精神分裂症患者的前瞻记忆比较研究

近年来有越来越多的心理学家从神经心理学角度对前瞻记忆进行研究,其中涉及较多的是正常被试与脑损伤患者之间的前瞻记忆比较。本文则针对目前关注比较少的精神分裂症这种特殊的脑损伤病人,通过对28名精神分裂症患者与30名正常被试在一定试验条件下进行前瞻记忆研究,试图发现其与正常被试在前瞻记忆的水平、影响因素以及自我评价方面的差异并分析其原因。     

去甲肾上腺素对习得性长时程突触增强的影响

在大鼠条件性饮水反应的建立和巩固过程中,在每天训练之前,通过预先与记录电极一起埋植在海马齿状回的注药管,微量注射去甲肾上腺素(NE),观察其对海马齿状回的习得性长时程突触增强的影响。结果表明:NE能增强突触效应;训练作业前注NE易化了习得性长时程突触增强的形成,但对其巩固无影响;同时相应地易化了动物条件反应的建立。提示NE参与海马齿状回的习得性长时程增强的形成。本文对其可能的作用机制进行了讨论。     

Adults who are more anxious and were anxiously attached as children report later first memories

Here, we examined retrospective reports of adults’ earliest autobiographical memory, the age of this report and whether the reported age was associated with exposure to early life adversity, current anxiety and childhood attachment. Across four studies, we found that reporting a later ‘earliest’ memory was associated with higher self-reported anxiety in both American (Studies 1, 2 and 4) and Australian (Study 3) samples. Furthermore, in Studies 2–4, we found that reporting a later earliest memory uniquely predicted anxiety when controlling for number of adverse childhood events (a risk factor for the development of anxiety). In Study 4, we established that this relation is partially mediated by childhood anxious attachment. Although we consistently demonstrated that later earliest memories were associated with current anxiety, we found little evidence for a relation between reported age at the time of earliest memory and childhood adversity. We also found no evidence of gender differences in the associations of interest. These results suggest that poorer memory of early childhood is associated with greater childhood anxious attachment and anxiety in adulthood. The implications of this work are discussed in terms of the adaptive nature of autobiographical memory and the development of a coherent life narrative.     

The effects of task-irrelevant threatening stimuli on orienting- and executive attentional processes under cognitive load

Human visual attention is biased to rapidly detect threats in the environment so that our nervous system can initiate quick reactions. The processes underlying threat detection (and how they operate under cognitive load), however, are still poorly understood. Thus, we sought to test the impact of task-irrelevant threatening stimuli on the salience network and executive control of attention during low and high cognitive load. Participants were exposed to neutral or threatening pictures (with moderate and high arousal levels) as task-irrelevant distractors in near (parafoveal) and far (peripheral) positions while searching for numbers in ascending order in a matrix array. We measured reaction times and recorded eye-movements. Our results showed that task-irrelevant distractors primarily influenced behavioural measures during high cognitive load. The distracting effect of threatening images with moderate arousal level slowed reaction times for finding the first number. However, this slowing was offset by high arousal threatening stimuli, leading to overall shorter search times. Eye-tracking measures showed that participants fixated threatening pictures more later and for shorter durations compared to neutral images. Together, our results indicate a complex relationship between threats and attention that results not in a unitary bias but in a sequence of effects that unfold over time.     

Semantic boost on episodic associations: an empirically-based computational model

Words become associated following repeated co-occurrence episodes. This process might be further determined by the semantic characteristics of the words. The present study focused on how semantic and episodic factors interact in incidental formation of word associations. First, we found that human participants associate semantically related words more easily than unrelated words; this advantage increased linearly with repeated co-occurrence. Second, we developed a computational model, SEMANT, suggesting a possible mechanism for this semantic-episodic interaction. In SEMANT, episodic associations are implemented through lateral connections between nodes in a pre-existent self-organized map of word semantics. These connections are strengthened at each instance of concomitant activation, proportionally with the amount of the overlapping activity waves of activated nodes. In computer simulations SEMANT replicated the dynamics of associative learning in humans and led to testable predictions concerning normal associative learning as well as impaired learning in a diffuse semantic system like that characteristic of schizophrenia.     

TOMM Performances and Self-Reported Symptoms of Depression and Anxiety

The Test of Memory Malingering (TOMM) is the most frequently used symptom validity test (SVT) by neuropsychologists and appears to be robust in the context of a number of neurological and psychiatric conditions. The current study cross-validated and extended prior research by examining the relation between scores on self-report measures of depression and anxiety, independently and combined, and scores on the TOMM in an outpatient neuropsychology clinic. A total of 262 files were reviewed, 67 of which contained complete data on the TOMM, Beck Depression Inventory-II, and the State-Trait Anxiety Inventory. Results show that scores on self-report inventories of depression and anxiety are not significantly related to scores on the TOMM, cross-validating previous research. Extending prior research, current analyses demonstrate that TOMM scores are not significantly influenced by the combined relation of self-reported symptoms of depression and anxiety. Findings support the utility of the TOMM with patients reporting affective disturbances.     

The adaptive nature of children's overestimation in a strategic memory task

Kindergarten, first-, and third-grade children were given a multitrial sort-recall task with different items on each trial. Children were asked to predict how many items they would recall prior to each trial. We classified children into high- and low-overestimation groups based on their prediction accuracy on the first two trials and assessed changes in recall and strategy use over trials (trials 4/5 minus trials 1/2). Following predictions, at all grades, children in the high-overestimation group showed greater gains (or fewer losses) in recall than children in the low-overestimation group. Differences in strategy use over trials were generally nonsignificant. The results were interpreted as reflecting the adaptive nature of children's overestimation of their cognitive abilities.     

Beyond Fear Emotional Memory Mechanisms in the Human Brain

ABSTRACT— Neurobiological accounts of emotional memory have been derived largely from animal models investigating the encoding and retention of memories for events that signal threat. This literature has implicated the amygdala, a structure in the brain's temporal lobe, in the learning and consolidation of fear memories. Its role in fear conditioning has been confirmed, but the human amygdala also interacts with cortical regions to mediate other aspects of emotional memory. These include the encoding and consolidation of pleasant and unpleasant arousing events into long-term memory, the narrowing of focus on central emotional information, the retrieval of prior emotional events and contexts, and the subjective experience of recollection and emotional intensity during retrieval. Along with other mechanisms that do not involve the amygdala, these functions ensure that significant life events leave a lasting impression in memory.     

Retelling Is Not the Same as Recalling: Implications for Memory

ABSTRACT— In contrast to laboratory free recall (which emphasizes detailed and accurate remembering), conversational retellings depend upon the speaker's goals, the audience, and the social context more generally. Because memories are frequently retrieved in social contexts, retellings of events are often incomplete or distorted, with consequences for later memory. Selective rehearsal contributes to the memory effects, as does the schema activated during retelling. Retellings can be linked to memory errors observed in domains such as eyewitness testimony and flashbulb memories; in all of these situations, people retell events rather than engage in verbatim remembering.     

Autobiographical memory in posttraumatic stress disorder before and after treatment

Although overgeneral retrieval of autobiographical memories has been repeatedly demonstrated in posttraumatic stress disorder (PTSD), no studies have indexed overgeneral retrieval before and after treatment of PTSD. Autobiographical memory was assessed in PTSD participants (n=20) prior to commencing cognitive behaviour therapy and 6 months after therapy completion. Fifteen participants completed both assessments. Improvement in PTSD symptoms was significantly associated with improved retrieval of specific memories and decreased retrieval of categoric memories in response to positive cues. These data suggest that symptom reduction during treatment of PTSD leads to greater access to specific memories of positive experiences.