Mental time travel after trauma: the specificity and temporal distribution of autobiographical memories and future-directed thoughts

The present study investigated the relationship between trauma exposure and specificity and temporal distribution of autobiographical memories and future-directed thoughts. A group of sexual assault victims were compared with women without previous trauma exposure in relation to specificity of autobiographical memories, as measured by the Autobiographical Memory Task (AMT) and specificity of future-directed thoughts as measured by the Future Cueing Task (FCT). The temporal distribution of future-directed thoughts and autobiographical memories was studied by asking the participants to estimate when each memory reported on the AMT had occurred and when each future event reported on the FCT would occur. The results showed no difference between the trauma group and the controls on specificity of autobiographical memories and future-directed thoughts. In line with a review of Moore and Zoellner (2007), PTSD symptoms as measured by the Impact of Event Scale (IES) correlated negatively with specificity. Furthermore, we observed no difference in temporal distribution of future-directed thoughts or autobiographical memories between trauma exposed participants and controls.     

Retrieval-induced forgetting after trauma: a study with victims of sexual assault

The Retrieval-Induced Forgetting (RIF) paradigm is used to study how the repeated retrieval practice of particular memories impairs the retrieval of related memory traces. A study is reported where this automatic form of forgetting was investigated in a group of sexual-assault victims and a control group. Using a recognition-cued RIF task, the present study examined RIF with neutral, positive, negative and trauma-specific stimuli. Response time data showed that irrespective of previous trauma exposure, a RIF effect was observed for neutral material, but not for emotional material. No differences in RIF between the trauma group and the control group were found. Inconsistencies with previous literature and the implications for emotional memory are discussed.     

Familiarity,Cued and Free Odor Identification and Their Association with Cognitive Functioning in Middle Aged and Older Adults

ABSTRACT

The aim of the present study was to examine the association between familiarity of odors, cued and free odor identification performance and cognitive function in elderly adults. It was further investigated how age affects performance on the various odor tasks. A third aim was to investigate the role of familiarity in explaining performance on the free identification task. One hundred and thirty-six participants (aged 45–79 years) with normal olfactory sensitivity were assessed with the Scandinavian Odor Identification Test (SOIT) and standardized tests of cognitive function. Familiarity did not correlate with any measure of cognitive function, while verbal identification performance was associated with several cognitive measures, although correlations were modest. In this sample, free odor identification was affected by increasing age to a marginally larger extent than cued identification performance and familiarity ratings. The results suggest that the different olfactory tasks involve different levels of cognitive processing.     

Motor limitation in dual-task processing under ballistic movement conditions

The standard bottleneck model of the psychological refractory period (PRP) assumes that the selection of the second response is postponed until the first response has been selected. Accordingly, dual-task interference is attributed to a single central-processing bottleneck involving decision and response selection, but not the execution of the response itself. In order to critically examine the assumption that response execution is not part of this bottleneck, we systematically manipulated the temporal demand for executing the first response in a classical PRP paradigm. Contrary to the assumption of the standard bottleneck model, this manipulation affected the reaction time for Task 2. Specifically, reaction time for Task 2 increased with execution time for Task 1. This carryover effect from Task 1 to Task 2 provides evidence for the notion that response execution can be part of the processing bottleneck.     

Control over speeded actions: a common processing locus for micro- and macro-trade-offs?

Cognitive control processes associated with long- and short-term adjustments of human behaviour have attracted much interest recently. It is still unclear, however, whether the mechanisms underlying these adjustments share a common locus within the chain of stimulus-response processing. In order to address this issue, the present study employed a speed-accuracy instruction producing a macro-trade-off, whereas micro-trade-off was studied by means of posterror slowing in reaction time (RT). Participants performed a spatially compatible or incompatible four-stimuli-to-two-response alternative choice RT task. Reliable variations in micro-and macro-trade-off as well as effects of spatial compatibility were found in RT and error rate. Most importantly, posterror slowing was larger when instruction stressed accuracy rather than speed, an effect being independent of spatial compatibility. Because the influence of speed-accuracy instruction and posterror slowing on performance was strongest for response alternations, together present findings suggest that the mechanisms underlying micro- and macro-trade-offs have one common locus at the level of motor processing. Additional influences of macro-trade-off on premotoric processing are likely.     

Self-other differences in children's perceptions about the causes of important events

Three studies examined differences between children's (ages 8-15) beliefs about the effectiveness of multiple internal and external causes for producing outcomes in their own lives versus in those of their peers. Differences specific to the school domain were found: Starting at age 11 or 12, children perceived internal causes as more important for others than for themselves; and only beliefs about the self related to perceived control. More strikingly, a sample of gifted children, who presumably receive social feedback that they are different from their peers, reported that (a) they exerted more control and possessed more ability than their peers and (b) other children knew less about the causes of school performance and had to rely more on effort and powerful others; only beliefs about the self correlated to cognitive performance. These results suggest that self-other differences are produced by both developmental change and environmental opportunities.     

Generalization peak shift in rats under conditions of positive reinforcement and avoidance

Rats were trained to discriminate between two click frequencies. One frequency was associated with either variable-interval food reinforcement (Experiment 1) or free-operant avoidance (Experiment 2). The other frequency was associated with the absence of food in Experiment 1 and the absence of shock in Experiment 2. On a click frequency generalization test, the rats in both experiments showed positive peak shift with the shape of the relative gradients being very similar. This is the first reported instance of peak shift in rats when responding was maintained by an avoidance contingency. Nondifferentially trained controls showed that this shift was due exclusively to associative processes, with nonassociative stimulus factors in themselves apparently making no contribution to increased rates at particular stimulus values. These results show the comparability of appetitive and aversive control and support the position that gradient differences do not result from approach versus avoidance per se.     

Inducing the familiarity effect

The task required subjects to judge whether members of six-letter consonant string pairs were physically identical. Some (repeated) strings were presented on each of the 16 training sessions, while other (nonrepeated) strings were presented only during a single session. An advantage in matching time of repeated strings over nonrepeated strings was obtained which increased in a roughly linear fashion during training and which persisted for at least 7 weeks after the last training session. Detailed analyses of thedifferent responses and the results of several transfer tasks suggest that perceptual processing is indeed facilitated by acquired information about which letters usually follow others and about the positions in which these sequences of letters are likely to occur, but provide no evidence that this facilitation derives from the formation of visual features which are larger than single letters.