NIBS as a research tool in studying and enhancing episodic memory in the left prefrontal cortex

In the absence of effective treatments for memory disorders including dementia, NIBS methods are being tested for studying and enhancing memory. Anodal transcranial direct-current stimulation (atDCS) is a safe, non-invasive method of stimulating the brain and modulating neural activity through electrodes placed on the scalp. Controversy has surrounded the implementation of atDCS as a research and clinical tool because of inconsistency in effects and a limited understanding of atDCS parameters and mechanisms. Heterogeneity in atDCS parameters across studies could contribute to the inconsistency in effects. Thus, the current research included a systematic ethodological investigation of atDCS as a potential research and clinical tool. Two meta-analyses and a set of five methodological experiments analysed the efficacy of atDCS given a consistent set of parameters. In younger adults, atDCS led to a weak and volatile effect under certain conditions that fluctuated with modifications to verbal stimuli and sample size. While there was a robust improvement in memory following atDCS over the left PFC in Experiment 1, this effect did not remain consistent in direct and conceptual replications. The metaanalyses provided support to this investigation by demonstrating that when effect sizes were pooled together across all eligible published studies, the average effect size was close to zero. When only the studies in the current investigation were pooled together, the effect size was larger but also non-significant. Thus, the results inform future considerations of atDCS as a research and clinical tool and provide recommendations for the limited applications of atDCS with a framework for applying effective parameters that take into account individual differences. Furthermore, through the course of the investigation of atDCS, novel findings about episodic memory processes and neural correlates were revealed, confirming the importance of activity in the ventrolateral prefrontal cortex (VLPFC) to episodic memory formation. These findings on VLPFC function were further extended with an investigation of the cognitive mechanisms of atDCS effects on VLPFC 3 function in Chapter 6 and an examination of the time window and process in the VLPFC that was most crucial to memory formation with repetitive transcranial magnetic stimulation (rTMS) in Chapter 7. Together, the findings contributed to developing a clearer understanding of atDCS effects on episodic memory and the episodic processes that occur in the VLPFC. This understanding can inform future research in NIBS with other cognitive functions and the development of memory nterventions that can target the VLPFC

An investigation into the efficacy of reflexology on acute pain in healthy human subjects

Reflexology incorporates the use of specific pressure techniques to the feet, hands or ears. There are many anecdotal claims for reflexology in the treatment of various conditions such as migraine, arthritis and multiple sclerosis but very little clinical evidence exists for reflexology in the management of pain per se. Pain is a worldwide concern and 10% of the UK population suffer from chronic pain, making demands on an already overstretched NHS service. Members of the public seek more control over their wellbeing and there is a growing trend towards complementary medicine. Reflexology, one of the many complementary medicine modalities available, may be a suitable adjunct to pain management by helping to reduce the number of medications and associated side-effects from continued drug use. This research therefore, enters at a time when the call for scientific evidence is sought and offers new evidence for the efficacy of reflexology in acute pain. The principal aims of these experiments were to investigate the acute effects of: i) Chapter 3 - standard reflexology on changes in basal physiological parameters, such as blood pressure (mmHg), heart rate (bpm), and core body temperature (°C). Fourteen healthy subjects were recruited to a crossover design study in which they participated in one 30 min session of standard reflexology and one 30 min session of sham Transcutaneous Electrical Nerve Stimulation (TENS) given one week apart. The results showed a significant decrease in heart rate (bpm) during and post standard reflexology when compared to a sham TENS (control). ii) Chapter 4 - standard reflexology in an ice pain experiment. Outcome measures were recorded for (a) pain threshold (s) i.e. the time it takes for the subject to find the experience painful, (b) pain tolerance (s) i.e. the time it takes until the subject can no longer keep his/her hand in the ice water and c) heart rate (bpm) pre and post ice plunge. Sixteen healthy volunteer subjects were recruited to this crossover design study to participate in one 45 min session of standard reflexology and one 45 min session of sham TENS (control) given one week apart. The results revealed a significant increase in both pain threshold (s) and tolerance (s) following standard reflexology when compared to the sham TENS (control). There was also a decrease in heart rates (bpm) following standard reflexology prior to and post ice immersions which were maintained for 60 min, although the effect was non-significant for the post ice immersion. iii) Chapter 5a - standard and light reflexology in an ice pain experiment. Thirty healthy volunteer subjects participated in this study to compare the effects of standard and light reflexology with a ‘no treatment’ control. Outcome measures were recorded for pain threshold (s), pain tolerance (s) and post treatment pre and post ice plunge heart rate (bpm). Subjects participated in one 45 min session each of standard and light reflexology and one 45 min control session consisting of no treatment given one week apart in a Latin square design. The results showed a significant increase in pain threshold following both standard and light reflexology and significant increases in pain tolerance for standard but not light reflexology. Pre-ice plunge, post treatment heart rates (bpm) were significantly lower following both standard and light reflexology and there was a transient decrease in heart rate post-ice plunge, post treatment for light reflexology. iv) Chapter 5b – An alternative statistical analysis on the effects of standard and light reflexology in an ice pain experiment. This chapter represents an alternative method of analysing the data where there are large interindividual variations in responses. The results showed significant biphasic responses, e.g. nociceptive and anti-nociceptive to the effects of both standard and light reflexology when compared to a no treatment control. These results extend the observations made in Chapter 4 and 5a. v) Chapter 6 - mechanical reflexology in an ice pain experiment. Twelve young and healthy subjects were recruited to participate in one 20 min session of mechanical reflexology and one 20 min session of sham TENS (control), give one week apart in a crossover design. Outcome measures were recorded for pain threshold (s), pain tolerance (s) and heart rate (bpm). The results showed no significant effects of mechanical reflexology treatment when compared to sham TENS (control) on either pain threshold or pain tolerance, although there were some transient benefits of mechanical reflexology on pain threshold during stimulation and on pain tolerance post stimulation. vi) Chapter 7 - repeated standard reflexology treatments in an ice pain experiments In this experiment eleven healthy female subjects were recruited to participate in three consecutive weeks of 45 min standard reflexology and three consecutive weeks of 45 min sham TENS (control). The treatments were given in a crossover fashion and there was a minimum one week break between treatments and crossover. Outcome measures were recorded for pain threshold (s), pain tolerance (s), pre and post ice plunge heart rate (bpm) and blood pressure (mmHg). The results showed no significant differences between the two treatments, but there was a general trend for an increase in the mean pain threshold and tolerance following standard reflexology. There was however, some drop-off in the effect on pain tolerance. This result should be interpreted with caution due to the small number of subjects and the large interindividual variations. Furthermore, there were no cumulative effects of treatment on either blood pressure or heart rate. vii) Miscellaneous Chapter – pressure applications in reflexology. This study was carried out using the Tactilus® Freeform Sensor system to measure the effects of three distinct pressure modes of reflexology: a) static, b) standard dynamic and c) light dynamic on four different regions of the foot sole: i) medial edge, ii) arch, iii) heel and iv) the ankle on different foot types. The data showed variations in average maximum pressure values according to the foot type and area treated. Conclusion Manually applied reflexology increases pain threshold and tolerance which seems to be independent of any changes in autonomic function.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Bioinformatics

This book is divided into different research areas relevant in Bioinformatics such as biological networks, next generation sequencing, high performance computing, molecular modeling, structural bioinformatics, molecular modeling and intelligent data analysis. Each book section introduces the basic concepts and then explains its application to problems of great relevance, so both novice and expert readers can benefit from the information and research works presented here