Delusions and theories of belief

Cognitive neuropsychiatry is a branch of cognitive psychology that seeks to explain neuropsychiatric symptoms in terms of disruptions or damage to normal cognitive processes. A key objective of this approach is to use insights derived from the study of pathological symptoms to inform accounts of premorbid cognitive systems. Delusions, in particular, can be considered to represent dysfunction of the cognitive processes underlying belief formation, so studying delusions may provide unique insights into nonpathological belief. While this approach has provided compelling accounts for a range of delusions in terms of putative cognitive dysfunctions, it is less clear that it has achieved progress in its reciprocal goal of informing understanding of belief more generally. In this review, we trace the origins of the cognitive neuropsychiatric approach and consider the reasons for the lack of progress. We propose a tentative framework to overcome these challenges and suggest directions for future research.     

言语与空间任务指令对数字-空间联结编码的影响

以1～9除5外的阿拉伯数字和汉字标签“左”“右”为实验材料,采用数字奇偶判断任务,探讨任务指令对数字-空间联结编码的影响。结果发现：言语任务指令条件下,词语一致性与物理一致性的交互作用显著,且词语一致和不一致时均未发现空间-数字联合反应编码效应（SNARC）,表明言语-空间编码在数字-空间联结中更有优势;空间任务指令条件下,物理一致性主效应显著,且词语一致和不一致时均出现了SNARC效应,表明视觉空间编码更有优势。说明数字-空间联结编码受实验任务指令的影响,被试会根据任务指令设置的情景选择视觉空间编码或言语-空间编码对数字进行空间联结。     

Interference and the representation of order within associations

In the presence of interference, recall of pairs can critically depend on the diagnostic power of memory of the order of items within the pair. Models of pair memory make different assumptions about whether and how such order information is stored, from convolution-based models, which assume no explicit storage of order, to matrix models and several models that assume a pair is learned by concatenating the representations of the constituent items, which lead to perfect within-pair order memory (given retrieval of the pair). Here we investigate memory for associations and within-pair order by examining the relationship between forward and backward probes of pairs subject to order-dependent associative interference in a double-function list paradigm. Associative interference disrupted the high correlation between forward and backward recall accuracy that is typically observed in standard paired-associate learning, challenging matrix and concatenation-based models. However, participants could overcome some interference due to within-pair order ambiguity, challenging directionally ambiguous convolution-based models. Unexpectedly, the test–retest correlation was reduced for pairs under the influence of interference compared to control pairs. This finding is incompatible with all existing implementations of the model classes we consider. Any model must include an assumption that order encoding (but not retrieval) is unreliable, and the form of this additional mechanism may depend intimately on how a given model is designed. In sum, our findings suggest that within-pair order memory is neither poor nor perfect, pointing to a fallible mechanism for within-pair order learning in verbal association-memory tasks.     

Avicenna's Conception of the Efficient Cause

The concept of efficient causation originates with Aristotle, who states that the types of cause include ‘the primary source of the change or rest’. For Medieval Aristotelians, the scope of efficient causality includes creative acts. The Islamic philosopher Avicenna is an important contributor to this conceptual change. In his Metaphysics, Avicenna defines the efficient cause or agent as that which gives being to something distinct from itself. As previous studies of Avicenna's ‘metaphysical’ conception of the efficient cause attest, it takes God as a model agent. This essay considers whether Avicenna's ‘metaphysical’ conception of the efficient cause applies to natural agents. It ultimately argues that Avicenna offers a unified view of the efficient cause, which includes both divine and natural agents. On this view, an efficient cause gives being to another and is simultaneous with its effect. While Avicenna's defence of this view is an important chapter in the history of the concept of the efficient cause, it is also of interest in its own right. By appeal to a version of the principle of sufficient reason, it challenges a widespread view that causes are temporally prior to their effects.     

Is the perceived present a predictive model of the objective present?

ABSTRACT

Processing latencies for coherent, high level percepts in vision are at least 100?ms and possibly as much as 500?ms. Processing latencies are less in other modalities, but still significant. This seems to imply that perception lags behind reality by an amount equal to the processing latency. It has been proposed that the brain can compensate for perceptual processing latencies by using the most recent available information to extrapolate forward, thereby constructing a model of what the world beyond the senses is like now. The present paper reviews several lines of evidence relating to this hypothesis, including the flash-lag effect, motion-induced position shifts, representational momentum, static visual illusions, and motion extrapolation at the retina. There are alternative explanations for most of the results but there are some findings for which no competing explanation has yet been proposed. Collectively, the evidence for extrapolation to the present is suggestive but not yet conclusive. An alternative account of compensation for processing latencies, based on the hypothesis of rapid emergence of percepts, is proposed.     

Perception and production of object-related grasping in 6-month-olds

In this study, 6-month-olds’ perception of an object-related human grasping action was compared with their level of grasping performance using a within-participants design. In the action perception task, infants were presented with the video of an actor’s grasping movement toward an occluded target object. Subsequently, an expected and an unexpected final state of this grasping movement were presented simultaneously, and infants’ looking times were measured. In the action production task, infants were presented with three graspable objects. Infants’ grasping behavior was coded to be either palmar or thumb-opposite grasping. Results indicate that infants who were already able to perform a thumb-opposite grasp differentiated between the two final states in the action perception task by looking longer toward the unexpected final state. In contrast, infants who showed only palmar grasps looked equally long toward both final states. This finding supports the assumption that action perception and action control are already closely related in infants as young as 6 months.