Meera Modi, Pursuer of Wisdom
Originally published May 2008.
Buzz. Buzz. Buzz. Groggily open your eyes. Stumble out of bed. Brush your teeth. Get dressed. Step out of your front door. Only to realize you forgot to put on your pants. And there you are standing in your undies on your front step with a bus stop full of giggling grade-schoolers across the street. BUZZ. BUZZ. BUZZ. You wake up, fully clothed in your own bed. It was only a dream. Most people are unable to differentiate a dream world from the physical world while dreaming. It is striking that often the only way to determine that a given set of experiences are in fact a dream is to wake up. Following this logic, one wonders if one was never to wake up, would you ever know that the preceding experiences were only a dream? This dilemma has led philosophers throughout time to postulate that given our perception of the world is the same in dreams and in reality at the moment we perceive them, we may always be dreaming.
Philosophers from Plato to Aristotle to the Eastern philosopher Zhuangzi and Rene Descartes all have in some formed proposed the “Dream Hypothesis”: that there is uncertainty in trusting our senses to distinguish between the dream state and the awake state and consequently we can never be certain of in which state we exist. Descartes believed that this doubt came from two observations. One, that everything he sensed while awake he believed he could also sense while dreaming. And since he knew that his dream senses were not activated by external stimuli, there was Meera Modi no way to be certain that his wakeful senses were aroused any differently. And two, if he could not truly account for his origin, there is no way to determine in which realm he actually existed.
In lieu philosophers of modern psychologists have tried to directly investigate the differences between the cognitive dream state and the cognitive awake state. A systematic assessment of the cognitive, metacognitive and emotional qualities of recent waking and dreaming episodes concluded that qualitatively the two experiences are very similar. Dreams contain the same higher-order cognition as awake experiences, such as attentional processes, internal commentary and public selfconsciousness. However the two states differed in recollections of choice, eventrelated self-reflection and affect.
Our senses deceive us not only in dreams but also in hallucinations. An fMRI investigation of a schizophrenic individual experiencing a visual hallucination showed increased brain activity in the visual areas that corresponded to the content of the hallucination. Neuroscientists have yet to capture the dreaming state using fMRI but based on the similarities expressed in the dream recollection and the activation patterns seen in visual hallucinations, one could rationally hypothesize that in terms of our sensory processing, the dream state is the same as the awake state. BUZZ. BUZZ. BUZZ.
For further reading:
Descartes, Rene “Meditations on First Philosophy (Meditation Six)”
Kahan TL, LaBerge S, Levitan L, Zimbardo P. (1997) Similarities and differences between dreaming and waking cognition: an exploratory study. : Conscious Cogn. Mar;6 (1):132-47
Oertel V, Rotarska-Jagiela A, van de Ven VG, Haenschel C, Maurer K, Linden DE. (2007) Visual hallucinations in schizophrenia investigated with functional magnetic resonance imaging. Psychiatry Res. Dec 15;156(3):269-73.