{"content":[{"text":"Syntax and the Brain","bbox":{"left":0.658921,"top":0.047029,"width":0.16499600000000003,"height":0.016779000000000002}},{"text":"1.2 The algorithmic level – sentence processing","bbox":{"left":0.118039,"top":0.092483,"width":0.37405700000000003,"height":0.016779000000000002}},{"text":"Once the computational theory is established, it is then possible to investigate how it is that the \n computational problem is solved. In the case of the cash register’s need to solve the problem of \n addition, several possible algorithms are possible depending on the basic units that are used to \n compose the representation. For example, if the basic units of the representation are the base-10 \n Arabic numerals (0, 1, 2, 3…), then one possible algorithm is the “carry-over” procedure familiar \n to all school children: add the digits farthest to the right (least significant), and if the sum \n exceeds 9, carry over the leftmost digit of the sum to the next column to the left. Crucially, other \n units could be chosen for the representation, such as base-2 or binary units (0,1), which will \n necessitate a different algorithm for executing the addition. In other words, representational \n assumptions constrain algorithmic choices. Furthermore, there may be several different \n algorithms available for any given choice of units of representation, in which case the choice of \n algorithm may depend upon issues of efficiency or the desire to make certain types of \n information more easily available than others. Just as syntactic theory is in many ways a \n computational theory of sentences, the theories of sentence processing developed by \n psycholinguists are in many ways algorithmic theories. As we will see shortly, theories of \n sentence processing begin with different representational assumptions drawn from the \n computational theory (some assume that the basic units are words and syntactic rules, others that \n the basic units are syntactic frames) that constrain the types of algorithms that are proposed \n (structure-generation versus retrieval and unification).","bbox":{"left":0.118039,"top":0.127332,"width":0.764448,"height":0.330415}},{"text":"1.3 The implementational level – neurolinguistics","bbox":{"left":0.118039,"top":0.475816,"width":0.389883,"height":0.01677899999999999}},{"text":"Obviously there are multiple ways to physically implement a device like a cash register. One \n could use multiple spinning cylinders like the analog cash registers of the 20th century, or \n microchips as is common in computers today. However, the choice of implementation constrains \n both the units of the representation and the algorithms that are available for executing addition: \n analog cylinders tend to use base-10 numerals and an algorithm similar to the “carry-over” \n procedure, whereas computers use a binary representation and a bit-wise calculation. When it \n comes to cognitive tasks such as vision or sentence processing, the physical implementation is \n obviously the human brain. And although we know relatively little about the types of \n representations and algorithms that the human brain can (and cannot) implement, it is clear that \n the areas of the brain that form the network for any given cognitive task must be capable of \n carrying out at least one algorithm that solves the computational problem of the task. The task of \n developing an implementational theory of sentences rests with neurolinguists, as they leverage \n neuropsychological patient studies and various neuroimaging technologies (e.g., fMRI, PET, \n EEG, MEG) to identify the neural circuits involved in sentence processing.","bbox":{"left":0.118039,"top":0.510665,"width":0.760144,"height":0.243143}},{"text":"1.4 The interaction across levels","bbox":{"left":0.118039,"top":0.771877,"width":0.25316900000000003,"height":0.01677899999999999}},{"text":"In principle, the three levels are only loosely related: for any given computational theory, there \n are any number of algorithms that can be adopted, and any number of physical devices that can \n be used to implement a given algorithm. In fact, the very definition of the computational level \n suggests that it can be investigated completely independently of the other two levels, as it is \n defined as the properties of the problem that are independent of how it is solved. However, in","bbox":{"left":0.118039,"top":0.806726,"width":0.746459,"height":0.08647499999999997}},{"text":"2","bbox":{"left":0.872941,"top":0.938847,"width":0.009804000000000035,"height":0.01677899999999999}}],"images_bbox":[],"images_bbox_not_text_overlap":[]}