Predictors of decision-making on the Iowa Gambling Task: independent effects of lifetime history of substance use disorders and performance on the Trail Making Test

Poor decision-making and executive function deficits are frequently observed in individuals with substance use disorders (SUDs), and executive deficits may contribute to poor decision-making in this population. This study examined the influence of lifetime history of an alcohol, cocaine, heroin, or polysubstance use disorder on decision-making as measured by the Iowa Gambling Task (IGT) after controlling for executive ability, demographic characteristics, and current substance use. Participants (131 with lifetime history of SUD and 37 controls) completed the IGT and two neuropsychological tests: the Trail Making Test and the Controlled Oral Word Association Test. Control participants performed significantly better than those with a lifetime SUD history on the IGT, but performance on the neuropsychological tests was comparable for the two groups. A lifetime SUD diagnosis was associated with performance on the IGT after controlling for covariates, and Trail Making Test performance was associated with IGT performance in both SUD and control participants.     

The role of the magnocellular and parvocellular pathways in the attentional blink

The attentional blink refers to the transient impairment in perceiving the 2nd of two targets presented in close temporal proximity in a rapid serial visual presentation (RSVP) stream. The purpose of this study was to examine the effect on human attentional-blink performance of disrupting the function of the magnocellular pathway--a major visual-processing pathway specialized in temporal segregation. The study was motivated by recent theories that relate the attentional blink to the limited temporal resolution of attentional responses, and by a number of poorly understood empirical findings, including the effects on the attentional blink of luminance adaptation and distraction. The attentional blink was assessed for stimuli on a red background (Experiment 1), stimuli on an equiluminant background (Experiment 2), and following flicker or motion adaptation (Experiment 3), three psychophysical manipulations known to disrupt magnocellular function. Contrary to our expectations, the attentional blink was not affected by these manipulations, suggesting no specific relationship between the attentional blink and magnocellular and/or parvocellular processing.     

A case for inhibition: visual attention suppresses the processing of irrelevant objects

The present study investigated the ability to inhibit the processing of an irrelevant visual object while processing a relevant one. Participants were presented with 2 overlapping shapes (e.g., circle and square) in different colors. The task was to name the color of the relevant object designated by shape. Congruent or incongruent color words appeared in the relevant object, in the irrelevant object, or in the background. Stroop effects indicated how strong the respective area of the display was processed. The results of 4 experiments showed that words in the relevant object produced larger Stroop effects than words in the background, indicating amplification of relevant objects. In addition, words in the irrelevant object consistently produced smaller Stroop effects than words in the background, indicating inhibition of irrelevant objects. Control experiments replicated these findings with brief display durations (250 ms) and ruled out perceptual factors as a possible explanation. In summary, results support the notion of an inhibitory mechanism of object-based attention, which can be applied in addition to the amplification of relevant objects.     

Reactivation-dependent amnesia in Pavlovian approach and instrumental transfer

The theory of memory reconsolidation relates to the hypothesized restabilisation process that occurs following the reactivation of a memory through retrieval. Thus the demonstration of reactivation-dependent amnesia for a previously acquired memory is a prerequisite for showing that such a memory undergoes reconsolidation. Here we show that the appetitive Pavlovian representations that underlie Pavlovian approach and Pavlovian-instrumental transfer are destabilized following their retrieval. This reactivation-dependent amnesia demonstrates that the general motivational or incentive properties of appetitive conditioned stimuli, as well as their conditioned reinforcing properties, can be reduced by blocking memory reconsolidation.     

Trial-by-trial effects in the affective priming paradigm

In this paper, we yield evidence for the dependence of affective priming on the congruency of the previous trial. Affective priming refers to the finding that valence categorizations of targets are facilitated when the preceding prime is of the same valence. In two experiments, affective priming was diminished after incongruent trials (i.e., prime and target were of different valence), whereas, significant affective priming was observed after congruent trials (i.e., prime and target were of same valence). We compare this pattern to the known sequential dependencies in Stroop- and Eriksen-type tasks. Furthermore, our results can help to improve the statistical power of studies in which the affective priming task is used as a measure for automatic evaluations of attitude-objects.     

Generalization of conditioned fear-potentiated startle in humans: experimental validation and clinical relevance

Though generalization of conditioned fear has been implicated as a central feature of pathological anxiety, surprisingly little is known about the psychobiology of this learning phenomenon in humans. Whereas animal work has frequently applied methods to examine generalization gradients to study the gradual weakening of the conditioned-fear response as the test stimulus increasingly differs from the conditioned stimulus (CS), to our knowledge no psychobiological studies of such gradients have been conducted in humans over the last 40 years. The current effort validates an updated generalization paradigm incorporating more recent methods for the objective measurement of anxiety (fear-potentiated startle). The paradigm employs 10, quasi-randomly presented, rings of gradually increasing size with extremes serving as CS+ and CS−. The eight rings of intermediary size serve as generalization stimuli (GSs) and create a continuum-of-similarity from CS+ to CS−. Both startle data and online self-report ratings demonstrate continuous decreases in generalization as the presented stimulus becomes less similar to the CS+. The current paradigm represents an updated and efficacious tool with which to study fear generalization—a central, yet understudied conditioning-correlate of pathologic anxiety.     

Do fish count? Spontaneous discrimination of quantity in female mosquitofish

The spontaneous tendency to join the largest social group was used to investigate quantity discrimination in fish. Fish discriminated between shoals that differed by one element when the paired numbers were 1vs2, 2vs3 and 3vs4, but not when 4vs5 or larger. Using large numerosities (>4), the ability to discriminate between two numbers improved as the numerical distance between them increased and a significant discrimination was found only with ratios of 1:2 or smaller (4vs8, 8vs16 and 4vs10). Experiments to control for non-numerical variables evidenced the role played by the total area of stimuli with both large and small numerosities; the total quantity of movement of the fish within a shoal appeared also important but only when large numerosities were involved. Even though the pattern of discrimination exhibited by female mosquitofish is not fully consistent with any of the existing models of quantity representation, our results seem to suggest two distinct mechanisms in fish, one used to compare small numbers of objects and one used when larger numerosities are involved.     

Does self-consciousness increase or decrease priming effects? It depends

Self-consciousness has been shown to both increase and decrease the magnitude of prime-to-behavior effects. In this paper, we decouple the facets of self-consciousness into internal state awareness and self-reflectiveness and show that self-consciousness can be associated with multiple influences on automatic behavior. Specifically, we conducted an experiment demonstrating that increased internal state awareness decreased the magnitude of the prime-to-behavior effect, whereas increased self-reflectiveness amplified the effect. These effects operated independently of self-monitoring and suggest a multiple process approach to understanding prime-to-behavior effects.     

Similarities and differences between traumatic and emotional memories: review and directions for future research

The authors review theory and empirical research on the characteristics of memories for traumatic versus emotional events, with the goal of bringing together the cognitive and clinical perspectives on this issue. They consider the most important approaches to the study of traumatic and emotional memory and summarize the results of recent studies that have compared autobiographical recollections of traumatic and nontraumatic emotional experiences (positive and negative), either in nonclinical or clinical samples. Overall, findings from the current empirical literature are inconsistent. Although some researchers have found that traumatic memories are retrieved differently than are emotional memories, others have demonstrated that the phenomenological characteristics of these memory types are highly similar. The authors discuss methodological issues that could help researchers to interpret the inconsistencies found in the empirical findings. Last, they suggest possible directions for future research that may advance researchers' knowledge of memory, trauma, and emotion.