The Influence of Stimulus Properties on Category Construction.

It has been demonstrated that when people free classify stimuli presented simultaneously in an array, they have a preference to categorize by a single dimension. However, when people are encouraged to categorize items sequentially, they sort by "family resemblance," grouping by overall similarity. The present studies extended this research, producing 3 main findings. First, the sequential procedure introduced by G. Regehr and L. R. Brooks (1995) does not always produce a preference for family resemblance sorts. Second, sort strategy in a sequential procedure is sensitive to subtle variations in stimulus properties. Third, spatially separable stimuli evoked more family resemblance sons than stimuli of greater spatial integration. It is suggested that the family resemblance sorting observed is due to an analytic strategy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of partial pairing on scale values derived from the method of paired comparisons.

How can the measurement of attitudes and opinions, by the use of scales involving the method of paired comparisons, be improved? An attempt was made to describe the relationship between scale values derived from partial and complete paired comparison judgments. "One complete and five partial pairing schedules were used, and 60 Ss, who had been randomly assigned to one of these six conditions, scaled the names of 30 nationality groups. The results of the study indicated that partial pairing scale values rather closely approximated those obtained from a complete pairing when the number of observations was reduced as much as 50% of the complete pairing matrix. Beyond this point further reduction seemed to yield a more drastic modification in the scale values obtained. The rating task implications of partial pairing were discussed." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response bias and Murdock's D scale.

Murdock's D scale predicts a U shaped curve of % correct identification as a function of the position of the stimulus. An inadequacy in the D scale was brought to light in an absolute judgment study by this author. Ss displayed a powerful response bias, avoiding end responses, when judging line lengths. A simple correction for such a response frequency imbalance is suggested, and with this correction the line-length data support the D scale approach to the quantification of distinctiveness. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus generalization and schizophrenia.

Paranoid and nonparanoid schizophrenics, on and off drugs, were compared with medical inpatients for stimulus-generalization responsivity. The stimuli were lines differing in length, and the response alternatives differed in amplitude. There were no significant differences in gradients of stimulus generalization among the groups. This finding opposes Mednick's original anxiety-drive theory of schizophrenia, especially his assumption that schizophrenics overgeneralize. The finding does not oppose Mednick's amended theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Graphic ratings and attitude measurement: A comparison of research tactics.

This paper suggests that under certain conditions attitudes may be measured as validly and as reliably with a single "attitude report question" as with a multi-item attitude scale. 84 physicans responded to 8 Guttman scales, and also rated their attitudes on 8 comparable graphic rating scales. These data were factor analyzed, and the communalities used as an estimate of the minimal scale reliability. In general, the graphic rating scales proved as reliable as the Guttman scales. An examination of the interscale correlations showed that similar conclusions would be drawn from either technique. It is suggested that a single graphic rating may usefully substitute for a multi-item attitude scale when the attitude continuum is unidimensional. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The length of the retention interval, forgetting, and subjective similarity.

A long retention interval tends to result in the poor retention known as forgetting. A high subjective similarity between stimuli frequently produces their poor retention. Thus, a long retention interval may increase the subjective similarity between stimuli (the RIISS hypothesis), and this increase may produce forgetting. To examine this hypothesis, college students made speeded same-different discriminations between two lines or tones of different lengths or frequencies that were 400 ms or 3,300 ms apart, and they rated the similarity of these stimuli. The long interval produced poorer overall performance as expected, but also produced poorer performance on different than same stimuli, implying that it increased the subjective similarity between the initial and subsequent stimuli, and it also increased rated similarity, in support of the RIISS hypothesis. The position that stored stimuli lose less common information than distinctive information explains RIISS evidence better than does perturbation theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Insular cortex and consummatory successive negative contrast in the rat.

Rats that are expecting a high value reward (e.g., 1.0 M sucrose) show an exaggerated underresponding when they are instead given a low value reward (e.g., 0.15% saccharin), an effect termed successive negative contrast (SNC). In the present experiment, insular cortex-lesioned (ICX) rats showed normal responsivity to sucrose and saccharin prior to the reward downshift. However, when switched from sucrose to saccharin during the postshift trials these rats displayed no evidence of SNC. Indeed, over the downshift trials these ICX rats consistently drank more saccharin than the ICX rats maintained on saccharin throughout the experiment. Potential interpretations are discussed including a lesion-induced impairment in the ability to accurately recognize the novelty of the postshift saccharin stimulus. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus pooling and social perception.

"The effects of stimulus pooling on judgments of personal attractiveness were investigated in an orthogonal factorial design, using as stimulus components identification type photographs which had been previously scaled on attractiveness… . The implications of the findings for (a) social perception… and (b) group judgment were considered." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of scale administrator on employee attitude responses.

"The results gave support to the following hypotheses: 1. A threat to employees' feelings of anonymity results in their responding more favorably to an attitude survey than employees not so threatened. 2. A threat to anonymity results in differential amounts of response distortion depending upon the content of different items comprising the questionnaire. 3. Employees feeling a threat to anonymity tend to give fewer and shorter responses to open-end questions than employees not so threatened." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Metacognitive control and the spacing effect.

[Correction Notice: An erratum for this article was reported in Vol 36(3) of Journal of Experimental Psychology: Learning, Memory, and Cognition (see record 2010-08037-021). In the article “Metacognitive Control and the Spacing Effect,” by Lisa K. Son (Journal of Experimental Psychology: Learning, Memory, and Cognition, 2010, Vol. 36, No. 1, pp. 255–262), lenient scores were reported instead of strict scores in two Performance Data sections of the text. The strict scores were correctly used in the analyses and figures. On page 259, the data corrections are as follows: The mean level of performance for items that were massed was 17.3 rather than 27.48, whereas that of spaced items was 30.6 rather than 34.02. The mean performance for those items in which a spacing schedule was imposed was 22.6 rather than 28.90, and the mean for the massed items was 21.9 rather than 27.48. On page 260, the data corrections are as follows: The mean for the massed items was 5.0 rather than 10.3; for spaced items, the mean was 29.3 rather than 36.2. Children using the forced spacing strategy had a mean performance of 11.7 rather than 20.7. This mean score was still almost double that of the forcibly massed items, M = 5.2 rather than 11.1.] This study investigates whether the use of a spacing strategy absolutely improves final performance, even when the learner had chosen, metacognitively, to mass. After making judgments of learning, adult and child participants chose to mass or space their study of word pairs. However, 1/3 of their choices were dishonored. That is, they were forced to mass after having chosen to space and forced to space after having chosen to mass. Results showed that the spacing effect obtained for both adults and children when choices were honored. However, using a spacing strategy when it was in disagreement with the participant’s own choice, or forced, did not enhance performance for the adults (Experiment 1). And although performance was enhanced for the children (beyond massing strategies), it was not as good as when the spacing decisions were self-chosen (Experiment 2). The data suggest that although spacing is an effective strategy for learning, it is not universal, particularly when the strategy is not chosen by the learner. In short, metacognitive control is often crucial and should be honored. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus and response fidelity in team training.

Transfer performance of 2-man teams was observed in a simulated radar-controlled aerial intercept task following either high or low stimulus (S-) fidelity and either high or low response (R-) fidelity training treatments. Both high S- and high R-fidelity training treatments resulted in superior transfer task performance; however, the effects of high R-fidelity training were relatively brief. It was concluded that whereas both are desirable, it is less important to provide high R-fidelity training at least for tasks where the major output requires verbal communication skills. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of a communication on attitude change and scale judgments.

"The purposes of this study were to assess the effects of a persuasive communication on attitude change and on judgments of the scale values of opinion items and to examine the relationship between attitude change and evaluations of the communication. An experimental group of subjects was exposed to a communication advocating abolution of capital punishment, after which they evaluated the communication, judged the scale values of 36 opinion statements, and revealed their own attitudes by responding to 20 opinion items… . The major results are: The communication changed attitudes in the direction advocated. But the groups were alike in their judgments of the scale values of the related opinion statements. Hence, a change in scale judgments is not a necessary condition for attitude change." From Psyc Abstracts 36:01:3GD33W. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A follow-up study influence of individual opinion on the construction of an attitude scale.

The present study was done in order to more or less replicate an earlier study by Hinckley (see 7: 1179) on the relationship between individual opinion and the construction of an attitude scale. Using Thurstone's technique of attitude scale construction, 2 sets of scale values for 114 statements were obtained from the sorting of 2 groups of Ss. The 2 groups were separated on the basis of their attitudes toward Negroes and the problem was to compare the sortings and scale values of Group I with the sortings and scale values of Group II. The results of this study were as follows: (a) the correlation coefficient between the scale values of Group I and the scale values of Group II was .9437. (b) This correlation of .94 can be compared with the correlation coefficient computed in the earlier study of .98. (c) There was no tendency for the statements to be placed in more extreme positions by either group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus predifferentiation: Some generalizations and hypotheses.

A survey of the research literature concerned with stimulus predifferentiation reveals sufficient agreement to permit generalizable conclusions in 2 broad areas: kind of verbal pretraining given, and the amount of such training. The adequacy of several theoretical interpretations of sensory predifferentiation are discussed. 38 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Indirect Learning of Event Sequences: The Effects of Divided Attention and Stimulus Continuity.

In a serial reaction time (SRT) task, the learning curve is steeper when the stimuli are presented in a repeating sequential manner rather than in random order (Nissen & Bullemer, 1987). This is true even when subjects report being unaware of the presence of the repeating sequence. The present study examines the nature of this learning under conditions designed to reduce attentional resources and to disrupt the continuity of stimuli. In the first three experiments, subjects were trained in the SRT task, with or without the addition of a secondary tone counting task, and with repeating or non-repeating sequences. The results suggest that some sequence learning occurred despite the presence of a secondary task. Experiment 4 examined the extent of sequence learning when the inter-stimulus interval was varied between trials. The overall results suggest that despite reduced attentional allocation and discontinuous stimulus presentation, some sequence learning occurs. This result supports other work suggesting a dissociation between learning when measured explicitly, and when assessed through performance indicators. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intertrial interval as a contextual stimulus: Further analysis of a novel asymmetry in temporal discrimination learning.

Four experiments investigated discrimination learning when the duration of the intertrial interval (ITI) signaled whether or not the next conditional stimulus (CS) would be paired with food pellets. Rats received presentations of a 10-s CS separated half the time by long ITIs and half the time by short ITIs. When the long ITI signaled that the CS would be reinforced and the short interval signaled that it would not be (Long+/Short?), rats learned the discrimination readily. However, when the short ITI signaled that the CS would be reinforced and the long interval signaled that it would not (Short+/Long?), discrimination learning was much slower. Experiment 1 compared Long+/Short? and Short+/Long? discrimination learning with 16-min/4-min or 4-min/1-min ITI combinations. Experiment 2 found no evidence that Short+/Long? learning is inferior because the temporal cue corresponding to the short interval is ambiguous. Experiment 3 found no evidence that Short+/Long? learning is poor because the end of a long ITI signals a substantial reduction in delay to the next reinforcer. Long+/Short? learning may be faster than Short+/Long?because elapsing time involves exposure to a sequence of hypothetical stimulus elements (e.g., A then B), and feature-positive discriminations (AB+/A?) are learned quicker than feature-negative discriminations (A+/AB?). Consistent with this view, Experiment 4 found a robust feature-positive effect when sequentially presented CSs played the role of elements A and B. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decoupling Stimulus Duration From Brightness in Metacontrast Masking: Data and Models.

A brief target that is visible when displayed alone can be rendered invisible by a trailing stimulus (metacontrast masking). It has been difficult to determine the temporal dynamics of masking to date because increments in stimulus duration have been invariably confounded with apparent brightness (Bloch's law). In the research reported here, stimulus luminance was adjusted to maintain constant brightness across all durations. Increasing target duration yielded classical U-shaped masking functions, whereas increasing mask duration yielded monotonic decreasing functions. These results are compared with predictions from 6 theoretical models, with the lateral inhibition model providing the best overall fit. It is tentatively suggested that different underlying mechanisms may mediate the U-shaped and monotonic functions obtained with increasing durations of target and mask, respectively. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Stimulus salience and retrospective revaluation.

The effect of conditioning or extinguishing the more salient element of a previously reinforced compound on responding to the less salient element of that compound was assessed in rats. Experiment 1 established that the 2 elements making up an audiovisual compound differed significantly in salience. In Experiment 2A, compound conditioning was followed by either reinforcement or extinction of either the less or more salient element. On test, evidence of retrospective revaluation of the less salient element was found but not of the more salient element. In Experiment 2B, extinction of the more salient element was found to be more effective than its reinforcement in producing retrospective revaluation of the less salient element. The implications of these results are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Impressions of groups as a function of the stimulus values of their individual members.

Beginning with a model of social perception in which the perceiver is assumed to operate according to the conventional canons of statistical inference, it was hypothesized that trait judgments of groups of individuals represented by facial photographs would match the mean values of these photographs judged individually and that confidence and the amount of information required before a judgment is reported will vary inversely with the variance in the set of photographs comprising the group, and directly with the significance of the judgment for the judge. Using different procedures and measures of the dependent variables, 2 experiments were performed which agreed in supporting the hypotheses. (PsycINFO Database Record (c) 2010 APA, all rights reserved)