What is an image and what is a neural pattern?
"When I use the term image, I always mean mental image. A synonym for image is mental pattern. I do not use the word image to refer to the pattern of neural activities that can be found, with current neuroscience methods, in activated sensory cortices - for instance, in the auditory cortices in correspondence with an auditory percept; or in the visual cortices in correspondence with a visual percept. When I refer to the neural aspect of the process I use terms such as neural pattern or map."Images can be conscious or nonconscious... Nonconscious images are never accessible directly. Conscious images can be accessed only in a first-person perspective (my images, your images). Neural patterns, on the other hand, can be accessed only in a third-person perspective. If I had the chance of looking at my own neural patterns with the help of the most advanced technologies, I would still be looking at them from a third-person perspective."
Images are not just visual
"By the term images I mean mental patterns with a structure built with the tokens of each of the sensory modalities - visual, auditory, olfactory, gustatory, and somatosensory. The somatosensory modality (the word comes from the Greek soma which means "body") includes varied forms of sense: touch, muscular, temperature, pain, visceral, and vestibular. The word image does not refer to "visual" image alone, and there is nothing static about images either. The word also refers to sound images such as those caused by music or the wind, and to the somatosensory images that Einstein used in his mental problem solving - in his insightful account, he called those patterns "muscular" images. Images in all modalities "depict" processes and entities of all kinds, concrete as well as abstract. Images also "depict" the physical properties of entities and, sometimes sketchily, sometimes not, the spatial and temporal relationships among entities, as well as their actions. In short, the process we come to know as mind when mental images become ours as a result of consciousness is a continuous flow of images many of which turn out to be logically interrelated. The flow moves forward in time, speedily or slowly, orderly or jumpily, and on occasion it moves along not just one sequence but several. Sometimes the sequences are concurrent, sometimes convergent and divergent, sometimes they are superimposed. Thought is an acceptable word to denote such flow of images."Constructing images
"Images are constructed either when we engage objects, from persons and places to toothaches, from the outside of the brain toward its inside; or when we reconstruct objects from memory, from the inside out, as it were. The business of making images never stops while we are awake and it even continues during part of our sleep, when we dream. One might argue that images are the currency of out minds. The words I am using to bring these ideas to you are first formed, however briefly and sketchily, as auditory, visual, or somatosensory images of phonemes and morphemes, before I implement them on the page in their written version. Likewise, those written words now printed before your eyes are first processed by you as verbal images before they promote the activation of yet other images, this time nonverbal, with which the "concepts" that correspond to my words can be displayed mentally. In this perspective, any symbol you can think of is an image, and there may be little leftover mental residue that is not made of images. Even the feelings that make up the backdrop of each mental instant are images, in the sense articulated above, somatosensory images, that is, which mostly signal aspects of the body state. The obsessively repeated feelings that constitute the self in the act of knowing are no exception."Images may be conscious or nonconscious. It should be noted, however, that not all images the brain constructs are made conscious. There are simply too many images being generated and too much competition for the relatively small window of mind in which images can be made conscious - the window, that is, in which images are accompanied by a sense that we are apprehending them and that, as a consequence, are properly attended. In other words, metaphorically speaking, there is indeed a subterranean underneath the conscious mind and there are many levels to that subterranean. One level is made of images not attended, the phenomenon to which I have just alluded. Another level is made of the neural patterns and of the relationships among neural patterns which subtend all images, whether they eventually become conscious or not. Yet another level has to do with the neural machinery required to hold records of neural patterns in memory, the kind of neural machinery which embodies innate and acquired implicit dispositions."
http://world.std.com/~awolpert/gtr398.html