特质正念与控制点调节日常生活中知觉压力对消极情绪的影响

考察日常生活中知觉压力对消极情绪的动态影响,检验特质正念的调节作用,并进一步探索正念的调节作用是否在不同控制点的个体中存在差异。共有95名在校大学生完成正念注意觉知量表（MAAS）,罗特控制点量表（LOCS）,并通过动态评估的方式,完成每天2次,持续14天的在日常生活情境中针对知觉压力和消极情绪的密集型追踪测量。多层线性模型结果表明：（1）在个体内水平,个体某一时刻的知觉压力可以显著预测个体下一时刻的消极情绪;（2）个体的正念水平越高,日常生活中知觉压力对消极情绪的预测力越低;（3）个体越倾向于内控,日常生活中知觉压力对消极情绪的预测力越低;（4）个体越倾向于外控,正念对日常生活中知觉压力影响消极情绪的调节作用越强。本研究验证了正念对日常生活中压力反应的保护作用,并提示外控者在面临压力时更有可能从正念中获益。     

Anticipatory attention during the sleep onset period

To examine whether anticipatory attention or expectancy is a cognitive process that is automatic or requires conscious control, we employed a paired-stimulus event-related potential (ERP) paradigm during the transition to sleep. The slow negative ERP wave observed between two successive stimuli, the Contingent Negative Variation (CNV), reflects attention and expectancy to the second stimulus. Thirteen good sleepers were instructed to respond to the second stimulus in a pair during waking sessions. In a non-response paradigm modified for sleep, participants then fell asleep while tones played. As expected, N1 decreased and P2 increased in amplitude systematically with the loss of consciousness at sleep onset; the CNV was increasingly more positive. Sleep onset latency was correlated with the amplitude of the CNV. The systematic attenuation of the CNV waveform at sleep onset and its absence in sleep indicates that anticipatory attention requires endogenous conscious control.     

Plasticity associated with escalated operant ethanol self-administration during acute withdrawal in ethanol-dependent rats requires intact matrix metalloproteinase systems

Repeated cycles of ethanol intoxication and withdrawal associated with dependence induce neuroadaptations in a variety of brain systems. Withdrawal-induced negative emotional states can be ameliorated by ethanol consumption; a learned process termed negative reinforcement. Accordingly, a dependence-induced phenotype is escalated ethanol self-administration. Matrix metalloproteinases (MMPs) are proteolytic enzymes which degrade the extracellular matrix to allow for synaptic reorganization and plasticity. To test the hypothesis that an intact MMP system is required for animals to learn about the negative reinforcing effects of ethanol and display escalated self-administration during acute withdrawal when ethanol-dependent, male Wistar rats were trained to self-administer ethanol and then assigned to either acute or chronic MMP inhibition treatment groups. The chronic treatment group received intracerebroventricular (ICV) infusions of the broad spectrum MMP inhibitor FN-439 or artificial cerebrospinal fluid (aCSF) via osmotic minipumps during a 1 month ethanol dependence induction period and subsequent post-dependence induction self-administration sessions that occurred during acute withdrawal. The acute treatment group only received ICV FN-439 or aCSF on the day of self-administration sessions following dependence induction during acute withdrawal. The results showed that inhibition of MMPs attenuated escalated ethanol self-administration following chronic and acute exposure conditions. Furthermore, once learning (i.e., plasticity) had occurred, MMP inhibition had no impact on escalated response patterns and animals previously subjected to MMP inhibition that did not escalate evidenced normal escalations in operant ethanol self-administration once FN-439 treatments were terminated. Thus, the present data identified that an intact MMP system is required for the escalated responding that occurs during acute withdrawal in dependent animals and implicate such escalation as a learned response.     

No evidence for a cue mismatch in negative priming

An experiment is reported in which the cue mismatch hypothesis of negative priming, an important novel variant of the mismatching hypothesis, was tested. A cue mismatch and a no mismatch condition were contrasted in a visual discrimination task. In the prime display of cue mismatch ignored-repetition trials, the colour of the prime distractor was different from the colour of the cue indicating the selection feature (coloured square). In probe displays, cue and repeated stimulus had the same colour. In the no mismatch condition, the visual cue was neutral in terms of colour (always black), so that there was always no cue mismatch between prime and probe displays. Contrary to the prediction of the cue mismatch hypothesis, the negative priming effect was not larger in the cue mismatch than in the no mismatch condition. The cue mismatch hypothesis must therefore be rejected. In contrast, the episodic retrieval account is consistent with the results.     

Magnitude of negative priming varies with conceptual task difficulty: Attentional resources are involved in episodic retrieval processes

In a variant of the negative priming (NP) procedure, the larger of two presented animals is to be named in each trial. Eight animals of different sizes are used, which allows a manipulation of conceptual task difficulty in terms of pair distance (difficult: one step, versus easy: three steps) on the series. Distances are varied for prime pairs and probe pairs orthogonally. NP effects were found for easy (wide) probe distances (Experiments 1 and 2) and, additionally, for easy (wide) prime distances (Experiment 2). This pattern is interpreted in terms of different theories of NP, which emphasize either forward-acting (prime to probe) or backward-acting (probe to prime) processes. The present results are most compatible with a backward-acting mechanism defined by the episodic retrieval perspective; they are less compatible with a forward-acting inhibition perspective. The results have implications for resource requirements of retrieval-based accounts of NP.     

Comparing positive and negative patterning in human learning

In human causal learning, positive patterning (PP) and negative patterning (NP) discriminations are often acquired at roughly the same rate, whereas PP is learned faster than NP in most experiments with nonhuman animals. One likely reason for this discrepancy is that most causal learning scenarios encourage participants to treat the presentation and omission of the relevant outcome as two events of comparable significance and likelihood. To investigate this, the current experiments compared PP and NP using a predictive learning paradigm based on a mock gambling task. In Experiment 1, one outcome (winning) was made more salient by being less frequent than the alternative outcome (losing). Under these circumstances, PP was learned faster than NP. In Experiment 2, subjects learned two PP and two NP discriminations, one involved win versus no change outcomes, the other involved lose versus no change outcomes. The subjects learned PP faster than NP, but only when discriminating win from no change. We argue that a difference in difficulty between PP and NP relies on a difference in the salience of the outcomes, consistent with the predictions of a relatively simple model of associative learning.     

Extreme elemental processing in a high schizotypy population: Relation to cognitive deficits

The cognitive deficits observed in schizophrenia have been characterized as a failure to utilize task-setting information to guide behaviour, especially in situations in which there is response conflict. Recently, we have provided support for this account; high schizotypy individuals demonstrated inferior biconditional discrimination performance compared to low scorers, but were not impaired on a simple discrimination that did not require the use of task-setting cues. These results may, however, also be explained by the way in which individuals with high schizotypy process stimulus compounds. Here, we examine the initial approaches to solving biconditional and control discrimination tasks of participants with high and low schizotypy scores. In particular, we focus on performance during the first block of training trials to capture processing style before the acquisition of the discrimination tasks. Participants scoring highly on the introvertive anhedonia subscale (which has been allied to the negative and cognitive symptoms of schizophrenia) demonstrated better biconditional performance during the first block of training trials than did low-schizotypy individuals, consistent with a highly elemental approach to stimulus processing. Subsequent recognition tests confirmed this analysis demonstrating that the pattern of performance observed in participants with high schizotypy was associated with a failure to discriminate conjunctions of items that had been seen before from those that had not. These results suggest that the negative/cognitive symptoms of schizophrenia may reflect an extreme bias towards elemental, as opposed to configural, processing of stimulus conjunctions.     

Episodic retrieval processes take place automatically in auditory negative priming

Episodic retrieval processes involved in negative priming have been argued to be susceptible to the proportion of attended repetition trials. The more trials with the same prime and probe response, the more beneficial should it be to retrieve the prime episode, particularly its response. Retrieval of the prime episode, however, is task-inappropriate for ignored repetition trials, leading to negative priming. Correspondingly, visual negative priming increases with the proportion of attended repetition trials. We tested whether the same is true for the auditory modality. Three attended repetition proportion groups (0–25–50%) showed the same amount of negative priming. All groups committed more prime response errors in ignored repetition than in control trials, implying that prime response retrieval took place. Thus, retrieval processes in auditory negative priming appear to be automatic and cannot be influenced as easily as in the visual domain. In Experiment 2, the proportion of ignored repetition trials was manipulated (25–50–75%) to test whether auditory negative priming can be strategically manipulated at all. Similar to the visual modality negative priming was reduced with increasing proportion of ignored repetition trials. Differences between visual and auditory short-term memory are discussed to account for the results.     

An investigation of monitoring for sleep-related threat in primary insomnia

In Study 1, individuals with primary insomnia (n=32) and good sleepers (n=38), recruited from a university population, completed a semi-structured interview. The interview assessed monitoring for sleep-related threat, negative thoughts and safety behaviours, at night and during the day. Compared to good sleepers, individuals with insomnia reported more frequent monitoring at night and during the day, more negative thoughts associated with monitoring at night and during the day, and the use of more safety behaviours associated with monitoring at night. A path analysis showed that the total monitoring frequency was significantly positively related to the score for total negative thoughts, which in turn, was significantly positively related to the total number of safety behaviours used. Study 2 aimed to test the generalisability of these findings in a clinical sample of individuals with primary insomnia (n=23). The results indicated that the clinical sample also engaged in monitoring for sleep-related threat, experienced negative thoughts and used safety behaviours. Further, more severe insomnia was associated with more negative thoughts and the use of more safety behaviours associated with monitoring at night. Together, these results are consistent with the proposal that monitoring for sleep-related threat functions to maintain insomnia by triggering negative thoughts and the use of safety behaviours. Future research is required to verify the proposed causal status of monitoring, using prospective designs and experimental manipulations.     

Interpretation and judgmental biases in social phobia

Previous research demonstrated that social phobia is characterized by content-specific interpretation and judgmental biases. The present study investigated whether this interpretation bias occurs not only in ambiguous, but also in positive and negative social events, and whether social phobic patients (SPs) are more characterized by a judgmental bias in costs than in probability. Besides, we argued that the judgmental bias observed in former studies could also be attributed to accurate estimations of SPs (of, for example, stuttering). Therefore, we assessed judgmental bias by the ratings of probability and costs of a negative evaluation (e.g. ‘people dislike me’) and not, as in previous studies, of negative social events (e.g. ‘stuttering’). SPs (n=228) and normal controls (n=33) were presented social and non-social events ranging from positive to profoundly negative. They ranked four different interpretations on likelihood to assess interpretation bias, and rated the profoundly negative interpretation on probability and cost to assess judgmental bias. SPs demonstrated content-specific interpretation and judgmental biases that also occurred in positive and negative social events. In contrast with expectations, SPs were characterized by a judgmental bias in both costs and probability.