Cortical stimulation has been used for brain mapping for over a century, and a standard assumption is that stimulation interferes with task execution due to local effects at the stimulation site. Stimulation can however produce afterdischarges which interfere with functional localization and can lead to unwanted seizures. We previously showed that cognitive effort can terminate these afterdischarges, when termination thus occurs, there are electrocorticography changes throughout the cortex, not just at sites with afterdischarges or sites thought functionally important for the (...) cognitive task used, and thresholds for afterdischarges and functional responses can change among stimulation trials. We here show that afterdischarge termination can occur prior to overt performance of the cognitive tasks used to terminate them. These findings, taken together, demonstrate that task-related brain changes are not limited to one or a group of functional regions or a specific network, and not limited to the time directly surrounding overt task execution. Discrete locations, networks and times importantly underpin clinical behaviors. However, brain activity that is diffuse in location and extended in time also affect task execution and can affect brain mapping. This may in part reflect fluctuating levels of attention, engagement, or motivation during testing. (shrink)

Significant research has been devoted to detecting people in images and videos. In this paper we describe a human de- tection method that augments widely used edge-based fea- tures with texture and color information, providing us with a much richer descriptor set. This augmentation results in an extremely high-dimensional feature space (more than 170,000 dimensions). In such high-dimensional spaces, classical machine learning algorithms such as SVMs are nearly intractable with respect to training. Furthermore, the number of training samples is much (...) smaller than the dimensionality of the feature space, by at least an order of magnitude. Finally, the extraction of features from a densely sampled grid structure leads to a high degree of multicollinearity. To circumvent these data characteristics, we employ Partial Least Squares (PLS) analysis, an effi- cient dimensionality reduction technique, one which pre- serves significant discriminative information, to project the data onto a much lower dimensional subspace (20 dimen- sions, reduced from the original 170,000). Our human de- tection system, employing PLS analysis over the enriched descriptor set, is shown to outperform state-of-the-art tech- niques on three varied datasets including the popular INRIA pedestrian dataset, the low-resolution gray-scale Daim- lerChrysler pedestrian dataset, and the ETHZ pedestrian dataset consisting of full-length videos of crowded scenes. (shrink)

This selection of papers that were presented (or nearly so!) to the Boston Colloquium for the Philosophy of Science during the seventies fairly re presents some of the most disturbing issues of scientific knowledge in these years. To the distant observer, it may seem that the defense of rational standards, objective reference, methodical self-correction, even the distin guishing of the foolish from the sensible and the truth-seeking from the ideological, has nearly collapsed. In fact, the defense may be seen to (...) have shifted; the knowledge business came under scrutiny decades ago and, indeed, from the time of Francis Bacon and even far earlier, the practicality of the discovery of knowledge was either hailed or lamented. So the defense may be founded on the premise that science may yet be liberating. In that case, the analysis of philosophical issues expands to embrace issues of social interest and social function, of instrumentality and arbitrary perspective, of biological constraints (upon knowledge as well as upon the species-wide behavior of human beings in other relationships too), of distortions due to explanatory metaphors and imposed categories, and of radical comparisons among the perspectives of different civilizations. Some of our contributors are frankly programmatic, showing how problems must be formulated afresh, how evasions must be identified and omissions rectified, but they do not reach their own completion. (shrink)

Implicit processes almost certainly preceded explicit processes in our evolutionary history, so they are likely to be more resistant to disruption according to the principles of evolutionary biology [Reber, A. S. . The cognitive unconscious: An evolutionary perspective. Consciousness and Cognition, 1, 93–133.]. Previous work . Knowledge, nerves and know-how: The role of explicit versus implicit knowledge in the breakdown of a complex motor skill under pressure. British Journal of Psychology, 83, 343–358.]) has shown that implicitly learned motor skills remain (...) stable under psychological pressure and concurrent cognitive demands, and recently [Poolton, J. M., Masters, R. S. W., & Maxwell, J. P. . Passing thoughts on the evolutionary stability of implicit motor behaviour: Performance retention under physiological fatigue. Consciousness and Cognition, 16, 456–468.] showed that they also remain stable under conditions of anaerobic fatigue that would have significantly challenged the survival skills of our ancestors. Here we examine the stability of an implicitly learned motor skill under fatigue conditions that primarily tax a different physiological system , but which have equally strong evolutionary connotations. Participants acquired a throwing task by means of an errorless learning method or an errorful method. Motor performance in the errorless condition, but not the errorful condition, remained stable following an exhaustive VO2 max. running test. Our findings replicate and extend the work of Poolton et al., providing further support for Reber’s evolutionary distinction between implicit and explicit processes. (shrink)

Proceedings of the Boston Colloquium for the Philosophy of Science 1969/1972.

During the last twelvemonth we have been engaged in finally preparing for press the first volume of our text of Livy in the Bibliotheca Classica Oxoniensis, and we now desire to submit beforehand to the judgement of scholars some of the chief alterations in the current text that we have been led to adopt. It will be seen that some proportion of them consist of little more than a defence of the MS tradition; and where we have proposed changes of (...) our own, we have, we believe, rigorously confined ourselves not merely to such suggestions as can be readily reconciled with the reading of at least one good manuscript, but to such as provide in each case a tenable explanation of the origin of all the variants in all the MSS that we have consulted. In several difficult places we have become persuaded that corruption has arisen through slight and accountable dislocations of order, and in a still larger number from the incorporation of marginal or interlinear glosses not differing in character from those which still appear in great numbers in all the MSS of the 9th to the 12th centuries, but which have not forced their way into the text. A typical example will be found in our note on V. 2. 8. (shrink)

Restitere primo obstinatis animis; deinde ut obtinentes locum †uires ferebant† audent ultro gradum inferre.

Plato's fondness for words compounded with παν- is obvious at the most cursory reading of his works; this characteristic of his style becomes even more striking when his use of these words is compared with their frequency in earlier authors. An investigation of Platonic usage in this respect, relatively easy since the publication of Leonard Brandwood's Word Index to Plato , yields interesting results. Whether the effect of the παν-prefix is intensive or determinative , Plato has a tendency to associate (...) these words with some sort of disapproval; this disapproval is sometimes explicit enough and can sometimes be inferred from the use of the word, or of a word related to it, in other contexts. The words may be used ironically, as πγκαλος often is and πσσοος always. Another sort of disapproval springs from what may be called Plato's general dislike of (promiscuous plurality, excess and variety; for a philosopher who believes in single, unchanging Forms there is something intrinsically objectionable in such words as πμπολυς and παντοδαπς. It also transpires that Plato may have coined a number, of these words and that he was probably the first prose writer to import others from poetry; in the face of the fragmentary nature of surviving Greek literature it would be unwise to be more dogmatic. The following, somewhat dry, survey will, it is hoped, throw some light on the usage of these interesting words. (shrink)

Plato's fondness for words compounded with παν- is obvious at the most cursory reading of his works; this characteristic of his style becomes even more striking when his use of these words is compared with their frequency in earlier authors. An investigation of Platonic usage in this respect, relatively easy since the publication of Leonard Brandwood's Word Index to Plato, yields interesting results. Whether the effect of the παν-prefix is intensive or determinative, Plato has a tendency to associate these words (...) with some sort of disapproval; this disapproval is sometimes explicit enough and can sometimes be inferred from the use of the word, or of a word related to it, in other contexts. The words may be used ironically, as πγκαλος often is and πσσοος always. Another sort of disapproval springs from what may be called Plato's general dislike of (promiscuous plurality, excess and variety; for a philosopher who believes in single, unchanging Forms there is something intrinsically objectionable in such words as πμπολυς and παντοδαπς. It also transpires that Plato may have coined a number, of these words and that he was probably the first prose writer to import others from poetry; in the face of the fragmentary nature of surviving Greek literature it would be unwise to be more dogmatic. The following, somewhat dry, survey will, it is hoped, throw some light on the usage of these interesting words. (shrink)