Several researchers have hypothesized that implicit memory remains stable across the lifespan. Empirical support with children has been difficult to interpret due to methodological weaknesses including baseline variation, floor and ceiling effects, and lack of experimental dissociations. A new measure of repetition priming, the picture fragment completion task, was developed to account for these weaknesses while being appropriate for both children and adults. Adults and children aged 4, 6, and 8 (N = 156) completed either the picture fragment completion task or an explicit memory test made from same materials. Subjects of all ages performed equally on the priming test while performance increased with age on the explicit memory test. For all ages, the levels of processing manipulation affected only the explicit memory test. Thus, subjects were not using effortful strategies on the priming test. These results form a solid foundation for studying other developmental issues in implicit memory.

No description available.

Apolipoprotein E-knockout (apoEKO) mice were characterized behaviorally to evaluate the impact of apolipoprotein E deficiency on spatial learning and memory function at different ages. Wild type and knockout mice were tested in two tasks assessing spatial memory function, Morris water maze (MWM) and Radial arm maze (RAM). Both young and aged apoEKO mice backcrossed six generations displayed deficits in the MWM. However, young and aged 10th generation apoEKO mice did not display any deficits in the MWM or the RAM when spatial cues that could be used to solve these tasks were provided. Removal of spatial cues after training had occurred also did not result in an impairment. In contrast, apoEKO mice were impaired when spatial cues were removed from the beginning of training. This result suggests that these mice are less able to utilize non-spatial cues to solve these tasks. The impairments observed in the MWM and RAM were not the result of impaired reference memory function, but rather appeared to arise from a dysfunction in working memory. Additional tests assessing sensorimotor gating function (Prepulse inhibition), and emotionality (the Open field, the Elevated plus maze) suggested that these cognitive deficits did not arise from alterations in sensorimotor gating function or emotionality, as both young and aged apoEKO mice performed at levels similar to those observed in their aged C57BL/6J control groups.

No description available.

It is a tenable theory that there are marked individual differences in the facility with which people apprehend novel and enigmatic features in their perceptual fields and invest these data with probable or plausible meanings. [...]

<p> Research on social judgment typically emphasizes one of three processes that enable unequivocal understanding of events with ambiguous causality. In the <i>social influence perspective</i>, people are susceptible to the interpretations offered by others. In the <i>explicit attitudes perspective</i>, people interpret events in line with their consciously held attitudes and values. In the <i>implicit attitudes perspective</i>, people interpret events in line with unconscious biases. The model investigated in the present study assumes that these processes vary in salience depending on people&rsquo;s mindset. When an event is encoded in high-level terms (i.e., its consequences), people&rsquo;s judgments reflect their explicit attitudes. When encoded in low-level terms (i.e., its details), however, such attitudes are less accessible, rendering people susceptible to social influence. In the absence of social influence, people with a lower-level mindset form judgments that reflect their relevant implicit attitudes. These hypotheses were tested in the context of an altercation between an African-American and a White male for which responsibility could reasonably be allocated to either party. Participants with low versus high implicit racial bias toward Blacks read a narrative concerning this altercation under either a low-level or a high-level mindset and then read a summary that blamed one of the parties or they did not read a summary. As predicted, low-level participants allocated responsibility to the African-American if they had a high implicit racial bias and to the White if they had a low implicit racial bias, regardless of the summary manipulation. Contrary to prediction, however, high-level participants&rsquo; allocation of responsibility did not reflect their explicit prejudicial attitudes. Instead, they corrected for their implicit biases in their trait inferences and affective reactions, in line with research suggesting that a high-level mindset promotes self-regulatory processes in social judgment.</p>

<p> Few studies have examined differences between online and offline gamblers, with no study to date enlisting the participation of online gamblers in a laboratory-based study. Moreover, research indicates that there is a link between escape and problem gambling, however, no study to date has examined this relationship in online gamblers using an experimental design. The current study is the first to address these gaps in the literature. All 420 participants participated in the non-experimental phase of the study, and 50 participants participated in the experimental phase. All participants completed a demographics form, SOGS, PGSI, GFA-R, BDI-SF, discounting task, and a gambling motivations questionnaire. In the experimental phase, participants' mood state was manipulated using hypothetical scenarios before gambling. The results indicated that online gamblers had a higher rate of problem-gambling severity than offline gamblers, and that online gamblers have used gambling to escape to a greater degree than offline gamblers. In terms of differences in the gambling behavior of online and offline gamblers, online gamblers were found to have played more hands and committed more errors than offline gamblers. No statistically significant results were found across mood conditions, or when the interaction between participants' gambler status and mood condition was examined, although trends in the hypothesized direction were observed. No statistically significant group differences were observed when online gamblers' rate of discounting certain outcomes was compared to offline gamblers' rates. Taken together, these results suggest that some of the differences between online and offline gamblers may help explain the higher prevalence of problem gambling among online gamblers. Although gambling to escape was found to be positively correlated with problem-gambling severity, the experimental results did not support this finding. Future studies should investigate the relationship between escape and problem gambling in online gamblers by using a different manipulation. A more knowledgeable understanding of the differences between online and offline gamblers will lead to better treatment outcomes for individuals who suffer from a gambling addiction.</p>

Transfer of training is the degree to which a skill or principle learned in one environment can be applied in another environment. Most research that demonstrates transfer relies on the use of hints or explicit instructions identifying the applicability of the information learned in training to the test task. Critics charge that this is not really transfer at all, but simply following instructions. The research reported herein describes an efficient means for testing hypotheses in a fault diagnosis task that, although it would appear to be an obvious strategy, requires an extremely simple training task for subjects to detect. Subjects in Experiment 1 apply the learned principle to a slightly more complex but similar problem, demonstrating near transfer. Subjects in Experiment 2 apply the principle in a completely dissimilar task, exhibiting far transfer.

Consistent biases in the perception of risk have been demonstrated by research. An imaging task was used in this study in an attempt to change those perceptions. The task consisted of sketching scenarios depicting an accident involving eight different hazards. The task effected a change in self risk ratings taken before and after the task, but the change was different for each of two groups of hazards. The hazards were divided into a high and a low group based on the pre-task self risk ratings. Lawnmower, toaster, coffee maker, and bicycle were found to be initially perceived as low risk. Pesticide, swimming pool, asbestos, and power saw were in the initially perceived high risk group. Pre-post self risk rating change scores showed an increase for the low risk group and a decrease for the high risk group. The interaction between sketching and not sketching an accident and the initial perceptions of low and high risk was significant. This finding lends hope that the accident scenario imaging method can be used to correct biases in the perception of risk of certain hazards. An additional analysis addressed the relationship between the perception of risk and other cognitions. Self risk ratings were found to be more closely related to probability estimates for injuries to self than to injury frequency estimates for the general public. Frequency and probability estimates do not tell the whole story, however, as far as risk perception is concerned. Perceptions for the severity of the consequences of an injury caused by the hazard, the catastrophic potential of the hazard, the ease of imagining an injury caused by the hazard, and the extent of exposure to the hazard are also significantly related to the perception of risk to self presented by the hazard. Important differences were observed in this study between perception of risk for self and for others. These findings highlight important considerations in the study and measurement of risk perception which is an important part of any effort to de-bias risk perception. When risk perception is found to be biased in a potentially harmful manner, an understanding of the role of the cognitive availability of accident scenarios and how to change that availability might then be used to correct those biases.

Latent inhibition (LI) is the attenuation in the acquisition of Pavlovian conditioning to a conditioned stimulus (CS) due to prior extensive exposure to that CS. It is assumed that LI is an animal model of attention in that animals learn to ignore the preexposed CS. The present series of experiments investigated the effects of selective serotonergic (5-HT) ligands known to increase 5-HT neurotransmission on LI using a conditioned emotional response (CER) procedure. In experiment 1, rats preexposed (PE) to 40 presentations of a tone CS acquired CER suppression more slowly than vehicle-treated nonpreexposed (NPE) animals, suggesting LI was obtained. Administration of 10 mg/kg fluoxetine (i.p.) did not influence CER acquisition in PE animals, suggesting that LI was not affected by fluoxetine. However, it was assumed that 40 CS presentations exerted a powerful LI effect, which might mask any effect of fluoxetine. Consequently, we assessed the effects of 5-HT ligands on LI following 10, rather than 40, CS preexposures. Under these conditions, both acute fluoxetine (experiment 2), and chronic (14 day) fluoxetine (experiment 3) administration, were found to augment LI. Experiment 4 suggested that acute administration of the 5-HT2 agonist DOI (2.5 mg/kg) also enhances LI. Experiment 5 revealed that 1 mg/kg 8-OH-DPAT did not influence LI, suggesting that postsynaptic 5-HT1a receptors are not involved in LI. These results suggest that enhancement of 5-HT neurotransmission enhance LI and that this effect is mediated, in part, through the 5-HT2 receptor subtype. The results are discussed within the context of the switching model of LI, which suggests that the effects of 5-HT are mediated through the modulation of the mesolimbic dopamine pathway.