Research in Psychology and Behavioral Sciences
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Research in Psychology and Behavioral Sciences. 2014, 2(3), 54-58
DOI: 10.12691/rpbs-2-3-1
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Food for Thought: the Efficiency of Glucose Metabolism Predicts the Self-generation of Temporally Distant Cognition

Riby L.M.1, , Orme E.1, Greer J.1, Gillan A.1, Griffiths R.2, Aspray T.3, Scholey A.4 and Smallwood J.5

1Department of Psychology, Northumbria University, Newcastle upon Tyne, UK

2Sir Charles Gairdner Hospital, Perth, Western Australia

3Centre for Brain Ageing and Vitality, Newcastle University, UK

4Centre for Human Psychopharmacology, Swinburne University, Melbourne, Australia

5Department of Psychology, University of York, UK

Pub. Date: August 18, 2014

Cite this paper:
Riby L.M., Orme E., Greer J., Gillan A., Griffiths R., Aspray T., Scholey A. and Smallwood J.. Food for Thought: the Efficiency of Glucose Metabolism Predicts the Self-generation of Temporally Distant Cognition. Research in Psychology and Behavioral Sciences. 2014; 2(3):54-58. doi: 10.12691/rpbs-2-3-1


The generation of thought independent of environmental input occupies almost half of mental life and is important for skills such as creativity and planning. To understand how this ubiquitous cognitive process relates to the brain's ‘energy budget’, a cross-sectional study is carried out to examine how the capacity for mental time travel relates to the efficiency with which adults metabolize glucose, the brain’s primary source of fuel. On day 1 the ability of a group of 36 younger and 36 older individuals to metabolize glucose was assessed using the gold standard two-hour glucose tolerance test. Twenty-four hours later, the same group of participants returned to the laboratory to perform a non-demanding choice reaction time task during which experience sampling was used to assess the frequency with which they generated thoughts that were unrelated to the here and now. Analysis indicated that younger individuals who were the most efficient at metabolizing glucose exhibited mental time travel that spanned longer time periods. Given the importance of self-generated thought in daily life these results suggest that the capacity to mentally simulate events not present in the immediate environment is highly dependent on efficient glucose metabolism.

glucose glucose tolerance mind wandering; attention cognition self-generated thought

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[1]  Killingsworth, M. A., & Gilbert, D. T. A Wandering Mind is an Unhappy Mind. Science, 330, 932. 2010.
[2]  Smallwood, J. Distinguishing how from why the mind wanders: a process-occurrence framework for self-generated thought. Psychological Bulletin, 139, 519-535. 2013.
[3]  Tulving, E. Episodic Memory: From Mind to Brain. Annual Review of Psychology, 51, 1-25. 2002.
[4]  Baird, B., Smallwood, J., Mrazek, M. D., Kam, J. W. Y., Franklin, M. S., & Schooler, J. W. Inspired by Distraction: Mind Wandering Facilitates Creative Incubation. Psychological Science, 23, 1117-1122. 2012.
[5]  Smallwood, J., Ruby, F. J. M., & Singer, T. Letting go of the present: Mind-wandering is associated with reduced delay discounting. Consciousness and Cognition, 22, 1-7. 2013.
[6]  Baird, B., Smallwood, J., & Schooler, J. W. Back to the future: Autobiographical planning and the functionality of mind-wandering. Consciousness and Cognition, 20 (4), 1604-1611. 2011.
[7]  Barron, E., Riby, L. M., Greer, J., & Smallwood, J. Absorbed in Thought: The Effect of Mind Wandering on the Processing of Relevant and Irrelevant Events. Psychological Science, 22 (5), 596-601. 2011.
[8]  Smallwood, J., Schooler, J. W., Turk, D. J., Cunningham, S. J., Burns, P., & Macrae, C. N. Self-reflection and the temporal focus of the wandering mind. Consciousness and Cognition, 20 (4), 1120-1126. 2011.
[9]  Levinson, D. B., Smallwood, J., & Davidson, R. J. The Persistence of Thought Evidence for a Role of Working Memory in the Maintenance of Task-Unrelated Thinking. Psychological Science, 23 (4), 375-380. 2011.
[10]  Christoff, K., Gordon, A., Smallwood, J., Smith, R., & Schooler, J. W. Experience sampling during fMRI reveals default network and executive system contributions to mind wandering. Proceedings of the National Academy of Sciences, USA, 106, 8719-8724. 2009.
[11]  Mason, M. F., Norton, M. I., Van Horn, J. D., Wegner, D. M., Grafton, S. T., & Macrae, C. N. Wandering Minds: The Default Network and Stimulus-Independent Thought. Science, 315 (5810), 393-395. 2007.
[12]  Stawarczyk, D., Majerus, S., Maquet, P., & D'Argembeau, A. Neural Correlates of Ongoing Conscious Experience: Both Task-Unrelatedness and Stimulus-Independence Are Related to Default Network Activity. Plos ONE 6 (2), e16997. 2011.
[13]  Riby, L. M., & Riby, D. M. Glucose, ageing and cognition: the hippocampus hypothesis.In Ballesteros S (Ed). Pp 79-92. Age, Cognition and Neuroscience/Envejecimiento, Cognicio´n y Neurociencia, UNED, Varia: Madrid. 2006.
[14]  Smith, M. A., Riby, L. M., van Eekelen, J. A. M., & Foster, J. K. Glucose enhancement of human memory: A comprehensive research review of the glucose memory facilitation effect. Neuroscience and Biobehavioural Reviews, 35 (3), 770-783. 2011.
[15]  Messier, C., Awad-Shimoon, N., Gagnon, M., Desrochers, A., & Tsiakas, M. Glucose regulation is associated with cognitive performance in young nondiabetic adults. Behavioural Brain Research, 222 (1), 81-88. 2011.
[16]  Riby, L. M., McLaughlin, J.,Riby, D. M. & Graham, C. Lifestyle, glucose regulation and the cognitive effects of glucose load in middle-aged adults. British Journal of Nutrition, 100, 1128. 2008.
[17]  Smith, M. A., & Foster, J. K. Glucoregulartory and order effects on verbal episodic memory in healthy adolescents after oral glucose administration. Biological Psychology, 79, 209-215. 2008.
[18]  Smith, M. A., Riby, L. M., Sünram-Lea, S. I., Van Eekelen, J. A. M., & Foster, J. K. Glucose modulates event-related potential components of recollection and familiarity in healthy adolescents. Psychopharmacology, 205, 11-20. 2009.
[19]  Smith, M. A., Hii, H. L., Foster, J. K., & van Eekelen, J. A. M. Glucose enhancement of memory is modulated by trait anxiety in healthy adolescent males. Journal of Psychopharmacology, 60-70. 2011.
[20]  Riby, L. M., Marriott, A., Bullock, R., Hancock, J., Smallwood, J., & McLaughlin, J. The effects of glucose ingestion and glucose regulation on memory performance in older adults with mild cognitive impairment. European Journal of Clinical Nutrition 63, 566-571. 2009.
[21]  Awad, N., Gagnon, M., & Messier, C. The Relationship Between Impaired Glucose Tolerance, Type 2 Diabetes, and Cognitive Function. Journal of Clinical and Experimental Neuropsychology, 26 (8), 1044-1080. 2004.
[22]  Riby, L. M., Meikle, A., & Glover, C. The effects of age, glucose ingestion and gluco-regulatory control on episodic memory. Age and Ageing, 33 (5), 483-487. 2004.
[23]  Riby, L.M. The impact of age and task domain on cognitive performance: A meta-analytic review of the glucose facilitation effect. Brain Impairment (Cognitive Ageing Special Issue) 5, 145-165. 2004.
[24]  Giambra, L. M. Task-unrelated thought frequency as a function of age: A laboratory study. Psychology and Aging 4 (2), 136-143. 1989.
[25]  Giambra, L. M. The influence of aging on spontaneous shifts of attention from external stimuli to the contents of consciousness. Experimental Gerontology, 28 (4-5), 485-492. 1993.
[26]  McVay, J. C., Meier, M. E., Touron, D. R., & Kane, M. J. Aging ebbs the flow of thought: Adult age differences in mind wandering, executive control, and self-evaluation. Acta Psychologica, 142, 136-147. 2013.
[27]  Jackson, J. D., & Balota, D. A. Mind-wandering in younger and older adults: Converging evidence from the sustained attention to response task. Psychology and Aging, 27 (1), 106-119. 2012.
[28]  Wagner, U., Degirmenci, M., Drosopoulos, S., Perras, B., & Born, J. Effects of Cortisol Suppression on Sleep-Associated Consolidation of Neutral and Emotional Memory. Biological Psychiatry, 58 (11), 885-893. 2005.
[29]  Buckner, R. L., Andrews-Hanna, J. R., & Schacter, D. L. The Brain’s Default Network; Anatomy, Function, and Relevance to Disease. Annals of the New York Academy of Sciences, 1124, 1-38. 2008.
[30]  Harrison, B. J., Pujol, J., López-Solà, M., Hernández-Ribas, R., Deus, J., Ortiz, H., Soriano-Mas, C., Yücel, M., Pantelis, C., & Cardoner, N. Consistency and functional specialization in the default mode brain network. PNAS, 115 (28), 9781-9786. 2008.
[31]  Immordino-Yang, M.H., Christodoulou, J.A. & Singh, V. Rest Is Not Idleness:Implications of the Brain’s Default Mode for Human Development and Education, Perspectives on Psychological Science, 7 (4), 352-364. 2012.
[32]  Hagger, M. S., Wood, C., Stiff, C., & Chatzisarantis, N. L. Ego depletion and the strength model of self-control: a meta-analysis. Psychological Bulletin, 136 (4), 495. 2010.
[33]  Bernhardt, B. C., Smallwood, J., Tusche, A., Ruby, F., Engen, H., Steinbeis, N., & Stinger, T Medial prefrontal and anterior cingulate cortical thickness predicts shared individual differences in self-generated thought and temporal discounting. Neuroimage.
[34]  Gailliot, M. T., & Baumeister, R. F. The physiology of willpower: Linking blood glucose to self-control. Personality and Social Psychology Review, 11, 303-327. 2007.