What Can You See? — Some Questions About the Content of Visual Experience

Dr Tom McClelland – The Architecture of Consciousness Project – University of Manchester

There are some prop­er­ties you can see and some you can­not. When you look at the pic­ture below, for instance, what do you see? I see col­ours such as the yel­low­ness of the banana, I see shapes such as the banana’s curve, I see spa­tial rela­tions such as the banana’s prox­im­ity to the man’s head and I see tex­tures such as the smooth­ness of the man’s neck­tie. There are oth­er prop­er­ties I don’t see. I don’t see the banana’s prop­erty of being a source of potassi­um or its prop­erty of cost­ing 28p. And I don’t see the man’s prop­erty of being a mem­ber of the Labour Party or his prop­erty of being an eld­er broth­er. On the basis of what I see I might judge that the things I’m look­ing at have these prop­er­ties, but that’s not the same as actu­ally see­ing those prop­er­ties. After all, prop­er­ties like ‘being a source of potassi­um’ just aren’t the kind of thing that one could see.

MillBanana

The examples I’ve men­tioned shouldn’t be too con­ten­tious, but there are many kinds of prop­erty that do cause con­tro­versy. For instance, can you see what kind of object some­thing is, such as see­ing the smal­ler object as a banana and the lar­ger object as a man? Can you see caus­al prop­er­ties such as the banana being sup­por­ted by the hand, or afford­ances such as the banana being edible? Can you see aes­thet­ic prop­er­ties such as the banana’s beauty, or mor­al prop­er­ties such as the man’s vir­tue? Can you see the iden­tity of objects, like see­ing the man as David Miliband?

There is a great deal of debate in philo­sophy about these con­ten­tious cases, and the dis­putants fall into two camps. The first camp are con­ser­vat­ives, and they say that our visu­al exper­i­ences are lim­ited to the basic kinds of prop­erty I first lis­ted: col­ours, shapes, spa­tial rela­tions and tex­tures (e.g. Prinz 2012; Brogaard 2010). These con­ser­vat­ives shouldn’t be con­fused with polit­ic­al Conservatives, but like polit­ic­al Conservatives they are big on aus­ter­ity – they take an aus­tere view of visu­al exper­i­ence that excludes all the con­ten­tious prop­er­ties. The second camp are lib­er­als, and this camp adopts a much more inclus­ive view of per­cep­tion (e.g. Siegel 2012; Bayne 2009). They hold that at least some of the con­ten­tious prop­er­ties can be visu­ally exper­i­enced. Again, this kind of lib­er­al shouldn’t be con­fused with polit­ic­al Liberals, but like polit­ic­al Liberals they are end­lessly arguing among them­selves about just how lib­er­al they should be — the prop­erty of being a man is surely per­mit­ted as a vis­ible prop­erty, but might per­mit­ting the prop­erty of being vir­tu­ous be a step too far?

Now, which camp are you in? The ques­tions I’ve been ask­ing are about what it’s like for you to have the visu­al exper­i­ence you have when you look at the photo above. Conservatives would offer an aus­tere descrip­tion of your exper­i­ence involving only the lim­ited range of prop­er­ties that they coun­ten­ance. If you think that such a descrip­tion fully cap­tures what your visu­al exper­i­ence is like, then you’re a con­ser­vat­ive (don’t worry — that doesn’t come with any polit­ic­al com­mit­ments). If, on the oth­er hand, you think there’s more to your visu­al exper­i­ence than is cap­tured by the aus­tere descrip­tion, then you’re some kind of lib­er­al, and will have to reflect care­fully on just how wide the range of prop­er­ties you can see is.

I’m a lib­er­al, but I’m think­ing care­fully about just how lib­er­al we should be. Specifically, I’m inter­ested in wheth­er we can see a spe­cial cat­egory of prop­erty called ‘scene cat­egor­ies’. When we open our eyes we don’t just see objects – we also see the wider envir­on­ments in which those objects are embed­ded. The philo­sophy of per­cep­tion tends to focus on our per­cep­tion of objects — there is end­less dis­cus­sion of wheth­er we can see an object as a pine tree, for instance, but no real dis­cus­sion of wheth­er we can see a scene as a forest (e.g. Siegel 2012). I think this is an over­sight and that we should ask ourselves wheth­er we can per­ceive scene cat­egor­ies such as being a forest, being a beach, being a field, being a street, or being a car­park.

Trees

Consider the image above. Besides see­ing the vari­ous shapes, col­ours, spa­tial rela­tions and tex­tures in this image do you also see the scene as a forest? Is the scene’s prop­erty of being a forest part of your visu­al exper­i­ence? Conservatives would say that it is not, and would deny that any such scene cat­egory can be per­ceived. They would accept, of course, that we recog­nise the scene as a forest — they would just deny that this recog­ni­tion is per­cep­tu­al. On their view, we see cer­tain pat­terns of col­our and shape and then judge that the scene is a forest. However, I think that a com­bin­a­tion of empir­ic­al and philo­soph­ic­al con­sid­er­a­tions cast doubt on this con­ser­vat­ive view. There are good reas­ons to adopt a lib­er­al view that acknow­ledges we can see scenes as forests or as beaches in much the same way as we can see objects as green or as tall. Conservatives will need some con­vin­cing that we visu­ally exper­i­ence scene cat­egor­ies, and you might need some con­vin­cing too. My case for this has two steps: the first step con­cerns the ‘visu­al’ bit of ‘visu­al exper­i­ence’ and the second step con­cerns the ‘exper­i­ence’.

If con­ser­vat­ives deny that we per­ceive scene cat­egor­ies, they have to say that we recog­nise scene cat­egor­ies through some kind of post-per­cep­tu­al cog­nit­ive pro­cess, such as mak­ing a judge­ment on the basis of what we see. The empir­ic­al data counts against such a view in at least four ways. First, judge­ment is rel­at­ively slow, but our recog­ni­tion of scene cat­egor­ies is incred­ibly fast. Thorpe et al. (1996), for instance, found that when sub­jects were shown images in a scene cat­egor­isa­tion task, their brains showed Event Related Potentials (ERPs) as early as 150 mil­li­seconds after being shown the image. Second, it is gen­er­ally thought that only atten­ded areas of the visu­al field are avail­able to judge­ment, but our recog­ni­tion of scene cat­egor­ies often seems to be inat­tent­ive (see Li et al, 2002). Third, the speed at which we make dis­crim­in­at­ive judge­ments about a stim­u­lus can gen­er­ally be improved if we’re famil­i­ar with the stim­u­lus, or if we form appro­pri­ate expect­a­tions about the stim­u­lus. However, an early study by Biederman et al (1983) sug­gests that famili­ar­ity and expect­a­tion do not speed up our cat­egor­isa­tion of scenes, indic­at­ing that scene cat­egor­isa­tion is an auto­mat­ic per­cep­tu­al pro­cess. Fourth, per­cep­tu­al pro­cesses dis­play a phe­nomen­on known as ‘per­cep­tu­al afteref­fects’ (which you can find more about here). Post-perceptual pro­cesses do not dis­play this effect, but a study by Greene & Oliva (2010) indic­ates that scene cat­egor­isa­tion is sus­cept­ible to aftereffects.

Interpreting this data is not always straight­for­ward, but it cer­tainly looks like scene cat­egor­ies can be recog­nised per­cep­tu­ally, not just through post-perceptual judge­ments. But I’m not home free yet. It’s one thing to per­cep­tu­ally pro­cess a prop­erty but quite anoth­er to per­cep­tu­ally exper­i­ence it. Since I claim that we per­cep­tu­ally exper­i­ence scene prop­er­ties, I have more work to do. This is where some philo­soph­ic­al con­sid­er­a­tions need to be intro­duced to sup­ple­ment the empir­ic­al data. Liberals use some­thing called ‘con­trast cases’ to show that our visu­al exper­i­ence is more rich than con­ser­vat­ives think. Contrast cases are pairs of visu­al exper­i­ences that dif­fer from each oth­er in ways that con­ser­vat­ives are unable to account for. Such cases drive the fol­low­ing argu­ment against conservatives:

  1. The two exper­i­ences are alike with respect to all conservative-permitted prop­er­ties i.e. they rep­res­ent all the same col­ours, shapes, spa­tial rela­tions and textures.
  2. The two exper­i­ences are nev­er­the­less dif­fer­ent i.e. what it’s like to under­go the first visu­al exper­i­ence is dif­fer­ent to what it’s like to under­go the second.
  3. Therefore the two exper­i­ences must dif­fer with respect to prop­er­ties not per­mit­ted by conservatives.

Here is a clas­sic example used by liberals:

Black Whit

To begin, this image looks to most people like a mean­ing­less jumble of black and white patches. But if you look closely you can recog­nise it as a pic­ture of a cow (the face is on the left and is look­ing towards you). This rev­el­a­tion changes what your visu­al exper­i­ence is like, but the con­ser­vat­ive can’t explain this change because there is no dif­fer­ence in the col­ours, shapes (etc.) that you see. Surely what changes is that you start to see the image as a cow? Conservatives deny that we see this kind of prop­erty, but this con­trast case sug­gests they are wrong. Perhaps a sim­il­ar example can be found in which we come to visu­ally exper­i­ence a scene cat­egory. Consider the fol­low­ing image:

Waterfall

Again, you might start by see­ing mean­ing­less patches of black and white but then come to recog­nise that this scene is a water­fall. To make sense of this change, it seems we must say that we visu­ally exper­i­ence the prop­erty of being a water­fall. Here’s anoth­er kind of example often used by liberals:

Duck Rabbit

You might first recog­nise this image as a rab­bit then recog­nise it as a duck. Your visu­al exper­i­ence rep­res­ents the same conservative-permitted prop­er­ties in both cases, so the change must involve some more con­ten­tious prop­erty, such as visu­ally exper­i­en­cing the image first as a rab­bit then as a duck. Again, we might be able to find a counter-part to this example involving scene cat­egor­ies. Consider the fol­low­ing image:

Waves

These sand dunes look a lot like waves, and you might be able to switch between visu­ally exper­i­en­cing this scene as a desert then visu­ally exper­i­en­cing it as a sea. If so, this would again be a case in which we see scene categories.

Although these brief argu­ments are far from con­clus­ive, they offer a taste of the lar­ger case I hope to make in favour of the vis­ib­il­ity of scene cat­egor­ies. Ultimately though, there’s only one way to decide where you stand on these issues, and that is to ask your­self what you can see!

 

REFERENCES

 

Bayne, T. (2009). Perception and the Reach of Phenomenal Content. Philosophical Quarterly, 59(236), 385–404.

Biederman, I., Teitelbaum, R. C., & Mezzanotte, R. (1983). Scene Perception: A Failure to Find a Benefit From Prior Expectancy or Familiarity. Journal of Experimental Psychology, 9(3), 411–429.

Brogaard, B. (2013). Do we per­ceive nat­ur­al kind prop­er­ties? Philosophical Studies, 162 (1), 35–42.

Greene, M. R., & Oliva, A. (2010). High-Level Aftereffects to Global Scene Properties. Journal of Experimental Psychology, 36(6), 1430–1442.

Li, F. F., VanRullen, R., Koch, C., & Perona, P. (2002). Scene cat­egor­iz­a­tion in the near absence of atten­tion. Proceedings of the National Academy of Sciences of the United States, 99(14), 9596–9601.

Prinz, J. (2012). The Conscious Brain: How Attention Engenders Experience. Oxford: OUP.

Siegel, S. (2012). The Content of Visual Experience. Oxford: OUP.

Thorpe, S., Fize, D., & Marlot, C. (1996). Speed of Processing in the Human Visual System. Nature, 381, 520–523.

 

16 thoughts on “What Can You See? — Some Questions About the Content of Visual Experience”

  1. Tom,
    thank you for the inter­est­ing post, I hope it’s not too late to leave some obser­va­tions — sorry if they are going to be quite long, but I’m fas­cin­ated by the issue as well.

    First, a some­how pro­voc­at­ive ques­tion. Your main claim is that “we don’t just see objects — we also see the wider envir­on­ment in which those objects are embed­ded”. Does any­one really dis­agree with this claim? It’s true that philo­soph­ers tend to focus on examples such as the per­cep­tion of an apple in order to ask ques­tions about what prop­er­ties we can visu­ally exper­i­ence, isol­at­ing indi­vidu­al objects in a way that may seem arbit­rary. Yet I am unsure wheth­er they would deny that the broad­er scene is vis­ible too. After all, a beach or a street is made of objects.
    Perhaps you want to claim that — over and above indi­vidu­als with their prop­er­ties — we can per­ceive groups, col­lec­tions and oth­er aggreg­ates as hol­ist­ic wholes instead as of mere sums of indi­vidu­al objects. On the face of it, this seems a plaus­ible idea. Being a forest, being a crowd, being a flock may be good examples. Does this make sense to you?

    Second, let’s grant that the empir­ic­al evid­ence sug­gests that recog­ni­tion of scene cat­egor­ies is not some­thing like an infer­ence based on per­cep­tion which leads to a judge­ment. Thus, per­cep­tu­al recog­ni­tion is not the same as a judge­ment. Still, someone may argue that the fact that we can recog­nise scene cat­egor­ies without neces­sar­ily form­ing expli­cit judge­ments does not yet show that we can per­ceive those cat­egor­ies. Recognising is one thing, per­ceiv­ing is anoth­er. The former — accord­ing to at least some the­or­ists — is not required for the latter.

    Third, aspect-downing pic­tures. Without any need to think that we can per­ceive prop­er­ties such as being a cow, you may explain the visu­al phe­nom­en­al switch you under­go when an object appears to you in the pic­ture by appeal to prop­er­ties such as organ­isa­tion­al or Gestalt prop­er­ties. Paying atten­tion to the col­ours and shapes on the 2D sur­face leads you to group the vis­ible ele­ments in such a way that a 3D object emerges. Sure, the object is a cow; and since you know what cows look like, you recog­nise a cow being depic­ted in the pic­ture. But is it neces­sary to recog­nise it as a cow or to see it as a cow in order to have a phe­nom­en­ally dif­fer­ent exper­i­ence from the exper­i­ence of see­ing a flat sur­face covered in colour?
    Think of sim­pler examples of ambigu­ous fig­ures, such as this (dis­cussed in Peacocke’s Sense and Content,1983). You can see the dots either as columns or as rows (depend­ing on wheth­er you give more weight to group­ing by col­our or by prox­im­ity). Such a group­ing, though it may involve atten­tion, does not depend on con­cep­tu­al or recog­ni­tion­al capa­cit­ies. Perhaps a sim­il­ar explan­a­tion also works for the aspect-downing cow pic­ture. True enough, the cow and water­fall pic­tures are indeed pic­tures, “in” which we exper­i­ence 3D objects that are not really there. So there may well be a fur­ther level which dis­tin­guish pic­ture per­cep­tion from the per­cep­tion of simple visu­al group­ings. Still, recog­nising the seen-in object as a cow or a water­fall does not seem neces­sary to under­go a phe­nom­en­al switch.
    Incidentally, I’d like to high­light how your scene-perception pro­pos­al may have the advant­age of avoid­ing whatever argu­ments one may advance against the pro­pos­al that we can per­ceive nat­ur­al kind prop­er­ties (such as being a cow). In order to do so, how­ever, you would need to insist that e.g. see­ing a pine forest as a forest — as a whole, as a uni­fied scene… — does not imply see­ing it as a pine forest, i.e. it does not imply see­ing its trees as being pine trees instead of being anoth­er kind of tree. 

    Finally, I would be inter­ested in know­ing more about your the desert/sea example. One nat­ur­al descrip­tion of the case is this: the pic­ture is inde­term­in­ate about the object or scene it depicts; not­ably, it is inde­term­in­ate with respect to the object’s or scene’s col­ours; thus, we may equally inter­pret it either as a pic­ture of a sea or as a pic­ture of a desert. Yet this inter­pret­a­tion does not amount to a per­cep­tu­al dif­fer­ence. For instance, it is not the case that in the “sea” exper­i­ence you see the curved dark lines as depict­ing con­vex 3D shapes where­as in the “desert” exper­i­ence you see them as depict­ing con­cave 3D shape (in con­trast with an ambigu­ous case like this). Perhaps you may start ima­gin­ing that the scene you see in the pic­ture is blue in one case and sandy in the oth­er, but visu­al imagery is not per­cep­tion. Surely we visu­ally exper­i­ence a 3D object or scene over and above col­ours and shapes, but why it should be such a spe­cif­ic prop­erty as being a sea as apposed to being a desert. Can you explain why you think it’s a case of per­cep­tion of those scene categories?

    I under­stand you weren’t able to go into much detail in a blog post, but if you are able to respond in the com­ments I would be inter­ested in bet­ter under­stand­ing your view. Thank you!

    1. Hi Giulia. Many thanks for these com­ments. They’ve giv­en me a lot to think about. I’ll post a sep­ar­ate reply for each comment…

  2. I don’t think any­one would dis­agree with my claim that we per­ceive scenes and not just indi­vidu­al objects. My worry isn’t that philo­soph­ers deny the exist­ence of scene per­cep­tion but that they tend to *ignore* it. Some philo­soph­ers might assume that per­ceiv­ing a scene is just a mat­ter of per­ceiv­ing some com­plex of objects that con­sti­tute the scene, but there are at least two reas­ons to doubt this: 1) some scenes aren’t con­sti­tuted by objects (or at least not by per­cept­ible objects) – ocean scenes aren’t made of objects and although a beach might tech­nic­ally be made of grains of sand we don’t have to per­ceive these indi­vidu­ally to per­ceive the beach; 2) the psy­cho­lo­gic­al data seems to sug­gest that much scene-processing occurs in par­al­lel to object-processing rather than being built upon object pro­cessing. This sug­gests that much of what’s involved in recog­nising a scene is psy­cho­lo­gic­ally inde­pend­ent of object recog­ni­tion. You men­tion that I might want to say that we per­ceive groups (etc.) as more than the sum of their parts. As it hap­pens, I do want to say this – there’s some inter­est­ing data sup­port­ing such a view. However, for the reas­ons above I don’t think that this cap­tures what’s involved in scene per­cep­tion. Recognising some­thing as a forest involves more than rep­res­ent­ing an aggreg­ate of trees.

  3. Your second com­ment high­lights the fact that a crude dicho­tomy of per­cep­tion and judge­ment is prob­ably too simplist­ic to cap­ture the range of psy­cho­lo­gic­al states we enjoy. If it was a straight­for­ward choice between say­ing a) that we can only judge scene cat­egor­ies or b) that we can per­ceive scene cat­egor­ies, I hope to have tipped the bal­ance in favour of ‘b’. But if we intro­duce kinds of recog­ni­tion between per­cep­tion and judge­ment I’m open to the pos­sib­il­ity that scene recog­ni­tion falls into one of those oth­er kinds. The prob­lem is that I don’t think we yet have a work­able account of what those oth­er kinds of recog­ni­tion are.

  4. Your third com­ment high­lights a couple of cru­cial ques­tions in the philo­soph­ic­al lit­er­at­ure sur­round­ing the con­tent of per­cep­tu­al exper­i­ence: 1) might changes to atten­tion cap­ture what’s going on in con­trast cases?; 2) can per­cep­tu­al exper­i­ence rep­res­ent ‘nat­ur­al kind’ prop­er­ties that are typed by their under­ly­ing nature rather than by their out­ward appearance?
    My response to the first ques­tion is that I don’t think changes in atten­tion exhaust what hap­pens when we recog­nise an image as (for instance) a water­fall. My reas­ons for this are a little com­plex, but the two main points are; a) that scene recog­ni­tion often seems to occur inat­tent­ively, sug­gest­ing we can per­cep­tu­ally exper­i­ence scene cat­egor­ies without hav­ing to attend to that scene, and; b) that scene recog­ni­tion (unlike object recog­ni­tion) isn’t achieved by attend­ing to loc­al fine-grained fea­tures of a scene but rather by pro­cessing the over­all glob­al prop­er­ties of the visu­al field.
    My response to the second ques­tion is that, as you sug­gest, there are good reas­ons to doubt that per­cep­tu­al exper­i­ence can rep­res­ent nat­ur­al kinds. This indic­ates that the only scene cat­egor­ies that are per­cept­ible are those that aren’t typed by nat­ur­al kinds, thus being a pine forest would be inad­miss­ible but being a forest is prob­ably admiss­ible. Of course, anoth­er option is to deny that these wor­ries about nat­ur­al kinds stand up to scru­tiny, and I wouldn’t want to rule out that pos­sib­il­ity too hastily.

  5. My argu­ment assumes that *some­thing* in your per­cep­tu­al exper­i­ence changes when you shift from see­ing the image as a sea scene then see­ing it as a desert scene. If you don’t have this kind of switch­ing exper­i­ence, my argu­ment doesn’t get off the ground. If you do have this switch­ing exper­i­ence, my argu­ment is that per­cep­tu­al rep­res­ent­a­tion of scene cat­egor­ies is the best explan­a­tion of the switch. The switch can’t be a mat­ter of com­ing to see the image as 3D because both exper­i­ences rep­res­ent the scene to have the same con­tours. The switch can’t be a mat­ter of attend­ing to loc­al low-level prop­er­ties asso­ci­ated with being the sea, then attend­ing to loc­al low-level prop­er­ties asso­ci­ated with being a desert, because the pic­ture doesn’t involve any such dia­gnost­ic prop­er­ties. Nor can the switch be a mat­ter of ima­ging the scene as blue in the first exper­i­ence then ima­gin­ing it as yel­low in the second exper­i­ence because you can (I think!) achieve the rel­ev­ant switch without ima­ging the scene as hav­ing any col­our. Having ruled out all of those, it seems we have to start look­ing at high-level prop­er­ties instead of low-level prop­er­ties, and here I think that scene cat­egor­ies like being the sea and being a desert are the most obvi­ous candidates.
    I con­cede that there’s a lim­it to how much weight I can put on the con­ten­tious sea/desert case. That’s why I’ve been try­ing to accu­mu­late a lar­ger col­lec­tion of examples that sup­port my argu­ment. I post some of these below…

  6. Hi Tom,

    thank you for the help­ful replies. In point of fact, I also tried to post links to pic­tures (Peacocke’s example of dots) and a pic­ture of shaded circles that you can see either as con­cave or as con­vex semispheres.
    I’ll have a closer look at your com­ments and try to respond asap.

  7. Tom,

    many thanks for your replies. Here are some point-by point follow-ups.

    1) Thank you for cla­ri­fy­ing your claim. In order to have a bet­ter grasp of the dist­ict­ive­ness of scene per­cep­tion, may you tell us more about the empir­ic­al data you men­tion? Can you give an example of exper­i­ment show­ing how scene-processing does not depend (or is not wholly determ­ined by) object processing?
    This leads me to a much wider ques­tion: how is pro­cessing related to per­cep­tu­al exper­i­ence and its con­tent? I cer­tainly don’t expect you to offer us a full the­ory of such a rela­tion, but you may have a sketchy idea. Questions like this would prob­ably always appear at some point when you are using (cer­tain kinds of) empir­ic­al evid­ence in sup­port of a philo­soph­ic­al thesis.

    2) Fair enough. So my ques­tion becomes: do you think per­cep­tion always implies recog­ni­tion, so that there is no such a thing as per­cep­tu­al dis­crim­in­a­tion without per­cep­tu­al recog­ni­tion? Relatedly, what does recog­nising an object — or recog­nising the object as hav­ing a cer­tain prop­erty — require?
    As you may ima­gine, I’m more of a sup­port­er of the inde­pend­ence of per­cep­tu­al capa­cit­ies from recog­ni­tion­al capa­cit­ies. Yet this is entirely irrel­ev­ant, as I just want to see where you are com­ing from.

    1. 1) One the best stud­ies that seems to show scene recog­ni­tion is not driv­en primar­ily by object recog­ni­tion is Greene, M. R., & Oliva, A. (2009). Recognition of nat­ur­al scenes from glob­al prop­er­ties: see­ing the forest without rep­res­ent­ing the trees. Cognitive Psychology(58), 137–176. (they also cite a num­ber of oth­er stud­ies that point to the same conclusion).
      I don’t have any­thing espe­cially insight­ful to say about the rela­tion­ship between pro­cessing and per­cep­tu­al exper­i­ence. I think it’s a *neces­sary con­di­tion* of a prop­erty being part of the con­tent of per­cep­tu­al exper­i­ence that it is pro­cessed per­cep­tu­ally. The real chal­lenge for philo­soph­ers and psy­cho­lo­gists is to estab­lish the *suf­fi­cient con­di­tions* but I can avoid this worry because I nev­er say “this prop­erty is pro­cessed in this way, there­fore it’s part of the con­tent of per­cep­tu­al experience.”

    2. 2) I think I’m using ‘recog­ni­tion’ as a label for pro­cessing a prop­erty that’s neut­ral on wheth­er the prop­erty in ques­tion is rep­res­en­ted in per­cep­tion, in belief or in some oth­er way. Perhaps that term is mis­lead­ing. I think that to per­ceive a prop­erty is to rep­res­ent it in some way. You might call such rep­res­ent­a­tion recog­ni­tion, or might pre­serve the label ‘recog­ni­tion’ for a par­tic­u­lar kind of rep­res­ent­a­tion. I’m not sure.

  8. 3) I do agree with you that attend­ing to low-level prop­er­ties such as shapes, col­ours, spa­tial pos­i­tions etc. can­not explain the phe­nom­en­al change we under­go with aspect-downing pic­tures and (twice) with ambigu­ous pic­tures. It can­not explain the change we exper­i­ence with the simple dots fig­ure either. Coming to per­ceive more detailed shapes or more determ­in­ate col­ours thanks to focus­ing our atten­tion is clearly not related with those phe­nom­en­al switches in any inter­est­ing way.

    Your b) point — we achieve scene recog­ni­tion by pro­cessing glob­al prop­er­ties of the visu­al field — is con­sist­ent with the view that dif­fer­ences in per­cep­tu­al atten­tion can account for the phe­nom­en­al switches at least with the sim­pler, non-representational fig­ures. By attend­ing to the shapes and col­ours, we do not merely per­ceived them as more determ­in­ate, but we group them/organise them in such a way that a new prop­erty is per­ceived. This should be some kind of Gestalt prop­erty, which is a good example of glob­al prop­erty since it is neither redu­cible to nor super­veni­ent on lower-level per­ceiv­able prop­er­ties (in her book, Siegel briefly men­tions a sim­il­ar pro­pos­al as an altern­at­ive explan­a­tion of an alleged instance of nat­ur­al kind perception).

    However, if your a) point is cor­rect — atten­tion is simply not required for scene recog­ni­tion / per­cep­tion — then the pro­pos­al wouldn’t be a viable option.

    1. 3) I like the idea that per­cep­tion of glob­al prop­er­ties is ana­log­ous to per­cep­tion of gestalt prop­er­ties. Of course, I’d then need to work out what the rela­tion­ship is between per­cep­tu­ally exper­i­en­cing those glob­al gestalt prop­er­ties and per­cep­tu­ally exper­i­en­cing scene categories.
      As you say, point ‘a’ would help my argu­ment a lot. Unfortunately, the evid­ence in favour of this is not clear-cut, so I can­’t rely on it too much.

  9. 4) As for the sea/desert pic­ture, I’m thorn between deny­ing that there is a phe­nom­en­al dif­fer­ence — in con­trast with visu­ally ambigu­ous fig­ures, this pic­ture does sup­port two inter­pret­a­tions but does not sup­port two dif­fer­ent visu­al exper­i­ences — and look­ing for anoth­er explan­a­tion of the over­all con­trast between the “sea” and the “desert” exper­i­ence. I undoubtedly agree that neither attend­ing to loc­al low-level fea­tures (see reply 3 above) nor going from see­ing a 2D sur­face to see­ing to a 3D scene can account for the phe­nom­en­al difference.

    By the way, I really want to SEE the oth­er pic­tures — I’m sure you appre­ci­ate how this is dif­fer­ent from trust­ing your report 

    1. Of course, I would­n’t expect you to trust my report 🙂 I’ll send you the most recent draft of my paper then you can see all the examples and a bib­li­o­graphy of some of the most inter­est­ing stud­ies I’ve looked at. Thanks again for all your com­ments — it’s been very help­ful to work my ideas through further.

  10. : — ) Can you dir­ect me to stud­ies where the examples are discussed?

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