistent with the generalization that transfer of serial learning decreases as the degree of positional remoteness of the items, from one task to the next, is increased. These results and those of recent studies concerning H. Ebbinghaus's (1913) derived-list paradigm are readily interpretable in terms of a "positional" version of the concept of remote associations. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Depth perception in a stereoscopic display as a function of number of stimuli, depth range, and number of scale markers.

Ss were tested on 2 tasks, ranking dots in order of depth and specifying actual depth in space, to determine the effects of number of stimuli, depth range, and number of scale markers on depth discrimination. When ranking was required, increasing the number of dots presented resulted in decreased accuracy. The number of dots did not affect accuracy when specific depth assignments were required. Increasing the number of dots resulted in significantly greater time to complete the task. As depth range was increased, accuracy improved regardless of task and time scores decreased for the ranking task. Decrease in number of scale markers resulted in increased time and error scores. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Speed and accuracy of scale reading as a function of the number of reference markers.

The speed and accuracy of determining target position on a polar coordinate display as a function of the number of scale rings were investigated for displays ranging in diameter from 5 to 11 inches, with 1, 3, 5, 10, 20, or 40 scale rings. "Error of interpolation (in percentage of the total range of the display) decreased as a function of the number of scale rings used. The frequency of gross errors (misidentification of scale rings) and the time required to make readings increased as a function of the number of scale rings. Increasing display size improved interpolation accuracy slightly and decreased the frequency of gross errors markedly. Constant errors of interpolation were found to be a function of the position of the target between scale rings and also a function of the number of scale rings used." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cued recall and free recall as a function of the number of items per cue.

Tested the generality of M. Earhard's (see record 1967-13073-001) findings that (a) the number of items/cue determines the rate of cued-recall learning, and (b) free-recall Ss perform as well as cued Ss under the conditions of 6 or 8 items/cue. Categorized materials consisting of English nouns were given to a total of 135 undergraduates in 2 free-recall and 7 cued-recall conditions. Differences were obtained between cued-recall Ss who had 6 or less and 8 or more items/cue. Free-recall Ss performed as well as 6.6 items/cue, which exactly replicates Earhard's result with alphabetized word lists. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual target location as a function of number and kind of competing signals.

Using 20 college students, the influence of hue and shape on ability of operators to correctly describe location of objects, reflected on radar picture tubes, was studied. Variables included number of target signals, values of hue-shape combinations, number of signals, and the distribution of this competition between the hue and shape dimensions. The number of targets had by far the greatest effect on task time. Hue rather than shape is the critical factor. (15 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Kamin effect as a function of number of prior unsignaled inescapable shocks.

3 groups of 30 naive male albino Sprague-Dawley rats received 1, 5, or 10 unsignaled inescapable shocks either .02, 2.5, 4, 10, or 24 hrs prior to 1-way avoidance training. For each phase an additional 6 Ss were assigned to a no-shock control group. Trials to criterion in avoidance learning were a nonmonotonic function of time since prior inescapable shock; poorest performance was shown at intermediate shock-acquisition intervals. The locus of maximum performance decrement shifted to longer intervals with increasing numbers of prior inescapable shocks. Also, variability in performance increased, then decreased, as a function of time since inescapable shock in a manner parallel to the changes in performance means. Findings indicate that unsignaled inescapable shock is sufficient to produce Kaminlike effects. (15 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Extinction of avoidance in rats as a function of duration and number of blocked trials.

Gave 15 groups of 8 Sprague-Dawley rats each avoidance training in a runway. Each S was then blocked in the presence of the CS for either 1, 5, or 12 trials, each lasting for either 0, 5, 10, 50, or 120 sec. Results indicate that the greater the number of blocked trials and the greater the length of each blocked trial, the less the resistance to extinction. The key variable in determing the resistance to extinction was total blocking time as opposed to either the number of blocked trials or length of each blocked trial. (PsycINFO Database Record (c) 2010 APA, all rights reserved)