Children's memory for complex autobiographical events: does spacing of repeated instances matter?

Often, when children testify in court they do so as victims of a repeated offence and must report details of an instance of the offence. One factor that may influence children's ability to succeed in this task concerns the temporal distance between presentations of the repeated event. Indeed, there is a substantial amount of literature on the "spacing effect" that suggests this may be the case. In the current research, we examined the effect of temporal spacing on memory reports for complex autobiographical events. Children participated in one or four play sessions presented at different intervals. Later, children were suggestively questioned, and then participated in a memory test. Superior recall of distributed events (a spacing effect) was found when the delay to test was 1 day (Experiment 1) but there was little evidence for a spacing effect when the delay was 1 week (Experiment 2). Implications for understanding children's recall of repeated autobiographical events are discussed.     

Priming cue encoding by manipulating transition frequency in explicitly cued task switching

Explicitly cued task switching with multiple cues per task permits three types of transitions: cue repetitions (cue and task repeat), task repetitions (cue changes but task repeats), and task alternations (cue and task change). The difference between task alternations and task repetitions can be interpreted as a switch cost, but its magnitude varies substantially across experiments. We investigated how switch cost is affected by transition frequency (how often subjects repeat and switch tasks) with an experiment in which each transition had a frequency of .70 in separate sessions. Switch cost was smallest when task alternations were frequent and largest when task repetitions were frequent. Mathematical modeling of the data indicated that the different “switch costs” reflected priming of cue encoding for frequent transitions. Interpretations of our findings based on automatic priming from memory retrieval of past transitions and strategic priming from transition expectancies are discussed.     

A controlled trial of cognitive-behavior therapy combined with vestibular rehabilitation in the treatment of dizziness

Dizziness is a common and often untreated symptom in the general population. The aim of this study was to investigate the effects of a combined cognitive-behavioral/vestibular rehabilitation (VR) program, using a randomized control design. A total of 29 participants were randomized to treatment consisting of psychoeducation, vestibular exercises, relaxation and cognitive interventions, or to serve as waiting list controls. Measures of dizziness-related handicap, dizziness-provoking movements, and daily diary registrations of dizziness symptoms at pre- and post-treatment showed statistically significant improvements in many domains, which translated to moderate effect sizes. These findings provide preliminary support for the combination of Cognitive-behavioral therapy (CBT) and VR methods in the treatment of dizziness.     

Strategic and automatic threat processing in chronic musculoskeletal pain: a startle probe investigation

Attentional bias research with chronic pain samples has yielded conflicting results. In the present investigation the startle paradigm was used to test the postulate that fear-based mechanisms play an important role in attentional biases for pain-related threat in chronic pain. Participants, including 31 individuals with chronic musculoskeletal pain and 20 healthy controls, completed a startle task designed to measure attention to different types of words (neutral vs sensory pain vs affective pain vs health catastrophe) presented at different levels of cognitive processing (strategic vs automatic). Measures of fear-based individual difference variables, including anxiety sensitivity and fear of pain, were also completed. Startle amplitudes and latencies to acoustic startle probes that followed word presentations were recorded. Data were analyzed with repeated measures ANOVAs and correlational analysis. Significant between-group differences were found indicating that, relative to chronic pain participants, healthy controls had higher startle amplitude index scores for health catastrophe words. There was also a trend among patients with chronic pain for greater startle amplitude index scores for strategic presentations of sensory pain words. In the automatic condition, all participants demonstrated a lower startle latency index for sensory words relative to both affect and health catastrophe words, suggesting participants had more difficulty disengaging from affect and health catastrophe words or were more avoidant of sensory words. Correlational analyses indicated that startle response indices for words related to health catastrophe became more pronounced for chronic pain patients as anxiety sensitivity and fear of pain increased. Implications and directions for future research are discussed.     

Distinctiveness models of memory and absolute identification: evidence for local, not global, effects

Many models of memory assume that the probability of remembering an item is related to how distinctive that item is relative to all the other items in the set, with no distinction made between the contributions of near or far items. These “global” distinctiveness models do well in accounting for the ubiquitous serial position effects observed in numerous memory paradigms, including absolute identification. Here, we provide experimental confirmation of Bower's (1971) suggestion that, contrary to a fundamental prediction of global distinctiveness models, midseries items can be more discriminable than their immediate neighbours. We show that such data are consistent with a revised distinctiveness account in which the factor affecting discrimination performance is primarily the distinctiveness of an item relative to its close neighbours.     

Hierarchical control of cognitive processes: switching tasks in sequences

Hierarchical control of cognitive processes was studied by examining the relationship between sequence- and task-level processing in the performance of explicit, memorized task sequences. In 4 experiments, switch costs in task-switching performance were perturbed by sequence initiation times that varied with sequence complexity, preparation time, and type of sequence transition (repetition or switch). Hierarchical control was inferred from these sequence initiation time effects and the recurrent finding of no switch cost at the first serial position across sequences, the point at which sequence-level processes are likely active in maintaining or instantiating a hierarchical control structure in working memory. These findings resonate with past research on motor programs and serial memory and provide new insights into the concepts of task set and control.     

Brain activation during semantic processing in autism spectrum disorders via functional magnetic resonance imaging

Language and communication deficits are core features of autism spectrum disorders (ASD), even in high-functioning adults with ASD. This study investigated brain activation patterns using functional magnetic resonance imaging in right-handed adult males with ASD and a control group, matched on age, handedness, and verbal IQ. Semantic processing in the controls produced robust activation in Broca's area (left inferior frontal gyrus) and in superior medial frontal gyrus and right cerebellum. The ASD group had substantially reduced Broca's activation, but increased left temporal (Wernicke's) activation. Furthermore, the ASD group showed diminished activation differences between concrete and abstract words, consistent with behavioral studies. The current study suggests Broca's area is a region of abnormal neurodevelopment in ASD, which may be linked with semantic and related language deficits frequently observed in ASD.     

Characteristics of successful fakers versus unsuccessful fakers: is empathy, intelligence, or personality associated with faking PTSD on the MMPI-2?

Moyer, Burkhardt, and Gordon found in 2002 that some individuals could fake PTSD on the MMPI-2. In light of these results, a follow-up study was conducted to assess whether attributes such as empathy, intelligence, subjectivity, or insightfulness influenced ability to fake a PTSD profile on the MMPI-2. 35 subjects from the previous study were divided into two groups, successful fakers and unsuccessful fakers. Analysis indicated no significant differences between groups on the measures of empathy or intelligence. However, a significant difference was found between groups on the Schizophrenia and Cynicism scales and falling just short of significance on the Hypochondriasis scale. These results suggested that individuals able to fake PTSD are more insightful and less subjective, which makes them better at role-playing.