Semantically induced distortions of visual awareness in a patient with Balint’s syndrome

We present data indicating that visual awareness for a basic perceptual feature (colour) can be influenced by the relation between the feature and the semantic properties of the stimulus. We examined semantic interference from the meaning of a colour word (‘‘RED”) on simple colour (ink related) detection responses in a patient with simultagnosia due to bilateral parietal lesions. We found that colour detection was influenced by the congruency between the meaning of the word and the relevant ink colour, with impaired performance when the word and the colour mismatched (on incongruent trials). This result held even when remote associations between meaning and colour were used (i.e. the word ‘‘PEA” influenced detection of the ink colour red). The results are consistent with a late locus of conscious visual experience that is derived at post-semantic levels. The implications for the understanding of the role of parietal cortex in object binding and visual awareness are discussed.     

View-invariant object category learning, recognition, and search: how spatial and object attention are coordinated using surface-based attentional shrouds

How does the brain learn to recognize an object from multiple viewpoints while scanning a scene with eye movements? How does the brain avoid the problem of erroneously classifying parts of different objects together? How are attention and eye movements intelligently coordinated to facilitate object learning? A neural model provides a unified mechanistic explanation of how spatial and object attention work together to search a scene and learn what is in it. The ARTSCAN model predicts how an object's surface representation generates a form-fitting distribution of spatial attention, or "attentional shroud". All surface representations dynamically compete for spatial attention to form a shroud. The winning shroud persists during active scanning of the object. The shroud maintains sustained activity of an emerging view-invariant category representation while multiple view-specific category representations are learned and are linked through associative learning to the view-invariant object category. The shroud also helps to restrict scanning eye movements to salient features on the attended object. Object attention plays a role in controlling and stabilizing the learning of view-specific object categories. Spatial attention hereby coordinates the deployment of object attention during object category learning. Shroud collapse releases a reset signal that inhibits the active view-invariant category in the What cortical processing stream. Then a new shroud, corresponding to a different object, forms in the Where cortical processing stream, and search using attention shifts and eye movements continues to learn new objects throughout a scene. The model mechanistically clarifies basic properties of attention shifts (engage, move, disengage) and inhibition of return. It simulates human reaction time data about object-based spatial attention shifts, and learns with 98.1% accuracy and a compression of 430 on a letter database whose letters vary in size, position, and orientation. The model provides a powerful framework for unifying many data about spatial and object attention, and their interactions during perception, cognition, and action.     

Sexual Side Effects of Antidepressant Medications: An Informed Consent Accountability Gap

Sexual side effects of antidepressant medications are far more common than initially reported, and their scope, quality, and duration remain poorly captured in the literature. Antidepressant treatment emergent sexual dysfunctions may decrease clients’ quality of life, complicate psychotherapy, and damage the treatment alliance. Potential damage to the treatment alliance is greatest when clients have not been adequately informed of risks related to sexual side effects. It had previously been assumed that sexual side effects always resolve shortly after medications are discontinued. Emerging evidence, however, suggests that in some individuals, sexual dysfunction side effects may persist indefinitely. The authors argue that all psychologists should be well-informed about sexual side effects risks of antidepressant medications, should routinely conduct a pre-medication baseline assessment of sexual functioning, and take an active role in the informed consent process.

Developmental shifts in fMRI activations during visuospatial relational reasoning

To investigate maturational plasticity of fluid cognition systems, functional brain imaging was undertaken in healthy 8-19 year old participants while completing visuospatial relational reasoning problems similar to Raven's matrices and current elementary grade math textbooks. Analyses revealed that visuospatial relational reasoning across this developmental age range recruited activations in the superior parietal cortices most prominently, the dorsolateral prefrontal, occipital-temporal, and premotor/supplementary cortices, the basal ganglia, and insula. There were comparable activity volumes in left and right hemispheres for nearly all of these regions. Regression analyses indicated increasing activity predominantly in the superior parietal lobes with developmental age. In contrast, multiple anterior neural systems showed significantly less activity with age, including dorsolateral and ventrolateral prefrontal, paracentral, and insula cortices bilaterally, basal ganglia, and particularly large clusters in the midline anterior cingulate/medial frontal cortex, left middle cingulate/supplementary motor cortex, left insula-putamen, and left caudate. Findings suggest that neuromaturational changes associated with visuospatial relational reasoning shift from a more widespread fronto-cingulate-striatal pattern in childhood to predominant parieto-frontal activation pattern in late adolescence.     

The psychological treatment of memory impairment: A review of empirical studies

Memory impairment is a frequent effect of many different forms of brain dysfunction. Memory impairment is also a frequent focus of treatment interventions, and there have been many different treatment methods suggested. The suggested methods include direct retraining, the use of spared skills in compensating for the impairment (alternate functional systems), and the use of behavioral strategies to circumvent the manifest memory dysfunction (behavioral prosthetics). Unfortunately, there are very few studies comparing the various suggested treatment methods. The present paper evaluates the empirical evidence related to the treatment of memory dysfunction and suggests directions for future investigations. Although the evidence is not conclusive, it appears that some forms of treatment may be helpful in remediating certain types of memory impairment. An approach likely to be productive would include some consideration of the impaired neurological and psychological mechanisms responsible for the manifest memory deficit as well as a consideration of the etiology of the injury thought to be causally related to the memory deficit. As yet, there have been no rigorous empirical evaluations of these considerations.     

非失语脑中风患者的神经心理障碍与一年疗效和康复预测的关系

本文以７９例脑中风患者为对象,研究结果如下：１．自编ＡＤＬ,再测信度和结构效度合格。２．一年前后ＡＤＬ、ＤＮＦ及疗效与同期测定的插棍测验、瑞文测验、小棍测验、临摹图形、说同类词及抑郁（一年后）有显著相关。３．初发病时这些指标及图形拼凑测验与一年后ＡＤＬ、ＤＮＦ及疗效也有显著相关。４．ＤＮＦ１和ＡＤＬ１对疗效有明显预测作用,可解释变量的３５％（ＡＤＬ２）、３７％（疗效）和４１％（ＤＮＦ２）。单独心理变量可解释变量的２７％（ＡＤＬ２）、３３％（ＤＮＦ２）和２１％（疗效）。     

Sleep apnea syndrome: Symptomatology,associated features,and neurocognitive correlates

This article reviews the essential features, types, prevalence, pathophysiology, and neuropsychological correlates associated with the sleep apnea syndrome. Persons who experience the intermittent hypoxia and fragmented sleep characteristic of the sleep apnea syndrome tend to exhibit moderate symptoms of diffuse cognitive dysfunction as well as multiple emotional and psychosocial sequela. It is concluded that more research is required in order to elucidate the relationship between the hypoxic parameters and neurocognitive deficits seen in the sleep apnea syndrome, and that neuropsychological assessment might represent a means whereby the effectiveness of various treatments for sleep apnea may be evaluated.     

发展性阅读障碍的理论及眼动研究

关于发展性阅读障碍,国外研究者,基于认知和生物因素,先后提出了语音缺陷论、小脑缺陷论、一般性大细胞功能障碍论等对发展性阅读障碍进行解释,并考察了患者的眼动特征,提出了有效的诊治方法。目前,汉语发展性阅读障碍研究主要局限在语音和正字法领域,也涉及局部脑区的功能缺陷,但还未从多角度测查其成因,如眼动。这里,在理论梳理的基础上,系统探讨了发展性阅读障碍者的眼动特征,如注视时间、注视次数、眼跳、回视等,及视觉加工的眼动机制     

High neuromagnetic activation in the left prefrontal and frontal cortices correlates with better memory performance for abstract words

The ability to store and manipulate online information may be enhanced by an inner speech mechanism that draws upon motor brain regions. Neural correlates of this mechanism were examined using event-related functional magnetic resonance imaging (fMRI). Sixteen participants completed two conditions of a verbal working memory task. In both conditions, participants viewed one or two target letters. In the “storage” condition, these targets were held in mind across a delay. Then a probe letter was presented, and participants indicated by button press whether the probe matched the targets. In the “manipulation” condition, participants identified new targets by thinking two alphabetical letters forward of each original target (e.g., f → h). Participants subsequently indicated whether the probe matched the newly derived targets. Brain activity during the storage and manipulation conditions was examined specifically during the delay phase in order to directly compare manipulation versus storage processes. Activations that were common to both conditions, yet disproportionately greater with manipulation, were observed in the left inferior frontal cortex, premotor cortex, and anterior insula, bilaterally in the parietal lobes and superior cerebellum, and in the right inferior cerebellum. This network shares substrates with overt speech and may represent an inner speech pathway that increases activity with greater working memory demands. Additionally, an inverse correlation was observed between manipulation-related brain activity (on correct trials) and test accuracy in the left premotor cortex, anterior insula, and bilateral superior cerebellum. This inverse relationship may represent intensification of inner speech as one struggles to maintain performance levels.     

Metaphorically feeling: comprehending textural metaphors activates somatosensory cortex

Conceptual metaphor theory suggests that knowledge is structured around metaphorical mappings derived from physical experience. Segregated processing of object properties in sensory cortex allows testing of the hypothesis that metaphor processing recruits activity in domain-specific sensory cortex. Using functional magnetic resonance imaging (fMRI) we show that texture-selective somatosensory cortex in the parietal operculum is activated when processing sentences containing textural metaphors, compared to literal sentences matched for meaning. This finding supports the idea that comprehension of metaphors is perceptually grounded.