夢遊者有意識嗎？

09-05

明顯我們無法知道正在夢遊，醒來時沒有記憶的人是否有意識。
但是考慮到他們的行為可以十分複雜，似乎有理由認為他們在夢遊時是有意識的，只是無法形成記憶而已（或無法有效鞏固短期記憶，以至於在醒來時無法回憶起來）。
除了失憶以外，是否有其他理由使人懷疑他們在夢遊時並沒有意識？
「...it seems likely that sleepwalkers are truly unconscious even as they engage in reasonably complex - sometimes remarkbly complex - interactions with the world.」
& p. 59

謝邀

一般來說，我們討論意識時常常會限制於普通人清醒 (awaken) 的狀態，而其他的各種意識狀態我們統稱為 altered states of consciousness (ASCs)，比如說有 sleeping and dreaming states, drug-induced states, pathological states, anesthesia, hypnotism 之類的。還有一些爭議性比較大的，exceptional human experience (EHE)，除了 lucid dreaming 基本被公認存在以外，其他像 out of body experience，near-death experience 什麼的就很玄乎了。

Williamson James (&<Varieties of Religious Experience&> 1902)在上個世紀初就意識到了這些狀態對於理解意識問題的關鍵性：

One conclusion was forced upon my mind at that time, and my impression of its truth has ever since remained unshaken. It is that our normal waking consciousness, rational consciousness, whilst all about it, parted from it by the filmiest of screens, there lie potential forms of consciousness entirely different. We may go through life without suspecting their existence; but apply the requisite stimulus, and at a touch they are there in all their completeness, definite types of mentality which probably somewhere have their field of applicatoin and adaptation. No account of the universe in its totality can be final which leaves these other forms of consciousness quite disregarded. How to regard them is the question

然而這些東西在很長一段時間裡卻極少得到哲學和認知科學的研究[1]。

在 clinical neurosciences 中意識常常被分為兩個部分(反正哲學裡不這麼分): arousal (i.e. wakefulness, vigilance, or level of consciousness) and awareness of environment and of self (i.e. contents of consciousness). Arousal refers to the behavioural continuum that occurs between sleep and wakefulness and awareness refers to the thoughts and feelings of an individual (Steven Laureys Arousal vs awareness in Tim Bayne, Axel Cleeremans Patrick Wilken &<The Oxford Companion to Consciousness&> 2007). 夢遊時的神經狀態相關研究很少(畢竟這東西確實不好研究)：Bassetti, C., Vella, S., Donati, F., Wielepp, P., and Weder, B. SPECT during sleepwalking. 2000 表明 large areas of frontal and parietal association cortices remained deactivated during sleepwalking.

下圖 (Vanessa Charland-Verville, Audrey Vanhaudenhuyse, Steven Laureys and Olivia Gosseries The Scientific Study of Coma and Related States in Steven M. Miller &<The Constitution of Phenomenal Consciousness&> 2015)

UWS = unresponsive wakefulness syndrome
MCS? = minimally conscious minus
MCS+ = minimally conscious plus
EMCS = emergence from minimally conscious state
LIS = locked-in syndrome

根據圖中的分類，somnambulism or sleepwalking, a parasomnia occurring during deep sleep, is a further example of transient non-responsiveness with partially preserved arousal and semi-purposeful behaviour such as ambulation。它沒有那種 awareness, 但是 arousal 的程度很高。至於它應該算有意識嗎，真正的難題在於我們並沒有一個足夠有效的意識概念來應對各種 ASCs。

原文里提到的兩篇文章都很有用，還有一個 Etzel Cardena Michael Winkelman &<Altering Consciousness: Multidisciplinary Perspectives&> 2011 兩卷本，無論做哲學還是認知(神經或心理)科學都強烈推薦 Volume1 里的 preface, chapter 1,2 這三篇。

[1]睡眠和夢境方面，認知神經科學還有一些研究，比如關於 REM 和非 REM 下的神經狀態，記憶機制的相關研究；但哲學界除了把它作為懷疑論問題的來源，很少對其系統討論，這個狀態一直持續到大約上世紀末，少有的反例有 Sartre，Dennett，Churchland

謝 @Mon1st 邀！

結論：沒有意識。

理由：睡行症是睡眠覺醒障礙的一種，是指起始於睡眠前1／3階段中NREM睡眠期的一系列複雜行為，以患者在睡眠中行走或其他離床的複雜行為為基本臨床特徵，睡行症俗稱「夢遊」，但近年來研究發現，睡行症是機體從慢波睡眠中不完全覺醒導致的結果，此時大腦皮層的運動和視覺區域覺醒而記憶或判斷區域並未覺醒，故發作時出現的行為是一種無意識行為，並無明顯的夢境體驗，故更名為睡行症，但夢遊一詞仍廣為流傳。

參考文獻：

Cock V C D. Sleepwalking[J]. Current Treatment Options in Neurology, 2016, 18(2):1-9.

分享梅奧關於睡行症的介紹：

Overview

Sleepwalking — also known as somnambulism — involves getting up and walking around while in a state of sleep. More common in children than adults, sleepwalking is usually outgrown by the teen years. Isolated incidents of sleepwalking often dont signal any serious problems or require treatment. However, recurrent sleepwalking may suggest an underlying sleep disorder.

Sleepwalking in adults has a higher chance of being confused with or coexisting with other sleep disorders as well as medical conditions.

If anyone in your household sleepwalks, its important to protect him or her from potential injuries related to sleepwalking.

Symptoms

Sleepwalking usually occurs early in the night — often one to two hours after falling asleep. Its unlikely to occur during naps. A sleepwalking episode can occur rarely or often, and an episode generally lasts several minutes, but can last longer.

Someone who is sleepwalking may:

Symptoms

Someone who is sleepwalking may:

Get out of bed and walk around
Sit up in bed and open his or her eyes
Have a glazed, glassy-eyed expression
Not respond or communicate with others
Be difficult to wake up during an episode
Be disoriented or confused for a short time after being awakened
Not remember the episode in the morning
Have problems functioning during the day because of disturbed sleep
Have sleep terrors in addition to sleepwalking

Sometimes, a person who is sleepwalking will:

Do routine activities, such as getting dressed, talking or eating
Leave the house
Drive a car
Engage in unusual behavior, such as urinating in a closet
Engage in sexual activity without awareness
Get injured, for example, by falling down the stairs or jumping out a window
Become violent during the period of brief confusion immediately after waking or, occasionally, during sleepwalking

When to see a doctor

Occasional episodes of sleepwalking arent usually a cause for concern and typically resolve on their own. You can simply mention the sleepwalking at a routine physical or well-child exam. However, consult your doctor if the sleepwalking episodes:

Occur often — for example, more than one to two times a week or several times a night
Lead to dangerous behavior or injury to the person who sleepwalks or to others
Cause significant sleep disruption to household members or the person who sleepwalks
Result in daytime symptoms of excessive sleepiness or problems functioning
Start for the first time as an adult
Continue into your childs teen years

Causes

Sleepwalking is classified as a parasomnia — an undesirable behavior or experience during sleep. Sleepwalking is a disorder of arousal, meaning it occurs during N3 sleep, the deepest stage of non-rapid eye movement (NREM) sleep. Another NREM disorder is sleep terrors, which can occur together with sleepwalking.

Many factors can contribute to sleepwalking, including:

Sleep deprivation
Stress
Fever
Sleep schedule disruptions, travel or sleep interruptions

Sometimes sleepwalking can by triggered by underlying conditions that interfere with sleep, such as:

Sleep-disordered breathing — a group of disorders featuring abnormal breathing patterns during sleep (for example, obstructive sleep apnea)
Taking certain medications, such as hypnotics, sedatives or certain medications used for psychiatric disorders
Substance use, such as alcohol
Restless legs syndrome
Gastroesophageal reflux disease (GERD)

Risk factors

Factors that may increase the risk of sleepwalking include:

Genetics. Sleepwalking appears to run in families. Its more common if you have one parent who has a history of sleepwalking, and much more common if both parents have a history of the disorder.
Age. Sleepwalking occurs more often in children than adults, and onset in adulthood is more likely related to other underlying conditions.

Complications

Sleepwalking itself isnt necessarily a concern, but a person who sleepwalks can:

Hurt themselves — especially if they walk near furniture or stairs, wander outdoors, drive a car or eat something inappropriate during a sleepwalking episode
Experience prolonged sleep disruption, which can lead to excessive daytime sleepiness and possible school or behavior issues
Be embarrassed or experience problems with social relationships
Disturb others sleep
Rarely, injure someone else nearby

題主我給你提供個樣本，我室友每晚說夢話，似乎總是在做激烈的鬥爭或者跟七大姑八大姨吵架，最近已經嚴重到半躺起來看著我了，還用壓抑的聲音叫我關窗戶，我嚇得屁滾尿流趕緊下床去關，然後他就滿意地睡下了。到早上啥也不記得。

所以我猜是有意識的吧，而且現在是凌晨一點……我好害怕！

挺有意思的問題，其實當初看到心靈哲學的殭屍問題的時候就在想，夢遊的人不就有些像這種殭屍嗎？所以如果夢遊的人確實沒有意識，那就是對二元論的一個強有力支持。但是又一細想我就打消了這個念頭，為何？一種比較簡單的想法是，因為夢遊的人在現實中所做的動作，其實是源於他的夢境。他在現實中走路，抬手，或者說話，其實都是源於他在自己夢境中所做的同樣的事情。你很難想像一個人根本就不處在夢境中但是卻會走路，抬手，說話等等（起碼我自己很難想像這種情況，因為這會使這些動作和行為失去原因）。有時候你叫醒了夢遊的人，他會說他剛才在哪哪走路來著，而那就是他的夢境。所以即便處於夢遊狀態，似乎仍然是有意識的。

一個有意思的問題，也是一個公說公有理的問題。

如果說有意識，我們開車走一段熟悉路途時是無意識的。如果說無意識，手術後的H.M.顯然是有意識的。