Spontaneous alternation behavior.

Research concerned with spontaneous alternation behavior in rats is examined and related to learning theory. It is concluded that alternation behavior can no longer be adequately interpreted in terms of Hull's concept of reactive inhibition. The notion of stimulus satiation as an explanation of alternation behavior has received general support from the research literature, but some data seem to require a more general theoretical explanation. Motivational concepts such as curiosity are suggested. 47 references. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous recovery of excitation and inhibition.

In two conditioned suppression experiments with rats as subjects, the authors examined two classes of accounts of spontaneous recovery of excitation and inhibition. One view suggests that spontaneous recovery occurs due to greater temporal instability of inhibitory associations, whereas the other posits that spontaneous recovery occurs due to greater temporal instability of second-learned associations. These accounts diverge in predictions concerning spontaneous recovery when the first-learned association is inhibitory and the second-learned association is excitatory. Using different designs, Experiments 1 and 2 found spontaneous recovery of both excitation and inhibition. The results support the view that spontaneous recovery occurs due to faster waning of second-learned associations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

How is emergent writing based on drawing? Analyses of children's products and their sorting by children and mothers.

Writing and drawing produced by children 28-53 months old were compared. Israeli and Dutch preschoolers were asked to draw and write, to classify their products as drawing and writing, and to decide what they had drawn or written. Israeli and Dutch mothers classified the products. Scores on a scale for writing composed of graphic, "writing-like," and symbolic schemes showed improvement with age. Recognition of drawings as drawings preceded recognition of writings as writings. Scores on writing and drawing were substantially correlated, even with age partialed out, suggesting (a) that when children start drawing objects referentially, they write by drawing "print" and (b) that progress in object drawing involves progress in drawing print, so that their writing becomes more writing-like. Children unable to communicate meaning by writing spontaneously resort to drawing-like devices, indicating the primacy of drawing as a representational-communicative system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous alternation behavior in humans: Implications for psychological research.

It is suggested that 1 response-influencing variable in psychological experiments may be the individual S's need for sensory variation as manifested in alternation behavior. The proposition is put forth that in an experimental situation where a discriminatory response to one of a series of successively presented stimuli is required, the organism will seek to optimize the amount of stimulus variability or complexity by alternation behavior. (32 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous recovery and dishabituation of ethanol-reinforced responding in alcohol-preferring rats.

This study examined whether habituation, a decrease in responsiveness to a repeatedly presented stimulus, occurs to ethanol reinforcers in alcohol-preferring (P) rats. Three fundamental properties of habituation were evaluated: generality, spontaneous recovery, and dishabituation. In each experiment, P rats' lever pressing was reinforced by 10% ethanol on a variable-interval 15-s schedule during 50-min sessions. Experiment 1 evaluated the generality of habituation to repeatedly presented stimuli by using ethanol and water reinforcers. Rates of responding were higher for ethanol than they were for water. Additionally, the within-session patterns of responding differed for each reinforcer, suggesting that the pattern of responding was specific to the exact nature of the repeatedly presented reinforcer. Experiment 2 examined spontaneous recovery, an increase in responsiveness to a habituated stimulus when that stimulus is not presented for a time, by separating experimental sessions by 5 min, 2 hr, or 24 hr. Early-session rates of responding during Session 2 were slower than the corresponding rates during Session 1 when sessions were separated by 5 min or 2 hr. Response rates and within-session patterns of responding during Sessions 1 and 2 were similar when sessions were separated by 24 hr. Experiment 3 tested for dishabituation, a restoration of responsiveness following the presentation of an extraneous stimulus, by presenting a tone or a light 24 min and 55 s into the session. Rates of responding temporarily increased after the tone was presented. The results of these experiments support the idea that habituation contributes to the regulation of ethanol consumption. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous cognition and HIV risk behavior.

Theories of cognitive processes and risk behavior have not usually addressed spontaneous forms of cognition that may co-occur with, or possibly influence, behavior. This study evaluated whether measures of spontaneous cognition independently predict HIV risk behavior tendencies. Whereas a trait-centered theory suggests that spontaneous cognitions are a by-product of personality, a cognitive view hypothesizes that spontaneous cognitions should predict behavior independently of personality. The results revealed that spontaneous cognition was an independent predictor of behavior tendencies in cross-sectional analyses. Its predictive effect was stronger than drug use, a frequently emphasized correlate of HIV risk behavior in the literature, and comparable with sensation seeking in magnitude. The results suggested that a relatively spontaneous form of cognition may affect HIV risk behavior. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The Person Reference Process in Spontaneous Trait Inferences.

Five studies examined whether spontaneous trait inferences uniquely reference the person who performed a trait-implying behavior. On each study trial in 5 studies, participants saw 2 faces and a behavioral sentence referring to one of them. Later, participants saw face-trait pairs and indicated whether they had seen the trait word in the sentence presented with the face. Participants falsely recognized implied traits more when these traits were paired with actors' faces than with control faces. This effect was replicated for a large set effaces (120), after a week delay between study and recognition test, when equal attention was paid to each face, and when the orientation of the face at recognition was different from the orientation at encoding. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

碳酸镧沉淀的自发结晶性能

根据碳酸镧沉淀与结晶过程中溶液pH值和沉淀粒度的测定结果,对碳酸镧沉淀的自发结晶性能进行了研究,结果表明碳酸镧自发结晶的活性区域位于碳酸氢铵与镧离子的沉淀反应摩尔比1∶1～2.8∶1之间。而在高配比区域碳酸镧的结晶是惰性的。考察了加料方式、加料速度、加料比等对碳酸镧结晶的影响,并对碳酸镧的结晶化机理进行了讨论,提出了相关的沉淀和结晶过程的化学反应方程式。     

Ascertaining deviant behavior in children.

A central problem in the use of children's behavior inventories involves the verity of endorsements made by reporters. Therefore, procedures for constructing, administering, and scoring a deviant behavior inventory were developed so as to minimize and control over- and under-reporting error. To minimize false negatives, comprehensive coverage, a not sure response category, a re-sort procedure, and use of 5 reporters were included. To control false positives, clarity and specificity of working, a detailed inquiry, and independent validity judgments were included. In 20 deviant behavior inventory assessments of school children a considerable amount of both types of error was demonstrated when measured against the independent validity judgments, suggesting caution in the use of similar behavioral assessments which neglect to control for such error. (28 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous Recovery From Forward and Backward Blocking.

This article demonstrates and analyzes spontaneous recovery of stimulus control following both forward and backward blocking in a conditioned suppression preparation with rats. Experiment 1 found, in first-order conditioning, robust forward blocking and an attenuation of it following a retention interval. Experiment 2 showed, in sensory preconditioning, recovery of responding following both forward and backward blocking. Also, the results of this experiment indicated that response recovery to the blocked stimulus cannot be explained by an impaired status of the blocking stimulus after a retention interval. Experiment 3, also in sensory preconditioning, suggested that spontaneous recovery following both forward and backward blocking in Experiment 2 was due to impaired associative activation of the blocking stimulus' representation during testing with the blocked stimulus. Although no contemporary model of associative learning can explain these results, a modification of R. R. Miller and L. D. Matzel's (1988) comparator hypothesis is proposed to do so. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Familial correlates of aggression in nondelinquent male children.

An extension of the Sears' studies of lower class families based on a 5-year period of direct home observation of the family group. The aggressive children were more closely supervised by parents, had dominant mothers, were exposed to inconsistent methods of discipline, and had parents who were punitive but placed low demands on the children. From Psyc Abstracts 36:01:3FG79M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Displaced aggression in young children.

Young children played a card game in which some Ss associated losses with a child-figure card and winnings with a plain card, while others associated losses with a plain card and winnings with the child-figure card. Following the card game, Ss played a shooting game in which they selected targets from among pairs of figures that varied from the card game figure on a dimension of physical similarity. Both sexes showed a significant tendency to select, as targets, either figures more like or figures less like the card game figure. There were no differences in target choices as a function of conditions. Among Ss who lost to the card game figure, boys and girls differed, boys favoring more like figures and girls favoring less like figures. The Ss also shot the card game figure itself. Boys who lost the most to that figure shot the greatest number of times; those who lost less, the fewest numbers of times; and boys who won from the figure were in between. No differences were found for girls. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous emission in the ellipsoidal nanocrystals

The equation was presented for the spontaneous emission rate A_nano of the two-level optical centers in the subwavelength ellipsoidal nanocrystals embedded in a dielectric medium. An important result was that the ratio A_nano/A_bulk could be estimated without recourse to a particular local-field model. On the ground of this equation the expression was derived for linestrength of electric-dipole transition in trivalent rare-earth ions. The applicability of the Judd-Ofelt equation for nanoparticles was discussed.     

Implicit Self-Attitudes Predict Spontaneous Affect in Daily Life.

In 2 studies, the authors examined the degree to which implicit self-attitudes predicted people's spontaneous affective experiences in daily life. Across both studies, implicit attitudes toward the self (as measured by Implicit Association Tests) strongly predicted negative feeling states (as measured by computerized experience-sampling procedures), suggesting that implicit self-attitudes may be linked to changes in undifferentiated negative affect. Explicit attitudes toward the self generally did not account for these relations. Findings extend understanding of the factors that contribute to experienced affect and are the first to empirically link implicit self-attitudes with phenomenological affective experience in real-life settings over time. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous Recovery of Excitation but Not Inhibition.

Five magazine approach experiments with rats and 1 sign-tracking experiment with pigeons explored the possibility of an analogue to spontaneous recovery of excitatory conditioning from extinction: spontaneous recovery of inhibitory conditioning from training. Stimuli were 1st treated as conditioned inhibitors and then as conditioned exciters or as irrelevant to reinforcement. At issue was whether the passage of time after the 2nd treatment would allow partial restoration of the initial conditioned inhibition. The experiments differed in the design used to study recovery, the manner of reinforcing the inhibitor, the means of testing for recovery, the time interval allowed for recovery, and the species used. None of the experiments found evidence for recovery of the inhibitory learning with time, despite the concurrently measured presence of spontaneous recovery of excitatory conditioning after extinction. These experiments suggest that changes with time may be preferential to the learning that occurs during extinction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous recovery but not reinstatement of the extinguished conditioned eyeblink response in the rat.

Reinstatement—the return of an extinguished conditioned response (CR) after reexposure to the unconditioned stimulus (US)—and spontaneous recovery—the return of an extinguished CR with the passage of time—are 2 of 4 well-established phenomena that demonstrate that extinction does not erase the conditioned stimulus (CS)–US association. However, reinstatement of extinguished eyeblink CRs has never been demonstrated, and spontaneous recovery of extinguished eyeblink CRs has not been systematically demonstrated in rodent eyeblink conditioning. In Experiment 1, US reexposure was administered 24 hr prior to a reinstatement test. In Experiment 2, US reexposure was administered 5 min prior to a reinstatement test. In Experiment 3, a long, discrete cue (a houselight), present in all phases of training and testing, served as a context within which each trial occurred to maximize context processing, which in other preparations has been shown to be required for reinstatement. In Experiment 4, an additional group was included that received footshock exposure, rather than US reexposure, between extinction and test, and contextual freezing was measured prior to test. Spontaneous recovery was robust in Experiments 3 and 4. In Experiment 4, context freezing was strong in a group given footshock exposure but not in a group given eye shock US reexposure. There was no reinstatement observed in any experiment. With stimulus conditions that produce eyeblink conditioning and research designs that produce reinstatement in other forms of classical conditioning, we observed spontaneous recovery but not reinstatement of extinguished eyeblink CRs. This suggests that reinstatement, but not spontaneous recovery, is a preparation- or substrate-dependent phenomenon. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Three Turtles in Danger: Spontaneous Construction of Causally Relevant Spatial Situation Models.

In 4 experiments, the author explored the spontaneous construction of spatial situation models during discourse comprehension by using the sentence-recognition paradigm of J. D. Bransford, J. R. Barclay, and J. J. Franks (1972). In Experiment 1, signaling causal relevance of spatial relations was a necessary precondition for replicating their original finding of spontaneously constructed spatial representations. Causal relevance was ensured in the subsequent experiments by a judgment task indirectly demanding the evaluation of described spatial relations with regard to causal relevance. Participants spontaneously constructed spatial situation models of text presented auditorily or visually. Effects of spontaneous construction were more reliable when encoding was easier. The results suggest a revised interpretation of J. D. Bransford et al.'s study and corroborate recent evidence showing that relevant spatial information in texts is reliably represented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous recovery of extinguished fear responses deepens their extinction: A role for error-correction mechanisms.

A series of experiments used a within-subject design to study spontaneous recovery of fear responses (freezing) to an extinguished conditioned stimulus (CS) in rats. Experiments 1, 2, 3, and 4 demonstrated that: a remotely extinguished CS elicited more freezing than a recently extinguished one on a common test; that the CS showing recovery underwent greater response loss across additional extinction than the one lacking recovery; and that spontaneous recovery and deepening of response loss survived reconditioning. Experiment 5 demonstrated that an excitor extinguished in compound with a CS showing recovery suffered greater loss than an excitor extinguished in compound with a CS not showing recovery, implying that the differential change is regulated by a common error term. Experiments 6 and 7 demonstrated that extinction of a compound composed of two CSs, one showing recovery and a second lacking recovery, produced greater loss to the CS that showed recovery, implying that the change is also regulated by individual error term. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Spontaneous arterial thrombosis in children

Spontaneous peripheral artery thrombosis in children is rare. We present 2 cases, in both of which the diagnosis was delayed. Acute arterial insufficiency should be considered in children who have clinical symptoms of leg pain, pallor, and reduced pulses. Angiography is the gold standard to confirm or exclude the diagnosis.     

Ethnic cleavage among young children.

"Ethnic cleavage among preschool children was studied using various test situations where choices of associates could be observed. It was found that ethnic cleavage does exist when choices are made significant to young children. The results are compared with other related findings and attempts are made to explain them theoretically." (PsycINFO Database Record (c) 2010 APA, all rights reserved)