Biomedical subjects

Frances Martin

Publications and source records attributed to Frances Martin.

6 recordsLinked to original sources

PubMed2006

Neural correlates of performance trade-offs and dual-task interference in bimanual coordination: an ERP investigation.

Previous behavioural studies have provided a framework for understanding coordination dynamics using traditional dual-task methodology. The central cost associated with stabilising bimanual coordination patterns has been inferred from performance trade-offs during the concurrent performance of a probe reaction time (RT) task. The present study aimed to provide a direct measure of central cost by assessing electrophysiological correlates of performance trade-offs under dual-task conditions. Event-related potentials (ERPs) were recorded from 16 participants while an anti-phase bimanual coordination task and a visual three-stimulus task were performed under single task conditions and under dual-task conditions in which either task was prioritised. The visual task required a foot response to low probability target stimuli, while low probability distracter and high probability standard stimuli were ignored. Consistent with previous research, there was a performance trade-off between pattern stability and RT to visual targets when the coordination task was prioritised relative to when the visual task was prioritised. This was accompanied by a significant reduction in central P3a amplitude elicited by distracter stimuli and parietal P3b amplitude elicited by target stimuli. These findings indicate that prioritisation and thus stabilisation of the motor task reduced the amount of central/perceptual and automatic attentional resources available to perform the visual task providing insight into CNS mechanisms that constrain the coordination of movement through the allocation of attentional resources.

Adolescent↗

PubMed2004

A method for estimating long-range power law correlations from the electroencephalogram.

Recent research has found long-range electroencephalogram (EEG) power law correlations, indicating time scale invariance. However, the EEG is also rather noisy, displaying short-term decorrelation like white noise--i.e., what is scale invariant at one time period may disappear in the next. The paradoxical combination of short-range divergence, but long-range correlations, suggests that any long-range correlations detected in one sample may be spurious, since they could be related to amplitude fluctuations. To overcome this problem, this paper suggests a new technique for analysing EEG signals segmented by zero-crossings, using detrended fluctuation analysis (DFA), evaluated across two time periods (TIME) and different sites (SITE). A mean scaling exponent across all subjects and sites of alpha = 0.67 was observed. MANOVA analysis indicates no significant main effect for TIME or interaction with SITE, suggesting that the zero-crossing method may be successful in determining the fractal nature of EEG dynamics across relatively long time scales.

Cerebral Cortex↗

PubMed2003

The impact of the nurse-physician relationship on barriers encountered by nurses during pain management.

The aim of the current investigation was to examine the barriers encountered by Tasmanian registered nurses when attempting to provide optimal pain management. The impact of nurse satisfaction with their professional relationship with physicians during pain management on the types of barriers encountered was also examined. A total of 1,015 registered nurses completed a 21-item survey that examined the types of barriers encountered during pain management. In addition, data were gathered on nurses' satisfaction with their professional relationship with physicians during pain management. More than one-third of the respondents indicated that they had encountered at least one type of barrier to providing optimal pain relief, including insufficient cooperation by physicians and inadequate prescriptions of analgesic medications. Nurses who did not feel adequately consulted by physicians were significantly more likely to encounter barriers such as insufficient cooperation by patient's physicians and inadequate prescription of analgesic medications. The barriers to effective pain management encountered by nurses were affected by their relationship with physicians. Education, for both nurses and physicians, concerning the role of the nurse in the workplace will help to ensure that nurses encounter fewer barriers during pain management. Optimal pain management practice will result if guidelines for dealing effectively with barriers are tailored to the specific type of institution and the unit within those institutions.

Adult↗

PubMed2002

Effects of lorazepam and oxazepam on perceptual and procedural memory functions.

RATIONALE: Lorazepam has been found to consistently impair performance on both episodic and perceptual priming tasks, whereas other benzodiazepines have shown perceptual priming to be preserved. However, it has recently been postulated that benzodiazepines may exert time-dependent effects on implicit memory processes after research findings indicated some benzodiazepines, other than lorazepam, impair performance on priming tasks when tested at the time of peak plasma concentration level after benzodiazepine administration. OBJECTIVES: To compare time-dependent effects of lorazepam and oxazepam on implicit memory tasks, specifically perceptual priming and procedural learning. METHODS: Thirty-three healthy female undergraduates were randomised to one of three time groups (pre-peak, peak, post-peak) and administered placebo, 2.5 mg lorazepam, and 30 mg oxazepam, in counterbalanced order, at 1-week intervals. Assessments included word-stem completion (perceptual priming) and rotary pursuit (procedural learning) tasks. RESULTS: At all time intervals, lorazepam but not oxazepam significantly impaired perceptual priming but procedural learning was preserved under both drugs. CONCLUSIONS: These findings are consistent with previous research showing a differential effect of lorazepam in impairing perceptual memory but the notion that benzodiazepines exert time-dependent effects on implicit memory processes was not supported.

Adolescent↗

PubMed2002

The effects of single-dose lorazepam on memory and behavioural learning.

To assess the influence of lorazepam on memory and behavioural learning, a non-clinical sample of undergraduate psychology students (n = 24), received lorazepam (2.5 mg) or placebo orally. Pre-drug and post-drug neuropsychological assessment comprised the Rey auditory verbal learning test, verbal fluency test, digit span and word stem completion. Relative to placebo, lorazepam induced a marked deficit in delayed free-recall, perceptual priming, and written word fluency, with preservation of digit span. Behavioural learning was assessed on a computer-aided vicarious exposure treatment for obsessive-compulsive disorder, administered post-drug, and repeated 1 week later, drug free. Compared to placebo, lorazepam treated participants enacted 51% less exposure activity on the behavioural learning task post-drug. Whilst both groups enacted increased exposure at the drug-free session, exposure activity was 49% less in the lorazepam group, indicating a carryover effect of the impaired learning under drug 1 week before. There were no significant differences between lorazepam and placebo on indices of overall activity on the program. These results suggest lorazepam-induced impairment in the ability to learn behavioural strategies, possibly due to impaired acquisition of information into long-term episodic memory. These findings suggest caution in the co-prescribing of benzodiazepines in people undergoing behavioural therapies in clinical populations.

Adolescent↗

PubMedDate not supplied

The impact of the nurse-physician professional relationship on nurses' experience of ethical dilemmas in effective pain management.

The aims of the current investigation were (1) to examine the ethical and professional conflicts experienced by Tasmanian registered nurses in attempting to provide optimal pain management, and (2) to examine nurse satisfaction with their professional relationship with physicians and with their level of involvement in pain management. A total of 1,015 registered nurses completed a 21-item survey examining ethical and professional conflicts encountered during patient pain management. Data also were gathered investigating nurse satisfaction with their involvement in and professional relationship with physicians during pain management. The respondents who felt adequately consulted by physicians were significantly more likely to instigate the consultation process than the respondents who felt that they were not adequately consulted by physicians about their patient's pain status. This was marked in relation to the need for increased pain relief medications. Nurses who did not feel adequately consulted by physicians were significantly more likely to experience ethical conflicts such as concerns about undermedication and patient reluctance to report pain. Nurses' concerns related to ethical conflicts concerning effective pain management are affected by their relationship with physicians. Education, for both nurses and physicians, concerning the role of the nurse in the workplace will help to ensure that these conflicts do not arise. Guidelines concerning the level of patient care at which consultation is necessary will ensure fewer conflicts and greater nurse satisfaction in the workplace.

Analgesics↗