Lighting for people with dementia - CiteSeerX

6 downloads 0 Views 459KB Size Report
Address for correspondence: Judith Torrington, School of ... many of those affected, very high levels of ...... CM, Newberg AB, Alavi A. Visual processing.

Lighting Res. Technol. 39,1 (2007) pp. 81–97

Lighting for people with dementia JM Torrington BA BArch RIBA and PR Tregenza BArch MBdgSc PhD RIBA MCIBSE CEng School of Architecture, The University of Sheffield, Western Bank, Sheffield, UK Received 16 May 2006; revised 4 September 2006; accepted 10 October 2006 Guidelines for the design of lighting in residential buildings used by people with dementia are derived from the results of two research projects and a literature review. General guidance on lighting for the older person is summarised and the special requirements of those living with dementia are examined under four headings: the diurnal cycle, a view of nature and the outside world, support for individual and social activities, and recognition of place. The aim is a visual environment that enhances physical well-being and enjoyment of life.

1. Introduction This is a review of lighting conditions that may enhance the well-being of people with Alzheimer’s disease or dementia in other forms. In the UK, it is estimated that 62% of care home residents are affected,1 and that most care homes and sheltered housing units, whether or not intended for the cognitively disabled, have some residents with dementia. The number increases as life expectancy becomes greater. The paper arises from two multi-disciplinary research projects. The first, which ran from 2000 to 2004 and called Design in Caring Environments (DICE), examined standards and guidelines for the design of care homes for older people. The work included a literature review;2 a comprehensive survey of 38 residential care homes in Sheffield and Rotherham (UK); quality-oflife measures of around 400 residents in these homes; and assessment of staff and management attitudes and practices. The buildings and the way they were used were recorded on the Sheffield Care Environment Assessment Matrix (SCEAM), and multivariate analyses Address for correspondence: Judith Torrington, School of Architecture, The Arts Tower, Western Bank, Sheffield S10 2TN. ß The Chartered Institution of Building Services Engineers 2007

were applied to the data. Parker et al.,3 give the main results. The second project, 2003–2006, INDEPENDENT, examined the role of technology in enhancing the well-being of people with dementia. The programme involved focus groups and interviews with dementia sufferers and their carers, discussing their needs and wishes, which led to design and testing of prototype applications.4,5 An outcome of both projects was the clear need for comprehensive guidance on the lit environment for the cognitively impaired. Most existing design recommendations concentrate on ways of enhancing the visual ability of the ageing eye. There is, however, increasing evidence that a building environment can provide more than shelter and support: it can be therapeutic and it can be a factor in enabling those with chronic illness to maintain enjoyable activities.6,7 Lighting is a significant component of a therapeutic environment: eg, So¨rensen and Brunnstro¨m demonstrated that improving the lighting in old people’s living areas improved their self-reported quality of life.8 The importance of lighting as an element in design for older people has also been observed in architectural practice.9 In our surveys, we did not find conditions that imply a general need for a standard 10.1177/1365782806074484

82

JM Torrington and PR Tregenza

prescribing the minimum acceptable quality of environment. What clearly is required is a brief for lighting that enhances well-being and enjoyment of life; in particular, a set of guidelines based on research evidence. This evidence suggests, however, that guidance must extend beyond visual performance and freedom from discomfort – the scope of most lighting design guides – to the basic planning of the building, and to factors related to the management of a care home. Furthermore, research is far from conclusive in some topics. Often, when assessing whether to endorse a particular feature we cannot ask, ‘Is the benefit of this proven?’ Instead, we consider, ‘Does the probable benefit outweigh the disadvantages of implementation?’ and, in general, we would err on the side of inclusion. The effect of the building’s environment on its users tends to be most noticeable in residential care homes, and it is from research in these that most data are obtained. There are, however, several other residential situations, such as the family home, sheltered housing and long stay hospitals, and our recommendations apply equally to these and, where appropriate, to day-care buildings. 2. Structure of paper We begin by listing some characteristics of the ageing eye, and their implications for lighting. The resulting recommendations for design are the context in which we examine the specific needs of people with dementia. These needs are reviewed under four headings: 1) Exposure to a diurnal cycle of darkness and bright light; 2) Provision of a natural external view; 3) Support for activity and social interaction; 4) Enhanced recognition of ‘place’. In each category, we summarise evidence from the research literature and from our own findings, and consider the implications for lighting design. Although by ‘lighting’ we Lighting Res. Technol., 39,1 (2007) pp. 81–97

mean all the effects of electric lighting and windows on the visual environment, these are not the only relevant factors. Not only are visual criteria inherently inter-related with the other physical environmental variables, but the effectiveness of a building depends strongly on the way it is used – the social setting and, in a care home, management attitudes and practices. In the first two of the above categories, there are well-known research results concerned primarily with light, and we deduce what design criteria they imply. In the third and fourth categories, the available research focuses mainly on the design and management of the building as a whole. For these, we set out the objectives, and discuss the contribution to be made by the lighting designer. 3. The ageing eye Dementia is primarily a disease of later life, so recommendations for those with dementia must be set within the context of the lighting requirements of the older person (see, eg, Illuminating Engineering Society of North America10 and Barker11). The main changes in vision due to ageing may be summarised as follows:  There is a reduction of both contrast and illuminance of the image projected onto the retina. This is due to a yellowing and decreased transmittance of the optical elements of the eye, and a significant increase in the amount of light that is scattered by them. Disability glare (the effect of a veiling luminance) is, therefore, more pronounced; a higher luminance of the immediate task area and higher contrast within the task (eg, between printed type and paper) can ameliorate deteriorating visual task ability.  There is an increased prevalence of retinal dysfunction, especially in people over the age of 70. This has various causes but, for

Lighting for people with dementia

many of those affected, very high levels of illuminance can compensate, in part, for the deterioration of vision.  Discomfort glare tends to be increasingly pronounced with age.  Dark-to-light and light-to-dark adaptation times increase with age.  There is very great variation in the vision of older people. These characteristics of the ageing eye impose general constraints on lighting and surface finishes. 3.1 Glare from sources of light Sources within residents’ fields of view should be of low luminance or indirect rather than small and bright. They should be positioned away from users’ directions of sight. Windows should have means of excluding low-elevation sunlight; silhouetting by windows at the ends of corridors, and elsewhere on lines of sight should be avoided. 3.2 Uniformity The lighting of rooms should not be such that there are dark areas where contrast with the brighter parts of the room inhibits vision. The most common cause of this in the residential homes we surveyed was a failure to supplement partial daylight with adequate electric lighting. The recommendation sometimes made, that rooms should be illuminated evenly must, however, be qualified. Very uniform lighting (eg, a diffusing luminaire suspended from the centre of the ceiling) minimises illuminance differences between surfaces and diminishes clues to the form of the room. For people with dementia, this may hinder orientation and, if similar lighting is used in other rooms, make recognition of particular spaces harder. 3.3 Reflections and surface materials Specular reflections in shiny materials can cause both disability and discomfort glare. They hinder perception of the actual surface

83

position, and mask a surface’s underlying colour. Many of the building and furnishing surfaces in care homes have to be easily cleaned, therefore, glossy finishes are widely specified. The following factors should be considered:  In most situations, it is an advantage visually to minimise the specular component of reflectance; matt surfaces are preferable.  Where glossy surfaces must be used, light sources should be located, so that they do not produce specular reflections close to users’ lines of sight.  For users with impaired vision, tactile sensing is important; in Section 7, below, we discuss in addition the importance of ‘authenticity’, and of achieving consistency between information given by the different senses. 3.4 Visual tasks Everyday activities involve a wide range in the scale of tasks: recognition of places; awareness of hazards, such as steps; personal activities, such as bathing; reading and writing; watching television; picking up small objects. In a care home, in addition to residents’ needs, there are those of the care and nursing staff, visitors and other groups. Task visibility is enhanced by:  increasing the apparent size and the contrast of detail in the object (eg, the use of magnifying lens, colour coding, directional illumination), emphasising the crucial visual characteristics of the task;  avoiding bright zones within the field of view around the task;  increasing the illuminance on the task. The result of an increase in illuminance is significant if the existing level is low, if the task is very exacting in contrast or size, or if the user has certain retinal disorders; but if Lighting Res. Technol., 39,1 (2007) pp. 81–97

84

JM Torrington and PR Tregenza

the illuminance is already high, the effect of an increase is negligible. A fear of falling inhibits the activity of frail older people. Falling is the most common serious accident of old age, and poor vision is one cause. Harwood, in a review of the literature on visual problems and falls, found that poor visual acuity approximately doubled the risk of falling.12 Accidents can occur both when a step is not perceived and when a change of floor material is mistakenly seen as a change of level. So that frail or visually-impaired people can move with confidence, the directionality of the lighting and choice of surface materials must enhance the view of floor plane, emphasising continuity and indicating changes of level. We have noted above that a highly-polished floor finish reduces visibility of the surface plane by its mirroring of other objects, particularly light sources. Both glossy and matt surfaces, such as carpet, must have a change of colour or a contrasting nosing at level changes. Yellowing of the ageing eye has the result that colours in the blue-purple range are perceived less strongly than those in the redyellow part of the spectrum. The need to delineate changes of level is important in all rooms, not just circulation areas. Although regulations may prohibit internal steps in some building types, changes of level occur in other ways. Special attention should be given to bathrooms and showers, where spectacles might be removed; and to chairs, where the seat edge can become invisible if the seat material is similar in colour brightness and pattern to the floor material. If there is a large difference between the ambient brightness of adjacent spaces, such as at the entrance to a building at night, slow light-dark adaptation times make changes of level exceptionally hazardous; they must be, therefore, very strongly accented. In line with the discussion in Section 6, it is desirable that supportive lighting be provided for a broad range of activities, and for the Lighting Res. Technol., 39,1 (2007) pp. 81–97

visual requirements of all residents. Our observations in the DICE project suggest that in a communal building this is better achieved by providing a range of sitting and activity areas with different lighting than adopting a single condition throughout. These guidelines are summarised in Table 3.

4. Recommendations for people with dementia 4.1 A diurnal cycle of darkness and bright light 4.1.1 Seasonal affective disorder (SAD) and daylight illuminance

The recorded incidence of clinical depression is lower among older people than in young adults, but these data may reflect a significant under-reporting; depression is a symptom of many of the illnesses associated with ageing,13 and in particular, it is common among patients in the early stages of dementia,14 although the inter-relationship between dementia and depression is not fully understood.15,16 There is a substantial literature on SAD, a depressive illness that varies with the time of year.17,18 It can occur during winter, with symptoms common to other types of mental depression, such as oversleeping, mood changes, lack of energy, over-eating; there is also a summer form in which the symptoms tend to be the opposite – lack of sleep, loss of appetite, weight loss. The winter form is the more usual and is found mainly in young adults, but it affects older people, and females more than males. The mechanism of the winter disease is clearly related to exposure to light: the symptoms are relieved when the sufferer receives daily exposure to a bright source of light; they disappear with the onset of summer and recur in autumn; and they are found predominantly in people living at latitudes distant from the equator.19

Lighting for people with dementia

The summer form of SAD is much rarer, and is not necessarily a response to high levels of light; it may be due to other factors, such as overheating or behavioural changes during hot summer months. Although the type of daylight climate in which SAD tends to occur is known, there is little precise evidence about the regime of illuminances that triggers the disease. Therapeutic doses, however, are better understood: when daily exposure to bright light is used clinically as an anti-depressive, typically the patient spends 30 minutes every morning facing a ‘light box’ – fluorescent lamps mounted behind a diffusing screen – which produces 10 klx at the patient’s eyes. A lower level of light, 2.5 klx, may be used with a dosage of 1–2 hours. It is found that the light treatment for SAD patients is more effective during the morning than the afternoon, and the normal recommendation is for exposure to light immediately after waking.17 In the absence of strong evidence that lower illuminances are effective in preventing the onset of SAD, we consider the therapeutic values as a possible design requirement. Figure 1 shows how typical winter illuminances outdoors vary with latitude; they give mean daylight levels, not for the shortest day of the year, but a month later, 21 January, which is more representative of the winter period as a whole. The horizontal axes of the graphs extend from 208, just within the tropics, to 608, close to the arctic circle. Graph (a) shows illuminance on a vertical surface and is approximately the illuminance on the eyes. For the upper curves, the sun is shining and the receiving surface is orientated to face the sun; the two lower curves show the average illuminance on the surface when the sun is obscured. Graph (b) gives the time of sunrise on 21 January. The graphs show that at latitudes of 508 and more, not only are the hours of daylight short, but outdoors the mean diffuse illuminance on the eye barely exceeds the levels

85

needed for SAD therapy. On an overcast day, somebody who, by age or illness, is confined indoors could receive a therapeutic dose of light energy only by remaining close to a window for several hours. When the sun shines, there is ample light. It is probably not just for its warmth that sunlight in a room is welcomed in cold winter climates, its high brightness may stimulate a real uplifting of mood in those affected by winter depression. Dementia patients, and older people in a residential home setting generally, tend to have significantly less exposure to environmental light than people living in the community.20,21 In our own survey of care homes, we found, that in winter it was common for residents to remain continuously indoors for several days. We found, too, that many of the homes were conversions of large old houses and had low levels of daylight in communal rooms.

Figure 1 Variation of daylight availability with latitude. (a) Mean illuminance on a vertical surface facing the solar azimuth at 09:00 hours and noon on 21 January. (Calculated values based on empirical equations59). (b) Time of astronomical sunrise

Lighting Res. Technol., 39,1 (2007) pp. 81–97

86

JM Torrington and PR Tregenza

4.1.2 Circadian rhythms

A common symptom of dementia is dislocation of diurnal rhythms.22 Dementia sufferers who tend to be awake and active at night risk, first, inadequate exposure to daylight and, second, a disruption of the daily sequence of physiological changes, with the resulting symptoms of depression and sleep disorder. The use of light exposure to ameliorate these symptoms has been tested experimentally.18,23,24 It has been shown that an increase of light exposure lessened sleep disturbances of patients with dementia and of older people generally. Some have reported amelioration of agitated or aggressive behaviour, but this was not found in other studies.25,26 Some people exhibit symptoms of the ‘sundowning’ syndrome, an increase in agitated behaviour as evening approaches.27 This tends to occur in the middle years of the disease, rather than in the early and final stages. The symptoms are associated with decreasing daylight, but this is not necessarily causal: they are also associated with decreased daytime activity and increased nocturnal disturbance.22 In care homes, residents with advancing dementia tend to make remarks such as ‘I am just visiting here, I will be going home later’. We noted this in our surveys, and it supports the hypothesis that one cause of the sundowning syndrome is confusion or anger at being confined. However, La Garce,28 demonstrated a literal interpretation of the effect. In a carefully planned experiment over a 12-month period, subjects were observed in two rooms which were identical except that afternoon sunlight was excluded from one, room illuminances being compensated. In the room without sunlight penetration disturbed behaviour was significantly less. 4.1.3 Discussion

There is no suggestion that SAD is the principal form of depression among older Lighting Res. Technol., 39,1 (2007) pp. 81–97

people, but in climates, such at that of the UK, where winter illuminance within buildings is often low, the likelihood of it occurring in some people confined indoors is high. The evidence is very strong that the absence of a clear day-night lighting cycle has a deleterious effect on health, and this may be especially significant for people with dementia. We conclude that all residential buildings used by dementia sufferers should have one or more freely accessible internal areas with strong daylight. A semi-outdoor space, such as a heated conservatory, would be ideal. In high latitude climates, it should receive direct sunlight, preferably in the morning, but there should, of course, be blinds or other means of solar control. The daylit areas should be useable for normal daytime activities. Care must be taken to avoid glare from lowelevation sunlight (discussed in Section 5). If it is impossible to provide a strongly daylit room, an area with a high illuminance from electric lighting is an alternative. The vertical surfaces of the room must be strongly lit, but without glare; fluorescent lamps with good colour rendering can be used. Artificial skylights – ceiling installations resembling roof openings – offer a means of achieving this, but the need for authenticity (discussed below) should be noted. A period of darkness in the diurnal cycle is necessary, therefore, electric lighting at night should be controlled to provide dark sleeping conditions in bedrooms. In care buildings, there is a potential conflict with requirements of supervision and safety; this may be resolved by, for instance, the use of movement detectors. 4.2 A natural external view 4.2.1 Therapeutic effects

An attractive or interesting view from windows can have a therapeutic effect or can reduce discomfort. In a comprehensive literature review, Farley and Veitch,29 report

Lighting for people with dementia

that windows with views onto nature may enhance working and well-being in a number of ways, including life satisfaction. They conclude also that a view outside is important, not only for its restorative quality, but as a means of enhancing control over the environment. As instances of individual studies, Wilson,30 found a significantly lower incidence of patients with post-operative depression in rooms with windows compared to those in windowless rooms; Ulrich,31 showed that patients recovering from surgery in a ward with windows overlooking trees required less powerful analgesic drugs and had shorter recovery times than matched groups of patients in a ward with a view only of a brick wall. From observations in care homes, Chalfont,32 reports that the presence of view windows can trigger social interactions: people tend to group in seats around an attractive window, and the view itself provides an easy opening for conversation. Recommendations for immediate implementation made by Ulrich et al.,33 in a review of the role of the physical environment in hospital buildings included the provision for patients of stress-reducing views of nature, and improvement of lighting, especially natural lighting. It is been found in almost every study,29 that the views most preferred by subjects, and those most effective in reducing discomfort, are natural scenes – trees, water, open landscape – rather than urban places. Preferred views also tend to extend from nearby objects to distant objects and the sky, rather than be limited in the span of distance. In our observations in care homes, we have noted two additional factors. First, views of the everyday activity of people are attractive to those who are confined indoors. Where there is a choice of seats in rooms used during the day, those most preferred tend to be those with a view of people outside (such as of children on their way to school) or which

87

overlook the entrance areas of the care home. Second, many dementia sufferers are very old, with seriously impaired vision, and unable to appreciate small distant objects. We note also that older people living in their own homes are fiercely defensive of views that they possess and, if these would be diminished by the erection of a new building, raise strong objections to planning consent. Hospitals, schools and workplaces have been studied, but there has been little specific research on the value of view in residential homes or to people with dementia. Similarly, there has been little directly applicable research on window position and size in relation to view, although there is some work to confirm the common-sense assumptions that preferred window sizes increase with distance from the window wall,34 and the preferred shape of window depends on the function of the space.35 Empirical advice on detailed design is given in various design guides and standards (see, eg, References36–41): sill and head heights should be appropriate to people’s positions – lying, sitting, standing or moving; windows at the end of corridors cause people to be seen in silhouette, and give unpleasant reflections in shiny wall and floor surfaces; and low altitude sunlight penetrating deeply into a room can give disturbing dazzle. 4.2.2 Discussion

The evidence is strong that the provision of a natural view can have a measurable beneficial effect, although there has been little specific research on the value of a view to people with dementia. We conclude that the provision of windows providing natural or interesting views is almost universally welcomed by building users, and that the presence of a view may have beneficial effects on the health of dementia sufferers and people confined within a building. The extent and quality of views from the site should be a factor in the Lighting Res. Technol., 39,1 (2007) pp. 81–97

88

JM Torrington and PR Tregenza

choice of a location for residential buildings, and the building design should ensure that residents receive the benefit of these. A view of high quality ranges in extent from nearby to distant features and the sky; it contains natural objects, such as trees and water; and, for those confined within buildings, it shows people in everyday activities outdoors. Window positions and sill heights should be related to the probable activities of people, in particular, whether they are walking, standing or sitting. 4.3 Lighting to support activities 4.3.1 Dementia-related visual impairment

Alzheimer’s disease can itself cause visual dysfunction.18,42–44 Summarising recent research, Butter describes evidence for two main neuronal pathways with different functions in visual processing, one supporting colour perception, pattern recognition and recognition of people and objects, the other associated with spatial perception. Both can be impaired by Alzheimer’s disease, but there appears to be agreement that the former (‘what’) pathway is more affected than the latter (‘where’) pathway.45 Van Rhijn et al.,46 studying people with dementia noted approximately half had impaired ability in face, object and letter-word perception tasks, while significantly fewer, 30%, were impaired in a spatial dot location task. Patients with Alzheimer’s disease are, however, found to be significantly impaired in depth

perception.47 There is particular support for the use of enhanced colour and contrast.42,48 4.3.2 The range of activity

The well-being of a person with dementia can be substantially improved by increasing the number of enjoyable activities undertaken. Widely used methods of quantifying the quality of life of people with dementia, such as Dementia Care Mapping,49 and the Pleasant Events Schedule-AD,50 are based on person-centred care, and have an underlying assumption that engaging in a range of activity is beneficial. In general, there exists a strong association between activity and quality of life while ageing.51 In the Independent project, we used focus groups of dementia sufferers and their carers to build up lists of desirable activities; Table 1 is an example. It should be noted that listed are normal everyday activities, and that the first item is social participation. The importance of social interaction in ameliorating the progress of dementia has been shown in several studies, for instance.52,53 The aim, therefore, is to provide a physical and social environment in which a person with dementia can continue the activities that he or she has enjoyed throughout their life. Necessarily, there are constraints: some activities are difficult to achieve in a communal home and some are limited by the person’s own abilities. Most important is the approach taken by carers and by those who manage residential homes. An important

Table 1 Ranking of desirable activities mentioned by people with dementia and their carers in focus groups Rank

Activity

Rank

Activity

1 2 3 4 5 6 7 8

Social participation Community participation Physical activity Creative activities Activities of daily living (such as cleaning, cooking) Music Conversation Pottering outside

9 10 10 11 12 13 14 15

Food and eating Enjoyment of nature Reminiscence Pottering in the home Humour Mind games (such as jigsaws) Reading Television

Lighting Res. Technol., 39,1 (2007) pp. 81–97

Lighting for people with dementia

finding from the DICE project was that for care home residents who were moderately independent, there was an inverse association between their quality of life and the overall measure of safety in the care home.3 We interpret this to mean that where the regime places a strong emphasis on safety, the residents are restricted in their scope of possible activities or their environment controlled. An example already implied is that sleeping patterns may deteriorate where, for supervision, there is lighting all night. Other instances are the restricting of residents’ freedom to go outside, because of risk of falling or discomfort, and the limiting of social contact with visitors. 4.3.3 Discussion

Increasing the range of possible activities open to people with dementia is likely to enhance their well-being, especially when they are provided with the opportunity to continue activities that they have enjoyed for many years. The opportunity for these can be influenced by a building’s characteristics at two scales. First, the overall form of the interior planning can determine the way in which people may form groups, have privacy, enjoy daylight. For instance, long narrow corridors can inhibit conversational groups, and deep building forms tend to reduce the proportion of the interior that has an external view. Second, the detailed design of building elements can determine accessibility, physical support and safety. An example is the way in which fire doors hinder mobility and social interaction. Widening the scope of activities implies the provision of any physical support needed; it is clear that not only should users be safe, but that they are helped by feeling that they are safe. Safety should not be a reason for restricting desired activities, but one of the objectives of creative design. This aim of enabling people with dementia to maintain enjoyable activities provides a

89

direction for the design of lighting and of a building’s internal environment as a whole. 4.3.4 Circulation areas

Conventionally, these elements of a building – corridors, staircases, lobbies, hallways – are mere links between rooms; for many building types it is often a design aim to minimise the area they occupy. But for dementia sufferers, who may spend much of their waking hours walking about the building, the quality of the routes themselves is as important as the static spaces. Designed imaginatively, circulation spaces can be used to bring views and natural light into the building; and they can incorporate secondary spaces and points of interest that enhance social interactions and provide places for individual activities. The provision of such areas – seats by a window, alcoves with good lighting, comfortable chairs overlooking a public space – is strongly welcomed by residents; in our surveys, we noted that where these are provided in residential homes they are widely used. The habit of continuously walking about, a symptom of many dementia sufferers, is distressing when the person becomes disorientated or is mistaken in recognising a location. This occurs especially in buildings with symmetrical plan forms and where floor layouts are identical between stories.54 We suggest that lighting could significantly assist wayfinding in two ways. 4.3.4.1 Ensuring that different areas within the building are visually distinct The importance

of recognisable patterns of light and colour is greatest when other clues are few – when, eg, there is uniformity in the size, shape and materials of rooms. But perceptual theory implies that if variation between spaces is random or meaningless, confusion may increase; whereas if the lighting varies systematically and is related in a Lighting Res. Technol., 39,1 (2007) pp. 81–97

90

JM Torrington and PR Tregenza

common-sense way with the building’s overall form and the functions of adjacent spaces, the recognition of location and direction can be enhanced. We discuss this further in next section. Windowless interior corridors give few clues about orientation, especially when they are interrupted with fire doors. Windows that overlook familiar external scenes provide a sense of direction, so do views of central interior elements, such as atria. Long internal views can enable a person to see the intended destination.

4.3.4.2 Providing orientating views

As the daylight in a room, particularly the sunlight, varies with the orientation of the windows, natural lighting may be a means of differentiating otherwise similar spaces. 4.4 Recognition of ‘place’ Dementia sufferers retain personality and awareness of a long life, and intelligence persists, but with increasing severity of the disease there is loss of ability to recall recent events. At an advanced stage, a sufferer may have memories of times long past, but awareness only of the immediate present. This causes distress and confusion: frequent questions are ‘Where am I?’, ‘What am I doing here?’ The perception of place is a central topic in cognitive psychology and the literature is substantial. We shall first set out the principles then consider specific applications. In the present context, ‘place’ means somewhere that people (a) behave in a specific way, (b) expect specific behaviour in others, and (c) can recognise from particular characteristics of the physical surroundings. Recognition of a place is the result of linking the sensory input with remembered characteristics of places from earlier experience. Places are, thus, associated with names which denote categories: ‘pub’, ‘market’, ‘beach’, ‘dining room’; the name is usually qualified: ‘my Lighting Res. Technol., 39,1 (2007) pp. 81–97

garden’, ‘the dull waiting-room’, ‘a dirty corridor’; and individual places may be associated with one or more specific names, ‘Hyde Park’, ‘Sydney’. When a person has recognised a place, it acquires all the associations accumulated from experience of that type of place. These determine whether the person ‘owns’ the space: whether he or she assumes the right to change it, even in minor ways, such as switching on lights. They also determine the person’s expectations, and, therefore, the degree of satisfaction with what is there. Normally, recognition occurs below conscious awareness; but if there is ambiguity, or if the clues to recognition do not match any concept of a place that can be recalled from previous experience, a person experiences uncertainty; this is frequently experienced by those with dementia. Barker,55 uses the term ‘behavioural setting’ to describe a response to a place that includes expectations of both of specific physical characteristics and of the ways in which people would behave in that environment. He argues that places have synomorphy when there is congruence between people’s actions and the physical and social setting. A building that gives inconsistent clues to its purpose can leave a user unsure about the setting and the appropriate behaviour.56 A common example of inconsistency is a residential home that is decorated at a domestic scale, but retains features of an institutional building: room size, floor materials, fire doors and smoke detectors, exit signs, for example. In our surveys, we have recorded anecdotes of confusion occurring in this situation. They include cases where the dementia sufferers believed they were back in school, and an example in which a resident became distressed because she assumed that she was in a restaurant and had no money with her. We have noted confusion arising from failure to understand the nature of multi-purpose spaces, and rooms with a very

Lighting for people with dementia

specific function, such as chapels or shrines, tend not to be occupied for other purposes, such as social conversation, even when that use is permitted and acceptable. Fear can arise in the failure to recognise hoists and other equipment for bathing.6 Old memories of places provide a structure for recollection and reminiscence, and this can be therapeutic.57 Places linked with emotions are far more likely to be remembered that those without special associations. 4.4.1 Discussion

The challenge to the designer is two-fold: a) to make the various spaces within the building, and the building as a whole,

91

consistent with user experience acquired many years ago; b) to make the building self-consistent. The requirement of self-consistency implies a need for authenticity – that places and objects should be as they purport to be. It is a need to avoid the confusion that arises when different senses receive different messages; where, for instance, a room looks superficially like a room in a private house, but sounds or smells like an institutional space. It is also the avoidance of fake characterisation, such as imposing a cottage-like scheme of decoration on a large room. The aim is, however, to do more than merely avoid confusion. It is to aid spatial

Table 2 Typical characteristics of spaces in a gradation from private to public areas Type of space

Scale and contents

Lighting and decoration

Personal rooms, with hierarchy of increasing privacy: sitting area, bed space, bathroom, toilet.

Small domestic scale Individual possessions and memorabilia; own furniture and choice of decoration.

Rooms for special purpose: religious worship, reading, music, television.

Small to large group size, depending on purpose.

Windows size and position related to individual use. Domestic scale luminaires, local lighting, small scale variation of brightness. Individual decoration. Where consistent with safety, user control of window opening, blinds and curtains, luminaires. Lighting and decoration related to function. Special areas may be highlighted.

Group activity spaces, dining rooms, lounges.

General circulation routes. These often contain alcoves for individuals or small groups; these are especially effect where there is an external view.

Entrance areas

Recognisable by attributes of function, often symbolic. Room sizes related to number of residents. Larger scale than domestic in fittings and furniture. Recognisable by attributes of function; objects and pictures related to group interests and culture. The progression from private to public is one of increasing scale of space and decreasing personalisation and privacy.

Public and semi-public areas. Notice boards, travel timetables, information to visitors, seating, coat and umbrella racks.

Residents may control luminaires and windows. Some areas with strong daylighting. General lighting with local lighting for task performance or to enhance character of space. Decoration style related to semi-public rooms. Staff control of lighting and windows.

Main routes may be denoted by higher illuminances. Lighting and decoration of circulation areas can indicate the function of adjacent rooms. Security and emergency lighting is usually required. Staff control the lighting and windows along primary routes; residents may control these in alcoves and gathering areas. Floor and other finishes compatible with outdoor clothing. Usually daylit spaces with view over approach to entrance.

Lighting Res. Technol., 39,1 (2007) pp. 81–97

92

JM Torrington and PR Tregenza

Table 3 Summary of lighting recommendations for older people in residential accommodation generally 1. Minimise direct glare Aims: To avoid discomfort and disability glare from sources of light. (a) Windows should have blinds or other means of excluding low elevation sunlight. It is preferable for windows not to be placed at the end of corridors or in other positions where people or objects are seen in silhouette against the window. If this is unavoidable, window brightness should be reduced by blinds or curtains and the silhouetted figures should receive extra illumination. (b) Electric light sources should be of low illuminance or indirect if they lie within the visual field of users. In general, sources should be placed as far as possible from users’ lines of sight. 2. General lighting without large brightness differences Aims: To avoid visual disability from excessive brightness contrast within a room; to enhance visual differences between rooms. (a) Rooms with windows that do not provide strong daylighting throughout the space should have supplementary electric lighting to increase the brightness in the darker parts of the room and to reduce contrast with the view outside. (b) At night, and during the day in rooms with little daylighting, electric lighting should illuminate the all the major room surfaces well. They should, however, be differences of illuminance or colour between the different walls and between walls and ceiling. (c) Rooms which are similar in form or function should be differentiated by differences in lighting or decoration. 3. Minimise reflected glare Aims: To avoid reflection of bright sources. (a) Wherever possible, surface finishes should not be glossy. (b) Where specular reflection is unavoidable, bright sources of light should be placed so their reflections are not close to users’ lines of sight. 4. Increase the visibility of tasks Aims: To enhance the ability to see differences of brightness and colour (a) ‘Task’ here means the visual requirements of every activity of the older person. Tasks range in scale: walking about, interacting with other people, reading, threading a needle. (b) Task performance is improved by: (i) increasing contrast within the task area (for example, by indicating steps with a white nosing); (ii) avoiding direct or reflected glare; (iii) increasing task illuminance. (c) Special consideration should be given enhancing the visibility of changes of level.

recognition by systematically providing clues which are inherent to the particular spaces of the building. We suggest an approach to this: A gradation of interior spaces from ‘private’ to ‘public’ occurs in most types of building; it is an important characteristic of residential homes. It is recognisable by various attributes – the layout of furniture, the activity of people, the form of lighting, the presence of specific objects, the degree of personalisation. People’s behaviour varies consistently with the gradation, reflecting a hierarchy of permitted access, from areas open to the public to the closest personal spaces owned by individuals.58 Private spaces exhibit personal possessions; they tend to be domestic scale in lighting and decoration; rooms may be small, and windows designed to give individual views. Rooms with evidence of group activities are clearly shared spaces; their furniture and fittings are usually larger in scale. Entrance Lighting Res. Technol., 39,1 (2007) pp. 81–97

areas are recognisable by their surface finishes, and changes of sound, light and air movement from opening doors and nearby windows; they contain payphones, transport timetables. Table 2 is based on our survey of residential homes in the Sheffield and Rotherham, UK. It gives typical characteristics of the various spaces in a residential care home. These are normal attributes of a building and for a person with dementia they provide clues by which different types of space can be recognised. The aim is to achieve synomorphy – a consistency between the use of the space and its physical characteristics. Lighting is clearly central to this: lamps, luminaires and windows, both in their characteristics as objects and in the patterns of light they produce, have strong associations with the perceived nature of particular places. Tables 3 and 4 summarise the recommendations for lighting.

Lighting for people with dementia

93

Table 4 Summary of recommendations for people with dementia 1. Diurnal daylight cycle Aims: To ensure that residents have sufficient daylight exposure to minimise the risk of SAD; to ensure that they experience a 24-hour cycle of light and dark. (a) Residential buildings used by dementia sufferers should have freely accessible internal areas with strong daylight. In high latitude climates these areas should receive direct sunlight penetration wherever possible, but there should be blinds or other means of control. The daylit areas should be useable for normal daytime activities. Intermediate indoor-outdoor spaces such as conservatories satisfy these requirements. (b) Electric lighting at night should be controlled to provide dark sleeping conditions. 2. View Aims: To provide potentially therapeutic views; to enhance opportunities for social interaction. (a) The extent and quality of views from the site should be a factor in the choice of a location for residential buildings, and the building design should ensure that residents receive the benefit of these. (b) Preferred views are of natural scenes rather than the built environment; people confined within a building enjoy seeing the activities of people outside. (c) Window positions and sill heights should be related to the probable activities of people, in particular whether they are walking, standing or sitting. (d) Seating and areas for social interaction should be provided beside view windows. 3. Support for activities Aims: To enable residents to continue activities they have enjoyed through their lifetime; to enhance opportunities for social interaction. (a) The lighting and choice of surface finishes of the building and of visual tasks within it should enhance the ability of the ageing eye, especially by emphasising contrast differences. Changes of level should be emphasised by increasing contrast between surfaces in different planes, for example: at entrances, between seats and floor, in showers and bathrooms. (b) The circulation areas of the building should be treated as important elements in the design. They should be attractive places and contain alcoves and other areas for personal use and social contact. They should not be treated homogeneously in lighting and decoration: to aid wayfinding, the appearance of routes should vary systematically. 4. Recognition of ‘place’ Aims: That interior spaces should be recognisable by dementia sufferers with no memory of recent experience. (a) The information given by all the senses must be consistent. There must be consistency between the perceived nature of a room and people’s behaviour within it. The clues to the nature of the room must be consistent with a commonsense understanding of the building. (b) The normal differences of rooms on a private-public gradation and the associated ranges of personalisation, size and scale, and of surface finishes and types of lighting, can provide a systematic framework for lighting design decisions.

5. Concluding discussion It is clear from the research evidence that guidance on lighting design for people with dementia should not be limited to consideration of visual tasks and compensation for deteriorating eyesight. The well-being of those who are physically and cognitively frail is affected by their overall exposure to the cycle of day and night, to sunlight and view. Their freedom from anxiety and the extent to which they can continue the activities they enjoy depend on their perception of the whole place, as well as on the physical support that the building provides. Achieving these conditions requires the involvement of the architect and the client,

not just the specialist lighting designer: matters such as the orientation of a building, its basic shape and the planning of circulation routes are determined by the brief, and by decisions at the early design stages. Guidelines should address the whole design team. Furthermore, the advice should not be prescriptive: in this paper we have attempted to describe the background and the objectives and we would emphasise the need for creative design. This is especially necessary for care homes. In the UK, these are subject to more constraining regulation than almost any other type of building: yet in lighting, as in other aspects of architecture, innovation is necessary if the provision of supporting environments is to be enhanced. Lighting Res. Technol., 39,1 (2007) pp. 81–97

94

JM Torrington and PR Tregenza

This paper focussed on the specific needs of people with dementia, but there are two interesting matters of generality: 1. We have emphasised the need for synomorphy – consistency between the apparent physical environment and social behaviour, and between the different senses of the physical environment. When synomorphy occurs, recognition of a place is usually below conscious awareness: the building is taken for granted, the focus is on the purposes of the user. But complexity and contradiction are elements of architectural composition, and these imply that a place should be noticed for its own sake. A building may provoke thought, and hold the viewer’s attention by saying more than can be revealed at a quick glance. It can contain references to recent events, to cultural memories and to the other arts; but any resulting ambiguity may be worse than confusing to a distressed person. In architectural theory, therefore, design for those with dementia lies at the extreme of a dimension that extends from buildings that are focussed on the support of the user – where tasks are hazardous, where there is risk of distress or where people are nervous – to buildings that are themselves to be an object of display – the fashionable shop, the house that advertises its owners attainments, the monument. 2. It may be noted that very few of the recommendations given could not be applied beneficially to any residential building, such as a hotel or a block of apartments. The requirements of people with dementia give a magnified view of normal everyday needs.

Acknowledgements We thank our colleagues and co-investigators for their direct and indirect contributions to this paper. In the DICE project, Professor Kevin Morgan of the University of Loughborough, Lighting Res. Technol., 39,1 (2007) pp. 81–97

Dr Kevin McKee, Mrs Chris Parker and Dr Sarah Barnes of the University of Sheffield. In the INDEPENDENT project, Dr Andrew Sixsmith, Grant Gibson and Pam Clark from the University of Liverpool, Professor Roger Orpwood and James Chadd from the University of Bath Institute of Medical Engineering (BIME), Dr Garuth Chalfont from the University of Sheffield School of Architecture. Valued collaborating organisations were Dementia Voice, Northamptonshire County Council, Sheffcare and Huntleigh Healthcare. The study has been greatly assisted by the participation of older people, relatives, staff, managers and owners of care homes and community support teams. DICE and INDEPENDENT were sponsored by the UK Engineering and Physical Science Research Council (EPSRC) as part of its EQUAL programme. In writing a paper of this kind, an author is greatly helped by earlier literature reviews, and we would mention especially the publications of Boyce,18 Day et al.,6 and Farley and Veitch.29 We are grateful to the referees and the technical editor of Lighting Research and Technology for their constructive suggestions.

References 1 Matthews F, Dening T. Prevalence of dementia in residential care. Lancet 2002; 360: 225–26. 2 Barnes S, McKee KJ, Morgan K, Parker CJ, Torrington JM, Tregenza PR. The design of caring environments and the quality of life of older people. Ageing Soc. 2002; 22: 775–89. 3 Parker C, Barnes S, McKee K, Morgan K, Torrington J, Tregenza P. Quality of life and building design in residential and nursing homes for older people. Ageing Soc. 2004; 24(6): 941–62. 4 Torrington J. What has architecture got to do with dementia care? Explorations of the relationship between quality of life and building design in two EQUAL projects. Qual. Ageing 2006; 7(1): 38–48.

Lighting for people with dementia

5 Sixsmith A, Orpwood R, Torrington J. Quality of life technologies for people with dementia. Topics Geriatr. Rehab. (in press). 6 Day K, Carreon D, Stump C. The therapeutic design of environments for people with dementia: a review of the empirical research. Gerontologist 2000; 40(4): 397–416. 7 Bakker R. Sensory loss, dementia and environments. Generations 2003; XXVII(1): 46–51. 8 Sorensen S, Brunnstrom G. Quality of light and quality of life: an intervention study among older people. Lighting Res. Technol. 1995; 27(2): 113–18. 9 Manser M. The architecture of institutions for demented persons. Innovative Trends Psychogeriatr. 1989; 26: 22–27. 10 Illuminating Engineering Society of North America. Recommended practice for lighting and the visual environment for senior living. New York: Illuminating Engineering Society of North America, 1998. Report No: IESNA RP-28-98. 11 Barker P, Barrick, J, Wilson R. Building sighta handbook of building and interior design solutions to include the needs of visually impaired people. London: RNIB 1995. 12 Harwood RH. Visual problems and falls. Age Ageing 2001; 30(S4): 13–18. 13 Moriarty J. Assessing the mental health needs of older people: systematic review on the use of standardised measures to improve assessment practice. London: Social Care Workforce Research Unit, King’s College London, 2002. 14 Edwards J. Research highlights: dementia and depression in older people. 2001 [cited 2006 06/ 01/2006]; Reprinted from IPA Bulletin volume 19 number 2]. (Available from http:// www.ipa-online.org/ipaonlinev3/publications/ bulletinarchive/dem_dep.asp). 15 Rabheru K. Depression in dementia: diagnosis and treatment. Psychiatric Times 2004; XXIII(13). 16 Boustani M, Watson L. The interface of depression and dementia. Psychiatric Times 2004; XXI(3). 17 Lam RW, Levitt AJE. Canadian consensus guidelines for the treatment of seasonal affective disorder: a summary of the Report of the Canadian Consensus Group on SAD.

18 19

20

21

22

23

24

25

26

27

28

29

95

Vancouver BC Canada: Clinical & Academic Publishing, 1999. Boyce P. Human factors in lighting, second edition. London: Taylor & Francis, 2003. Mersch PP, Middendorp HM, Bouhuys AL, Beersma DG, van den Hoofdakker RH. Seasonal affective disorder and latitude: a review of the literature. J. Affective Disorders 1999; 53(1): 35–48. Mishima K, Okawa M, Shimizu T, Hishikawa Y. Diminished melatonin secretion in the elderly caused by insufficient environmental illumination. J. Clin. Endocrinology Metabolism 2001; 86(1): 129–34. Campbell SS, Kripke DF, Gillin JC, Hrubovcak JC. Exposure to light in healthy elderly subjects and Alzheimer’s patients. Physiol. Behaviour 1988; 42: 141–44. Volicer L, Harper DG, Manning BC, Goldstein R, Satlin A. Sundowning and circadian rhythms in Alzheimer’s disease. Am. J. Psychiatry 2001; 158(5): 704–11. Lyketsos CG, Veiel LL, Baker A, Steele C. A randomized, controlled trial of bright light therapy for agitated behaviors in dementia patients residing in long-term care. Int. J. Geriatric Psychiatry 1999; 14(7): 520–25. Forbes DA, Peacock S, Morgan D. Nonpharmacological management of agitated behaviours associated with dementia. Geriatrics Ageing 2005; 8(4): 26–30. Mishima K, Okawa M, Hishikawa Y, Hozumi S, Hori H, Takahashi K. Morning bright light therapy for sleep and behaviour disorders in elderly patients with dementia. Acta Psychiatry Scandinavia 1994; 89: 1–7. Fetveit A, Skjerve A, Bjorvatn B. Bright light treatment improves sleep in institutionalised elderly-an open trial. Int. J. Geriatric Psychiatry 2003; 18(6): 520–26. Hopkins RW, Rindlisbacher P, GRant NT. An investigation of the sundowning syndrome and ambient light. Am J Alzheimer’s Care Related Disord. Res. 1992; 7(2): 22–27. La Garce M. Daylight interventions and Alzheimer’s behaviours-a twelve month study. J. Architectural Planning Res. 2004; 21(3): 257–69. Farley K, Veitch J. A room with a view: a review of the effects of windows on work and Lighting Res. Technol., 39,1 (2007) pp. 81–97

96

30 31 32

33

34

35

36 37 38 39 40

41 42

JM Torrington and PR Tregenza well-being. Ottowa, Canada: Institute for Research in Construction; 2001 August 2001. Report No.: RR136. Wilson L. Intensive care delirium: the effect of outside deprivation in a windowless unit. Arch. Intern. Med. 1972; 130: 225–26. Ulrich RS. View through a window may influence recovery from surgery. Science 1984; 224(42): 421. Chalfont GE. Connection to nature at the building edge: towards a therapeutic architecture for dementia care enviornments PhD thesis Sheffield. University of Sheffield, 2006. Ulrich R, Quan X, Zimring C, Choudhary R. The role of the physical environment in the hospital of the 21st Century: a once-in-a-lifetime opportunity. Report to The Center for Health Design for the Designing the 21st Century Hospital Project: Center for Health Systems and Design, College of Architecture, Texas A&M University; 2004 September 2004. Ne’eman E, Hopkinson RG. Critical minimum acceptable window size: a study of window design and provision of a view. Lighting Res. Technol. 1970; 2(1): 17–27. Butler D, Biner P. Effects of setting on window preferences and factors associated with those preferences. Environment Behav. 1989; 21(17–31). Torrington J. Care homes for older people. London: E&FN Spon, 1996. Torrington J. Upgrading buildings for older people. London: RIBA Enterprises, 2004. British Standards Institution. BS 8206: Part 2: 1992 Code of practice for daylighting. London: BSI, 1992. Judd S, Marshall M, Phippen P. Design for dementia. London: Hawker Publications Ltd., 1997. Calkins M. Design for dementia; planning environments for the elderly and confused. London: National Health Publishing, 1989. Calkins M. Creating successful dementia care settings. Health Professions Press, 2001. Cronin-Golomb A, Gilmore G. Visual factors in cognitive dysfunction and enhancement in Alzheimer’s disease. In Soraci S, MurataSoraci K, eds. Visual information processing. Westport: Praeger Publishers, 2003.

Lighting Res. Technol., 39,1 (2007) pp. 81–97

43 Cronin-Golomb A, Corkin S, Rizzo J, Cohen J, Banks K. Visual dysfunction in Alzheimer’s disease: relation to normal ageing. Ann. Neurology 1991; 29: 41–52. 44 Rizzo M, Anderson S, Dawson J, Nawrot M. Vision and cognition in Alzheimer’s disease. Neuropsychologia 2000; 38: 1157–69. 45 Butter C, Trobe J, Foster N, Berent S. Visualspatial defects explain visual symptoms in Alzheimer’s disease. Am. J. Ophthalmology 1996; 122(1): 97–105. 46 van Rhijn SJ, Glasser G, de Vries JJ, Clark CM, Newberg AB, Alavi A. Visual processing impairments and decrements in regional brain activity in Alzheimer’s disease. J. Clin. Experimental Neuropsychology 2004; 26(1): 11–23. 47 Mendez M, Cherrier M, Meadows R. Depth perception in Alzheimer’s disease. Percept. Motor Skills 1996; 83(3 Pt 1): 987–95. 48 Cernin PA, Keller BK, Stoner JA. Color vision in Alzheimer patients: can we improve object recognition with color cues? Ageing Neuropsychol. Cognition 2003; 10(4): 255–67. 49 Kitwood T, Bredin K. A new approach to the evaluation of dementia care. J. Adv. Health Nursing Care 1992; 1(5): 41–60. 50 Teri L, Logsdon R. Identifying pleasant activities of Alzheimer’s disease patients: the pleasant events schedule-AD. Gerontologist 1991; 31(1): 124–27. 51 Menec VH. The relation between everyday activities and successful ageing: a 6-year longitudinal study. J. Gerontol. B Psychol. Sci. Soc. Sci. 2003; 58(2): S74–82. 52 Fratiglioni L, Wang H-X, Ericsson K, Maytan M, Winblad B. Influence of social network on occurrence of dementia: a communitybased longitudinal study. Lancet 2000; 355: 1315–19. 53 Litwin H, Sharon S-E. The association between activity and well-being in later life: what really matters? Ageing Soc. 2006; 26(2): 225–42. 54 Passini R, Pigot H, Rainville C, Tetreault MH. Wayfinding in a Nursing Home for advanced dementia of the Alzheimer’s type. Environment Behav. 2000; 32(5): 684–710. 55 Barker RG. Ecological psychology: concepts and methods for studying the environment of

Lighting for people with dementia

56

57 58 59

human behaviour. Oxford: Oxford University Press, 1968. Tregenza PR, Lawson BR. Lighting criteria and meaning. In CIE/ARUP Symposium on visual environment April 24 and 25, 2002. The Royal Society London: Commission Internationale de l’Eclairage; 2002. Chaudhury H. Quality of life and place-therapy. J. Housing Elderly 2002; 17(1/2): 85–103. Barnes S. Space, choice and control and quality of life in care settings for older people. Sheffield: University of Sheffield, 2003. Tregenza PR. Measured and calculated frequency distributions of daylight illuminance. Lighting Res. Technol. 1986; 18(2): 71–74.

97

natural world and human activity is extremely important, for being isolated from these events is contrary to the normal human experience. Internal areas of strong daylight for bright light exposure coupled with dark sleeping areas at night are needed to reinforce circadian regulation and prevent sleep disorders, which negatively impact so many people living in care facilities. This natural solution should prove to be a better intervention to correct circadian rhythm disruption for people living with dementia than ‘‘light box’’ therapy, which requires an intellectual discipline that is beyond the abilities of people with dementia.

Discussion Comment on ‘Lighting Design Recommendations for People with Dementia’ by JM Torrington and PR Tregenza E Noell-Waggoner LC (Center of Design for an Aging Society, 9027 NW Bartholomew Drive, Portland, OR 97229, USA) It is my hope that this article will expand the awareness of owners/managers and the entire design team relative to issues beyond code compliance. This must happen if we are to truly serve those with dementia or mental impairment. People living with dementia experience their world on a sensory level and respond to it on an emotional basis. The emphasis on providing daylight and views to connect people living in care homes to the dynamics of the daily cycle of light and dark, changing weather, seasons of the year, the

Authors’ response to E Noell-Waggoner JM Torrington and PR Tregenza We are grateful for this comment. People with dementia tend to live in an environment with less sensory stimulation than people who are fortunate in not having a disabling disease. At an advanced stage of dementia a person’s surroundings tend to be so controlled by the requirements of physical care that he or she is almost denied the awareness and enlivening that comes from variation of light and dark, warm and cool, rough and smooth, and from many other sensory changes. It takes insight and imagination to design buildings that can enhance the enjoyment of life. This is true of architecture generally; but when the users have special needs a high level of creativity is necessary. It is not enough merely to satisfy code requirements.

Lighting Res. Technol., 39,1 (2007) pp. 81–97

Suggest Documents