Percepts are the things given by perception / taken in the act of perceiving.
Concepts are the things added to perception / things with the taken.
Traditional and Mainstream Contemporary Views
Most of modern psychology grows out of the tradition of "British Empiricism", at least in the sense that most psychologists assumed that perception gives some sort of atomistic units that must be put together and made sense of through some mental process. They assume that percepts - what is gotten from the world - are, as Gibson would somewhat mockingly say, a "scintillation of sensations", an inherently meaningless array of color points, pressure measures, scent elements, etc. Sometimes psychologists more generously start from something like the stationary retinal image, in which case percepts are a disconnected patchwork of colored shapes, sounds, touches, smells, etc.
From either of these starting points, the mind must provide relationships between the elements of sensation, and must provide meaning to clusters of those elements. This leads to the assertion, still occasionally found in the extreme form, that all relations are 'mental' and all meaning is 'mental'. By this understanding, concepts - what is added to the percepts - include any relationships we might express by a preposition (next to, part of, connected with, after, over, because of, etc.), as well as anything we might express in terms of category membership (chair, tall, smooth, dangerous, edible, disgusting, etc.).
I don't have a problem that Intro textbooks encourage this way of thinking, but I have a problem when they don't provide what is needed for students to think clearly along these lines. A few things that any exposition of concepts and percepts should make clear:
- Percepts are those things given directly, our most basic elements of experience. They are (psychologically) unmediated.
- How we arrive at our concepts is very mysterious, and if you don't like having a separate soul-stuff or mind-stuff, then you need a theory about how the physical brain can 'add' to what it gets from the world. (Incidentally, this is what the computer model of the mind is about, i.e. modern cognitive psychology, but the part of the textbook explicitly about 'cognitive psychology' is never meaningfully connected with the part that talks about 'concepts.' Uhg!)
- What we think the minds needs to supply is therefore a function of what we think we can get from the environment itself.
A bit of William James
William James's philosophy flips much of traditional psychology upside down, and asserts (usually convincingly) that the result is right-side up. Thus, it is a good place to start talking about alternatives to the traditional view. Many of James's criticisms involve the psychologists fallacy, wherein someone mistakes the endpoint of an process for the starting point of the process. I don't want to focus on the fallacy itself, but do want to explore one of James's critiques that involves the fallacy.
James claimed that the British Empiricists had it exactly backwards: The most basic unit of experience is the complex world in which we find ourselves - for example, right now my experience is of a room with a TV and two toddlers, a table, some chairs, a computer on which I am writing, etc. James points out that it is a complex and difficult-to-develop skill to "see" the world as composed of more basic elements - for example to see the table as composed of a brown circle connected to perpendicular thin rectangles. It is an even more sophisticated ability to "see" the world as 'in perspective' - for example, to see the table top as 'appearing as a brown oval' (because I am not viewing it from directly above).
This is not mere speculation on James's part, and one does not need to buy into his 'world of pure experience' to be convinced he is correct. Any study of the history of art, or of the development of artistic abilities within an individual, would instantly evidence that the ability to see the world as composed of basic elements, and especially to see it as 'in perspective', is a sophisticated skill. There would not be a thriving market for art books that show us the world broken up into basic shapes if everyone already saw the world that way with ease.
Although he did not bring up James, or the psychologists fallacy, Tom Stoffregen gave a heartfelt, incredibly serious, and also hilarious, talk on this subject at this years ICPA meeting entitled "How Plato is used to Brainwash Helpless Toddlers." In it Stoffregen showed examples of so-called "educational programs" designed to teach toddlers to see the world as composed of basic platonic elements. Imagine traumatically Disney-esque songs about how a person is just a circle on top of some rectangles. Tom felt that this was incredibly problematic, because he thought it was part of a vast conspiracy to make it difficult for his undergraduate students to understand what how perception really works (i.e., to understand perception from an Ecological perspective). It is... or at least it is part of a vast network of early childhood experiences that have that effect.
Of course, James would not label it problematic that people develop the ability to experience objects as composed of 'platonic elements', but James would have agreed that it is very problematic that people do not realize how hard it was for them to master this ability. By not examining the development of this skill, psychologists fell into the psychologists fallacy, they assumed that a sophisticated skill was what we started with, they assumed erroneously that the most basic state of vision is to register our world in terms of colored platonic forms. It is true that we can take the things we experience and break them apart into simpler pieces, but we are getting everything backwards if we thereby assume that we started with the smaller pieces!
In none of this does James reject the original meaning of the terms 'precept' and 'concept', but he suggesting that we have the contents of the categories backwards. James is suggesting that what we get directly is a world full of meaningful objects and events in relationships with each other (i.e., a 'stream' of things and happenings). He is further suggesting that from those direct experiences we 'mentally' create the categories of 'color', 'shape', 'element', etc. Thus, I perceive the table, and I sometimes conceive of it as a collection of connected basic shapes.
(For now I will skip over how the more eccentric stuff James wrote later in life alters this story a bit more.)
A few people have noted that Gibson's work can be best understood within the intellectual lineage of 'American Philosophy'. That is, Gibson's work connects strongly with James's work (see discussions by Harry Heft, Ed Reed, and a few other authors in my almost-out edited volume). One way to explain the relationship between is to say that Gibson was uncovering a mechanism by which James's claims could be true. That is, Gibson's theory takes as a description that people directly experience the objects and events of the world as interconnected and meaningful. Gibson claims that the organism 'resonates' with complex patterns of energy in the environment that are 'specific to' the objects and events of the surrounding world. Because objects and events have consequences for an active organism (in exactly the way that a disjointed scintillation of lights and sounds do not), what the organism 'gets' is inherently meaningful, in at least a minimal sense.
If it is true that we are sensitive to such complex patterns (higher-order invariants), and there is plenty of evidence that we are, then we can 'get' many (if not all) relationships between objects and events in our surrounding directly through perception, and 'get' many (in not all) meanings of those objects directly through perception. Thus 'percepts' can include relationships and meanings.
It is a problem when 'concepts' is taught without being contextualized by 'percepts'. It is problematic because the term makes no sense except as part of a pair, and because a failure to understand the relationship between the pair of terms makes it very difficult to discuss alternative ideas about what those categories should include. This has the most obvious effect of leaving students with an incomplete and disjointed understanding of the mainstream system they are being taught - some variant of modern cognitive psychology. It also causes the less obvious (to most people) problem, that students have tremendous difficulty understanding alternative approaches to mainstream psychology, including some of those rapidly gaining traction (i.e., variants of 'embodied cognition' and 'extended cognition').
Brief Connection with Future Discussion
Because the traditional distinction between precepts and concepts has been around for so long, people often think about challenges we face (both in our normal lives and in the lab) as being either perceptual or conceptual challenges. For example, a given experiment may be classified as either a 'perceptual task' or a 'conceptual task', based on whether we think people can succeed at the task based on percepts alone, or if we think it requires the use of concepts. This leads to much confusion when alternative approaches are discussed. For example, an essential goal of many ecological psychologists is to show that so-called 'conceptual tasks' can be solved with perceptual mechanisms. This quickly leads to a discussion in which the labels create unnecessary confusion. Everything essential in the declaration that "conceptual task X has been solved by perception means", is more cleanly expressed in the assertion "X is a perceptual task." But the latter claim is deemed a priori invalid by the mainstream. The battle for clarity thus often gets hijacked by the historic momentum of our terms.