View previous topic | View next topic

Perspective

Page 1 of 1

Pangerio
1062398.  Mon Mar 10, 2014 7:08 am Reply with quote

The following quote is from a booking I am currently reading, An Anthropologist on Mars, by Oliver Sacks:

"Sensation itself has no 'markers' for size and distance; these have to be learned on the basis of experience. Thus it has been reported that if people who have lived their entire lives in dense rain forest, with a far point no more than a few feet away, are brought into a wide, empty landscape, they may reach out and try to touch the mountaintops with their hands; they have no concept of how far the mountains are."

Does anybody know any more about this kind of thing, or where something of the sort may have been "reported"?

The chapter from which the extract is taken is about a guy who was blind for most of his life (had sight when child). He had his sight restored through medical intervention. Unlike those who 'remember' what seeing is like, a person who has is blind for most of his life does not have the skills required to see the way that sighted people see 'naturally', depth and distance are completely alien to them. They have experienced their life in time mostly (six steps and a chair shows up, two more and a table pops up), rather than in space and time. Apparently adapting to it proves immensely confusing, difficult and troubling. The chapter documents the difficulty of one such patient who, amongst other things describes how he saw street lights as "luminous stains stuck to the window-panes".

Anyways, was wondering whether anybody knew anything about the rainforest people. Was it an actual experiment with rainforest people, or a theoretical example?

 
ConorOberstIsGo
1062421.  Mon Mar 10, 2014 8:55 am Reply with quote

I had also heard something about rain forest tribes who, when shown images of elephants, assumed they were rat-sized for similar reasons. Something that could be related is something from a 2005 BBC show.
http://www.bbc.co.uk/sn/tvradio/programmes/howart/programmes.shtml

I couldn't tell you which episode it was but one of these episodes spends a few minutes discussing an Arab gentlemen who has never seen an image before. He had never seen a graphical representation and when he was asked what a painting of a rearing horse meant, he was unable to work it out. This might suggest that translating stereoscopic vision and perceiving it as 3D is a skill but perhaps so is understanding a 2D image as representing anything 3D.

Also worth noting is the experiments done with cats. (You may be aware of the experiments involving prismatic glasses that invert vision. The world seems upside down but eventually the subjects learn to cope with it and then the glasses are removed after days of this adjustment and the subjects fall all over the place as they struggle to recalibrate their sight.) The experiments demonstrate that vision is learnt and sort of puts a downer on The Matrix line about using one's eyes for the first time; the eyes wouldn't even develop physically properly if they hadn't been used.

My favourite experiment involves raising rats/kittens in mazes but the rats/kittens are raised in an environment with only vertical lines. After a month or so the rats/kittens are otherwise fine but cannot perceive horizontal lines; if you put them on a table they will walk right off it because they can't see the table's edge.

It's actually pretty inelegant; there are different brain areas that recognise lines of different angles. Wish I could find a diagram.

 
Pangerio
1062424.  Mon Mar 10, 2014 9:06 am Reply with quote

ConorOberstIsGo wrote:
I had also heard something about rain forest tribes who, when shown images of elephants, assumed they were rat-sized for similar reasons. Something that could be related is something from a 2005 BBC show.
http://www.bbc.co.uk/sn/tvradio/programmes/howart/programmes.shtml

I couldn't tell you which episode it was but one of these episodes spends a few minutes discussing an Arab gentlemen who has never seen an image before. He had never seen a graphical representation and when he was asked what a painting of a rearing horse meant, he was unable to work it out. This might suggest that translating stereoscopic vision and perceiving it as 3D is a skill but perhaps so is understanding a 2D image as representing anything 3D.

Also worth noting is the experiments done with cats. (You may be aware of the experiments involving prismatic glasses that invert vision. The world seems upside down but eventually the subjects learn to cope with it and then the glasses are removed after days of this adjustment and the subjects fall all over the place as they struggle to recalibrate their sight.) The experiments demonstrate that vision is learnt and sort of puts a downer on The Matrix line about using one's eyes for the first time; the eyes wouldn't even develop physically properly if they hadn't been used.

My favourite experiment involves raising rats/kittens in mazes but the rats/kittens are raised in an environment with only vertical lines. After a month or so the rats/kittens are otherwise fine but cannot perceive horizontal lines; if you put them on a table they will walk right off it because they can't see the table's edge.

It's actually pretty inelegant; there are different brain areas that recognise lines of different angles. Wish I could find a diagram.


That's really interesting, thanks. The amount of things that we take to be obvious but are actually learned in our early years is amazing. It is also sad that it tends to deludes many of us into thinking that everything is so simple and straightforward.

 
Jenny
1062460.  Mon Mar 10, 2014 11:08 am Reply with quote

When I was a student, I used to be one of a group that helped out a blind student (blind from birth) with notes. He and I were doing the same psychology course, and one of the things we studied was the psychology of perception, and seeing 3D shapes represented in 2D. This was difficult for my friend, obviously. He could follow diagrams if they were drawn on plastic sheets with a pen that left raised lines, but when I drew a skeleton picture of a box, in connection with a piece we were doing about how you can mentally 'switch' from one facet of the box being open to another facet, he was flummoxed. We partly solved it by getting a large cube and showing him which line represented which bit of the cube, but he had to take the rest on faith.

 
CharliesDragon
1062668.  Tue Mar 11, 2014 2:15 am Reply with quote

Interesting, Jenny.

For me this also ties in with some social issues, like if you are taught people with certain properties (skin colour, sexuality, gender) are worth less, your brain will interpret that as facts. It's a different kind of "seeing," but that's what I got thinking of.

It's also a reminder that people who process things differently, or haven't learned to process things the same way as you, are not stupid although it would be easy to label them as such.

(Depending on how much of an impact I've made here, some people might not be surprised this is what I drew out of the topic...)

 
knightmare
1062690.  Tue Mar 11, 2014 4:55 am Reply with quote

Quote:
if people who have lived their entire lives in dense rain forest, with a far point no more than a few feet away, are brought into a wide, empty landscape, they may reach out and try to touch the mountaintops with their hands; they have no concept of how far the mountains are.

Anyways, was wondering whether anybody knew anything about the rainforest people. Was it an actual experiment with rainforest people, or a theoretical example?


Apparently it never happened. The first quoted word is a clue: "if". And what about "may". Most likely it's an if-then based theory, assuming the people have never seen any far point of reference. Besides that, how would you know for sure that those healthy people have never seen a far point more than a few feet away.

 
julesies
1062785.  Tue Mar 11, 2014 12:20 pm Reply with quote

This might be referring to an experience noted by anthropologist Colin Turnbull. When Turnbull's pygmy guide Kenge left the dense forest for the first time in his life, he saw some buffalo a few miles away and asked what insects they were. When they drove closer to the buffalo, he became fightened because the buffalo grew larger and larger.

 
'yorz
1062787.  Tue Mar 11, 2014 12:25 pm Reply with quote

Sorry, couldn't resist

 
cornixt
1062822.  Tue Mar 11, 2014 3:17 pm Reply with quote

Even in a dense jungle there are spots where you can see dozens of meters away. No one would be dumb enough to think that mountains are an arms length away simple due to perspective caused by stereo vision - only a slight change in head position would tell them that they are at least several metres away. They would probably be awful at guessing how far away the mountains are or how high they are though.

 
knightmare
1062829.  Tue Mar 11, 2014 4:22 pm Reply with quote

Quote:
Turnbull speculates that as they approached Kenge might be thinking that the insects were turning into buffalo, or the tiny buffalo were growing; but all Kenge himself said was that he didn't think they were real buffalo.


"speculates"... "might be thinking"...

 
RLDavies
1062942.  Wed Mar 12, 2014 8:12 am Reply with quote

knightmare wrote:
Quote:
Turnbull speculates that as they approached Kenge might be thinking that the insects were turning into buffalo, or the tiny buffalo were growing; but all Kenge himself said was that he didn't think they were real buffalo.


"speculates"... "might be thinking"...

He had to speculate because Kenge refused to discuss the matter further.

 

Page 1 of 1

All times are GMT - 5 Hours


Display posts from previous:   

Search Search Forums

Powered by phpBB © 2001, 2002 phpBB Group