Evidence for inhibitory associations between the unique elements of two compound flavours

In each of two experiments, rats were pre-exposed to two flavoured solutions, saline-lemon and sucrose-lemon. For group ALT, trials with one solution alternated with trials with the other. Group BLK received all trials with one solution in a block, before any trials with the other. An associative theory suggests that the alternating, but not the blocked, schedule would establish an inhibitory association between sucrose and saline. To provide a retardation test of this inhibition, some animals in each group were then given a single pairing of saline and sucrose, experienced sodium depletion, and were finally tested for their consumption of sucrose. Sodium depletion increased consumption of sucrose more in group BLK than in group ALT. In groups given no saline-sucrose pairing, sodium depletion had only a small effect on sucrose consumption, which was the same in both groups. After multiple pairings of saline and sucrose, sodium depletion had an equally large effect on sucrose consumption in both ALT and BLK groups. These results imply that alternating pre-exposure to two compound solutions does establish an inhibitory association between their unique elements, and thus provide support for an associative theory of perceptual learning.     

Perceptual learning in flavor-aversion learning: Alternating and blocked exposure to a compound of flavors and to an element of that compound

Rats received different schedules of pre-exposure to a compound flavor (AX) and to one element of that compound (X). In Group ALT, exposure consisted of alternating trials with AX and X; Group BLK received a block with all AX trials before a separate block with all X trials (or vice versa). Discrimination between AX and X was assessed then by establishing an aversion to X and measuring the generalization of this aversion to AX. In Experiments 1A and 1B, generalization was less in Group ALT than in Group BLK. In Experiment 2, this latter result was confirmed and furthermore only Group ALT, and not Group BLK, showed less generalization than a group that received exposure to X alone. These results are discussed in terms of their implications for theories of perceptual learning.     

Effects of exposure on discrimination of similar stimuli and on memory for their unique and common features

Human participants received exposure to similar visual stimuli (AW and BW) that shared a common feature (W). Experiment 1 demonstrated that subsequent discrimination between AW and BW was more accurate when the two stimuli were preexposed on an intermixed schedule (AW, BW, AW, BW…) than when they were preexposed on a blocked schedule (AW, AW…BW, BW…): the intermixed-blocked effect. Furthermore, memory for the unique features of the stimuli (A and B) was better when the stimuli were preexposed on an intermixed schedule than when they were preexposed on a blocked schedule. Conversely, memory for the common features of the stimuli (W) was better when the stimuli were preexposed on a blocked schedule than when they were preexposed on an intermixed schedule. Experiment 2 again demonstrated the intermixed-blocked effect, but participants were preexposed to the stimuli in such a way that the temporal spacing between exposures to the unique features was equated between schedules. Memory for the unique and common features was similar to that found in Experiment 1. These findings support the proposal that perceptual learning depends on a mechanism that enhances memory for the unique features and reduces memory for common features.     

Formation of excitatory and inhibitory associations between absent events

Considerable evidence indicates that associations may be formed between two events even when one or both of them is absent at the time of learning. Previously, some researchers asserted that excitatory associations are formed when associatively activated representations for two events are paired, whereas others claimed that inhibitory associations are formed. In three experiments, the authors investigated the nature of tone-sucrose learning when associatively activated representations of those events were paired in the absence of either of the events themselves. Experiment 1 found substantial excitatory learning when the tone surrogate preceded the sucrose surrogate in training. Experiment 2 evaluated other accounts for the results of Experiment 1, and Experiment 3 found evidence for inhibitory tone-sucrose learning when the tone and sucrose surrogates were presented in simultaneous or backward order. The results indicated that the nature of representation-mediated learning is influenced by some of the same variables as more standard associative learning.     

Longitudinal associations between gender-typed skills and interests and their links to occupational outcomes

Although gender-based occupational segregation has declined in past decades, the world of work remains segregated by gender. Grounded in research showing that individuals tend to choose jobs that match their interests and skills, this study examined the longitudinal associations between gendered activity interests and skills from middle childhood through adolescence and tested gendered interests and skills, measured in adolescence, as predictors of occupational outcomes in young adulthood. Data were collected from 402 participants at four time points—when they averaged 10, 12, 16, and 25 years old. Results revealed that the longitudinal linkages between male-typed interests and skills were bidirectional, that both male-typed interests and skills in adolescence predicted working in male-typed occupations in young adulthood, and that skills, but not interests, predicted income. In contrast, female-typed interests predicted female-typed skills, but not the reverse, adolescent female-typed skills (but not interests) predicted working in female-typed occupations in young adulthood, and there were no links between female-typed interests or skills and income. Discussion focuses on the differential meanings and developmental implications of male- versus female-typed interests and skills.     

Delay-induced super-latent inhibition as a function of order of exposure to two flavours prior to compound conditioning

A number of recent conditioned taste aversion (CTA) experiments have demonstrated a super-latent inhibition (LI) effect—namely, a time-induced increase in the effects of stimulus preexposure when the interval between acquisition and test is spent in a context that is different from the other experimental contexts. Two CTA experiments with rats were conducted to examine the role of primacy in producing super-LI. In Experiment 1, one of two flavours was pre-exposed, following which a second flavour was preexposed. After the second preexposure, animals were conditioned by pairing a compound of the two preexposed flavours with LiCl. The test stage was conducted 1 or 21 days after conditioning, with the interval being spent in either the same or different contexts. In the test, animals were confronted with two bottles, each with one of the two preexposed flavours. Super-LI was obtained only for the first preexposed flavour in the 21-day delay group that spent the interval in a different context. Experiment 2 was designed to ensure that the effects in Experiment 1 represented LI, and to control for order of presentation of the flavours and time between preexposure and acquisition. The results replicated those of Experiment 1. The two experiments support the importance of primacy in the general super-LI experiment where CS-alone preexposure precedes CS-US.     

Sex moderates associations between prenatal glucocorticoid exposure and human fetal neurological development

Maternal cortisol levels (at 15, 19, 25, 31 and 37 weeks’ gestation) and fetal movement response to vibroacoustic stimulation (VAS; at 25, 31 and 37 weeks) were assessed in 190 mother‐fetus pairs. Fetuses showed a response to the VAS at 25 weeks and there was evidence of increasing maturation in the response at 31 and 37 weeks. Early elevations in cortisol predicted a failure to respond to the VAS at 25 weeks and later elevations in cortisol were associated with a larger response among fetuses when assessed near term. The associations between cortisol and VAS emerged earlier and were more apparent among female fetuses than among the males. The findings provide support for the role of prenatal glucocorticoids in shaping human fetal CNS development.     

Alternating prism exposure causes dual adaptation and generalization to a novel displacement

In two experiments, we examined the hypothesis that repeatedly adapting and readapting to two mutually conflicting sensory environments fosters the development of a separate adaptation to each situation (dual adaptation) as well as an increased ability to adapt to a novel displacement (adaptive generalization). In the preliminary study, subjects alternated between adapting their visuomotor coordination to 30-diopter prismatic displacement and readapting to normal vision. Dual adaptation was observed by the end of 10 alternation cycles. However, an unconfounded test of adaptive generalization was prevented by an unexpected prism-adaptive shift in preexposure baselines for the dual-adapted subjects. In the primary experiment, the subjects adapted and readapted to opposite 15-diopter displacements for a total of 12 cycles. Both dual adaptation and adaptive generalization to a 30-diopter displacementwere obtained. These findings may be understood in terms of serial reversal learning and “learning to learn.”     

The associations between non-suicidal self-injury and borderline personality disorder features among Chinese adolescents

This study examined the relative importance of four major BPD features, that is, affective instability, disturbed interpersonal relationship, unstable sense of self, and behavioral impulsivity, in explaining the presence, initiation, repetition, and discontinuation of non-suicidal self-injury (NSSI) among a 2-year follow-up sample of 4,782 (68.5% girls) Hong Kong Chinese secondary school students. Affective instability, disturbed interpersonal relationship and behavioral impulsivity were significantly associated with the presence of NSSI both concurrently and longitudinally. These three BPD features were also related to the future initiation of NSSI. On the other hand, only behavioral impulsivity made a significant contribution to the repetition of NSSI. Additionally, a lower level of affective instability was also associated with quitting NSSI. We discussed some possible mechanisms underlying the effects of different BPD features on different developmental stages of NSSI.     

Group entitativity and group perception: associations between physical features and psychological judgment

Two experiments tested whether the perceived entitativity of groups (i.e., cohesiveness) influences judgments about those groups, in terms of both their observable physical properties and underlying psychological traits. Entitativity was manipulated with groups whose members were similar or dissimilar in skin color. Experiment 1 demonstrated that beliefs about entitativity elicited more accurate judgments of skin color for entitative than nonentitative social groups, although memory for individual members of entitative groups was relatively impoverished. Experiment 2 revealed that entitative groups were viewed as not only physically similar but also psychologically homogeneous and elicited strong negative trait and behavioral judgments. Together, these findings suggest that physical properties (e.g., similarity) can create perceptions of psychological "groupness" that have important consequences for group perception.     

Alternating antagonism between two languages with successive recovery of a third in a trilingual aphasic patient

The recovery of the languages of an aphasic patient premorbidly almost equally proficient in Farsi and German, with a good knowledge of English, is described. For the first week post-trauma, the patient was in no condition to speak. He then spoke only a little Farsi for 5 days, after which he spoke only German for the next 3 weeks, even when addressed in Farsi by his unilingual relatives. The patient then switched back to using only Farsi for 4 days, after which he regained voluntary control over each of his languages, including English. The patient was repeatedly assessed with equivalent versions of the BAT (M. Paradis et al. 1987, Bilingual Aphasia Test). His residual capacities across languages are described. The patient differs from previously reported cases in that even his comprehension of Farsi was impaired during the period when only German was available for expression. The patient recovered voluntary control over the use of his three languages 1 1/2 months postonset.     

Genetic and caregiving-based contributions to infant attachment: unique associations with distress reactivity and attachment security

In the longitudinal study reported here, we examined genetic and caregiving-based contributions to individual differences in infant attachment classifications. For 154 mother-infant pairs, we rated mothers' responsiveness to their 6-month-old infants during naturalistic interactions and classified infants' attachment organization at 12 and 18 months using the Strange Situation procedure. These infants were later genotyped with respect to the serotonin-transporter-linked polymorphic region (5-HTTLPR). Maternal responsiveness uniquely predicted infants' attachment security. Infants' 5-HTTLPR variation uniquely predicted their subtype of attachment security at 12 months and their subtype of attachment insecurity at 12 and 18 months. The short allele for 5-HTTLPR was associated with attachment classifications characterized by higher emotional distress. These findings suggest that 5-HTTLPR variation contributes to infants' emotional reactivity and that the degree to which caregivers are responsive influences how effectively infants use their caregivers for emotion regulation. Theoretical implications for the study of genetic and caregiving influences are discussed.     

Long-delay associations between drug states produced in rats by injecting two drugs in sequence

Injection of pentobarbital after a rat has consumed saccharin solution usually produces a mild aversion to the saccharin. However, the pentobarbital-produced aversion is eliminated or attenuated by prior pairings of pentobarbital injections with lithium injections. This is called the Avfail (aversion failure) effect. The present experiments dealt with the effect of the temporal relation of the pentobarbital injection to the lithium injection. After forward pairings (pentobarbital before lithium) with delays between the two injections varying among groups from 2.5 min to 320 min, Avfail was invariably obtained. There was little effect of the length of the forward delay, although the Avfail effect appeared to be slightly stronger at 30-40 min or so. When the two drugs were injected simultaneously or in a backward sequence, there was a weakening of the flavor aversion produced by pentobarbital, but this is attributable to habituation to the drugs, not to Avfail.     

Nothing ventured nothing gained: Strong associations between reward sensitivity and two measures of Machiavellianism

Recent theoretical work on the Life History Theory and empirical findings on Machiavellianism suggest that Machiavellian individuals are motivated to acquire short-term benefits and prioritize situations with high potential rewards. Accordingly, in our study, we investigated the associations between reward/punishment sensitivity and Machiavellian interpersonal tactics with self-report measures. Moreover, as a first attempt, we investigated the correlates of Machiavellianism and the behavioral preference for rewards with the IOWA Gambling task (IGT). The results showed robust positive associations of Machiavellian behavioral characteristics with Sensitivity to Reward, and a moderately negative correlation with Sensitivity to Punishment. This finding was further supported by IGT: Machiavellians tended to make reward-oriented decisions.     

The influence of size in weight illusions is unique relative to other object features

Psychonomic Bulletin & Review - Research into weight illusions has provided valuable insight into the functioning of the human perceptual system. Associations between the weight of an object...     

Longitudinal associations between hostility in adolescents' family relationships and friendships and hostility in their romantic relationships.

This study examined longitudinal predictors of hostility in adolescents' romantic relationships. The sample included 110 adolescents and their parents from 72 families. Observational measures of parents' marital hostility and parent-child hostility and self-reports of hostility in close friendships were collected when adolescents ranged from 14 to 16 years old. Three years later, when they were 17 to 19 years old, adolescents reported on the hostility in their romantic relationships. Results indicated that hostility in parents' marital relationships and in adolescents' friendships accounted for independent variance in hostility in adolescents' later romantic relationships. Results highlight the importance of both family relationships and friendships for predicting hostility in adolescents' romantic relationships over time.     

Selective exposure in decided and undecided individuals: differential relations to automatic associations and conscious beliefs

People often show a preference for information that confirms their attitudes and beliefs, and this tendency is reduced for opinions that are not held with conviction. The present study shows that both decided and undecided individuals show a tendency to selectively expose themselves to confirmatory information, albeit with different antecedents and consequences. Whereas selective exposure in decided participants was predicted by conscious beliefs and not by automatic associations, selective exposure in undecided participants was predicted by automatic associations and not by conscious beliefs. Moreover, selective exposure led undecided participants to adopt conscious beliefs that were in line with their preexisting automatic associations. Conversely, for decided participants, selective exposure shifted automatic associations in a direction that was in line with their preexisting conscious beliefs. Implications for decision making and mutual influences of automatic associations and conscious beliefs in attitude change are discussed.     

Additional exposures to a compound of two preexposed stimuli deepen latent inhibition

The present experiments studied the role of error correction mechanisms in the latent inhibition of conditioned fear responses by conditioned stimulus (CS) preexposure. They demonstrated that a preexposed CS subjected to additional exposures in compound with either another preexposed stimulus or a novel stimulus was more latently inhibited than a preexposed CS which received additional exposures in isolation. They also showed that a preexposed CS subjected to additional exposures in compound with another preexposed stimulus was more latently inhibited than a preexposed CS given additional exposures in compound with a novel stimulus. These results were discussed in terms of the Hall-Rodriguez (2010) model of latent inhibition.     

Affective habituation: subliminal exposure to extreme stimuli decreases their extremity

Following a functional perspective on evaluation, the authors hypothesized that subliminal exposure to extreme stimuli (e.g., extremely negative or positive words) would lead these stimuli to be perceived as less extreme. This process--affective habituation--was tested in 4 experiments. In Experiment 1, participants were subliminally exposed to extremely positive and extremely negative words. In a subsequent explicit-judgment task, these words were rated as less extreme than extreme words that had not been presented. In Experiment 2, these results were replicated with an implicit evaluation measure. In Experiments 3 and 4, subliminal exposure to extreme positive and negative words made the words "behave" as words that are only moderately positive or negative. Several implications are discussed.