Subject: meaning / Gibson (and moderation) From: Stephen Grossberg <steve(at)CNS.BU.EDU> Date: Sat, 3 Mar 2001 09:29:12 -0800The discussion below is far-ranging. I just want to make a comment about the allusion by by John Neuhoff to Gibson below, notably his remark that >Information >(or meaning by some definitions) IS often ordered and structured in the >environment. However, organisms have evolved to take advantage of that information. There are now detailed neural models of visual perception and navigation that has clarified a number of these issues, including as they pertain to the work of Gibson. As one example of how the structure of the environment can interact with the structure that the brain has evolved to deal with it, you might want to check out the following article that is downloadable on my web page http://www.cns.bu.edu/Profiles/Grossberg. Grossberg, S., Mingolla, E., and Pack C. (1999). A neural model of motion processing and visual navigation by cortical area MST. Cerebral Cortex, 9, 878-895. This article quantitatively simulates detailed properties of cells in cortical area MST in response to optic flow stimuli AND psychophysical data about how human navigators estimate heading direction under a variety of conditions. Time-to-contact data have also been simulated by this model. Concerning the point that "organisms have evolved to take advantage of that information," it seems that the receptive fields of these cells, which benefit from the (positionally-variant) cortical magnification factor to estimate navigational properties like heading direction, have also developed to maximize their position-invariance properties for purposes of object tracking; see Figure 8 in the article. >X-Accept-Language: en >Date: Fri, 2 Mar 2001 10:46:03 -0500 >Reply-To: jneuhoff(at)acs.wooster.edu >Sender: AUDITORY Research in Auditory Perception ><AUDITORY(at)lists.mcgill.ca> >From: "John G. Neuhoff" <jneuhoff(at)acs.wooster.edu> >Organization: The College of Wooster >Subject: meaning / Gibson (and moderation) >To: AUDITORY(at)lists.mcgill.ca > >There are those who argue strongly both sides of this issue- that >meaning and information reside only in the environment or stimulus and >conversely that they reside only inside the heads of perceivers. Many >strict Gibsonians shun terms like "mental imagery" and "schema". >However, it seems reasonable that both camps are correct. Information >(or meaning by some definitions) IS often ordered and structured in the >environment. However, organisms have evolved to take advantage of that >information. Thus, it should come as no surprise that the organization >of things like brains would reflect as well as process the structure of >this environmental information. Al Bregman is right to suggest that we >can perceive without sensation. Paul Treffner is right to suggest that >environmental information can specify events. A wonderful example of >this perspective is that of Denny Proffitt at U. Virginia. I once saw >him give a talk on the "affordance" (a sacred Gibsonian term) of a >mental image. Perhaps Al Bregman and J. Gibson failed to convince each >other because they BOTH were right. > >-John Neuhoff > >Al Bregman wrote: >> >> Paul Treffner wrote: >> >> > Meaning? Meaning is *not* in the head!! How could it be?! >> Simple argument: >> > The meaning is perceived when the information is detected. >> Since the >> > information specifies an event in the world, the "meaning" >> (consequences, >> > implications, etc) is at least in the dynamical interaction of >> speaker and >> > listener. But certainly they are not in representations inside >> > the listener's head alone. >> >> Surely the mental schemas (in Piaget's sense), linguistic or >> otherwise, in terms of which we assimilate any perceptual input, >> or by means of which we guide the actions that deal with the >> input, are the "meaning" of that input. Different people can >> have different meanings for the same event, because they >> assimilate it to different schemas. For example, a young woman >> is looking attentively at a boastful young man, Adam. An > > onlooker, Brad, sees her intent gaze as admiration. Another guy, >> Charles, realizes that she thinks Adam's a jerk, but that she >> should be polite and pay attention to what he's saying. The >> "dynamical interaction" for Brad and Charles is the same, if it >> refers to the world of observable action, but the meanings are >> very different. Another example: a poet reading a magazine >> article on quarks doesn't get the same meaning from it as a >> science graduate. >> >> How can meaning be *anything but* in the head -- even though it >> may often control interactions with the world. A meaning (or >> schema) is a control system, located in the brain (which, >> according to my physiologist friends, is in the head). Its >> location in the head doesn't prevent its guiding interactions >> with the world. No brain, no meanings. Different brains, >> different meanings. >> >> Can you have meanings without sensory inputs? Try dreams. Can >> you have meanings without brains? Ask a brick. >> >> Of course "meaning" is part of a dyadic relation involving (1) a >> temporarily assembled structure of meanings (or schemas), for >> dealing with a certain thing or situation, and (2) the thing or >> situation itself -- which, according to Kant, we can never know >> *directly*, but only through the meanings we use in interpreting >> it. Sometimes the second term (the thing or situation itself) is >> something in the external world, and sometimes not, as when I >> reflect on my own thought processes. >> >> Some time ago, I published a lengthy paper that described mental >> schemas as >> generators of underlying patterns that interacted to control >> perception, cognition, >> and action. It may be of interest as an alternative to the >> theory of direct >> perception. I debated the issue with Jimmy Gibson, but we >> couldn't convince >> one another. >> >> Bregman, A.S. Perception and behavior as compositions of >> ideals. >> Cognitive Psychology, 1977, 9, 250-292. >> >> - Al >> ------------------------------------------------- >> Albert S. Bregman, Emeritus Professor >> Dept of Psychology, McGill University >> 1205 Docteur Penfield Avenue >> Montreal, QC, Canada H3A 1B1 >> >> Office: >> Phone: +1 (514) 398-6103 >> Fax: +1 (514) 398-4896 >> Home: >> Phone & Fax: +1 (514) 484-2592 >> Email: >> bregman(at)hebb.psych.mcgill.ca >> ------------------------------------------------- > >-- >_______________________________________ >John G. Neuhoff >Department of Psychology >The College of Wooster >Wooster OH 44691 > >Voice: 330-263-2475 >FAX: 520-244-5577 > >http://pages.wooster.edu/jneuhoff/index.htm > >Alternate email: jneuhoff(at)mediaone.net