Psychology Sleep And Dreaming Revision

[Queila Neubecker]

Acondition of body and mind which typically recurs for several hours every night, in which the nervous system is inactive, the eyes closed, the postural muscles relaxed, and consciousness practically suspended.

REM is the deepest stage of sleep and people spend approx. 2 hours dreaming during REM sleep. Characteristics of this stage include: Irregular breathing, Eyes jerking, Movement inhibition (paralysed muscles), an increase in heart rate and blood pressure and dreaming. Also, individuals experience sensory blockade which is when all incoming sensory information is stopped.

Your hormones can affect this cycle. When we are under stress, a hormone called adrenocortiotropic hormone (ACTH) is released from your pituitary gland which makes you feel more alert and releases cortisol. This interferes with your SCN trying to make its circadian rhythm.

Procedure: Siffre went into a cave in USA on 14th February 1972. He had a tent on a wooden platform, with a bed, a table and a chair. He had frozen food to eat and enough water to sustain him. Siffre completed different task such as:

Anxieties are repressed in the unconscious mind (an inaccessible part of the brain that holds hidden wishes and desires). This is different to the conscious (being consciously aware) and the pre-conscious/subconscious (being made consciously aware through thinking).

Dreams and their associated meanings vary across different cultures and periods of time. By the late 19th century, German psychiatrist Sigmund Freud had become convinced that dreams represented an opportunity to gain access to the unconscious. By analyzing dreams, Freud thought people could increase self-awareness and gain valuable insight to help them deal with the problems they faced in their lives. Freud made distinctions between the manifest content and the latent content of dreams.

Freud was not the only theorist to focus on the content of dreams. The 20th century Swiss psychiatrist Carl Jung believed that dreams allowed us to tap into the collective unconscious. The collective unconscious, as described by Jung, is a theoretical repository of information he believed to be shared by everyone. According to Jung, certain symbols in dreams reflected universal archetypes with meanings that are similar for all people regardless of culture or location.

One prominent neurobiological theory of dreaming is the activation-synthesis theory. According to this theory, dreams are electrical brain impulses that pull random thoughts and imagery from our memories. The theory posits that humans construct dream stories after they wake up, in a natural attempt to make sense of the nonsensical. However, given the vast documentation of the realistic aspects of human dreaming, as well as indirect experimental evidence that other mammals such as cats also dream, evolutionary psychologists have theorized that dreaming does indeed serve a purpose.

The continual-activation theory proposes that dreaming is a result of brain activation and synthesis. Dreaming and REM sleep are simultaneously controlled by different brain mechanisms. The hypothesis states that the function of sleep is to process, encode, and transfer data from short-term memory to long-term memory through a process called consolidation. However, there is not much evidence to back this up. NREM sleep processes the conscious-related memory (declarative memory), and REM sleep processes the unconscious related memory (procedural memory).

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The paradigmatic assumption that REM sleep is the physiological equivalent of dreaming is in need of fundamental revision. A mounting body of evidence suggests that dreaming and REM sleep are dissociable states, and that dreaming is controlled by forebrain mechanisms. Recent neuropsychological, radiological, and pharmacological findings suggest that the cholinergic brain stem mechanisms that control the REM state can only generate the psychological phenomena of dreaming through the mediation of a second, probably dopaminergic, forebrain mechanism. The latter mechanism (and thus dreaming itself) can also be activated by a variety of nonREM triggers. Dreaming can be manipulated by dopamine agonists and antagonists with no concomitant change in REM frequency, duration, and density. Dreaming can also be induced by focal forebrain stimulation and by complex partial (forebrain) seizures during nonREM sleep, when the involvement of brainstem REM mechanisms is precluded. Likewise, dreaming is obliterated by focal lesions along a specific (probably dopaminergic) forebrain pathway, and these lesions do not have any appreciable effects on REM frequency, duration, and density. These findings suggest that the forebrain mechanism in question is the final common path to dreaming and that the brainstem oscillator that controls the REM state is just one of the many arousal triggers that can activate this forebrain mechanism. The "REM-on" mechanism (like its various NREM equivalents) therefore stands outside the dream process itself, which is mediated by an independent, forebrain "dream-on" mechanism.

Dreams and dreaming have been discussed in diverse areas of philosophyranging from epistemology to ethics, ontology, and more recentlyphilosophy of mind and cognitive science. This entry provides anoverview of major themes in the philosophy of sleep and dreaming, witha focus on Western analytic philosophy, and discusses relevantscientific findings.

There are different ways of construing the dream argument. A strongreading is that Descartes is trapped in a lifelong dream and none ofhis experiences have ever been caused by external objects (theAlways Dreaming Doubt; see Newman 2019). A weaker reading isthat he is just sometimes dreaming but cannot rule out at any givenmoment that he is dreaming right now (the Now Dreaming Doubt;see Newman 2019). This is still epistemologically worrisome: eventhough some of his sensory-based beliefs might be true, he cannotdetermine which these are unless he can rule out that he is dreaming.Doubt is thus cast on all of his beliefs, making sensory-basedknowledge slip out of reach.

Importantly, both strong and weak versions of the dream argument castdoubt only on sensory-based beliefs, but leave other beliefsunscathed. According to Descartes, that 2+3=5 or that a square has nomore than 4 sides is knowable even if he is now dreaming:

Earlier versions tended to touch upon dreams just briefly and discussthem alongside other examples of sensory deception. For example, inthe Theaetetus (157e), Plato has Socrates discuss a defect inperception that is common to

Dreams also appear in the canon of standard skeptical arguments usedby the Pyrrhonists. Again, dreams and sleep are just one of severalconditions (including illness, joy, and sorrow) that cast doubt on thetrusthworthiness of sensory perception (Diogenes Laertius, Livesof Eminent Philosophers; Sextus Empiricus, Outlines ofPyrrhonism).

Augustine (Against the Academics; Confessions)thought the dream problem could be contained, arguing that inretrospect, we can distinguish both dreams and illusions from actualperception (Matthew 2005: chapter 8). And Montaigne (The Apologyfor Raymond Sebond) noted that wakefulness itself teems withreveries and illusions, which he thought were even moreepistemologically worrisome than nocturnal dreams.

Descartes devoted much more space to the discussion of dreaming andcast it as a unique epistemological threat distinct from both wakingillusions and evil genius or brain-in-a-vat-style arguments. His claimthat he has often been deceived by his dreams implies he also sawdreaming as a real-world (rather than merely hypothetical) threat.

In the Meditations, after discussing the dream argument,Descartes raises the possibility of an omnipotent evil geniusdetermined to deceive us even in our most basic beliefs. Contrary todream deception, Descartes emphasizes that the evil geniushypothesis is a mere fiction. Still, it radicalizes the dreamdoubt in two respects. One, where the dream argument left theknowability of certain general truths intact, these are cast in doubtby the evil genius hypothesis. Two, where the dream argument,at least on the weaker reading, involves just temporary deception, theevil genius has us permanently deceived.

One modernized version, the brain-in-a-vat thoughtexperiment, says that if evil scientists placed your brain in a vatand stimulated it just right, your conscious experience would beexactly the same as if you were still an ordinary, embodied humanbeing (Putnam 1981). In the Matrix-trilogy (Chalmers 2005),Matrixers live unbeknownst to themselves in a computer simulation.Unlike the brain-in-a-vat, they have bodies that are keptalive in pods, and flaws in the simulation allow some of them to bendits rules to their advantage.

Unlike dream deception, which is often cast as a regularly recurringactuality (cf. Windt 2011), brain-in-a-vat-style arguments are oftenthought to be merely logically or nomologically possible. However,there might be good reasons for thinking that we actually live in acomputer simulation (Bostrom 2003), and if we lend some credence toradical skeptical scenarios, this may have consequences for how we act(Schwitzgebel 2017).

At the end of the Sixth Meditation, Descartes suggests asolution to the dream problem that is tied to a reassessment of whatit is like to dream. Contrary to his remarks in the FirstMeditation, he notes that dreams are only rarely connected towaking memories and are often discontinuous, as when dream characterssuddenly appear or disappear. He then introduces the coherencetest:

But when I perceive objects with regard to which I can distinctlydetermine both the place whence they come, and that in which they are,and the time at which they appear to me, and when, withoutinterruption, I can connect the perception I have of them with thewhole of the other parts of my life, I am perfectly sure that what Ithus perceive occurs while I am awake and not during sleep.(Meditation VI. 24)

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