The Chinese room reacts just to syntax, or shape of symbols (is purely syntactic). But brains are full of structure. In the room, Chinese symbols sit scattered in "piles" on the floor or are moved around in "batches" or "bunches", or are stored jumbled up in "baskets" with no structural connections between the symbols.
The things computers process are called "symbols". Computers can build structure between symbols and react to, or follow, it, and often do. Virtual connections between memory locations can be established using pointers, and algorithms can follow the connections using the methods of direct memory addressing and indirection.
This structural, or relational, ability of the computer program can be mirrored in the Chinese room by adding to the room's ontology a new object type: string. Instances of string in the room can then connect tokenised Chinese symbols. Every piece of string has the same characteristics including length. They are the embodiment of structure, are relational elements of structure.
In the room, if the connections established between symbols are a causal consequent of temporal contiguity at the sensory surface resulting in contiguous sensory symbols exiting the sensor then entering the room, the connections between the sensory symbols record as internal structure the external instances of temporal contiguity at the sensory surface. Is such an internal structure an element of semantic content?
In the computer, if the internal memory structures built with pointers are trees, a program can walk the trees and emit as output copies of the leaves (symbols), without reacting to (identifying) the shapes of the symbols. The program merely copies and emits whatever it arrives at that has no children. The program contains no conditionals indexed on symbol shape.
Suppose Searle is blindfolded then walks a tree by following the string with his hands. When he arrives at a leaf (a card inscribed with a Chinese ideogram which card has no downward strings attached) he emits the card then continues on his tactile tree walk. Since the rules he is following do not instruct a reaction to the shape of any Chinese symbol (and hence do not contain an example or description of any Chinese symbol shape), does this mean the program in the rule book is non-syntactic with respect to Chinese symbols, and Searle manipulates the symbols non-syntactically?
In 2014, Searle says (his emphasis): "...a digital computer is a syntactical machine. It manipulates symbols and does nothing else" ("What Your computer Can't Know", in The New York Review of Books, October 9, 2014, section 2, para 7). String is not symbols. Is his careful avoidance of structure his fundamental mistake?