Identification of abnormal movements with 3D accelerometer sensors for seizure recognition

Human-activity recognition and seizure-detection techniques have gathered pace with the widespread availability of wearable devices. A study of the literature shows various studies for 3D accelerometer-based seizure detection that describe the selection of acceleration variables and controlled transformations, while discarding the remaining input variable contributions. The aim of this research is to evaluate feature extraction based on different techniques and with the advantage of an overview of all information on the problem. Three feature extraction techniques – namely, Locally Linear Embedding, Principal Component Analysis (PCA) and a Distance-Based PCA – are analyzed and their outcomes compared against K-Nearest Neighbor and Decision Trees. A realistic experimentation simulating epileptic mioclonic convulsions was performed. The PCA-based methods were found to produce solutions that managed the problem perfectly well, either learning specific models for each individual or learning generalized models.     

视觉词汇识别中的字符位置编码

在阅读中,为了进行视觉词汇的识别,需要对字符(字母或汉字)的顺序进行编码(位置信息编码)。本文介绍了拼音文字中的字母位置编码模型,包括开放双字母组模型、空间编码模型和重叠模型,综述了拼音文字和中文词汇识别中字符位置信息编码的研究成果,并对汉字位置信息编码研究提出了展望。     

Reference directions and reference objects in spatial memory of a briefly viewed layout

Two experiments investigated participants' spatial memory of a briefly viewed layout. Participants saw an array of five objects on a table and, after a short delay, indicated whether the target object indicated by the experimenter had been moved. Experiment 1 showed that change detection was more accurate when non-target objects were stationary than when non-target objects were moved. This context effect was observed when participants were tested both at the original learning perspective and at a novel perspective. In Experiment 2, the arrays of five objects were presented on a rectangular table and two of the non-target objects were aligned with the longer axis of the table. Change detection was more accurate when the target object was presented with the two objects that were aligned with the longer axis of the table during learning than when the target object was presented with the two objects that were not aligned with the longer axis of the table during learning. These results indicated that the spatial memory of a briefly viewed layout has interobject spatial relations represented and utilizes an allocentric reference direction.     

Stereotype priming in face recognition: interactions between semantic and visual information in face encoding

The accuracy with which previously unfamiliar faces are recognised is increased by the presentation of a stereotype-congruent occupation label [Klatzky, R. L., Martin, G. L., & Kane, R. A. (1982a). Semantic interpretation effects on memory for faces. Memory & Cognition, 10, 195-206; Klatzky, R. L., Martin, G. L., & Kane, R. A. (1982b). Influence of social-category activation on processing of visual information. Social Cognition, 1, 95-109]. For example, providing the label 'criminal' both during encoding and test improves recognition for previously unfamiliar faces that look like the stereotypical criminal. Experiments 1 and 2 both replicate this effect and show that the label exerts its influence during the encoding of stereotypical faces and has little influence at test. These findings indicate that semantic information that is congruent with novel stereotypical faces facilitates their encoding.     

Perception of speech reflects optimal use of probabilistic speech cues

Listeners are exquisitely sensitive to fine-grained acoustic detail within phonetic categories for sounds and words. Here we show that this sensitivity is optimal given the probabilistic nature of speech cues. We manipulated the probability distribution of one probabilistic cue, voice onset time (VOT), which differentiates word initial labial stops in English (e.g., "beach" and "peach"). Participants categorized words from distributions of VOT with wide or narrow variances. Uncertainty about word identity was measured by four-alternative forced-choice judgments and by the probability of looks to pictures. Both measures closely reflected the posterior probability of the word given the likelihood distributions of VOT, suggesting that listeners are sensitive to these distributions.     

The role of grammatical class on word recognition

The double dissociation between noun and verb processing, well documented in the neuropsychological literature, has not been supported in imaging studies. Recent imaging studies, in fact, suggest that once confounding with semantics is eliminated, grammatical class effects only emerge as a consequence of building frames. Here we assess this hypothesis behaviorally in two visual word recognition experiments. In Experiment 1, participants made lexical decisions on verb targets. We manipulated the grammatical class of the prime words (either nouns or verbs and always introduced in a minimal phrasal context, i.e., “the + N” or “to + V”), and their semantic similarity to a target (related vs. unrelated). We found reliable effects of grammatical class, and no interaction with semantic similarity. Experiment 2 further explored this grammatical class effect, using verb targets preceded by semantically unrelated verb vs. noun primes. In one condition, prime words were presented as bare words; in the other, they were presented in the minimal phrasal context used in Experiment 1. Grammatical class effects only arose in the latter but not in the former condition thus providing evidence that word recognition does not recruit grammatical class information unless it is provided to the system.     

Declarative Memory

ABSTRACT— Neuroimaging of declarative memory is not an endeavor divorced from psychology but, instead, is another path through which a more complete understanding of memory has emerged. Specifically, neuroimaging allows us to determine if differences between memory states emerge from quantitatively or qualitatively distinct underlying encoding operations. Further, it has allowed for greater specification of the putative control operations adopted when we make decisions about our memories. We describe some examples of insights provided by neuroimaging into the many and varied processes that support encoding and retrieval of declarative memory.     

Restating the role of phenomenal experience in the formation and maintenance of the Capgras delusion

In recent times, explanations of the Capgras delusion have tended to emphasise the cognitive dysfunction that is believed to occur at the second stage of two-stage models. This is generally viewed as a response to the inadequacies of the one-stage account. Whilst accepting that some form of cognitive disruption is a necessary part of the aetiology of the Capgras delusion, I nevertheless argue that the emphasis placed on this second-stage is to the detriment of the important role played by the phenomenology underlying the disorder, both in terms of the formation and maintenance of the delusional belief. This paper therefore proposes an interactionist two-stage model in which the phenomenal experience of the Capgras patient is examined, emphasised, and its relation to top-down processing discussed.