Worry and Sleep Length Revisited: Worry,Sleep Length,and Sleep Disturbance Ascribed to Worry

The author administered university students (N = 222; 152 women, 70 men) the Worry Domains Questionnaire (F. Tallis, G. C. L. Davey, & A. Bond, 1994) and a newly constructed scale (the Sleep Disturbance Ascribed to Worry Scale) to measure sleep disturbance attributed to worry. To revisit previous studies (i.e., E. Hartmann, F. Baekeland, & G. R. Zwilling, 1972; S. J. H. McCann & L. L. Stewin, 1988) that suggested that sleep length was positively related to worry, the author also asked the students a question about habitual sleep length. The results indicated that worry and sleep disturbance attributed to worry were negatively related to sleep length. A regression analysis revealed that worry was significantly negatively related to habitual sleep length irrespective of sleep disturbance ascribed to worry.     

Offline Improvement during Motor Sequence Learning Is Not Restricted to Developing Motor Chunks

Robust offline performance gains, beyond those that would be anticipated by being exposed to additional physical practice, have been reported during procedural learning and have been attributed to enhancement consolidation, a process by which memory is transformed in such a way that it is not only more resistant to forgetting but may also involve a reorganization of information that supports superior task execution. The authors assessed the impact of increasing within-session practice extent on the emergence of offline performance gains. Practice-dependent improvements occurred across 12 and 24 30-s practice trials of a 5-element motor sequencing task. Offline improvements were observed following both 12 and 24 trials. The improvement following 12 trials was associated with the formation of motor chunks important for establishing movement sequence structure. In contrast, the offline improvement after 24 trials was not related to further changes in movement structure beyond those that had emerged during practice. These data suggest that additional memory operations, beyond those needed to amalgamate subsequences of the SRT task, are susceptible to enhancement consolidation.     

Transfer of Motor Learning Engages Specific Neural Substrates During Motor Memory Consolidation Dependent on the Practice Structure

The authors investigated how brain activity during motor-memory consolidation contributes to transfer of learning to novel versions of a motor skill following distinct practice structures. They used 1 Hz repetitive Transcranial Magnetic Stimulation (rTMS) immediately after constant or variable practice of an arm movement skill to interfere with primary motor cortex (M1) or dorsolateral prefrontal cortex (DLPFC). The effect of interference was assessed through skill performance on two transfer targets: one within and one outside the range of practiced movement parameters for the variable practice group. For the control (no rTMS) group, variable practice benefited delayed transfer performance more than constant practice. The rTMS effect on delayed transfer performance differed for the two transfer targets. For the within-range target, rTMS interference had no significant affect on the delayed transfer after either practice structure. However, for the outside-range target, rTMS interference to DLPFC but not M1 attenuated delayed transfer benefit following variable practice. Additionally, for the outside-range target, rTMS interference to M1 but not DLPFC attenuated delayed transfer following constant practice. This suggests that variable practice may promote reliance on DLPFC for memory consolidation associated with outside-range transfer of learning, whereas constant practice may promote reliance on M1 for consolidation and long-term transfer.     

Does stress enhance or impair memory consolidation?

Three experiments examined the hypothesis that stress-induced arousal enhances long-term memory for experiences associated with arousing events. Contrary to expectations, in each experiment exposure to a stressor (arm immersion in ice water) interfered with, rather than enhanced, long-term memory for associated material. Despite varying the stimuli (words, pictures), their emotional value (positive, negative, neutral), the time between learning and stress inductions (0 to 1 minute), and opportunities for post-learning rehearsal, each experiment produced a significant reversal of the hypothesised effect. That is, in each experiment, exposure to a stressor interfered with, rather than enhanced, long-term memory for associated material. We conclude that the relationship between stress and memory consolidation is more bounded than previously believed.     

A Review of: “Greenwald,R. (2009). Treating Problem Behaviors: A Trauma-Informed Approach.”

This single-case-design experiment examined an intervention to decrease bed-sharing in children, ages 2 through 6. Three sessions were conducted with each parent. At the first session, parents described bed-sharing history and began collecting baseline data. At the second session, parents were instructed to employ the intervention. At the third session, parents were interviewed and offered continued support, if needed. Participants included three children who slept with their parents 4 or more nights per week. The intervention resulted in a substantial decrease in bed-sharing behavior for all participants, and parents reported being satisfied with the intervention.     

Attentional deficits in fibromyalgia and its relationships with pain,emotional distress and sleep dysfunction complaints

Cognitive complaints are common among subjects with fibromyalgia (FM). Yet, few studies have been able to document these deficits with cognitive tasks. A main limitation of existing studies is that attention has been broadly defined and the tasks used to measure attention are not designed to cover all the main components of the attentional system. Research on attention has identified three primary functions of attention, known as alerting, orienting and executive functioning. This study used the attentional network test-interactions task to explore whether and which of the three attentional networks are altered in FM. Results showed that FM patients have impaired executive control (greater interference), reduced vigilance (slower overall reaction time) and greater alertness (higher reduction in errors after a warning cue). Vigilance and alertness showed several relations with depression, anxiety and sleep quality. Sleep dysfunction was a significant predictor for alertness, whereas there were no significant predictors for vigilance. These findings highlight that the treatment of sleep difficulties in FM patients may help with some of their cognitive complaints.     

Time-limited effects of emotional arousal on item and source memory

Two experiments investigated the time-limited effects of emotional arousal on consolidation of item and source memory. In Experiment 1, participants memorized words (items) and the corresponding speakers (sources) and then took an immediate free recall test. Then they watched a neutral, positive, or negative video 5, 35, or 50?min after learning, and 24 hours later they took surprise memory tests. Experiment 2 was similar to Experiment 1 except that (a) a reality monitoring task was used; (b) elicitation delays of 5, 30, and 45?min were used; and (c) delayed memory tests were given 60?min after learning. Both experiments showed that, regardless of elicitation delay, emotional arousal did not enhance item recall memory. Second, both experiments showed that negative arousal enhanced delayed item recognition memory only at the medium elicitation delay, but not in the shorter or longer delays. Positive arousal enhanced performance only in Experiment 1. Third, regardless of elicitation delay, emotional arousal had little effect on source memory. These findings have implications for theories of emotion and memory, suggesting that emotion effects are contingent upon the nature of the memory task and elicitation delay.     

No Time of Day Modulation or Time Stamp on Multiple Memory Tasks in Rats

Various demonstrations of “time stamp” effects in the animal learning literature have reinforced the idea that circadian information is encoded as part of a combined internal/external representation of context and that this contextual information is utilized for complex retrieval processes supporting memory. The goal of the present series of experiments is to assess this idea by manipulating training/testing circadian times on a battery of learning and memory tasks commonly used in the rodent. The data obtained from five experiments using four different learning and memory paradigms provide no evidence for “time stamp” effects on place memory, context memory (aversive or appetitive), or S-R habit learning.     

Short-term memory impairment in vestibular patients can arise independently of psychiatric impairment,fatigue, and sleeplessness

Vestibular dysfunction is associated with visual short-term memory impairment; however, it remains unclear if this impairment arises as a direct result of the vestibular dysfunction or is a consequence of comorbid changes in mood, affect, fatigue, and/or sleep. To this end, we assessed the concurrence and interdependence of these comorbidities in 101 individuals recruited from a tertiary balance clinic with a neuro-otological diagnosis. Over fifty per cent of the sample showed reduced visuospatial short-term memory, 60% and 37% exceeded cut-off on the Beck Anxiety and Depression Inventories, respectively, 70% exceeded cut-off on the Fatigue Severity Scale, 44% reported daytime sleepiness on the Epworth Sleepiness Scale, and 78% scored above cut-off on the Pittsburgh Sleep Quality Index. The high concurrence of these symptoms gives reason to infer the existence of a vestibular cognitive affective syndrome. Structural equation modelling indicated that the significant statistical association between general unassisted posture (a marker of chronic vestibular dysfunction and strong predictor of falls risk) and short-term memory was not mediated by mood and wakefulness. Instead, the memory impairment related more directly to vestibular dysfunction. From a rehabilitation perspective, the implication is that if the vestibular disorder is treated successfully then the memory problem will likewise improve.