Research on the Recognition System in the Brain

The processing necessary to recognize any object is distributed, with color processed in one place, shape in another, orientation and location in still others (Wallis & Bulthoff, 1999). Distributed processing allows the recognition system to operate like an efficient committee, with different brain areas taking on small parts of a task and carrying them out simultaneously. This is the brain's version of what computer scientists call "parallel processing." Its great advantage is speed; a number of systems performing sub-tasks at the same time (in parallel) is faster than having one system do them one after the other (serially), especially when the work to be done is complex (Cytowic, 1996). At the same time, distributed processing underlies some of the differences in how students learn to recognize patterns. Individuals' varying abilities to identify color, shape, or location mean they face different recognition problems and will respond differently to particular learning materials and teaching techniques.

Distributed, parallel processing of individual elements helps the recognition system to categorize patterns. Indeed, recognition is rooted in classification. Our ability to recognize the letter H depends on understanding the essential elements that define a category we might call "H-ness." Color, size, and whether the symbol is ink on paper, carved wood, or molded plastic are irrelevant. The critical elements are the two generally parallel lines connected by a crossbar somewhere near the middle. The following symbols are not identical, but our understanding of H-ness lets us identify them all as upper-case H.

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Once thoroughly mastered, categories make future recognition flexible and fast, but learning them is a demanding task, and automatic, accurate recognition requires considerable practice. Recognizing that a particular stimulus fits into an established category is mainly accomplished by the recognition systems. Learning a whole new category, on the other hand, is a whole-brain activity, involving the strategic and affective systems along with the recognition systems (Robin & Holyoak, 1995).

The key role of pattern recognition in writing is illuminated by studying one of the most unusual neurological conditions reported in the literature: alexia without agraphia. Patients with this disorder are completely unable to read (they have alexia) yet they are able to write (they do not have agraphia). Such patients can actually write a sentence, but cannot read their own sentences back (Duffield et al. 1994; Erdem & Kansu, 1995). Alexia without agraphia is associated with damage to the posterior cortex, the area of the brain where the recognition system resides. The frontal cortex, where the motor production of written language is generated, is undamaged, enabling a form of writing to take place.

Patients with this syndrome may write, but they do not write well. With a damaged recognition system, their writing is limited to routinized expressions learned before they were injured, and they have limited capacity to generate extended text, or to monitor themselves during or following writing. These findings confirm the critical role played by the recognition system in writing. Recognition is equally essential when students are learning to write and when skilled writers write fluently.

Beginning writers must recognize the conventions of spoken and written language as a part of learning to master them. Learning to form the letter A or to write a sentence requires thorough understanding of the target pattern. Accurate knowledge of a pattern is more likely to lead to accurate reproduction of that pattern, though it does not guarantee it. As children are learning, the connection between recognizing and producing must constantly be active. This enables learners to set a goal, write, and evaluate and refine the result. This does not mean that children cannot engage in meaningful communication before mastering the conventional patterns of the language. With appropriate supports, or by using unconventional yet interpretable patterns (such as "invented spellings"), very young children can communicate effectively in writing. Ultimately, though, mastery of conventions forms the basis for efficient and effective written communication.

Mature, accomplished writers also constantly rely on the recognition system. The brain's recognition mechanisms are critical for all levels of self-monitoring, including evaluating graphemic and syntactic correctness, assessing effectiveness, and determining whether one's purpose has been accomplished. Does the piece conform to the structural requirements of the form (e.g., a letter, a résumé, a persuasive essay)? Does the piece meet the needs of the intended audience? Are the tone and language appropriate? The recognition system is constantly "in the loop" as mature writers write.

For all kinds of neurological reasons, far short of a syndrome such as alexia without agraphia, individuals differ tremendously in their capacity to recognize patterns and to apply that recognition as they write. Problems mastering sound-symbol correspondences, syntactic patterns, paragraph organization, and the structure of various kinds of compositions all can affect both reading and written expression. Awareness of the crucial role of pattern recognition in writing can help teachers support students with diverse recognition problems.