Light therapy for seasonal and nonseasonal depression: efficacy, protocol, safety, and side effects

Bright light therapy for seasonal affective disorder (SAD) has been investigated and applied for over 20 years. Physicians and clinicians are increasingly confident that bright light therapy is a potent, specifically active, nonpharmaceutical treatment modality. Indeed, the domain of light treatment is moving beyond SAD, to nonseasonal depression (unipolar and bipolar), seasonal flare-ups of bulimia nervosa, circadian sleep phase disorders, and more. Light therapy is simple to deliver to outpatients and inpatients alike, although the optimum dosing of light and treatment time of day requires individual adjustment. The side-effect profile is favorable in comparison with medications, although the clinician must remain vigilant about emergent hypomania and autonomic hyperactivation, especially during the first few days of treatment. Importantly, light therapy provides a compatible adjunct to antidepressant medication, which can result in accelerated improvement and fewer residual symptoms.     

Religious Experience,Religious Worldviews,and Near-Death Studies

The tense relation prevailing between representatives of conservative religion and other near-death researchers may be illumined by a look at the different functions religion has fulfilled in the past. Religion may be seen as centering on the meaningfulness of the world, on spiritual experience, or on salvation. In this essay, I sketch the place of these themes in the Great Religions. These themes have inherent mutual tensions that in the case of Christianity cannot necessarily be settled by appeal to the Bible, because different Christian groups have somewhat differing views of the source of authority. Furthermore, the Bible's authority is challenged by the results of modern scholarship. In light of these reflections, I see Michael Sabom's Light & Death (1998) as showing valuable data and insights but failing to respond to significant challenges.     

Using a modified Stroop task to implicitly discern the cognitive organization of alcohol expectancies

Alcohol expectancies have been statistically modeled as memory networks that influence future consumption. To test the organization of expectancies suggested by these models, a modified Stroop color-naming task incorporated expectancy words associated in past research with heavy and light drinking. Light and heavy drinkers ink-named expectancy targets after being cued with an alcohol beverage word or a nonalcohol beverage word. Consistent with predictions derived from statistical models, heavy drinkers displayed significant interference when arousing expectancy words had been primed by an alcohol beverage word, whereas light drinkers displayed significant interference when sedating expectancy targets had been so primed. These results reinforce the idea that mediation o falcohol use by expectancies may be implicit as well as explicit.     

Bright light treatment has limited effect in subjects over 55 years with mild early morning awakening

31 subjects, age 55 yr. or older, suffering from mild early morning awakening were randomized to either a bright light (10,000 lux) or to a red dim light placebo condition (200 lux). Light exposure took place in the evening in the patients' homes, 60 to 30 min. before bedtime and lasted for 3 wk. The subjects kept a sleep diary for 2 wk. and wore an actigraph for 1 wk. both before treatment and at post-treatment. Of the eight sleep diary outcome variables, significant effects that could be attributed to the light treatment were only detected for time spent in bed after final morning awakening. None of the six actigraph outcome variables yielded any significant effect of the light therapy. Explanations for the limited therapeutic effects of bright light treatment obtained in the present study are discussed, such as the criteria defining early morning awakening, the selection procedure, problems with compliance, age of the sample, and the dose of light. The lack of an objective circadian marker in this study could represent a problem concerning the timing of the light exposure. Despite the limited success of bright light therapy in this study, bright light therapy should still be considered as a treatment option for early morning awakening.     

光照对小鸡脑内神经细胞粘附分子表达的影响

胚胎发育晚期光照条件的不同,对小鸡后天的学习记忆能力有显著的影响,暗孵化小鸡表现出明显的长时记忆障碍。实验利用免疫组化的方法,分别对光孵化、正常孵化和暗孵化条件下,胚胎发育的第17、18、19、20、21天,小鸡脑内上纹体腹核(HV)中神经细胞粘附分子(NCAMs)的表达进行了观察。结果表明：暗孵化条件下孵出的小鸡,在一次性被动回避学习中,记忆保持水平显著低于光孵化组和正常孵化组;在胚胎发育的第20天NCAM的表达,在光孵化组和正常孵化组中显著增高,到胚胎发育的第21天,这种升高在正常孵化组中显著下降;而暗孵化组在整个观察过程中,NCAM表达水平一直非常低。这一结果提示,不同光照条件在孵化过程中,对NCAM表达的影响,参与了光照对小鸡后天学习记忆行为改变的过程。     

Effects of Dark Rearing and Light Exposure on Memory for a Passive Avoidance Task in Day-Old Chicks

Light exposure during embryogenesis is necessary for functional and morphological maturation in the domestic chick. In the present study, dark incubation was demonstrated to induce a weak amnestic effect on retention for a passive avoidance task and a diminution in discriminative memory ability in day-old chicks. Putative explanations based on possible motor, attentional, or visual impairment were excluded. Light exposure of dark-reared eggs, specifically during embryonic days E19 to E20, alleviated the retention and discrimination deficits. The processes which might mediate between prehatch light stimulation and posthatch behavioral effects are discussed.     

Light as a Solution to Puzzles AboutLight

Light is puzzling in modern physics–witness wave-particle duality, the two-slit experiment, and the invariant speed of light. These puzzles are not intrinsic to light but arise from overly narrow views of light. Disregarding the expansive, unitary nature of light that informs everyday experience, modern physics treats light as if it were self-bounded and separable. Further, physics assumes that light is not complicit with observations of light, that the two are separable. By likening light to light-illuminated entities, these attitudes set the stage for puzzles. When,however, conceptions of light are aligned with visual experience, those puzzles become occasions of understanding.This is because visual experience already embodies that aspect of light which physics finds so anomalous: nonseparability. Light's interactive vastness shows up wherever light shows up, and because no observer can back away from light or step outside its integrative embrace, different parts of light (photons) cannot be lifted out ofthe observation as distinct – i.e., distinctly-observed – entities. This revised version was published online in August 2006 with corrections to the Cover Date.     

The two-flash threshold: An evaluation of critical-duration and visual-persistence hypotheses

The two-flash threshold is reduced by increasing the duration of both pulses of light or light adapting the eye. Increasing the duration of the first pulse also decreases the two-flash threshold, contrary to what a critical-duration explanation of the threshold would predict. Decreasing the duration of the second pulse increases the threshold when the second pulse is very brief. Light adapting the eye under such conditions serves to increase the two-flash threshold, unlike the effect adaptation has when a long second pulse is used.     

A Light Theory with Heavy Burdens

In “ A Light Theory of Color”, Walter Sinnott-Armstrong and David Sparrow argue that color is neither a primary quality of objects, nor a disposition that objects have, nor a property of our visual fields. Rather, according to the view they present, color is a property of light. The present paper aims to show, first, that the light theory is vulnerable to many of the very same objections that Sinnott-Armstrong and Sparrow raise against rival views. Second, the paper argues that the strategies that Sinnott-Armstrong and Sparrow use to avoid certain objections are also available to proponents of rival accounts. This might only seem to show that the light theory is in the same shaky boat as other theories: suffering from the same problems but having the same tools for solving them. The paper concludes with a suggestion as to why this is not the case, but why the existence of the light theory is nevertheless likely to bring increased clarity to the debate about color realism.     

The near-death experience: An ancient truth,a modern mystery

The near-death experience (NDE), as an experience of whole-ness, an adventure in consciousness, and a metaphoric encounter with light, links theoretical physics with the occult, the Primordial Tradition, and various religious belief systems. Light as image, vehicle, and first cause ties the NDE to mystical experience. Where science sees mystery, religion sees metaphoric truth; the NDE as spiritual quest and physical encounter beckons to both disciplines for explanation.International Association for Near-Death StudiesDr. Fenske is President of the International Association for Near-Death Studies, and is engaged in the private practice of psychotherapy and the integration of psychology and religion. This paper is a revised version of her keynote lecture presented at the International Association for Near-Death Studies First Annual Conference, Rosemont, PA, June 1989.     

The relationship of television viewing to physical fitness and obesity

The purpose of this study was to determine the extent to which light, moderate, and heavy television viewing relates to multiple measures of obesity and physical fitness among 379 high school males. The Body Mass Index and Tucker's Perceived Somatotype Scale were employed to assess obesity; physical fitness was measured by six tests: pushups, pullups, sidestep, long jump, situps, and jog-walk. Results showed that light television viewers scored significantly better than heavy viewers on a composite fitness index and on pushups, pullups, sidestep, situps, and jog-walk considered individually. Similarly, light viewers performed better than moderate viewers on the composite fitness measure and on pushups, pullups, and jog-walk. Light viewers displayed a strong tendency toward better fitness than moderate viewers on the long jump, situps, and sidestep tests, although statistical significance was not attained. Light viewers were not significantly less obese than moderate or heavy viewers. Statistical control of the demographic variables, applied simultaneously, had little influence on the associations found in this study. The findings indicate that for purposes of good physical fitness, television viewing should be limited to one hour or less per day.     

Operant responding in Siamese fighting fish (Betta splendens) as a function of schedule of reinforcement and visual reinforcers

Siamese fighting fish were trained to emit an operant response that was reinforced by the opportunity to view a motion picture film image of another fish. Performance under various schedules of reinforcement was examined. When reinforcement followed every response and when reinforcement was delivered after every second response, the number of responses per session was higher than during operant level or during extinction. Reinforcement delivered following intervals of no responding (differential reinforcement of other behavior) markedly decreased responding. Light from a projector without film was found to be as effective a reinforcer as film reinforcement. Responding when projector light reinforcement followed every response was maintained at approximately the same level as that obtained under film reinforcement. Responses per session decreased when only the light was delivered on a differential-reinforcement-of-other-behavior schedule. The behavior of the fish during presentation of the film was markedly different from their behavior while the projector light was being presented.     

环境光照的认知功效及其调节因素与作用机理

自人类视网膜上发现存在新型的内在光敏感神经节细胞以来, 环境光照对个体生理心理功能的非视觉作用备受研究者青睐, 其中环境光照对认知功能的非视觉作用结果并不十分一致且内在机理尚不明确。环境光照的认知功效会受到光学参数、光照模式、时间因素、个体差异以及任务特征等的共同调节。未来的研究需要从环境光对心理认知功能的作用模式, 动态办公照明系统的开发, 面向特殊群体的个性化照明以及光照非视觉作用产生的分子生物学机制等视角进行扩展和深化。     

Neural correlates of Pavlovian conditioning in components of the neural network supporting ciliary locomotion in Hermissenda

Pavlovian conditioning in Hermissenda consists of pairing light, the conditioned stimulus (CS) with activation of statocyst hair cells, the unconditioned stimulus (US). Conditioning produces CS-elicited foot shortening and inhibition of light-elicited locomotion, the two conditioned responses (CRs). Conditioning correlates have been identified in the primary sensory neurons (photoreceptors) of the CS pathway, interneurons that receive monosynaptic input from identified photoreceptors, and putative pedal motor neurons. While cellular mechanisms of acquisition produced by the synaptic interaction between the CS and US pathways are well-documented, little is known about the mechanisms responsible for the generation or expression of the CR. Here we show that in conditioned animals light reduced tonic firing of ciliary activating pedal neurons (VP1) below their pre-CS baseline levels. In contrast, pseudorandom controls expressed a significant increase in CS-elicited tonic firing of VP1 as compared to pre-CS baseline activity. Identified interneurons in the visual pathway that have established polysynaptic connections with VP1 were examined in conditioned animals and pseudorandom controls. Depolarization of identified type I_e interneurons with extrinsic current elicited a significant increase in IPSPs recorded in VP1 pedal neurons of conditioned animals as compared with pseudorandom controls. Conditioning also enhanced intrinsic excitability of type I_e interneurons of conditioned animals as compared to pseudorandom controls. Light evoked a modest increase in IPSP frequency in VP1 of conditioned preparations and a significant decrease in IPSP frequency in VP1 of pseudorandom controls. Our results show that a combination of synaptic facilitation and intrinsic enhanced excitability in identified components of the CS pathway may explain light-elicited inhibition of locomotion in conditioned animals.     

Asymmetrical retention functions for sequences of light flashes or tone bursts in the rat

In Experiment 1, rats were trained in a symbolic delayed matching-to-sample task to discriminate sample stimuli that consisted of sequences of magazine light flashes. The intertrial interval was illuminated by the houselight for Group Light, and it was dark for Group Dark. Retention functions exhibited a choose-many response bias when the delay interval was illuminated by the houselight in both groups, and no consistent response bias when the delay interval was dark. In Experiment 2, rats were trained to discriminate sample stimuli that consisted of sequences of tone bursts. During delay testing, a different tone (i.e., different frequency and location than the sample tone) was present or absent during the delay interval. The retention functions exhibited a significant choose-many bias when tone was present during the delay and a choose-few bias when tone was absent. Asymmetrical retention functions for tone burst and light flash sequences are due to the similarity between the stimulus conditions of the delay interval and the modality of the sequential event being discriminated. These results are consistent with an instructional ambiguity explanation of response biases in memory for number.     

Lighting up cosy atmospheres in Denmark

This article explores the use of light to stage atmospheres in a residential area of Copenhagen, Denmark. Both natural and electrical lights enable visibility but they also impart a certain sense of place that influences the way people behave and feel. The article investigates how light is about more than individual perception and plays a crucial role in orchestrating a sense of community, solitude and ‘secureness’ at home. Such staging of atmospheres, it is argued, importantly relies on cultural premises and notions of intimacy, informality and relaxation, encompassed in the Danish term hygge, or cosiness. Light frames such sense of secureness and cosiness by allowing for visual oscillations between separation and connection of people, places and things. In this way, investigating the use of light in shaping atmosphere offers a lens to explore how connections and networks of people, emotions and things, shape the home and links interior and exterior spaces.     

LIGHT INTENSITY AND PERCEPTION OF THE VERTICAL

N yborg H. Light intensity and perception of the vertical: Two experiments with the Rod-and-Frame Test. Scand. J. Psychol ., 1972, 13 , 314–326.—Radical changes in light intensity of the visual field did not influence perception of the vertical appreciably as tested by means of a modified Rod-and-Frame Test apparatus in which the illumination of the rod and frame or of the frame alone was changed. Large individual differences in response to the Rod-and-Frame Test were found but little effect of changes in light intensity. A hypothesis that field dependent subjects would be more influenced than field independent by changes in light intensity of the rod and/or the frame was rejected.     

But for the bad, there would not be good: Grounding valence in brightness through shared relational structures

Light and dark are used pervasively to represent positive and negative concepts. Recent studies suggest that black and white stimuli are automatically associated with negativity and positivity. However, structural factors in experimental designs, such as the shared opposition in the valence (good vs. bad) and brightness (light vs. dark) dimensions might play an important role in the valence-brightness association. In 6 experiments, we show that while black ideographs are consistently judged to represent negative words, white ideographs represent positivity only when the negativity of black is coactivated. The positivity of white emerged only when brightness and valence were manipulated within participants (but not between participants) or when the negativity of black was perceptually activated by presenting positive and white stimuli against a black (vs. gray) background. These findings add to an emerging literature on how structural overlap between dimensions creates associations and highlight the inherently contextualized construction of meaning structures.