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.     

An analogue study of the effects of Psychological Debriefing on eyewitness memory

Sixty-one participants from the community participated in a randomised controlled trial of group debriefing to assess the effect of this intervention upon memory for a stressful event. Participants were randomly allocated to one of three groups: debriefing; debriefing with an experimenter confederate present (who supplied three pieces of misinformation to the group regarding the stressful event); and a no-treatment control. All groups were shown a very stressful video and were again reviewed after 1 month. Members of the debriefing group where a confederate provided misinformation were more likely to recall this misinformation as fact than members of the other two groups. The debriefing group was also more accurate in their recall of peripheral content than the confederate group. Across all groups, participants were found to be more accurate at central rather than peripheral recall yet more confident for incorrect memories of the video than correct memories.     

Dysfunctional implications of narrow window theory: variability in the intuitive assessment of correlation

Narrow Window theory, suggested by Y. Kareev ten years ago, has so far focused on one central implication of the limited capacity of working memory on intuitive correlation estimation, namely, overestimation of the distal population correlation. This paper points to additional and perhaps more dramatic implications due to the large dispersion of intuitive estimates: (a) large estimation errors, possibly causing overestimation of negligible rhos, misses of strong rhos, and distorted hierarchies of the rhos between different pairs of variables; and (b) large interpersonal differences in the estimation of any given rho and highly incongruent hierarchies of estimated correlations between different pairs of variables. These implications impede both individuals' adaptation to the empirical world and communication among themselves.