Skip to main content

Verified by Psychology Today

A Phenomenal Duplicate Talks to Her Zombie Twin

How much information is there in common between experience and function?

In our previous posts (Part 2 and Part 1), we introduced two peculiar characters from the consciousness debates: your phenomenal twin and your zombie twin. As a reminder, your phenomenal twin’s existence goes completely against neuroanatomical requirements for awareness because it lives in a dream-world in which your twin feels in the same way as you do but lacks a body or surrounding environment. Your zombie twin also challenges contemporary neuroscience because this thought experiment assumes that an identical copy of your body and its functions is not necessary to explain “what it is like to be you.” Zombie-you is identical to you “minus” consciousness—same behavior and appearance; it’s just that the “lights are off.”

Could there be a dialogue between your zombie twin (Z-you) and your phenomenal twin (P-you)? In a way, their combination is exactly who you are, so it should be the case that it is at least possible that they could enter into dialogue—a dialogue between “what it feels like to be you” and “you in all your physical glory.”

Illustration by Stefan Mosebach, used with permission.
"Internal" Dialogue
Source: Illustration by Stefan Mosebach, used with permission.

Here’s what it could sound like…

Z-you: Hi!

P-you: Well, hello, gorgeous. How are you?

Z-you: I’m fine. Healthy and heart beating at a slow pace today. How are you feeling?

P-you: I’m fine too. Feeling good and totally relaxed.

Z-you: Shall we sit over here and watch the sunset?

P-you: Sure, it’s particularly striking tonight, isn’t it? Brings back memories of those desert sunsets from that road trip we took in college… Oh, by the way, as you know, I cannot really sit down anywhere; it is you who should sit down. But I will be here right next to you, in your thoughts. Actually, I am quite literally “in your thoughts.”

Z-you: Well, you’re always happier when we sit; that’s why I suggested it. Anyway, I do remember that trip. The colors are very similar, lots of dark oranges and reds and the contrast with the night sky that approaches—these are indeed common during those desert nights. In fact, the colors made us take lots of photos.

P-you: But sadly, the photos couldn’t replicate the true intensity of the colors. Can you really feel what it is like to experience the colors, though?

Z-you: Hmm. I’m not sure about that, but I can tell you a lot about the colors; I actually think we have the same information about them that is communicable in a conversation. I mean, we both took the same visual perception classes at University. And we both remember the colors present during that long trip through the desert.

P-you: I’m getting rather nostalgic for that trip. And those youthful days 20 years ago when life felt simpler.

Z-you: Well, don’t get too romantic for those days. Sure we’ve been experiencing some stressful times recently, with crazy world leaders and an unpredictable pandemic, but the generation before us had similar stories to tell and likely felt like we do now. I mean, I understand what you’re saying: There is something about being young that can be longed for. But you’ve been enjoying middle age as well.

P-you: How dare you call me middle-aged!

Z-you: We both are. We seem to have the same inferences and beliefs and cognitive function, so even if you are ethereal, you are still middle-aged.

P-you: I know, I know. I just miss that feeling of newness when we were young, experiencing things for the first time, discovering new cities, making friends, finding new romances.

Z-you: Of course I remember all those things too. The newness does seem to convey a piece of information that we didn’t think about before. Even after seeing all those photos of Amsterdam, the first time we went there, there seemed to be surprises, at least based on your reactions.

P-you: I never thought I could fall in love with a city. Seeing the quirky old buildings almost falling on each other among the canals. The long summer days with gentle breezes, and then how the city gently lights when the night approaches. I didn’t think being there would have that strong of an effect on me.

Z-you: Yes, that first trip is encoded in our memory very strongly. And triggers certain emotional responses almost every time we think about it again. I must say, though, you really are a bit sentimental today.

P-you: Yeah… well… the sun is gone, and I’m feeling cold. Should we go find a café and get a glass of wine?

Z-you: Wine definitely warms us up when our body temperature drops. Let’s do that… As usual, I shall drink it, and you shall enjoy it.

P-you: So glad we’re usually in sync.

Z-you: Of course. We’re nearly identical. I know you well.

P-you: And I feel you well.

Scientifically speaking, some kind of functional connection must exist between what it is like to be you (your phenomenal experience) and what you say and do (your behaviors). If so, then it shouldn’t just be possible but necessary, according to the laws of science, that there could be an informational exchange between your purely phenomenal self (your phenomenal duplicate) and your zombie (your body). But this is exactly what the “hard problem of consciousness” challenges: namely, that nothing about what it is like to be you is necessitated by any physical information, no matter how sophisticated this information might be.

Fortunately, and independently of the intricacies surrounding the hard problem, the informational exchange between your phenomenal and physical self can be understood in terms of what Z-you and P-you pay attention to. Suppose P-you has a qualitative experience of a red apple over a blue table. Z-you has no such experience, but they can still point at the apple and say things about it, including what color-concepts apply to the apple and to the table.

Z-you and P-you both can have a conversation about the apple. The experiences of P-you will surprisingly match the expressions and behavior of Z-you. It is as if the correlation of information is very far from accidental. In fact, it seems to be necessitated somehow.

More precisely, information about the apple would be highly coordinated. But how exactly should this correlation about meaning be understood? Although we cannot solve this mystery here, we want to emphasize something very non-mysterious about this dialogue, namely that the information contained in what it is like to be you (and by implication P-you) matches very precisely the information Z-you uses to answer questions about the apple.

Thus, joint attention allows for some kind of communication between these two characters. We can start with what Z-you is disposed to do, then match their behavior with what P-you experiences or represents perceptually. The information correlation could be understood in terms of joint attention, and as we explained in previous posts (here and here), joint attention is the basis of successful communication. This means that while we cannot use neuroscience and psychology directly to answer all the conundrums raised by these characters, we can appeal to the information contained in joint attention to sketch out the beginnings of a possible answer.