Anthony Bloxham - Academia.edu (original) (raw)

Papers by Anthony Bloxham

Consciousness and cognition, Aug 1, 2024

Empirical investigations that search for a link between dreaming and sleep-dependent memory conso... more Empirical investigations that search for a link between dreaming and sleep-dependent memory consolidation have focused on testing for an association between dreaming of what was learned, and improved memory performance for learned material. Empirical support for this is mixed, perhaps owing to the inherent challenges presented by the nature of dreams, and methodological inconsistencies. The purpose of this paper is to address critically prevalent assumptions and practices, with the aim of clarifying and enhancing research on this topic, chiefly by providing a theoretical synthesis of existing models and evidence. Also, it recommends the method of Targeted Memory Reactivation (TMR) as a means for investigating if dream content can be linked to specific cued activations. Other recommendations to enhance research practice and enquiry on this subject are also provided, focusing on the HOW and WHY we search for memory sources in dreams, and what purpose (if any) they might serve.

Empirical investigations that search for a link between dreaming and sleep-dependent memory conso... more Empirical investigations that search for a link between dreaming and sleep-dependent memory consolidation have focused on testing for an association between dreaming of what was learned, and improved memory performance for learned material. Empirical support for this is mixed, perhaps owing to the inherent challenges presented by the nature of dreams, and methodological inconsistencies. The purpose of this paper is to address critically prevalent assumptions and practices, with the aim of clarifying and enhancing research on this topic, chiefly by providing a theoretical synthesis of existing models and evidence. Also, it recommends the method of Targeted Memory Reactivation (TMR) as a means for investigating if dream content can be linked to specific cued activations. Other recommendations to enhance research practice and enquiry on this subject are also provided, focusing on the HOW and WHY we search for memory sources in dreams, and what purpose (if any) they might serve.

British Journal of Psychology, Mar 7, 2022

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-... more This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

International Journal of Dream Research, Oct 1, 2014

Dreams can sometimes incorporate external sensory stimuli (e.g. sounds, smells and physical sensa... more Dreams can sometimes incorporate external sensory stimuli (e.g. sounds, smells and physical sensations) into their course and content, either directly or indirectly. This shows that the brain is still able to monitor, process, and perceive what is happening in the surrounding environment during sleep. This study, considered a pilot study due to only a small number of participants, aimed to examine stimulus incorporation in dreams using two auditory stimuli of different languages-one semantically meaningful to participants and one non-meaningful. We hypothesised that participants exposed to the semantically meaningful language would all report similar experiences to each other, and different from those exposed to the non-meaningful language. All participants first spent several weeks improving their dream recall abilities, and then came to the Sleep and Cognition Laboratory at the University of Lincoln for a two hour morning nap, during which a stimulus was played to them in Rapid-Eye-Movement (REM) sleep. They were awoken shortly after to provide a dream report. All dreams contained conversation or speech of some description, but due to participants' poor verbal memory for dream speech, we could not conclusively say that the stimuli were responsible for this effect. There were, however, at least two dreams with strong evidence to suggest that the stimuli were directly incorporated. Q-Methodology was used to assess similarity of dream experience. This resulted in three distinct factors: (1) calm, consistent, slightly emotional dreams; (2) emotional, normal, understandable dreams; and (3) unstable, inconsistent, unrealistic dreams. The configuration of factors amongst participants did not fully meet the predictions of the hypothesis; however, positive participant feedback on Q-sorting their dream experiences gives promise and potential for the use of Q-Methodology in future dream research. Future studies should employ an unstimulated control condition, train participants to improve verbal recall of dream speech, and ultimately, develop a theory of dreaming that includes a plausible explanation of external stimulus incorporation.

Frontiers in Nutrition, Sep 21, 2022

Sleep problems are extremely common in industrialized countries and the possibility that diet mig... more Sleep problems are extremely common in industrialized countries and the possibility that diet might be used to improve sleep has been considered. The topic has been reviewed many times, resulting in the frequent suggestion that carbohydrate increases the uptake of tryptophan by the brain, where it is metabolized into serotonin and melatonin, with the suggestion that this improves sleep. An alternative mechanism was proposed based on animal literature that has been largely ignored by those considering diet and sleep. The hypothesis was that, as in the hypothalamus there are glucose-sensing neurons associated with the sleep-wake cycle, we should consider the impact of carbohydrate-induced changes in the level of blood glucose. A metaanalysis found that after consuming a lower amount of carbohydrate, more time was spent in slow-wave sleep (SWS) and less in rapid-eye-movement sleep. As the credibility of alternative mechanisms has tended not to have been critically evaluated, they were considered by examining their biochemical, nutritional, and pharmacological plausibility. Although high carbohydrate consumption can increase the uptake of tryptophan by the brain, it only occurs with such low levels of protein that the mechanism is not relevant to a normal diet. After entering the brain tryptophan is converted to serotonin, a neurotransmitter known to influence so many different aspects of sleep and wakefulness, that it is not reasonable to expect a uniform improvement in sleep. Some serotonin is converted to melatonin, although the exogenous dose of melatonin needed to influence sleep cannot be credibly provided by the diet. This review was registered in the International Prospective Register of Systematic Reviews (CRD42020223560).

International Journal of Dream Research, Nov 1, 2018

Dream recall ability can vary between and within individuals, dependent on a number of infl uenci... more Dream recall ability can vary between and within individuals, dependent on a number of infl uencing factors, including personality dimensions, number of nocturnal awakenings, and attitudes towards dreaming. Only a few studies, however, consider the possible connection of dream recall ability to general waking memory ability, or the infl uence of being motivated to actively remember dreams. The present survey-based study had two major aims: 1) To search for correlates and relationships between memory for dreams and memory for waking experience; 2) To address the effect of motivation on dream recall ability, split for both dream recall frequency (DRF) and dream recall detail (DRD). These questions were assessed in 57 participants who completed an online survey, consisting of questions from the Mannheim Dream Questionnaire (MADRE) and a memory exercise for an original short story. DRF and DRD were positively related, but showed different patterns of relation with the other measures. Of most interest, participants who reported high DRD also remembered the most details from the story, suggestive of an overlap between waking and dream recall ability. However, this relationship was non-linear, as the lowest memory score came from the intermediate DRD group, not the low DRD group, hence a non-signifi cant correlation between DRD and score. DRF was unrelated to memory score, with no signifi cant differences between high and low DRF groups, and no signifi cant correlation between measures. This is likely due to the nature of the task being more compatible with memory for details. Correlations showed a consistent relationship between motivation and attitude measures, particularly the motivation to understand dreams. The most important points to be taken away from this study are: 1) there is apparent partial overlap between dream recall and waking memory for details; 2) being actively motivated to remember or understand dreams is an important variable to consider in future experiments; 3) and dream recall should be studied as its constituent parts of frequency and detail.

Current Developments in Nutrition

Objectives Carbohydrate is the nutrient most commonly said to influence sleep: it is proposed tha... more Objectives Carbohydrate is the nutrient most commonly said to influence sleep: it is proposed that a high intake increases the uptake of tryptophan by the brain, where it is metabolized into serotonin and melatonin. As this mechanism depends on the relative amount of carbohydrate and protein, studies were reviewed where diets differed in these macro-nutrients. Methods The Web of Science and Medline were interrogated using terms related to carbohydrate and sleep. Papers were retained if two diets, differing in the percentage of calories coming from carbohydrate, had been contrasted using either polysomnography or actigraphy. Measures considered with polysomnography included sleep onset time; sleep efficiency; rapid eye-movement (REM) and slow wave sleep (SWS). Measures examined from actigraphy included: sleep efficiency; duration of sleep. Meta-analysis was conducted using Review Manager 5.2 (Cochrane) using a random-effects model. Results With the polysomnography measures six studie...

International Journal of Dream Research, Oct 1, 2018

Dream recall ability can vary between and within individuals, dependent on a number of infl uenci... more Dream recall ability can vary between and within individuals, dependent on a number of infl uencing factors, including personality dimensions, number of nocturnal awakenings, and attitudes towards dreaming. Only a few studies, however, consider the possible connection of dream recall ability to general waking memory ability, or the infl uence of being motivated to actively remember dreams. The present survey-based study had two major aims: 1) To search for correlates and relationships between memory for dreams and memory for waking experience; 2) To address the effect of motivation on dream recall ability, split for both dream recall frequency (DRF) and dream recall detail (DRD). These questions were assessed in 57 participants who completed an online survey, consisting of questions from the Mannheim Dream Questionnaire (MADRE) and a memory exercise for an original short story. DRF and DRD were positively related, but showed different patterns of relation with the other measures. Of most interest, participants who reported high DRD also remembered the most details from the story, suggestive of an overlap between waking and dream recall ability. However, this relationship was non-linear, as the lowest memory score came from the intermediate DRD group, not the low DRD group, hence a non-signifi cant correlation between DRD and score. DRF was unrelated to memory score, with no signifi cant differences between high and low DRF groups, and no signifi cant correlation between measures. This is likely due to the nature of the task being more compatible with memory for details. Correlations showed a consistent relationship between motivation and attitude measures, particularly the motivation to understand dreams. The most important points to be taken away from this study are: 1) there is apparent partial overlap between dream recall and waking memory for details; 2) being actively motivated to remember or understand dreams is an important variable to consider in future experiments; 3) and dream recall should be studied as its constituent parts of frequency and detail.

British Journal of Psychology, 2022

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-... more This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

International Journal of Dream Research, 2018

Dream recall ability can vary between and within individuals, dependent on a number of influencin... more Dream recall ability can vary between and within individuals, dependent on a number of influencing factors, including personality dimensions, number of nocturnal awakenings, and attitudes towards dreaming. Only a few studies, however, consider the possible connection of dream recall ability to general waking memory ability, or the influence of being motivated to actively remember dreams. The present survey-based study had two major aims: 1) To search for correlates and relationships between memory for dreams and memory for waking experience; 2) To address the effect of motivation on dream recall ability, split for both dream recall frequency (DRF) and dream recall detail (DRD). These questions were assessed in 57 participants who completed an online survey, consisting of questions from the Mannheim Dream Questionnaire (MADRE) and a memory exercise for an original short story. DRF and DRD were positively related, but showed different patterns of relation with the other measures. Of m...

International Journal of Dream Research, Oct 1, 2014

Dreams can sometimes incorporate external sensory stimuli (e.g. sounds, smells and physical sensa... more Dreams can sometimes incorporate external sensory stimuli (e.g. sounds, smells and physical sensations) into their course and content, either directly or indirectly. This shows that the brain is still able to monitor, process, and perceive what is happening in the surrounding environment during sleep. This study, considered a pilot study due to only a small number of participants, aimed to examine stimulus incorporation in dreams using two auditory stimuli of different languages-one semantically meaningful to participants and one non-meaningful. We hypothesised that participants exposed to the semantically meaningful language would all report similar experiences to each other, and different from those exposed to the non-meaningful language. All participants first spent several weeks improving their dream recall abilities, and then came to the Sleep and Cognition Laboratory at the University of Lincoln for a two hour morning nap, during which a stimulus was played to them in Rapid-Eye-Movement (REM) sleep. They were awoken shortly after to provide a dream report. All dreams contained conversation or speech of some description, but due to participants' poor verbal memory for dream speech, we could not conclusively say that the stimuli were responsible for this effect. There were, however, at least two dreams with strong evidence to suggest that the stimuli were directly incorporated. Q-Methodology was used to assess similarity of dream experience. This resulted in three distinct factors: (1) calm, consistent, slightly emotional dreams; (2) emotional, normal, understandable dreams; and (3) unstable, inconsistent, unrealistic dreams. The configuration of factors amongst participants did not fully meet the predictions of the hypothesis; however, positive participant feedback on Q-sorting their dream experiences gives promise and potential for the use of Q-Methodology in future dream research. Future studies should employ an unstimulated control condition, train participants to improve verbal recall of dream speech, and ultimately, develop a theory of dreaming that includes a plausible explanation of external stimulus incorporation.

Frontiers in Nutrition

Sleep problems are extremely common in industrialized countries and the possibility that diet mig... more Sleep problems are extremely common in industrialized countries and the possibility that diet might be used to improve sleep has been considered. The topic has been reviewed many times, resulting in the frequent suggestion that carbohydrate increases the uptake of tryptophan by the brain, where it is metabolized into serotonin and melatonin, with the suggestion that this improves sleep. An alternative mechanism was proposed based on animal literature that has been largely ignored by those considering diet and sleep. The hypothesis was that, as in the hypothalamus there are glucose-sensing neurons associated with the sleep-wake cycle, we should consider the impact of carbohydrate-induced changes in the level of blood glucose. A meta-analysis found that after consuming a lower amount of carbohydrate, more time was spent in slow-wave sleep (SWS) and less in rapid-eye-movement sleep. As the credibility of alternative mechanisms has tended not to have been critically evaluated, they were...

Consciousness and cognition, Aug 1, 2024

Empirical investigations that search for a link between dreaming and sleep-dependent memory conso... more Empirical investigations that search for a link between dreaming and sleep-dependent memory consolidation have focused on testing for an association between dreaming of what was learned, and improved memory performance for learned material. Empirical support for this is mixed, perhaps owing to the inherent challenges presented by the nature of dreams, and methodological inconsistencies. The purpose of this paper is to address critically prevalent assumptions and practices, with the aim of clarifying and enhancing research on this topic, chiefly by providing a theoretical synthesis of existing models and evidence. Also, it recommends the method of Targeted Memory Reactivation (TMR) as a means for investigating if dream content can be linked to specific cued activations. Other recommendations to enhance research practice and enquiry on this subject are also provided, focusing on the HOW and WHY we search for memory sources in dreams, and what purpose (if any) they might serve.

Empirical investigations that search for a link between dreaming and sleep-dependent memory conso... more Empirical investigations that search for a link between dreaming and sleep-dependent memory consolidation have focused on testing for an association between dreaming of what was learned, and improved memory performance for learned material. Empirical support for this is mixed, perhaps owing to the inherent challenges presented by the nature of dreams, and methodological inconsistencies. The purpose of this paper is to address critically prevalent assumptions and practices, with the aim of clarifying and enhancing research on this topic, chiefly by providing a theoretical synthesis of existing models and evidence. Also, it recommends the method of Targeted Memory Reactivation (TMR) as a means for investigating if dream content can be linked to specific cued activations. Other recommendations to enhance research practice and enquiry on this subject are also provided, focusing on the HOW and WHY we search for memory sources in dreams, and what purpose (if any) they might serve.

British Journal of Psychology, Mar 7, 2022

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-... more This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

International Journal of Dream Research, Oct 1, 2014

Dreams can sometimes incorporate external sensory stimuli (e.g. sounds, smells and physical sensa... more Dreams can sometimes incorporate external sensory stimuli (e.g. sounds, smells and physical sensations) into their course and content, either directly or indirectly. This shows that the brain is still able to monitor, process, and perceive what is happening in the surrounding environment during sleep. This study, considered a pilot study due to only a small number of participants, aimed to examine stimulus incorporation in dreams using two auditory stimuli of different languages-one semantically meaningful to participants and one non-meaningful. We hypothesised that participants exposed to the semantically meaningful language would all report similar experiences to each other, and different from those exposed to the non-meaningful language. All participants first spent several weeks improving their dream recall abilities, and then came to the Sleep and Cognition Laboratory at the University of Lincoln for a two hour morning nap, during which a stimulus was played to them in Rapid-Eye-Movement (REM) sleep. They were awoken shortly after to provide a dream report. All dreams contained conversation or speech of some description, but due to participants' poor verbal memory for dream speech, we could not conclusively say that the stimuli were responsible for this effect. There were, however, at least two dreams with strong evidence to suggest that the stimuli were directly incorporated. Q-Methodology was used to assess similarity of dream experience. This resulted in three distinct factors: (1) calm, consistent, slightly emotional dreams; (2) emotional, normal, understandable dreams; and (3) unstable, inconsistent, unrealistic dreams. The configuration of factors amongst participants did not fully meet the predictions of the hypothesis; however, positive participant feedback on Q-sorting their dream experiences gives promise and potential for the use of Q-Methodology in future dream research. Future studies should employ an unstimulated control condition, train participants to improve verbal recall of dream speech, and ultimately, develop a theory of dreaming that includes a plausible explanation of external stimulus incorporation.

Frontiers in Nutrition, Sep 21, 2022

Sleep problems are extremely common in industrialized countries and the possibility that diet mig... more Sleep problems are extremely common in industrialized countries and the possibility that diet might be used to improve sleep has been considered. The topic has been reviewed many times, resulting in the frequent suggestion that carbohydrate increases the uptake of tryptophan by the brain, where it is metabolized into serotonin and melatonin, with the suggestion that this improves sleep. An alternative mechanism was proposed based on animal literature that has been largely ignored by those considering diet and sleep. The hypothesis was that, as in the hypothalamus there are glucose-sensing neurons associated with the sleep-wake cycle, we should consider the impact of carbohydrate-induced changes in the level of blood glucose. A metaanalysis found that after consuming a lower amount of carbohydrate, more time was spent in slow-wave sleep (SWS) and less in rapid-eye-movement sleep. As the credibility of alternative mechanisms has tended not to have been critically evaluated, they were considered by examining their biochemical, nutritional, and pharmacological plausibility. Although high carbohydrate consumption can increase the uptake of tryptophan by the brain, it only occurs with such low levels of protein that the mechanism is not relevant to a normal diet. After entering the brain tryptophan is converted to serotonin, a neurotransmitter known to influence so many different aspects of sleep and wakefulness, that it is not reasonable to expect a uniform improvement in sleep. Some serotonin is converted to melatonin, although the exogenous dose of melatonin needed to influence sleep cannot be credibly provided by the diet. This review was registered in the International Prospective Register of Systematic Reviews (CRD42020223560).

International Journal of Dream Research, Nov 1, 2018

Dream recall ability can vary between and within individuals, dependent on a number of infl uenci... more Dream recall ability can vary between and within individuals, dependent on a number of infl uencing factors, including personality dimensions, number of nocturnal awakenings, and attitudes towards dreaming. Only a few studies, however, consider the possible connection of dream recall ability to general waking memory ability, or the infl uence of being motivated to actively remember dreams. The present survey-based study had two major aims: 1) To search for correlates and relationships between memory for dreams and memory for waking experience; 2) To address the effect of motivation on dream recall ability, split for both dream recall frequency (DRF) and dream recall detail (DRD). These questions were assessed in 57 participants who completed an online survey, consisting of questions from the Mannheim Dream Questionnaire (MADRE) and a memory exercise for an original short story. DRF and DRD were positively related, but showed different patterns of relation with the other measures. Of most interest, participants who reported high DRD also remembered the most details from the story, suggestive of an overlap between waking and dream recall ability. However, this relationship was non-linear, as the lowest memory score came from the intermediate DRD group, not the low DRD group, hence a non-signifi cant correlation between DRD and score. DRF was unrelated to memory score, with no signifi cant differences between high and low DRF groups, and no signifi cant correlation between measures. This is likely due to the nature of the task being more compatible with memory for details. Correlations showed a consistent relationship between motivation and attitude measures, particularly the motivation to understand dreams. The most important points to be taken away from this study are: 1) there is apparent partial overlap between dream recall and waking memory for details; 2) being actively motivated to remember or understand dreams is an important variable to consider in future experiments; 3) and dream recall should be studied as its constituent parts of frequency and detail.

Current Developments in Nutrition

Objectives Carbohydrate is the nutrient most commonly said to influence sleep: it is proposed tha... more Objectives Carbohydrate is the nutrient most commonly said to influence sleep: it is proposed that a high intake increases the uptake of tryptophan by the brain, where it is metabolized into serotonin and melatonin. As this mechanism depends on the relative amount of carbohydrate and protein, studies were reviewed where diets differed in these macro-nutrients. Methods The Web of Science and Medline were interrogated using terms related to carbohydrate and sleep. Papers were retained if two diets, differing in the percentage of calories coming from carbohydrate, had been contrasted using either polysomnography or actigraphy. Measures considered with polysomnography included sleep onset time; sleep efficiency; rapid eye-movement (REM) and slow wave sleep (SWS). Measures examined from actigraphy included: sleep efficiency; duration of sleep. Meta-analysis was conducted using Review Manager 5.2 (Cochrane) using a random-effects model. Results With the polysomnography measures six studie...

International Journal of Dream Research, Oct 1, 2018

Dream recall ability can vary between and within individuals, dependent on a number of infl uenci... more Dream recall ability can vary between and within individuals, dependent on a number of infl uencing factors, including personality dimensions, number of nocturnal awakenings, and attitudes towards dreaming. Only a few studies, however, consider the possible connection of dream recall ability to general waking memory ability, or the infl uence of being motivated to actively remember dreams. The present survey-based study had two major aims: 1) To search for correlates and relationships between memory for dreams and memory for waking experience; 2) To address the effect of motivation on dream recall ability, split for both dream recall frequency (DRF) and dream recall detail (DRD). These questions were assessed in 57 participants who completed an online survey, consisting of questions from the Mannheim Dream Questionnaire (MADRE) and a memory exercise for an original short story. DRF and DRD were positively related, but showed different patterns of relation with the other measures. Of most interest, participants who reported high DRD also remembered the most details from the story, suggestive of an overlap between waking and dream recall ability. However, this relationship was non-linear, as the lowest memory score came from the intermediate DRD group, not the low DRD group, hence a non-signifi cant correlation between DRD and score. DRF was unrelated to memory score, with no signifi cant differences between high and low DRF groups, and no signifi cant correlation between measures. This is likely due to the nature of the task being more compatible with memory for details. Correlations showed a consistent relationship between motivation and attitude measures, particularly the motivation to understand dreams. The most important points to be taken away from this study are: 1) there is apparent partial overlap between dream recall and waking memory for details; 2) being actively motivated to remember or understand dreams is an important variable to consider in future experiments; 3) and dream recall should be studied as its constituent parts of frequency and detail.

British Journal of Psychology, 2022

This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-... more This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

International Journal of Dream Research, 2018

Dream recall ability can vary between and within individuals, dependent on a number of influencin... more Dream recall ability can vary between and within individuals, dependent on a number of influencing factors, including personality dimensions, number of nocturnal awakenings, and attitudes towards dreaming. Only a few studies, however, consider the possible connection of dream recall ability to general waking memory ability, or the influence of being motivated to actively remember dreams. The present survey-based study had two major aims: 1) To search for correlates and relationships between memory for dreams and memory for waking experience; 2) To address the effect of motivation on dream recall ability, split for both dream recall frequency (DRF) and dream recall detail (DRD). These questions were assessed in 57 participants who completed an online survey, consisting of questions from the Mannheim Dream Questionnaire (MADRE) and a memory exercise for an original short story. DRF and DRD were positively related, but showed different patterns of relation with the other measures. Of m...

International Journal of Dream Research, Oct 1, 2014

Dreams can sometimes incorporate external sensory stimuli (e.g. sounds, smells and physical sensa... more Dreams can sometimes incorporate external sensory stimuli (e.g. sounds, smells and physical sensations) into their course and content, either directly or indirectly. This shows that the brain is still able to monitor, process, and perceive what is happening in the surrounding environment during sleep. This study, considered a pilot study due to only a small number of participants, aimed to examine stimulus incorporation in dreams using two auditory stimuli of different languages-one semantically meaningful to participants and one non-meaningful. We hypothesised that participants exposed to the semantically meaningful language would all report similar experiences to each other, and different from those exposed to the non-meaningful language. All participants first spent several weeks improving their dream recall abilities, and then came to the Sleep and Cognition Laboratory at the University of Lincoln for a two hour morning nap, during which a stimulus was played to them in Rapid-Eye-Movement (REM) sleep. They were awoken shortly after to provide a dream report. All dreams contained conversation or speech of some description, but due to participants' poor verbal memory for dream speech, we could not conclusively say that the stimuli were responsible for this effect. There were, however, at least two dreams with strong evidence to suggest that the stimuli were directly incorporated. Q-Methodology was used to assess similarity of dream experience. This resulted in three distinct factors: (1) calm, consistent, slightly emotional dreams; (2) emotional, normal, understandable dreams; and (3) unstable, inconsistent, unrealistic dreams. The configuration of factors amongst participants did not fully meet the predictions of the hypothesis; however, positive participant feedback on Q-sorting their dream experiences gives promise and potential for the use of Q-Methodology in future dream research. Future studies should employ an unstimulated control condition, train participants to improve verbal recall of dream speech, and ultimately, develop a theory of dreaming that includes a plausible explanation of external stimulus incorporation.

Frontiers in Nutrition

Sleep problems are extremely common in industrialized countries and the possibility that diet mig... more Sleep problems are extremely common in industrialized countries and the possibility that diet might be used to improve sleep has been considered. The topic has been reviewed many times, resulting in the frequent suggestion that carbohydrate increases the uptake of tryptophan by the brain, where it is metabolized into serotonin and melatonin, with the suggestion that this improves sleep. An alternative mechanism was proposed based on animal literature that has been largely ignored by those considering diet and sleep. The hypothesis was that, as in the hypothalamus there are glucose-sensing neurons associated with the sleep-wake cycle, we should consider the impact of carbohydrate-induced changes in the level of blood glucose. A meta-analysis found that after consuming a lower amount of carbohydrate, more time was spent in slow-wave sleep (SWS) and less in rapid-eye-movement sleep. As the credibility of alternative mechanisms has tended not to have been critically evaluated, they were...