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office 2EFFECTS OF INDOOR LIGHTING ON MOOD AND COGNITION
100~ Kmz
Royal Institute of Technology, Department of Built Environment, Laboratory ofApplied Psychology, Box 88, S-801 02 Gtivle, Sweden
Abstract
Two experiments investigated the effect of indoor lighting on cognitive performance via mood. Experiment 1 varied two lighting parameters in a factorial, between-subject design: two illuminance levels (dim; 300 lx vs bright; 1500 lx) by two colour temperatures (‘warm’ white; 3000K vs ‘cool’ white; 4000K) at high CR1 (Colour Rendering Index; 95). In experiment 2 the parameters of lighting were identical to the first experiment, except for the low CR1 (CRI; 55). In both experiments gender was introduced as an additional grouping factor. Results in experiment 1 showed that a colour temperature which induced the least negative mood enhanced the performance in the long-term memory and problem-solving tasks, in both genders. In experiment 2, the combination of colour temperature and illuminance that best preserved the positive mood in one gender enhanced this gender’s performance in the problem-solving and free recall tasks. Thus, subjects’ mood valences and their cognitive performances varied significantly with the genders’ emotionally different reac- tions to the indoor lighting. This suggests, in practice, that the criteria for good indoor lighting may be revised, taking into account females’ and males’ emotional and cognitive responses as well.
Introduction
From birth, through the years of education and work settings to old people’s homes/hospital we sojourn in artificial milieus. Hence, we perform mentally and react emotionally within settings that are artificial, in contrast to environments where we have evolved and developed our internal faculties. Of course, there are occasions in between when people do visit and enjoy real natural settings. The point is, however, that for most of our lives we spend our time in man-made settings that entail, and expose us to, different physical indoor variables- one such is artificial light.
reliable experimental evidence that such indirect effects of lighting occur’ (Boyce, 1981, pp. 222-223). Recently, several papers have, however, tried to demonstrate the ‘indirect’, i.e. behavioral effects of lighting (e.g. Butler & Biner, 1987; Gifford, 1988; Veitch & Kaye, 1988; Biner et al., 1989; Heerwagen, 1990; Veitch et al., 1991). Taken together, these results are neither conclusive nor do they carry a framework for behavioral lighting research.
The present paper, however, outlines briefly and tentatively a heuristic aid for this kind of research: a model of artificial biotope and organism (see Fig. 1). This sketchy frame of reference focuses on a causation of affect from the luminous milieu on cognitive processes via moods.
According to a dictionary, a biotope defines a milieu of living (bias-mode of life; topos-place) and one of the definitions of an environment has to
Research concerning the effects of light on man has explored issues of light and human visual system to a significant degree (see e.g. Boyce, 1981; Megaw, 1992 for reviews). This framework has produced an extensive body of results which have do with influences (see e.g. Webster’s Third New
been broadly applied as general requirements and practical recommendations for qualitative lighting (e.g. Galer, 1987). However, these results are restricted to perception and perceptual tasks.
International Dictionary, 1968). If we first combine these definitions into a generic concept of influencing milieus of living and, second, divide it into two categories of settings then we obtain: (i) a natural biotope and (ii) an artificial biotope-the present article is concerned with the latter. This permits,
Are there any effects of lighting on other psycho- logical processes than the purely perceptual, e.g. on emotional, cognitive? ‘Unfortunately, whilst this in addition, a parallel inquiry and a production of is all plausible and widely believed there is little data that may reveal similar-dissimilar effects on
Cognition
FIGURE 1. A tentative model of artificial biotope and organism.
organism, produced by these two categorically different types of biotope. The experimental interface between the artificial milieu of living and the psychological organism is our measuring instrument, i.e. tasks that should be sensitive to changes in this biotiope as well as the reliable, valid measures of the psycho- logical processes involved. In sum, and following Fig. 1, it is hypothesized that: (i) the luminous milieu, a local artificial milieu of living, may act as a mood inducer that induces different mood valences in subjects; and (ii) that their cognitive processes at hand may, in turn, be affected via these moods.
assumed to account for a result as long as the scientist shows a parallel example-condition where that kind of result is produced.
Why did Baron et al. (19921 not obtain direct mood reactions to various lighting conditions? This is probably due to two major flaws in their experi- mental design, namely: (1) The affective state measure was administered after and not before exposure; (2) What was the exposure time? Subjects should stay in a luminous setting for at least a couple of hours in order to assure that if this variable really generates any kind of effects, a pro- longed time exposure would test this hypothesis. This research is in its early stages and what we
Recently, Baron et al. (1992) tried to show a similar line of affect, however, no effects of luminous condi- tions on mood were shown. Still, results were inter- must do is first investigate whether lighting condi- preted as if a positive mood was, indeed, at hand tions induce emotional states at all and second, and mediated the lighting effects seen in cognitive establish the exposure time limits (all or none, or performance! According to these authors, perfor- incremental) for this physical variable’s effect to mance on a dependent measure within a luminous be produced. Baron et al. (1992) did not specify exposure condition gives results similar to results the time exposure in their experiments. However, obtained on the same dependent measure, but looking at what subjects did, they were probably
within another condition where we know that a positive mood is present. It is possible, therefore, to conclude that mood accounts indirectly for the effects on performance in a luminous exposure condition, but the effects are not directly found. impair or enhance ongoing cognitive processes? Two ‘Together, these facts suggest that lighting condi- experiments are designed in sufficient detail to tions did indeed influence performance through the investigate this issue. The first experiment varied intervening variable of positive affect’ (Baron et al., three independent variables in a factorial, between- 1992, p. 26). However, compare this with: ‘Thus, subject design: two illuminance levels (dim; 300 lx there was no evidence . . . that subjects experienced vs bright; 1500 lx) by two colour temperatures differential affective reactions to the various lighting (‘warm’ white; 3000K-Kelvin vs ‘cool’ white; 4000K) conditions’ (Baron et al., 1992, p. 10). This kind of by gender. Illuminance and colour temperature argument should really be questioned, because if levels were chosen in order to investigate the this line of reasoning was generally applied by the results of preference studies (cf Flynn, 1977) which scientific establishment then everything could be indicated that subjects prefer dim vs bright and
exposed for around 20-40 min which is perhaps not sufficient for an emotional response.
Taken together: does a luminous setting act as a mood inducer and, if so, will these mood valences
100~ Kmz
Royal Institute of Technology, Department of Built Environment, Laboratory ofApplied Psychology, Box 88, S-801 02 Gtivle, Sweden
Abstract
Two experiments investigated the effect of indoor lighting on cognitive performance via mood. Experiment 1 varied two lighting parameters in a factorial, between-subject design: two illuminance levels (dim; 300 lx vs bright; 1500 lx) by two colour temperatures (‘warm’ white; 3000K vs ‘cool’ white; 4000K) at high CR1 (Colour Rendering Index; 95). In experiment 2 the parameters of lighting were identical to the first experiment, except for the low CR1 (CRI; 55). In both experiments gender was introduced as an additional grouping factor. Results in experiment 1 showed that a colour temperature which induced the least negative mood enhanced the performance in the long-term memory and problem-solving tasks, in both genders. In experiment 2, the combination of colour temperature and illuminance that best preserved the positive mood in one gender enhanced this gender’s performance in the problem-solving and free recall tasks. Thus, subjects’ mood valences and their cognitive performances varied significantly with the genders’ emotionally different reac- tions to the indoor lighting. This suggests, in practice, that the criteria for good indoor lighting may be revised, taking into account females’ and males’ emotional and cognitive responses as well.
Introduction
From birth, through the years of education and work settings to old people’s homes/hospital we sojourn in artificial milieus. Hence, we perform mentally and react emotionally within settings that are artificial, in contrast to environments where we have evolved and developed our internal faculties. Of course, there are occasions in between when people do visit and enjoy real natural settings. The point is, however, that for most of our lives we spend our time in man-made settings that entail, and expose us to, different physical indoor variables- one such is artificial light.
reliable experimental evidence that such indirect effects of lighting occur’ (Boyce, 1981, pp. 222-223). Recently, several papers have, however, tried to demonstrate the ‘indirect’, i.e. behavioral effects of lighting (e.g. Butler & Biner, 1987; Gifford, 1988; Veitch & Kaye, 1988; Biner et al., 1989; Heerwagen, 1990; Veitch et al., 1991). Taken together, these results are neither conclusive nor do they carry a framework for behavioral lighting research.
The present paper, however, outlines briefly and tentatively a heuristic aid for this kind of research: a model of artificial biotope and organism (see Fig. 1). This sketchy frame of reference focuses on a causation of affect from the luminous milieu on cognitive processes via moods.
According to a dictionary, a biotope defines a milieu of living (bias-mode of life; topos-place) and one of the definitions of an environment has to
Research concerning the effects of light on man has explored issues of light and human visual system to a significant degree (see e.g. Boyce, 1981; Megaw, 1992 for reviews). This framework has produced an extensive body of results which have do with influences (see e.g. Webster’s Third New
been broadly applied as general requirements and practical recommendations for qualitative lighting (e.g. Galer, 1987). However, these results are restricted to perception and perceptual tasks.
International Dictionary, 1968). If we first combine these definitions into a generic concept of influencing milieus of living and, second, divide it into two categories of settings then we obtain: (i) a natural biotope and (ii) an artificial biotope-the present article is concerned with the latter. This permits,
Are there any effects of lighting on other psycho- logical processes than the purely perceptual, e.g. on emotional, cognitive? ‘Unfortunately, whilst this in addition, a parallel inquiry and a production of is all plausible and widely believed there is little data that may reveal similar-dissimilar effects on
Cognition
FIGURE 1. A tentative model of artificial biotope and organism.
organism, produced by these two categorically different types of biotope. The experimental interface between the artificial milieu of living and the psychological organism is our measuring instrument, i.e. tasks that should be sensitive to changes in this biotiope as well as the reliable, valid measures of the psycho- logical processes involved. In sum, and following Fig. 1, it is hypothesized that: (i) the luminous milieu, a local artificial milieu of living, may act as a mood inducer that induces different mood valences in subjects; and (ii) that their cognitive processes at hand may, in turn, be affected via these moods.
assumed to account for a result as long as the scientist shows a parallel example-condition where that kind of result is produced.
Why did Baron et al. (19921 not obtain direct mood reactions to various lighting conditions? This is probably due to two major flaws in their experi- mental design, namely: (1) The affective state measure was administered after and not before exposure; (2) What was the exposure time? Subjects should stay in a luminous setting for at least a couple of hours in order to assure that if this variable really generates any kind of effects, a pro- longed time exposure would test this hypothesis. This research is in its early stages and what we
Recently, Baron et al. (1992) tried to show a similar line of affect, however, no effects of luminous condi- tions on mood were shown. Still, results were inter- must do is first investigate whether lighting condi- preted as if a positive mood was, indeed, at hand tions induce emotional states at all and second, and mediated the lighting effects seen in cognitive establish the exposure time limits (all or none, or performance! According to these authors, perfor- incremental) for this physical variable’s effect to mance on a dependent measure within a luminous be produced. Baron et al. (1992) did not specify exposure condition gives results similar to results the time exposure in their experiments. However, obtained on the same dependent measure, but looking at what subjects did, they were probably
within another condition where we know that a positive mood is present. It is possible, therefore, to conclude that mood accounts indirectly for the effects on performance in a luminous exposure condition, but the effects are not directly found. impair or enhance ongoing cognitive processes? Two ‘Together, these facts suggest that lighting condi- experiments are designed in sufficient detail to tions did indeed influence performance through the investigate this issue. The first experiment varied intervening variable of positive affect’ (Baron et al., three independent variables in a factorial, between- 1992, p. 26). However, compare this with: ‘Thus, subject design: two illuminance levels (dim; 300 lx there was no evidence . . . that subjects experienced vs bright; 1500 lx) by two colour temperatures differential affective reactions to the various lighting (‘warm’ white; 3000K-Kelvin vs ‘cool’ white; 4000K) conditions’ (Baron et al., 1992, p. 10). This kind of by gender. Illuminance and colour temperature argument should really be questioned, because if levels were chosen in order to investigate the this line of reasoning was generally applied by the results of preference studies (cf Flynn, 1977) which scientific establishment then everything could be indicated that subjects prefer dim vs bright and
exposed for around 20-40 min which is perhaps not sufficient for an emotional response.
Taken together: does a luminous setting act as a mood inducer and, if so, will these mood valences
Lighting Mood and Cognition 41 ‘warm’ vs ‘cool’ light. That is, dim illuminance and a advertisements) were paid 200 Swedish crowns
‘warm’ white light source may induce a positive mood more than bright illuminance and a ‘cool’ white light source if we translate preference measure as some kind of affective verbal report. The colour rendering parameter (Colour Rendering Index; CR11 Environmental setting. The experiment was con-
(c. 30 U.S. dollars) to participate. They were randomly assigned to eight groups with 12 subjects in each.
which has been neglected, or not controlled in previous studies (cf Baron et al., 1992) is also included for investigation and applied across experiments. High CR1 is employed across illuminance and colour temperature in experiment 1 compared to low CR1 in experiment 2.
‘warm’ white light source may induce a positive mood more than bright illuminance and a ‘cool’ white light source if we translate preference measure as some kind of affective verbal report. The colour rendering parameter (Colour Rendering Index; CR11 Environmental setting. The experiment was con-
(c. 30 U.S. dollars) to participate. They were randomly assigned to eight groups with 12 subjects in each.
which has been neglected, or not controlled in previous studies (cf Baron et al., 1992) is also included for investigation and applied across experiments. High CR1 is employed across illuminance and colour temperature in experiment 1 compared to low CR1 in experiment 2.
It must be noted that the ‘warm’ and ‘cool’ light sources refer to an chromatic scale diagram, where the colour temperature of white light sources range from 2700K to 6500K. At one end of this dimension- spectrum the light source is more reddish and, on the opposite side the light source is more bluish. Consequently, the reddish and bluish light sources’ appearances are attributed as ‘warm’ and ‘cool’.
Noise, psychosocial stress and their interaction in the workplace
Phil Leather*, Diane Beale, Lucy Sullivan
Institute of Work, Health and Organizations, University of Nottingham, Business School, Jubilee Campus, Wollaton Road, Nottingham NG8 1BB, UK
Received 6 September 2002; accepted 16 September 2002
Abstract
Occupational noise exposure has been linked with a range of negative health effects, with recent research emphasizing the need to understand the full context of sound events in explaining these relationships. An emerging theme within environmental psychology argues that physical features of the environment might work both directly on outcomes and interactively with either psychosocial work elements. In the present study, the interaction of noise with psychosocial job stress was explored for 128 office workers employed by a government agency in a city in the Midlands region of the UK. The results showed no direct effect of ambient noise levels upon job satisfaction, well-being or organizational commitment. However, lower levels of ambient noise were found to buffer the negative impact of psychosocial job stress upon these same three outcomes. Psychosocial job stress is, therefore, seen as a valuable heuristic in operationazing the context of sound events at work.
r 2002 Elsevier Science Ltd. All rights reserved.
1. Introduction
Exposure to occupational noise, that is, unwanted sound, has been linked with variety of adverse effects upon well-being over and above its obvious relationship with hearing loss (Kryter, 1970, 1994). In industrial settings, for example, noise exposure has been found to be associated with a range of indicators of physical health, including cardiac problems (Jansen, 1961; Cuesdan et al., 1977); sickness-related absenteeism (Cohen,1973); and self-reported fatigue (Carlestam, Karlslon, & Levi, 1973). Similarly, McDonald (1989) reported a dose-response relationship among blue collar workers between occupational noise exposure and symptoms of psychological distress. That noise has a negative impact upon job satisfaction is well documen- ted (Langdon, 1966; Nemecek & Grandjean, 1973; Boyce, 1974). Office workers, in particular, consistently report ‘‘the ability to concentrate without noise and other distractions’’ to be one of the most important aspects of the work environment (Louis Harris & Associates, 1978, 1980). In a survey of office renova- tions, Sundstrom, Town, Rice, Osborn, and Brill (1994) found declining job satisfaction amongst those office workers who experienced an increase in noise from
*Corresponding author. Tel.: +44-115-84-66638. E-mail address: phil.leather@nottingham.ac.uk (P. Leather).
two sources: telephones ringing and piped-in back- ground music. In this same study, environmental satisfaction, but not overall job satisfaction, was also found to be inversely related to the amount of noise deriving from people talking on the telephone and from typewriters.
Importantly, many studies have also demonstrated that these various negative effects of exposure to occupational noise are often contingent upon either the characteristics of the task at hand, or features of the broader work context. Nurminen and Kurppa (1989), for example, reported that pregnancy complications in women working under very noisy conditions were exacerbated when they were also subjected to the additional demands of shiftwork. Indeed, the interactive effect of occupational noise exposure and shiftwork upon various health indices is a consistently reported theme in the literature (see, for example, Cesana et al., 1982; Ottman, Rutenfranz, Neidhart, & Boucsein, (1987).
Carter and Beh (1989) and Mosskov and Ettema (1977) both report that the usual rapid habituation in elevated cardiovascular responses to acute noise ex- posure is blocked when people are simultaneously performing demanding cognitive tasks. A similar inter- active effect of noise and task demands was reported by Welch (1979) who found, in a study of Russian manufacturing plant, elevated cardiovascular functioning
0272-4944/03/$ - see front matter r 2002 Elsevier Science Ltd. All rights reserved. PII: S0272-4944(02)00082-8
www.elsevier.com/locate/jep
214 P. Leather et al. / Journal of Environmental Psychology 23 (2003) 213–222
only amongst those workers exposed to both louder noise and higher levels of workload demands. Likewise, Cottington, Matthews, Talbott and Kuller (1983) reported a significant interaction between noise and job stress on diastolic blood pressure levels in a further sampleofmanufacturingworkers.Lercher,Hortnagl, and Kofler (1993) found that a small positive association between noise exposure and diastolic blood pressure was amplified among those workers who also reported low levels of social support on the job.
As with its effects upon health outcomes, so the influence of occupational noise exposure upon perfor- mance has been found to be contingent upon a number of factors, including the nature of the noise and the type of task involved. Essentially, two summary conclusions can be drawn from the many laboratory investigations of the negative effects of noise upon performance. First, that the effects of unpredictable noise are more severe than are those of predictable noise. Second, that any negative effect of noise increases with task complexity. Thus, it is the interaction of unpredictable noise and high task complexity which has been found to result in increased errors in calculation, tracking and monitoring tasks, slower learning of new material and poorer recall and memorization (Sundstrom, 1986).
The overall conclusion to be drawn from the research investigating the effects of occupational noise upon both well-being and performance is that the full context of the situation needs to be taken into account when trying to understand those effects. Further evidence for this conclusion comes from the fact that technical noise measures explain only part of the inter-individual variance reported in noise annoyance (Kjellberg, Land- strom,Tesarz,Soderberg,&Akerlund,1996).As Kjellberg et al. (1996) point out; nonphysical noise characteristics and other situational and individual characteristics are also of great importance in determin- ing subjective responses to noise. There is, they argue, a fundamental need to understand the full context of sound events when researching the possible effects of noise. The potential for noise to interact with task constraints and other situational variables represents a major feature of this context.
Evans and Lepore (1992) and Evans, Johansson, and Carrere (1994) offer a conceptual and methodological framework that provides a valuable way of investigating the context of sound events in the workplace. Any feature of the physical environment, they argue, might work both directly on outcomes and/or interactively with either (a) psychosocial work elements or (b) other physical elements. It is with the first of these possible interactions that the present paper is concerned. Specifically, the idea to be explored here is that the effect of noise upon work outcomes might be either direct or indirect in nature. In suggesting a possible indirect influencing mechanism, an interaction is being
hypothesized between noise and a particular psychoso- cial factor, i.e. job stress.
Stress is operationalized in terms of Karasek’s model of job strain (karasek, 1979; Karasek & Theorell, 1990), wherein strain results from the interaction of high job demandsandlowdecisionlatitude.Ifnoisedoesinteract with job stress, then any negative impact should be greatest under conditions of both high stress and higher noise levels. Put another way, lower levels of noise might serve to buffer any negative effect of job strain More- over, this pattern of results should hold across a range of negative outcomes commonly associated with occupa- tional stress, such as reduced job satisfaction, impaired health and well-being, and increased psychological withdrawal (Cox, 1978, 1985; Cooper, 1985; Beehr, 1995).
As reviewed above, there are several lines of evidence in the research literature that implicitly or explicitly support this noise job stress interaction hypothesis. Laboratory studies, for example, have shown significant, increases in cardiovascular and neuroendocrine func- tioning to occur when individuals are exposed to noise during demanding mental tasks (Tafalla, Evan, & Cohen, 1988). Shift workers are similarly at greater risk of health complaints when working in noisy occupa- tional settings as compared to relatively quiet ambient conditions (Manninen, 1990). Matthews, Cottington, Talbott, Kuller, and Siegel (1987) found a parallel interaction between noise and job satisfaction, such that noise heightened job dissatisfaction only amongst those workers who were also unhappy with their jobs.
Leather, Pyrgas, Beale, and Lawrence (1998) explored as similar interaction between windows in the workplace andjobstressasthatnowbeinginvestigatedbetween noise and job stress. Postulating multiple influencing mechanisms by which windows might impact upon work outcomes, they found that sunlight penetration had a direct effect on job satisfaction, intention to quit and general well-being. Access to a view of nature, on the other hand, was found to buffer the negative impact of job stress on intention to quit and to have a similar, marginal, effect on general well-being.
In light of the growing recognition of the importance of possible interactions between physical and psychoso- cial work elements, two specific hypotheses are tested in this paper with respect to the impact of occupational noise exposure:
Hypothesis 1. Higher noise levels will be associated with lower job satisfaction, lower organizational commit- ment and poorer well-being (main effects).
Hypothesis 2. Noise exposure and job stress will interact such that lower levels of noise will buffer any negative effect of job strain, organizational commitment and well-being (moderator effect).
It should also be recognized that a direct effect of job strain upon job satisfaction, organizational commitment and well-being is tested in this moderator model (Baron & Kenny, 1986; Evans & Lepore, 1992; Evans et al., 1994). However, since the focus of this paper is upon the impact of noise with job strain being used as a means of operationalizing the importance of context, such direct effects will only be commented upon in passing.
Noise, psychosocial stress and their interaction in the workplace
Phil Leather*, Diane Beale, Lucy Sullivan
Institute of Work, Health and Organizations, University of Nottingham, Business School, Jubilee Campus, Wollaton Road, Nottingham NG8 1BB, UK
Received 6 September 2002; accepted 16 September 2002
Abstract
Occupational noise exposure has been linked with a range of negative health effects, with recent research emphasizing the need to understand the full context of sound events in explaining these relationships. An emerging theme within environmental psychology argues that physical features of the environment might work both directly on outcomes and interactively with either psychosocial work elements. In the present study, the interaction of noise with psychosocial job stress was explored for 128 office workers employed by a government agency in a city in the Midlands region of the UK. The results showed no direct effect of ambient noise levels upon job satisfaction, well-being or organizational commitment. However, lower levels of ambient noise were found to buffer the negative impact of psychosocial job stress upon these same three outcomes. Psychosocial job stress is, therefore, seen as a valuable heuristic in operationazing the context of sound events at work.
r 2002 Elsevier Science Ltd. All rights reserved.
1. Introduction
Exposure to occupational noise, that is, unwanted sound, has been linked with variety of adverse effects upon well-being over and above its obvious relationship with hearing loss (Kryter, 1970, 1994). In industrial settings, for example, noise exposure has been found to be associated with a range of indicators of physical health, including cardiac problems (Jansen, 1961; Cuesdan et al., 1977); sickness-related absenteeism (Cohen,1973); and self-reported fatigue (Carlestam, Karlslon, & Levi, 1973). Similarly, McDonald (1989) reported a dose-response relationship among blue collar workers between occupational noise exposure and symptoms of psychological distress. That noise has a negative impact upon job satisfaction is well documen- ted (Langdon, 1966; Nemecek & Grandjean, 1973; Boyce, 1974). Office workers, in particular, consistently report ‘‘the ability to concentrate without noise and other distractions’’ to be one of the most important aspects of the work environment (Louis Harris & Associates, 1978, 1980). In a survey of office renova- tions, Sundstrom, Town, Rice, Osborn, and Brill (1994) found declining job satisfaction amongst those office workers who experienced an increase in noise from
*Corresponding author. Tel.: +44-115-84-66638. E-mail address: phil.leather@nottingham.ac.uk (P. Leather).
two sources: telephones ringing and piped-in back- ground music. In this same study, environmental satisfaction, but not overall job satisfaction, was also found to be inversely related to the amount of noise deriving from people talking on the telephone and from typewriters.
Importantly, many studies have also demonstrated that these various negative effects of exposure to occupational noise are often contingent upon either the characteristics of the task at hand, or features of the broader work context. Nurminen and Kurppa (1989), for example, reported that pregnancy complications in women working under very noisy conditions were exacerbated when they were also subjected to the additional demands of shiftwork. Indeed, the interactive effect of occupational noise exposure and shiftwork upon various health indices is a consistently reported theme in the literature (see, for example, Cesana et al., 1982; Ottman, Rutenfranz, Neidhart, & Boucsein, (1987).
Carter and Beh (1989) and Mosskov and Ettema (1977) both report that the usual rapid habituation in elevated cardiovascular responses to acute noise ex- posure is blocked when people are simultaneously performing demanding cognitive tasks. A similar inter- active effect of noise and task demands was reported by Welch (1979) who found, in a study of Russian manufacturing plant, elevated cardiovascular functioning
0272-4944/03/$ - see front matter r 2002 Elsevier Science Ltd. All rights reserved. PII: S0272-4944(02)00082-8
www.elsevier.com/locate/jep
214 P. Leather et al. / Journal of Environmental Psychology 23 (2003) 213–222
only amongst those workers exposed to both louder noise and higher levels of workload demands. Likewise, Cottington, Matthews, Talbott and Kuller (1983) reported a significant interaction between noise and job stress on diastolic blood pressure levels in a further sampleofmanufacturingworkers.Lercher,Hortnagl, and Kofler (1993) found that a small positive association between noise exposure and diastolic blood pressure was amplified among those workers who also reported low levels of social support on the job.
As with its effects upon health outcomes, so the influence of occupational noise exposure upon perfor- mance has been found to be contingent upon a number of factors, including the nature of the noise and the type of task involved. Essentially, two summary conclusions can be drawn from the many laboratory investigations of the negative effects of noise upon performance. First, that the effects of unpredictable noise are more severe than are those of predictable noise. Second, that any negative effect of noise increases with task complexity. Thus, it is the interaction of unpredictable noise and high task complexity which has been found to result in increased errors in calculation, tracking and monitoring tasks, slower learning of new material and poorer recall and memorization (Sundstrom, 1986).
The overall conclusion to be drawn from the research investigating the effects of occupational noise upon both well-being and performance is that the full context of the situation needs to be taken into account when trying to understand those effects. Further evidence for this conclusion comes from the fact that technical noise measures explain only part of the inter-individual variance reported in noise annoyance (Kjellberg, Land- strom,Tesarz,Soderberg,&Akerlund,1996).As Kjellberg et al. (1996) point out; nonphysical noise characteristics and other situational and individual characteristics are also of great importance in determin- ing subjective responses to noise. There is, they argue, a fundamental need to understand the full context of sound events when researching the possible effects of noise. The potential for noise to interact with task constraints and other situational variables represents a major feature of this context.
Evans and Lepore (1992) and Evans, Johansson, and Carrere (1994) offer a conceptual and methodological framework that provides a valuable way of investigating the context of sound events in the workplace. Any feature of the physical environment, they argue, might work both directly on outcomes and/or interactively with either (a) psychosocial work elements or (b) other physical elements. It is with the first of these possible interactions that the present paper is concerned. Specifically, the idea to be explored here is that the effect of noise upon work outcomes might be either direct or indirect in nature. In suggesting a possible indirect influencing mechanism, an interaction is being
hypothesized between noise and a particular psychoso- cial factor, i.e. job stress.
Stress is operationalized in terms of Karasek’s model of job strain (karasek, 1979; Karasek & Theorell, 1990), wherein strain results from the interaction of high job demandsandlowdecisionlatitude.Ifnoisedoesinteract with job stress, then any negative impact should be greatest under conditions of both high stress and higher noise levels. Put another way, lower levels of noise might serve to buffer any negative effect of job strain More- over, this pattern of results should hold across a range of negative outcomes commonly associated with occupa- tional stress, such as reduced job satisfaction, impaired health and well-being, and increased psychological withdrawal (Cox, 1978, 1985; Cooper, 1985; Beehr, 1995).
As reviewed above, there are several lines of evidence in the research literature that implicitly or explicitly support this noise job stress interaction hypothesis. Laboratory studies, for example, have shown significant, increases in cardiovascular and neuroendocrine func- tioning to occur when individuals are exposed to noise during demanding mental tasks (Tafalla, Evan, & Cohen, 1988). Shift workers are similarly at greater risk of health complaints when working in noisy occupa- tional settings as compared to relatively quiet ambient conditions (Manninen, 1990). Matthews, Cottington, Talbott, Kuller, and Siegel (1987) found a parallel interaction between noise and job satisfaction, such that noise heightened job dissatisfaction only amongst those workers who were also unhappy with their jobs.
Leather, Pyrgas, Beale, and Lawrence (1998) explored as similar interaction between windows in the workplace andjobstressasthatnowbeinginvestigatedbetween noise and job stress. Postulating multiple influencing mechanisms by which windows might impact upon work outcomes, they found that sunlight penetration had a direct effect on job satisfaction, intention to quit and general well-being. Access to a view of nature, on the other hand, was found to buffer the negative impact of job stress on intention to quit and to have a similar, marginal, effect on general well-being.
In light of the growing recognition of the importance of possible interactions between physical and psychoso- cial work elements, two specific hypotheses are tested in this paper with respect to the impact of occupational noise exposure:
Hypothesis 1. Higher noise levels will be associated with lower job satisfaction, lower organizational commit- ment and poorer well-being (main effects).
Hypothesis 2. Noise exposure and job stress will interact such that lower levels of noise will buffer any negative effect of job strain, organizational commitment and well-being (moderator effect).
It should also be recognized that a direct effect of job strain upon job satisfaction, organizational commitment and well-being is tested in this moderator model (Baron & Kenny, 1986; Evans & Lepore, 1992; Evans et al., 1994). However, since the focus of this paper is upon the impact of noise with job strain being used as a means of operationalizing the importance of context, such direct effects will only be commented upon in passing.
More green space in a denser city: Critical relations between user experience and urban form
Alexander Stahle
Introduction
Two prevailing urban planning schemes – densi- fication and sprawl – have dominated the twenty- first century. These strategies, which have obvious consequences for green and open space, have frequently led to deadlocks in planning, espe- cially concerning green space exploitation. This conflict describes the well-known and long- debated dichotomy within urban planning and design: ‘dense’ or ‘green’. If Nozzi (2003) thinks that transportation planning is the key to cope with sprawl, the findings presented in this article show that open space planning can be just as powerful a tool to manage urban growth such as a qualitative densification of sprawl.
The strong dichotomy ‘dense’ or ‘green’, which I will claim can be very misleading, is illustrated by the urban theorist Henri Lefebvre’s obser- vation (1995) that there is a conflict between ‘the right to the city’ and ‘the right to nature’. In
planning processes, this antithesis can roughly be said to be represented by ‘the urbanists’, who fight for urban businesses, housing, social inte- gration and so on, and the ‘the environmentalists’, who fight for the conservation of green belts, parks and open spaces in the city.
Much has been written from the urbanist side of architecture and planning theory by both neomodernists and new urbanists (for example, MVRDV, 1998; CNU, 2000) to diminish or ques- tion the need or importance of green in cities, a claim that often is placed in relation to the modernist planning paradigms (for example, CIAM, Le Corbusier, Walter Gropius). There has also been recent research showing correla- tions between the amount of green space and the accessibility to service, which emphasizes the idea of an absolute relation between green space and urban quality (Reneland, 1999).
Alexander Stahle
Introduction
Two prevailing urban planning schemes – densi- fication and sprawl – have dominated the twenty- first century. These strategies, which have obvious consequences for green and open space, have frequently led to deadlocks in planning, espe- cially concerning green space exploitation. This conflict describes the well-known and long- debated dichotomy within urban planning and design: ‘dense’ or ‘green’. If Nozzi (2003) thinks that transportation planning is the key to cope with sprawl, the findings presented in this article show that open space planning can be just as powerful a tool to manage urban growth such as a qualitative densification of sprawl.
The strong dichotomy ‘dense’ or ‘green’, which I will claim can be very misleading, is illustrated by the urban theorist Henri Lefebvre’s obser- vation (1995) that there is a conflict between ‘the right to the city’ and ‘the right to nature’. In
planning processes, this antithesis can roughly be said to be represented by ‘the urbanists’, who fight for urban businesses, housing, social inte- gration and so on, and the ‘the environmentalists’, who fight for the conservation of green belts, parks and open spaces in the city.
Much has been written from the urbanist side of architecture and planning theory by both neomodernists and new urbanists (for example, MVRDV, 1998; CNU, 2000) to diminish or ques- tion the need or importance of green in cities, a claim that often is placed in relation to the modernist planning paradigms (for example, CIAM, Le Corbusier, Walter Gropius). There has also been recent research showing correla- tions between the amount of green space and the accessibility to service, which emphasizes the idea of an absolute relation between green space and urban quality (Reneland, 1999).
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