Single-incentive selective associations produced solely as a function of compound-stimulus conditioning context.

Barpressing was maintained in a tone-plus-light (TL) condition in 2 groups of rats by shock-related contingencies and in 2 other groups by food-related contingencies. Responding ceased in TL absence (TL). Contingency arrangements made TL hedonically positive, relative to TL, for 1 shock group and for 1 food group and hedonically negative for 1 shock group and for 1 food group. In a stimulus-element test, the visual modality was dominant when TL was hedonically positive, whereas auditory control increased when TL was negative, irrespective of the reinforcers involved. Within-incentive contingency manipulations produced selective associations hitherto ascribed to stimulus-reinforcer interactions, suggesting that biological constraints on learning may operate at the level of conditioned psychological states. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective interaction of homophtalazine derivatives with morphine

Binding of ATP to bovine serum albumin was shown by ultrafiltration and NMR. The binding was pH dependent. Scatchard analysis revealed that at pH 5.4, 6.4 and 7.4, dissociation constant Kd was 13, 40 and 120 microM, respectively, and no binding was observed at pH 8.4. The binding stoichiometry was 1:1 for all pH. Dimer of BSA did not bind ATP. From chemical shifts of 31P-NMR, Kd was estimated to be 15 microM at pH 5.4, which is very close to that determined by ultrafiltration. While adenosine did not interfere with the binding. GTP, dCTP, ADP, UTP, AMP, phosphate and pyrophosphate were competitive inhibitors and their inhibition constants Ki were 25, 32, 36, 50, 130, 1000 and 186 microM, respectively. Fatty acids such as lauric acid and palmitic acid did not interfere with the binding. Warfarin was a non-competitive inhibitor. Cl- competitively inhibited the binding, and the inhibition constant was 20 mM. The dissociation constants of the Cl- binding were reported to be 0.42 mM for the first binding site, 10-5 mM for the second and 303-143 mM for the third [G. Scatchard, W.T. Yap, J. Am. Chem. Soc., 86 (1964) 3434; G. Scatchard et al., J. Am. Chem. Soc. 79 (1957) 12]. This suggests that the ATP binding site may be the second Cl- binding site.     

Selective interference in memory: The imagery-repetition effect revisited.

In a continuous paired-associate learning task, 16 undergraduates utilized rote-repetition and integrative imagery encoding strategies on a trial-by-trial basis. Each imagery or repetition study item was followed by 0-4 imagery or repetition items before test. Error data showed high performance for both imagery and repetition items with imagery interpolated activity. Further, repetition interpolated activity reduced performance for both imagery and repetition encoded items, although this effect was more pronounced for repetition items. K. N. Clayton and M. W. Warren's (1976) model of retroactive interference was used to provide a theoretical framework for interpreting these results. With either a visual or dual coding interpretation of integrative imagery, greater modality-specific interference was found for repetition in contrast to imaginal coding. The differences in original learning and in nonspecific interference for these 2 strategies were small by comparison. Thus, the difference in modality-specific interference presumably forms the basis of the imagery-repetition effect. (French summary) (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inability to attain oral anticoagulation: warfarin-rifampin interaction revisited

The warfarin-rifampin interaction is a well-described but underappreciated drug interaction. A case is reported in which therapeutic anticoagulation could not be achieved after nearly 4 weeks of warfarin therapy because of simultaneous administration of rifampin. This patient had the highest warfarin clearance ever reported in the literature. The world's literature describing warfarin-rifampin interactions for the past 32 years was reviewed to suggest guidelines for warfarin dosage when rifampin is given simultaneously.     

Color-luminance interaction: data produced by oblique cross masking

Threshold-elevation (TE-) versus-mask-spatial-frequency (SF) curves and TE-versus-mask-contrast curves, produced by the oblique-masking technique, were reported for uncrossed stimuli (color-test-on-color-mask and luminance-test-on-luminance-mask) [Invest. Ophthalmol. Visual Sci. Suppl. 34, 751 (1993) and Vision. Res. 23, 873 (1983)]. The technique minimizes the artifacts that are due to spatial phase effects, spatial beats, spatial probability summation, and local cues. My goal was to measure these curves for crossed stimuli (color-test-on-luminance-mask and luminance-test-on-color-mask) by this oblique-masking technique and to compare the curves with those reported in previous studies. For this purpose threshold contrasts were measured by a yes-no procedure with randomized double staircases. Test targets were vertical spatially localized (D6) patterns, and masks were oblique sinusoidal patterns; both the test and the mask were presented simultaneously, for 2 s (Gaussian window), on a color monitor interfaced with an ATVista system and a Powell achromatizing lens. The test SF's were 0.125, 0.5, 2, 4, and 8 cycles per degree (cpd); mask SF's were 0.031-16 cpd; and mask contrasts were 6.25%-50%. Furthermore, the Red-Green channel was defined by the minimum flicker and the hue cancellation techniques. Results show mostly masking effect (TE > 1) at contrasts above threshold; sometimes, separability (TE = 1) and above-threshold facilitation (TE < 1) effects were also observed, depending on the test SF, the mask SF, the mask contrast, and the subject. In general, the magnitudes of TE's are smaller and the TE-versus-mask-SF curves are slightly narrower for the oblique-cross-masking conditions than those for the respective oblique uncross masking. In addition, the TE-versus-mask-contrast curves for the crossed conditions are mostly shallower than those for the respective uncrossed conditions. Furthermore, mostly the color-luminance asymmetry (color masks luminance more than luminance masks color) is found, in mild form, for SF's > or = 0.5 cpd. For the lower SF of 0.125 cpd, there is either a lack of asymmetry or a very mild asymmetry of the opposite kind (luminance masks color slightly more than color masks luminance) seems to prevail. In general, the oblique-masking data shows mild asymmetry and reduced facilitation; both are consistent with reduced local cues, similar to those shown by randomized phase data, thus making the data suitable for SF analysis; moreover, at high contrast, the masking data are consistent with those reported in previous studies.     

Selective associations in the observational conditioning of fear in rhesus monkeys.

Three experiments explored the issue of selective associations in the observational conditioning of fear. Experiment 1 results indicated that observer rhesus monkeys acquired a fear of snakes through watching videotapes of model monkeys behaving fearfully with snakes. In Experiment 2, observers watched edited videotapes that showed models reacting either fearfully to toy snakes and nonfearfully to artificial flowers (SN+/FL–) or vice versa (FL+/SN–). SN+/FL– observers acquired a fear of snakes but not of flowers; FL+/SN– observers did not acquire a fear of either stimulus. In Experiment 3, monkeys solved complex appetitive discriminative (PAN) problems at comparable rates regardless of whether the discriminative stimuli were the videotaped snake or the flower stimuli used in Experiment 2. Thus, monkeys appear to selectively associate snakes with fear. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Matters of the variable heart: Respiratory sinus arrhythmia response to marital interaction and associations with marital quality.

Maintenance of relationship quality requires self-regulation of emotion and social behavior, and women often display greater effort in this regard than do men. Furthermore, such efforts can deplete the limited capacity for self-regulation. In recent models of self-regulation, resting level of respiratory sinus arrhythmia, quantified as high-frequency heart rate variability (HF-HRV), is an indicator of self-regulatory capacity, whereas transient increases in HF-HRV reflect self-regulatory effort. To test these hypotheses in marriage, 114 young couples completed measures of marital quality and a positive, neutral, or negative initial marital task, preceded and followed by resting baseline assessments of HF-HRV. Couples then discussed a current marital disagreement. Resting HF-HRV was correlated with marital quality, suggesting that capacity for self-regulation is associated with adaptive functioning in close relationships. For women but not men, the negative initial task produced a decrease in resting HF-HRV. This effect was mediated by the husbands' negative affect response to the task and their ratings of wives as controlling and directive. When the subsequent disagreement discussion followed the negative initial task, women displayed increased HF-HRV during the discussion but a decrease when it followed the neutral or positive task. The valence of the initial task had no effect on men's HF-HRV during disagreement. Negative marital interactions can reduce women's resting HF-HRV, with potentially adverse health consequences. Women's reduced health benefit from marriage might reflect the depleting effects on self-regulatory capacity of their greater efforts to manage relationship quality. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Calibrating the sociometer: The relational contingencies of self-esteem.

A longitudinal daily diary study examined how chronic perceptions of a partner's regard for oneself might affect the day-to-day relational contingencies of self-esteem. Married partners each completed a diary for 21 days, and completed measures of satisfaction twice over the year. Multilevel analyses revealed that people who chronically felt more positively regarded compensated for one day's acute self-doubts by perceiving greater acceptance and love from their partner on subsequent days. In contrast, people who chronically felt less positively regarded by their partner internalized acute experiences of rejection, feeling worse about themselves on days after they feared their partner's disaffection. Over the year, such self-esteem sensitivity to rejection predicted declines in the partner' s satisfaction. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Structure of silicon carbide powders produced in interaction of silica with carbon black

Translated from Poroshkovaya Metallurgiya, No. 7(355), pp. 47–52, July, 1992.     

Selective associations in day-old chicks: When do CS traces become available for sickness-conditioned learning?

Barber and colleagues (T. A. Barber et al, see record 1998-02850-015; see also T. A. Barber et al, 1995) showed that male domestic chicks would not peck a bead presented 15 or more min before a lithium chloride (LiCl) injection, but would peck a bead presented less than 15 min before a LiCl injection. In 4 experiments, the authors (a) confirmed their initial observation, (b) showed that the effect is not due to retrograde amnesia produced by LiCl, and (c) confirmed that memories less than 15 min old are available for other types of learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective associations in one-day-old rats: Taste–toxicosis and texture–shock aversion learning.

Three experiments investigated cue-consequence specificity and long-delay learning in 187 1-day-old Sprague-Dawley rats and determined whether selective associations are accompanied by long-delay learning early in life. Ss learned aversions to a novel taste paired with Li-induced distress and to a tactile stimulus paired with brief electric shocks. However, aversions did not develop when taste was paired with shock or when the tactile stimulus was paired with Li treatment. The aversions occurred only when Li treatment immediately followed taste exposure and when shock was concurrent with exposure to the tactile stimulus. Findings indicate that selective associations in aversion learning are mediated by innate mechanisms that govern conditioning in the absence of extensive ontogenetic experience and show that selective associations are not sufficient for the occurrence of long-delay learning. (29 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective effects on prefrontal cortex serotonin by dopamine D3 receptor agonism: interaction with low-dose haloperidol

1. Negative symptoms of schizophrenia are characterized by amotivation, anhedonia and anergia. These aspects of the symptom profile can be modeled by D3 agonism in animal behavioral models. 2. Serotonergic systems have been implicated in pathophysiologic substrates for this disorder; most notably, in deficit state schizophrenia, as newer 'atypical' neuroleptics which are especially efficacious for treating this syndrome antagonize central 5-HT2 receptors. 3. FC regions may also be important in chronic negative symptoms, as hypofrontality has been associated with these schizophrenic features. 4. The author examined effects of a behaviorally-active dose of the D3 agonist, 7OH, on 5-HT metabolism in FC, and the ability of a low-dose neuroleptic treatment to antagonize this biochemical effect. 5. Acute administration of 7OH induced a selective decrease of 5-HT turnover in the FC without affecting metabolism of this transmitter in more subcortical DA regions. 6. Hal, which has previously been demonstrated to antagonize electrophysiologic, biochemical and behavioral effects of 7OH, was without effect on agonist-induced decreases in 5-HT turnover. 7. The biochemical association between D3 agonism and reductions of FC 5-HT may be significant for pathophysiologic mechanisms of negative symptoms, and antagonism of this effect may differ for neuroleptics with varying efficacy in alleviating these symptoms.     

Causal versus diagnostic contingencies: On self-deception and on the voter's illusion.

Two experiments tested the notion that people select actions that are diagnostic of favorable outcomes even though the actions do not cause those outcomes. In Exp I, 38 undergraduates immersed their forearm into a chest of circulating cold water before and after physical exercise. Depending on condition, Ss learned that a long life expectancy was associated with either increases or decreases in tolerance to cold water after the exercise. As predicted, Ss showed changes in tolerance on the 2nd trial in the direction correlated with a long, healthy life. In Exp II, 315 undergraduates encountered 1 of 2 theories about the sort of voters who determine the margin of victory in an election. Only one of the theories would enable voting Ss to imagine that they could induce other like-minded persons to vote. As predicted, more Ss indicated that they would vote given that theory than given a theory in which the S's vote would not be diagnostic of the electoral outcome, although the causal impact of the S's vote was the same under both theories. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Children's relationships with peers: differential associations with aspects of the teacher-child relationship

Associations between children's social competence with peers and differential aspects of their teacher-child relationships were examined in a longitudinal sample of 48 4-year-old children enrolled in child care as infants. Toddler security with teacher was negatively associated with hostile aggression and positively with complex peer play and gregarious behaviors. Prosocial behaviors and withdrawing behaviors were associated with preschool security with teacher. Dependence on teachers as a preschooler was associated with social withdrawal and hostile aggression. Positive toddler teacher socialization was associated with higher perceived peer acceptance. Preschool teacher negative socialization was negatively associated with complex peer play, teacher ratings of hesitancy, friendly enactment, and accidental attribution and positively related to teacher ratings of difficulty.     

Selective memory impairments produced by transient lidocaine-induced lesions of the nucleus accumbens in rats.

Reversible lidocaine-induced lesions of the nucleus accumbens (NAC) impaired performance on the spatial win-stay, but not on the cued win-stay, radial arm maze task. Pretraining lesions on the former task did not affect foraging for 4 pellets during either the training or test phases. In contrast, lesions given prior to the test phase significantly disrupted retrieval of 4 pellets on the 8-arm maze. Comparable deficits also were observed in rats trained to forage for 4 pellets on an 8-arm maze without prior win-shift experience. State-dependent drug effects were ruled out by replicating the disruptive effects of lidocaine infusions into the NAC on spatial win-shift performance in rats receiving this treatment prior to both training and test phases. These results suggest that the NAC may interact with the hippocampus to guide foraging behavior requiring memory of previous spatial locations on a maze. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Myofibroblastoma of the breast revisited: an etiologic association with androgens?

In order to test the hypothesis that normal gravity is an important influence on human serum [Erythropoietin] ([Epo]), the hematologic response to 16 d of 6 degrees head-down tilt (HDT, n = 6 men) was compared with 16 d of normal gravity exposure (CON, n = 7 men). Prior to bed rest, CON and HDT subjects, respectively, were similar in the following characteristics (mean +/- SD): age = 40 +/- 3, 39 +/- 6 yr; height = 181 +/- 5, 182 +/- 6 cm; weight = 88.5 +/- 11.3, 81.7 +/- 12.0 kg; maximal oxygen consumption in supine 6 degrees head-down tilt position (VO2max) = 2.63 +/- 0.38, 2.67 +/- 0.52 L.min-1; hematocrit = (Hct) 41.6 +/- 2.4, 43.0 +/- 3.4%; hemoglobin ([Hb]) = 15.1 +/- 1.0, 14.5 +/- 1.0 g.100 ml-1; plasma volume (PV) = 3829 +/- 857, 3768 +/- 512 ml; and [Epo] = 11.6 +/- 2.9, 10.0 +/- 6.2 mU.ml-1. Calculated red cell volume (RCV) was greater in HDT than CON (2845 +/- 410 vs. 2139 +/- 253 ml, p < 0.05) at baseline. Decreases in PV (-15%, 580 ml, p < 0.05) and an insignificant decrease in RCV (-12%, 354 ml, p = 0.07) were observed in the HDT group, with a concurrent 6% increase in [Hb] (p < 0.05). PV, RCV and [Hb] remained unchanged in the CON group. [Epo] remained unchanged during HDT (12.2 +/- 3.2; 10.8 +/- 3.8; 11.2 +/- 3.1; 11.2 +/- 2.6 mU.ml-1 for HDT days 1, 2, 8 and 16, respectively). There was no difference between CON and HDT groups in [Epo] before or during HDT. It was concluded that the insignificant change (-12%) in RCV observed during HDT was insufficient to stimulate an increase in [Epo], probably because the content of oxygen in arterial blood remained unaffected. The observation that [Epo] remained unchanged despite this loss of RCV during HDT also suggests a possible decrease in the responsiveness of the erythropoietic system to [Epo].     

Cataract associations with pinguecula and pterygium: the Blue Mountains Eye Study

PURPOSE: To determine associations between cataract types and pinguecula and pterygium. METHODS: The Blue Mountains Eye Study examined 3,654 persons aged 49 to 97 years near Sydney, Australia. A questionnaire was used to collect information on cataract risk factors. Slit-lamp examination recorded pinguecula and pterygium. Masked lens photograph grading assessed cataract. RESULTS: Pinguecula, found in 2,418 right eyes and 2,437 left eyes, was statistically significantly associated with cortical cataract (odds ratio [OR] = 1.40) after multivariate adjustment. Pterygium, found in 199 right eyes and 188 left eyes, was associated with posterior subcapsular cataract (OR = 1.90). CONCLUSIONS: Associations were found between cataract and the presence of either pinguecula or pterygium. These findings provide indirect support for Watermen Study findings, which link ultraviolet radiation to cataract.     

Selective associations and causality judgments: Presence of a strong causal factor may reduce judgments of a weaker one.

In 5 experiments, humans played video games in which 2 events or causes covaried with an outcome. In Exps 1 and 2, a highly correlated cause (a plane) of an outcome (success at traversing a minefield) reduced judgments of the strength of a weaker cause (camouflaging or painting a tank). In Exp 3, similar results were found when both causes were negatively correlated with the outcome. In Exp 4, strong positive or negative contingencies caused the Ss to reduce judgments of contingencies of the opposite polarity. These results can be accounted for by associative or connectionist models from animal learning such as the Rescorla-Wagner model. In Exp 5, this type of model was contrasted with a representational model in which Ss are claimed to monitor accurately the various contingencies but use a rule in which the presence of a strong contingency causes them to discount weaker contingencies. (PsycINFO Database Record (c) 2010 APA, all rights reserved)