Representation-mediated overshadowing and potentiation of conditioned aversions.

Examined the ability of CS-evoked representations of flavored substances to modulate the conditioning of LiCl-based aversions to simultaneously presented flavors or odors. In Exps I–III, 156 thirsty Sprague-Dawley rats first received pairings of an auditory CS with a flavored-water UCS; they then received pairings of a compound stimulus with a toxin. Exp IV examined the potentiation of aversion conditioning to a novel odor using 32 Ss. In Exp I, conditioning of a flavor was partially overshadowed when it was presented in compound with a tone that had been previously paired with another flavor. Exp II replicated that result and also found that conditioning to a flavor was not overshadowed when the flavor was presented in compound with a tone that had been paired with that same flavored substance. In Exps III and IV, conditioning to an odor stimulus was potentiated when it was presented in compound with either a tone or another odor that had been previously paired with a flavor stimulus. Results suggest that evoked representations of stimuli may substitute for those events themselves in a variety of associative functions. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The visible persistence of illusory contours.

Measured the visible persistence of illusory contours (ICs) in 2 experiments. In Exp 1, persistence was determined among 12 Ss for IC squares presented for 50 msec. Exp 2, with 10 Ss, varied target duration from 50 to 1,000 msec. For the control figures, visible persistence decreased with increasing target duration. However, with the IC targets, persistence increased sharply with increasing target duration and then decreased. Results suggest that the time it takes for the visual system to construct the subjective contour yields an overall increase in persistence, and this ongoing processing can be seen over long target durations. Data support the existence of cortical components of visible persistence. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of naloxone on shock-induced freezing and analgesia.

Six experiments, with 196 male Holtzman rats, examined whether mild shock activates an opiate analgesia. Exps I–III explored whether naloxone potentiates shock-induced freezing by blocking an opiate analgesia. In Exp I, Ss treated with naloxone (3 or 50 mg/kg, sc) froze more following mild shock. Exp II revealed that both dose levels of the drug increase pain reactivity. Results of Exp III suggest that a naloxone-induced increase in pain reactivity accounts for the drug's effect on freezing. Exps IV–VI investigated the nature of the analgesia induced by mild shock. In Exp IV, mild shock induced a profound analgesia as measured by the tail-flick test. In Exp V, mild shock elicited a transient naloxone-insensitive analgesia that rapidly dissipated to reveal an analgesia that was reversed by a high dose of naloxone. This suggests that mild shock activates both the nonopiate and the opiate form of analgesia. Exp V also showed that a low dose of naloxone potentiated shock-induced analgesia. Exp VI revealed that this potentiated analgesia was attenuated by a high dose of naloxone. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Required high effort increases subsequent persistence and reduces cheating.

Two experiments examined the effect of the degree of effort required in preliminary tasks on the persistence and cheating in subsequent tasks. Undergraduates (N?=?276) were administered mathematics problems and perceptual identifications requiring high effort for one group and low effort for another group. A control group received neither of these tasks. All Ss then received an anagram task in which success depended on persistence with no opportunity to cheat (Exp I) or success was improbable and depended on cheating (Exp II). In Exp I, increasing the degree of effort required in the preliminary tasks increased the number of anagrams subsequently solved and increased the duration spent on unsolved anagrams. In Exp II, requiring high effort in the preliminary tasks decreased how often Ss falsified their performances. Results suggest that honesty may be increased by generalized effects of rewarded high efforts. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Deindividuation: Effects of group size, density, number of observers, and group member similarity on self-consciousness and disinhibited behavior.

Predictions about the social causes of self-consciousness in groups were derived from the theory of deindividuation and tested in 3 experiments with 618 university students and adults. In Exp I, it was found that increasing group size was related to a decrease in self-consciousness. Group density did not influence self-consciousness. In Exp II, it was found that increases in the number of observers increased self-consciousness. In Exps I and II, self-reports of self-consciousness were independent of one's group, whereas the degree of behavioral disinhibition was highly correlated within groups. In Exp III, it was found that gender similarity within a group was related to lower self-consciousness. Findings support a perceptual/attentional model of self-consciousness within groups. Contrary to deindividuation theory predictions, however, behavior intensity did not vary across conditions in Exps I and II, even though self-consciousness did differ. This finding suggests that deindividuation theory is incomplete in its present form. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of physostigmine upon consolidation of memory in mice.

Investigated the influence of physostigmine upon the consolidation process in 4 experiments with 162 male DBA/2J mice. Ss were trained to escape shock in a 'Y'-maze. In Exp I physostigmine (.4 mg/kg, ip) impaired a previously learned task 2 days after initial learning but improved performance 11 days after initial learning. In Exps II and III, it was determined that the impairment of memory found on Day 3 was transitory and no longer evident once the drug was no longer active in an S's system. The findings of Exp IV, in which the Day 12 facilitory effect was examined, were essentially the same as those of Exps II and III. Results tend to support an inhibitory or motivational hypothesis rather than a consolidation hypothesis. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Habituation to shock and learned persistence in preweanling, juvenile, and adult rats.

In Exp I, a prolonged shock-habituation treatment given between runway acquisition and simple extinction promoted persistence in both preweanling and juvenile Holtzman rats. Exp II showed even stronger persistence effects in a punished-extinction test given after shock treatment, the effects being stronger in preweanlings than in juveniles. Exp III demonstrated that shock treatment at infant-to-preweanling age resulted in increased persistence that survived a 42-day retention interval in a nonreward extinction test. Exp IV demonstrated habituation to shock in preweanlings and juveniles in terms of recovery of suppression of milk intake in the shock situation and, compared with controls, in terms of reduced latency to eat in a punished-reward test at several retention intervals. Exp V showed that the strength of persistence to approach in a runway reflected the presumed degree of habituation in 70-day-old Ss. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Elaboration and recall of main ideas in prose.

Examined the utility of an elaboration hypothesis as a means of specifying "depth of processing" in memory for prose and as a guide for the construction of adjunct questions. 85 undergraduate and graduate students served as Ss in 5 experiments. Exp I examined the effects of different numbers of propositions within paragraphs on the recall of major ideas. Exp II replicated the procedures of Exp I but varied the topography of the text. Exp III examined processing time as an alternative explanation for the results observed in Exps I and II. Exp IV investigated a redundancy hypothesis as an alternative to an elaboration hypothesis. Exp V employed a procedure originally developed to test the effects of adjunct aids requiring different levels of elaboration on recall of prose. The results of Exps I–IV support the elaboration hypothesis in predicting recall of main ideas in paragraphs. The results of Exp V support the utility of employing an elaboration hypothesis as a heuristic for the construction of adjunct questions. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Illusory concomitant motion in ambiguous stereograms: Evidence for nonstimulus contributions to perceptual organization.

Performed 3 experiments to test whether perceptual organization is cognitively or motivationally penetrable. In Exp I, 8 undergraduate and graduate students viewed a reversible stereogram while instructed to hold 1 depth organization. Responses about depth were recorded indirectly by recording responses about direction of the illusory concomitant motion that is perceptually coupled to depth in a stereogram. It is contended that, inasmuch as perceptually coupled variables covary without necessary stimulus covariation, a postperceptual locus for any intention effects they exhibit is unlikely. Results show that instruction influenced perceived depth to a degree influenced by stimulus bias. Exps II and III examined the possibility that instructed intention might influence perception indirectly by influencing eye movements. Eight graduate student viewers' vergence position was measured directly through responses about alignment of a vernier nonius fixation. Findings from Exp II indicate an interaction between hold instruction and stimulus bias. However, unlike Exp I, instructed responses were larger with the depth response than with the motion response. Results from Exp III reveal that differential instructions produced different responses about perceptual organization, but that they were not reliably accompanied by different vergence movements. Overall findings suggest that instructed intention may influence perceptual organization by influencing internal nonstimulus components to the perceptual process. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Within-compound associations in unblocking.

Four experiments used rats in a conditioned suppression paradigm to investigate the role of associations between A and X in an unblocking procedure. Each experiment compared suppression to X after A had been followed by a single (+) or double (++) shock and AX had been followed by a single shock. In Exps I and II, 94 Holtzman female rats were trained to barpress for food before receiving combinations of a light, a tone, and footshock. In Exps III and IV, 64 male Sprague-Dawley rats received similar treatment before being tested for suppression. Suppression was greater to X after A++/AX+ training than after A+/AX+ training (unblocking). However, manipulations known to disrupt the association between X and A disrupted that unblocking. Exp I demonstrated both blocking and unblocking and showed that unblocking required pairing of the double shock with A. Exp II interposed separate nonreinforced presentations of A prior to testing X. Exps III and IV gave additional reinforced presentations of A, either before or after the AX+ trials. The success of these manipulations in attenuating unblocking suggests it is partly attributable to differences in the association between X and A rather than between X and reinforcer. That conclusion reduces the incompatibility between unblocking and the model of R. A. Rescorla and A. R. Wagner (1972). (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reciprocal relation between attitudes and behavior recall: Committing people to newly formed attitudes.

Reports 3 studies that used a total of 195 male and female undergraduates. Exp I showed that shifts in attitude were accompanied by shifts in the recall of the more qualitative rather than quantitative aspects of past behaviors. Exps II and III assessed the effects of recall on Ss' commitment to newly formed attitudes. On the premise that behavior recall is biased so as to be consistent with salient attitudes, it was hypothesized that recall would serve to increase Ss' commitment to their attitudes. In Exp II it was assumed that degree of commitment to an attitude would be reflected in the persistence of the attitude, behavioral intention, and actual behavior. As anticipated, Ss' intentions were more consistent with their attitudes when they had been prompted to recall attitudinally relevant behaviors. However, recall did not affect attitude persistence or actual behavior. In Exp III, commitment was measured by resistance to an attack on an attitude. Ss were more likely to maintain an attitude in the face of an attack if they had been induced to recall attitudinally relevant behaviors. The data support the hypothesis that attitudes can affect recall, which in turn affects commitment to the attitudes. (20 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Curvilinear effects of severity of punishment on species-typical aggressive display in Betta splendens..

Three experiments examined the effects of the severity of punishment, defined in terms of intensity/voltage (Exp I), duration (Exp II), and frequency combined with 2 levels of intensity (Exp III), on the aggressive display of Siamese fighting fish. Findings show that display duration was a curvilinear function of punishment severity regardless of whether severity was defined as intensity, duration, or frequency. Relative to nonpunished conditions, moderate levels of punishment increased display duration, whereas strong punishment led to suppression. Increased biting was observed with moderate levels of punishment frequency. Results are discussed in terms of adaptive significance of the organism's reaction to counteraggression. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Reading and generating normal and transformed sentences.

Three experiments (108 undergraduates) examined the relative contributions made in skilled and unskilled processing by data driven and conceptually driven processes. In Exp I, Ss recalled nouns and complete sentences after having read and generated meaningful and anomalous sentences. Generated and transformed sentences were better recalled than normal sentences if they were meaningful, but not if they were anomalous. Exp II used the same sentences as Exp I, except they were displayed in 3 typographies: normal orientation, mirror transformed, or rotated 180°. Results show that reading the transformed typography increased semantic interword organization. In Exp III, Ss had to generate sentences and read transformed typography. Results duplicate those in Exps I and II. It is concluded that a decrease in the efficiency of data driven processing causes an increase in semantic interword organization. (French abstract) (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effects of changes in response requirement and deprivation on the parameters of the matching law equation: New data and review.

The relation between response rate and reinforcement rate is described by the matching law equation. For an experiment in which there is just 1 explicit source of reinforcement, the equation has 2 parameters. The magnitude of 1 is equal to the response rate asymptote; the magnitude of the other is equal to the rate of reinforcement that maintains a one-half asymptotic response rate. This report describes experimental manipulations that affect these 2 parameters. Rats were trained on a series of variable-interval reinforcement schedules that provided reinforcement rates ranging from about 20 to 700 reinforcements per hour. The response was a lever press, and the reinforcer was water. In Exp I, the duration of the deprivation period was varied. Response rates maintained by the lower reinforcement rates showed the largest changes, and the parameter that is equal to the reinforcement rate for a one-half asymptotic response rate changed. In Exp II, the weight of the lever was varied. Response rates changed independently of reinforcement rate, and the parameter that is equal to the asymptotic response rate changed. In Exp III, manipulations from Exps I and II were combined. Results replicated those of Exps I and II. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learned helplessness and immunization: Sensitivity to response–reinforcer independence in immunized rats.

Exps I and II, with 62 male Holtzman rats, examined the learned helplessness and immunization effects using a test in which appetitive responding was extinguished by delivering noncontingent reinforcers. Contrary to learned helplessness theory, "immunized" Ss showed performance virtually identical to that of Ss exposed only to inescapable shock and different from that of nonshock controls. Exp II suggested that the helplessness effect and the lack of immunization were not due to direct response suppression resulting from shock. In Exp III, in which the immunization effect was assessed in 28 Ss by measuring the acquisition of a response to obtain food when there was a positive response–reinforcer contingency, immunization was observed. Results cannot be explained on the basis of proactive interference and instead suggest that Ss exposed to the immunization procedure acquired an expectancy of response–reinforcer independence during inescapable shock. Thus, immunization effects may reflect the differential expression of expectancies rather than their differential acquisition as learned helplessness theory postulates. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparison of the effects of morphine and immobilization stress on discrimination performance of rats.

Compared the effects of morphine and immobilization stress (IMS) on performance of 24 male Sprague-Dawley rats in discrete-trial, 2-choice discrimination tasks. In Exps I and II, 2 shocks of different intensities were discriminative stimuli (DSs) for choices in a T-maze. In Exps III and IV, responses were right and left leverpresses in an operant chamber, where correct responses were signaled by either shocks of different intensities (shock discrimination task) or by the position of a brief light flash (light discrimination task). In Exp I, both 70-min IMS and 5 mg/kg morphine induced greater disruptions in trials in which the higher shock was the DS and there were no significant differences between treatments. However, in Exp II, only the effects of morphine were blocked by 10 mg/kg naltrexone. In Exp III, the effects of IMS and morphine were not selective with respect to shock level in the shock discrimination task, nor were they task (shock vs light) selective. The effect of morphine was significantly greater than the effect of IMS in both tasks. Exp IV indicated that effects induced by actual alterations in the intensities of the DS shocks did not mimic those induced by either morphine or IMS but that abrupt decreases in the duration of the DS lights induced effects similar to those of morphine. Results indicate that (a) different mechanisms mediate the effects of IMS and morphine and (b) many of their behavioral effects in shock discrimination tasks are due to dissociative processes rather than alterations in perceived shock intensity. (52 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Identification and localization in tachistoscopic recognition: The effects of data- and resource-limitations.

Examined the effects of data- and resource-limits on mislocation and intrusion errors in a visual probe task. Mislocation errors were defined as responses to any letter that appeared in the test display but not in the position cued; intrusions were responses with letters that did not appear in the test display. Ss were 42 undergraduates with normal vision. Exp I manipulated the data-limits by changing both luminance and duration, and confirmed that decreasing stimulus energy increases intrusions and decreases the benefit of selective attention instructions. Exps II and III manipulated resource-limits by varying display size and the size of a defined subset of a display and showed that this manipulation primarily affected mislocation errors. Exp IV tested a minor point pertaining to the cue used in the previous studies. Results suggest that these errors may reflect 2 different processing operations, and that complete recognition of any visual stimulus involves both processes. (French abstract) (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Increasing compliance by improving the deal: The that's-not-all technique.

Seven experiments with 426 adolescents, undergraduates, and adults were conducted to examine the effectiveness of a compliance procedure known as the that's-not-all technique. The procedure involves offering a product at a high price, not allowing the customer to respond for a few seconds, then offering a better deal by either adding another product or lowering the price. Exps I–II demonstrated the effectiveness of this procedure over a control group that was given the better deal initially. Exps III–IV suggested that this effectiveness may be partially explained through a norm of reciprocity that calls for the customer to respond to the seller's new offer. Exp V suggested that the effect also results from an altering of the anchor point Ss use to judge the new price. Exp VI indicated the effectiveness of the procedure cannot be explained by the S perceiving the lower price as a bargain. Exp VII, which examined the differences between the that's-not-all and the door-in-the-face procedures, implied that the former technique is more effective than the latter. Overall findings demonstrate the effectiveness of the that's-not-all technique. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A structure-mapping model for word problems.

Tested predictions of a structure-mapping model for word problems in 4 experiments involving 132 undergraduates. In Exps I and II, Ss rated the potential usefulness of solutions for pairs of problems—mixture problems in Exp I and work problems in Exp II. The problems were either equivalent (same story, same procedure), similar (same story, different procedure), isomorphic (different story, same procedure), or unrelated (different story, different procedure). Ss in Exp III used an example solution for a work problem and a mixture problem to generate equations to related test problems that differed in their mappings from the example. In Exp IV, Ss matched concepts in the test problems to corresponding concepts in the examples to provide a direct measure of their ability to construct mappings across different problems. In Exps III and IV, Ss performed significantly better on isomorphic problems than on similar problems, and significantly better on work isomorphs than on mixture isomorphs. Results suggest that a structure-mapping model that emphasizes the transparency and structure of the mapping can be used to predict the usefulness of a solution. (19 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Simple reaction times and timing of serial reactions of middle-aged and old men

The timing control of serial reactions in 20 middle-aged (38-43 years) and 20 older men (57-63 years) was examined by using a task of tracking serial-light stimuli with and without the previous learning (Exps. III and II, respectively). In Exp. I, a control group of 20 college students (19-22 years) had significantly faster and less variable mean simple reaction times than the two other groups. For the serial reaction times (Exps. II and III), the control group had significantly faster mean reaction times than the other groups who did not differ. In Exp. III, there was no difference between the serial reaction times and the simple reaction times in the contrasting groups. In Exp. II, however, although the serial reaction times were significantly slower than the simple reaction times in the older group, the serial reaction times did not differ from the simple reaction times in the middle-aged group. The difference between these groups appeared to be due to the task in Exp. II being more difficult than that in Exp. III, suggesting the more complex the movement to be made, the slower the responses of older people. Advancing age seems to have a greater effect on central processing components than on the perceptual and motor output components of serial reactions.