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Research

Current Projects

FLAGSHIP

FLAGSHIP is a 4 year European study looking at the use of technology onboard ship. We are involved in two subprojects as follows: (1) Hollistic Decision Support - a project looking at how seafarers' decisions can be aided, particularly in emergency situations, (2) Health and Safety, Organisation & Processes - a study looking at working practices, perceptions of technology onboard ship and ways to improve ship operations.

Occupational Health and Safety study: Culture, Advice and Performance

The Occupational health & safety study: culture, advice and performance was a two year project funded by IOSH which began in December 2005. Its aim was to assess and compare the relative contributions of corporate safety culture and competent health and safety advice to corporate health and safety performance. Forty organisations from different sectors of industry across the UK took part in three questionnaire surveys.

Chronic Fatigue Syndrome (CFS)

Fatiguing illnesses, in particular Chronic Fatigue Syndrome (CFS), are difficult conditions to accurately determine and quantify. In a five year longitudinal study, wide ranging objective and subjective measures were administered to patients suffering from this condition. As a result, we now have more insight into the possible mechanisms at work in this illness. Several investigations were conducted, highlighting mood, cognitive performance and psychopathology in CFS, aspects of recovery in CFS and the role of antidepressant therapy in CFS. Our trial of a combination therapy (MCT) developed in Cardiff produced data indicating improvements in cognitive functioning in patients attending this form of therapy. These findings are unique as they represent an objective and, therefore, quantitative measure of improvement not yet seen. We are currently undertaking a three year follow-up of patients from this trial. Collaborative CFS studies include; Frenchay Hospital (Bristol), Action for ME (Bristol) and Imperial College (London).

Breakfast cereal, snacking, health, mood and cognition

A series of studies, funded by Kellogg’s, examined the effect of breakfast cereal and snacking on health, mood and cognition. Specifically, the aims of these studies were to: investigate both the immediate and longer-term impact of breakfast and/or a mid-morning snack on mental and physical health, well-being, mood and cognition; examine the effect of breakfast consumption on well-being and mood in families with primary school aged children; and explore whether any effect of breakfast and/or snacking was apparent in real life activities such as driving. A variety of methods were used including questionnaire and intervention studies and a cohort study of cognitive performance. Overall both breakfast and mid-morning snack consumption were associated with better mental health, mood and cognition.

 

Past Projects

Seafarers Fatigue Project

The issue of fatigue in seafarers was studied as part of a three phase project funded by the Maritime and Coastguard Agency (MCA) and the Health and Safety Executive (HSE). The aim of the project was to investigate the critical issue of Seafarers' fatigue which has received increasing attention in all areas of the maritime world. In phase one of the project the offshore oil industry was studied (Smith, Lane and Bloor, 2001), in phase two the focus was upon short sea and coastal trade (Smith, Lane, Bloor, Allen, Burke and Ellis, 2003) and in the final phase the deep sea and bulk sectors were investigated (Smith, Allen and Wadsworth, 2006). As well as investigating a broad range of vessel types, the project employed a wide range of investigative techniques, with both testing onboard ships and large scale surveys.

Scale and impact of illegal drug use by workers

The aim of the Scale and impact of illegal drug use by workers study was to: describe the prevalence of drug use among workers and the profile of drug users; investigate the effects of drug use on work performance; and determine whether there is an association between drug use and work accidents and injuries. A multi-method approach was used to address these aims, including a community based questionnaire survey and a cohort study of cognitive performance. The study showed that recreational drug use may reduce performance efficiency and safety at work. The final report is available to download here.

Scale and impact of psychotropic medication use by workers

The aim of the Scale and impact of psychotropic medication use by workers study was to: describe the prevalence of psychotropic medication use among workers; investigate the effects of psychotropic medication on work performance; and determine whether there is an association between psychotropic medication use and work accidents and injuries. A multi-method approach was used to address these aims, including a community based questionnaire survey and a cohort study of cognitive performance. The study showed that psychotropic medication use may reduce performance efficiency, and so affect safety at work. The final report is available to download here.

Ethnicity, work characteristics, stress and health study

The aim of the Ethnicity, work characteristics, stress and health study was to: determine whether different ethnic groups report similar levels of work stress and whether they show similar associations between work characteristics, work stress and health; determine whether different ethnic groups have similar profiles of associations between demographic and occupational factors and stress; and give guidance on work issues associated with ethnicity. This was a structured interview study which used a household quota sample design. The study showed that the combination of racial discrimination and ethnicity is powerfully influential on work stress. The final report is available to download here.

ESRC ROPA grant: Minor illnesses and Cognition

Upper respiratory tract illnesses, such as influenza or the common cold, are widespread, frequent and a major cause of absenteeism from education and work. In addition, recent research has demonstrated that these illnesses reduce well-being and can impair the efficiency of mental functioning. Initial evidence for such effects came largely from anecdotal reports and case histories. Studies of experimentally-induced influenza and colds have confirmed that such illnesses produce behavioural changes and the results can be briefly summarised as follows:

Both colds and influenza have selective effects on mental functioning, with only some aspects of performance being impaired. The profile of impairments has been found to be different in studies of influenza from those observed in experiments on the effects of colds.

Influenza impaired detection of stimuli presented at uncertain times or unknown locations. However, neither motor performance nor higher cognitive functions appear to be affected by influenza.

In contrast, the common cold impaired psychomotor function (e.g. hand-eye co-ordination; speed of psychomotor response) but had little effect on either detection tasks or those involving higher functions. The effects of influenza have been replicated in a study of naturally occurring illnesses involving virological techniques to identify the infecting agent. Similarly, studies of naturally occurring colds have confirmed that such illnesses reduce alertness and lead to psychomotor slowing.

Recent research has examined the effects of headache on mental functioning. Results from this study suggest that different aspects of memory (working memory; retrieval from semantic memory) are also impaired when individuals are suffering from a headache. Similarly, more severe viral infections, such as glandular fever, can produce more global impairments of cognitive function.

There were three main aims of the present research. The first aim was to extend research on minor illnesses and performance to cover a range of illnesses. A wider selection of cognitive tasks was used to provide a profile of the cognitive changes induced by the different illnesses. A second aim was to use well-established models of cognitive functions to investigate the mechanisms impaired by illness. The final aim was to provide some indication of the impact of the illnesses on real-life activities, such as driving, and efficiency at work.

The initial studies examined the effects of minor illnesses on performance of a range of cognitive tasks. Volunteers were tested when healthy and then repeated the procedure when they developed minor illnesses. Those who remained free from illness over the specified time period were re-tested as healthy controls. The battery of tests measured a range of functions (e.g. aspects of memory - episodic memory, semantic memory, working memory; selective and sustained attention; psychomotor function) and data from these studies provided information about the type of function impaired by different illnesses. The first study demonstrated that alertness was reduced in those with colds. This reduced alertness was associated with slower reaction times, slower encoding of new information, slower verbal reasoning and slower retrieval of information from semantic memory (general knowledge). The performance impairments were not associated with specific symptoms (e.g. nasal symptoms) but were related to a more general malaise. The second study examined the effects of headache, cough and sore throats on performance. Analyses of the effects of the different illnesses showed that there were some global effects apparent in all illnesses (e.g. more negative mood, slower reaction times in a focused attention task) but also a number of effects which were illness specific. Headache was associated with the greatest impairments with memory for word lists and the ability to sustain attention being impaired.

Once the profile of impairments has been established it is important to determine which mechanisms underlie these effects of illness on cognition. Mechanisms can be studied at various levels and some progress has been made in identifying the neurotransmitter basis of cold-induced performance changes. However, little is known of the cognitive processes that are impaired and yet there are established models which can be used to address this issue. Similarly, the possible role of disturbed sleep is unknown. Two studies were carried out to address these issues. The first showed that volunteers with colds have lost control of the speed-error tradeoff mechanism. The sleep of volunteers with colds was also examined using actimeters (which measure activity during sleep). The findings of this study suggested that having a cold may lead to slight impairments of sleep (being more restless, moving about more). However, the magnitude of the sleep disturbance could not account for the performance changes induced by the illnesses.

Another set of studies have examined the effects of having a cold on simulated driving. The first study used a computerized simulation of driving. The results showed that those with a cold hit the kerb more frequently and that they were slower responding to a secondary target. On the basis of these results a more realistic simulator was used in a second study (the University of Leeds Advanced Driving Simulator). The results confirmed that volunteers with colds were slower at responding to randomly appearing targets. In addition, those with colds had significantly more collisions with pedestrians crossing the road than the healthy volunteers. In addition to the driving simulation volunteers carried out a task designed to examine perceptions of time to collision. Those with colds were less able to determine whether collisions would or would not occur and also made more errors detecting a secondary target. Another method of assessing the real-life impact of minor illnesses has involved studying volunteers before and after work. The rationale behind this is that extra demands over the course of the day lead to a greater difference between the two measures. In the first study volunteers with colds were most impaired at the end of the day. A second study confirmed that colds impaired performance but showed a fairly uniform effect of time. These variable results may reflect differences in the nature of the illnesses or the demands present in the jobs of the two samples.

Overall, the present research has extended our knowledge of the effects of minor illnesses on cognitive performance. This has been achieved by obtaining new results on effects of different illnesses, possible mechanisms underlying these effects and the impact of the illnesses on real-life activities.

ESRC ROPA: The Psychology of the common cold: An integrated approach

Upper respiratory tract illnesses (URTIs), such as influenza and the common cold, are frequent, widespread and a major cause of absenteeism from work and education. It has been recognised for some time that there is enormous individual variation in susceptibility to these illnesses and in the severity of the symptoms. This has led to research that has considered the role of psychosocial characteristics (personality, stress, positive life events, social support and coping) and the importance of health related behaviours such as smoking, alcohol consumption and nutrition. Research has also investigated the effects of colds and influenza on performance and has shown that these illnesses produce selective performance impairments. For example, influenza impairs tasks where it is not known when or where a target stimulus will appear whereas colds lead to psychomotor slowing. Upper respiratory tract illnesses also induce mood changes and again these often differ depending on whether one is investigating colds or influenza. The main objective of the proposed research was to integrate these two areas of research by investigating whether factors that influence susceptibility to URTIs and severity of the illnesses are also important with regard to the mood changes and performance impairments induced by the illness.

In the first study the participants were 498 students (216 male, 282 female; mean age 21.6 years). Participants were recruited when healthy and at this point completed the psychosocial questionnaires and mood and performance tasks. They were asked to return if they developed an URTI (within 6-96 hours of the symptoms developing). Those who did not develop an URTI during the 12 week period were recalled as healthy controls.

One hundred and eighty eight of the participants developed URTIs. This group did not differ from those who remained healthy in terms of demographics. Similarly, no significant differences were found between the psychosocial scores of those who did and did not develop an URTI. Those who developed an URTI were more frequent consumers of alcohol than those who remained healthy. Smokers became ill more quickly than non-smokers. Those who developed illnesses more rapidly also had a higher frequency of daily hassles.

The URTI group reported a more negative mood than those who remained healthy. This was observed for all the mood dimensions. Those with an illness had slower response times in reaction time tasks and also showed more lapses of attention (occasional errors).

Total symptom score was associated with changes in all the mood dimensions. This effect was entirely due to the systemic symptoms and neither the nasal symptom score nor nasal secretion weight were associated with the mood changes. There were few significant associations between the performance changes induced by the URTIs and the psychosocial or health-related behaviour variables. The performance changes were not generally related to symptom severity. Similarly, few associations were found between the mood and performance changes.

In summary, the first study confirmed that upper respiratory illnesses lead to psychomotor slowing and impaired performance of tasks requiring sustained attention. Subjective reports of mood were also more negative in the ill group. Previous investigations of these topics have often been too small scale to determine whether the performance changes reflect the severity and nature of symptoms or whether they are due to the changes in mood. The present findings show that they are largely independent of such effects. The performance changes were also not modified by psychosocial characteristics and health-related behaviours. However, these factors were important with regard to development of the illnesses and the nature and magnitude of the symptoms. Susceptibility to illness was found to be related to alcohol consumption, smoking and frequency of daily hassles. These results confirm previous findings.

The second investigation involved a diary study. At baseline the participants completed the psychosocial questionnaires and carried out the computerised assessment of performance and rating of mood. They were then given a diary to complete on a weekly basis. This collected information on the presence/absence of upper respiratory tract illnesses, the nature of symptoms, use of medication and general physical and mental health that week. In addition, it provided an indication of mood (anxiety/depression), fatigue and cognitive difficulties. When volunteers developed a cold they returned to the laboratory and objective measures of symptom severity (temperature, weight of nasal secretion) were recorded. In addition, the mood rating and performance tasks were repeated to give an indication of the impact of the illness on behaviour. All volunteers returned to the laboratory once every four weeks and repeated the mood and performance tasks. This provided control data from the healthy volunteers that allowed comparison with those who developed colds at specific time points.

One hundred volunteers (51 female, 49 male; mean age 49 years, range 22 to 76 years) from a community participated in the study. Forty-seven participants developed at least one URTI during the course of the study. There were no significant demographic differences between those who developed URTIs and those who remained healthy. Those who became ill were sub-divided into those who reported a single illness and those who reported more than one illness. Those who had more than one illness reported significantly more negative life-events in the last 12 months. None of the other psychosocial variables differed across the groups. Those who developed multiple illnesses were less likely to eat breakfast and consume alcohol. Systemic symptoms were also correlated with perceived stress, trait anxiety, and loneliness and not eating breakfast. Volunteers with an illness had a more negative mood and slower response times. There were no significant associations between the mood changes and the performance changes. Similarly, the performance changes were not associated with symptoms, psychosocial variables and health-related behaviours.

In summary, the results from two large scale studies have provided evidence of the effects of URTIs on mood and performance. Similarly, they have shown that psychosocial factors and health-related behaviours may influence susceptibility to URTIs and the nature and extent of the symptoms. Both studies failed to demonstrate associations between variables influencing illness susceptibility and/or severity and the mood and performance changes.

ESRC ROPA: Effects of caffeine on mood, cognition and drink acceptability: Study of non-deprived volunteers.

There has been extensive research on the behavioural effects of caffeine and it is now well established that ingestion of caffeine is associated with increases in alertness, improved sustained attention and faster reaction times. These effects are most easily observed in low alertness situations and caffeine has been shown to influence a number of neurotransmitters that influence arousal (e.g. noradrenaline, acetylcholine). An alternative view of the effects of caffeine has been suggested by James (1994). He argues that caffeine has no beneficial effects but merely removes the negative effects associated with caffeine withdrawal. The present project conducted experiments to test this view, the general aim being to examine the effects of caffeine in non-deprived volunteers (and to compare the effects of caffeine in this group with the effects seen in caffeine withdrawn individuals). Several methods were used to examine this topic. The first involved testing volunteers after a day of normal caffeine consumption. The second tested non-consumers (who by definition cannot be considered caffeine deprived) as well as withdrawn consumers. The third method involved depriving volunteers for a period of 7 days (after which time any detrimental effects of withdrawal are considered to have gone) and then examining effects of caffeine.

Several dependent variables were examined. It was predicted that caffeine would increase ratings of alertness. In terms of performance, it was predicted that cognitive vigilance and speed of encoding of new information would be improved by caffeine in even non-fatigued volunteers. Other aspects of performance (simple reaction time and occasional long responses) were expected to show beneficial effects of caffeine only in low alertness situations. Caffeine has been shown to increase acceptability of novel drinks given to withdrawn individuals and this was also examined in the project. The same mood and performance tests were used in all the studies. Caffeine doses ranged from 1 to 2 mg/Kg and saliva samples were taken to assess caffeine intake. Typically, 50-70 volunteers were tested in each study (sample size varied depending on whether caffeine was manipulated between or within subjects).

The first two studies examined effects of caffeine after a day of normal consumption. In the first experiment, volunteers were tested in the early evening and then caffeine or placebo challenge was carried out followed by a second test 30 minutes later. The results showed that caffeine increased alertness, increased the speed of encoding of new information and improved cognitive vigilance even when volunteers had been consuming caffeine over the course of the day. The second study was similar to the first but volunteers remained in the laboratory to complete four test sessions over the course of the evening. The aim of this manipulation was to increase fatigue (due to a combination of prolonged work and circadian changes in alertness). A second caffeine challenge was included in this study which allowed us to address the issue of whether only the first dose of caffeine influenced mood and performance or whether a second dose produced an additional effect. Results from the first caffeine challenge confirmed those obtained in the first experiment. As volunteers became more fatigued other beneficial effects of caffeine (improved simple RT, fewer long responses) became apparent. The second dose of caffeine led to greater alertness and improvement in performance than the initial dose. Overall, these two studies demonstrated that effects of caffeine can be demonstrated in non-deprived volunteers and that different profiles of effects of caffeine are apparent in alert and fatigued individuals.

The next topic examined was whether caffeine produced behavioural change in non-consumers as well as withdrawn consumers. The results showed the expected effects of caffeine (increased alertness, increased speed of encoding of new information, improved cognitive vigilance, faster simple reaction time and fewer long responses). This effect was present in both non-consumers and withdrawn consumers. The saliva samples showed that both the non-consumers and withdrawn consumers were caffeine free at baseline, and that the two groups metabolized the caffeine at a similar rate.

The fourth experiment compared the effects of caffeine on non-consumers with effects on consumers who had caffeine withdrawn for 7 days. The negative effects of withdrawal typically disappear after a few days and if the effects of caffeine reflect removal of negative effects of withdrawal then no positive changes should be observed after withdrawal for a week. The results showed that the performance of both non-consumers and consumers who had caffeine withdrawn for 7 days improved after caffeine.

Overall, the results of these studies show that effects of caffeine can be demonstrated in non-withdrawn volunteers. Another study examined this issue by investigating the interactions between caffeine withdrawal, caffeine ingestion and subsequent liking of novel drinks. Previous research has shown that pairing of novel flavours with the post-ingestive effects of caffeine can lead to increased liking of the drinks but only in deprived caffeine consumers. This was examined here by comparing deprived consumers with non-deprived consumers and non-consumers. The results failed to replicate the established findings despite the fact that several positive controls showed that the methodology was detecting influences on acceptability (e.g. increased liking of novel drinks over successive days) and behavioural effects of caffeine (increased alertness after caffeine). Indeed, when caffeine was given in the novel drink the only significant effect of caffeine was in non-consumers, who reported a greater dislike of the caffeinated drinks. When caffeine was given prior to the novel group both withdrawn consumers and non-consumers reported an increased liking for the drink.

Overall, the present project proceeded smoothly and represents a well-designed study of effects of caffeine in non-deprived volunteers. Methodological features of the studies probably account for differences from some previous research by other groups. The studies carried out here had appropriate statistical power, used appropriate designs (e.g. included baseline measurements) and were analysed correctly (baseline measurements used as covariates; order of treatments included as a factor in within subject designs). Sensitive measures of mood and performance were used and saliva samples taken to determine amount of caffeine ingested.

The research has already been presented to the scientific community at appropriate conferences and the studies have been written up in report form with a view to journal submission early in 2004. The research has also been of interest to industry and lead to a number of potential collaborations. The findings suggest that future research on caffeine moves towards identification of mechanisms other than withdrawal reversal (e.g. neurotransmitter effects) and considers the real-life implications of the benefits of caffeine (e.g. effects on accidents/errors at work).