How does reading direction modulate perceptual asymmetry effects?

Left-side bias effects refer to a bias towards the left side of the stimulus/space in perceptual/visuospatial judgments, and are argued to reflect dominance of right hemisphere processing. It remains unclear whether reading direction can also account for the bias effect. Previous studies comparing readers of languages read from left to right with those read from right to left (e.g., French vs. Hebrew) have obtained inconsistent results. As a language that can be read from left to right or from right to left, Chinese provides a unique opportunity for a within-culture examination of reading direction effects. Chinese participants performed a perceptual judgment task (with both face and Chinese character stimuli; Experiment 1) and two visuospatial attention tasks (the greyscales and line bisection tasks; Experiment 2) once before and once after a reading task, in which they read Chinese passages either from left to right or from right to left for about 20 min. After reading from right to left, participants showed significantly reduced left-side bias in Chinese character perceptual judgments but not in the other three tasks. This effect suggests that the role of reading direction on different forms of left-side bias may differ, and its modulation may be stimulus-specific.     

Dissociable neural subsystems underlie visual working memory for abstract categories and specific exemplars

An ongoing debate concerns whether visual object representations are relatively abstract, relatively specific, both abstract and specific within a unified system, or abstract and specific in separate and dissociable neural subsystems. Most of the evidence for the dissociable subsystems theory has come from experiments that used familiar shapes, and the usage of familiar shapes has allowed for alternative explanations for the results. Thus, we examined abstract and specific visual working memory when the stimuli were novel objects viewed for the first and only time. When participants judged whether cues and probes belonged to the same abstract visual category, they performed more accurately when the probes were presented directly to the left hemisphere than when they were presented directly to the right hemisphere. In contrast, when participants judged whether or not cues and probes were the same specific visual exemplar, they performed more accurately when the probes were presented directly to the right hemisphere than when they were presented directly to the left hemisphere. For the first time, results from experiments using visual working memory tasks support the dissociable subsystems theory.     

空间隐喻和形状变化对物体内隐时间概念加工的影响

通过2个实验, 考察了空间隐喻和形状变化对物体内隐时间概念加工的影响。实验1通过对隐含时间关系的词对的语义相关判断发现, 形状变化物体隐含的“先前/后来”的时间概念与“左/右”的空间概念存在着对应关系, 断裂式变化(形状变化大)的物体比渐进式变化(形状变化小)的物体激发了更加明显的时间变化感, 但物体形状变化类型并未明显地影响对词对语义相关判断的速度和准确性。实验2通过对隐含时间关系的物体图片对的语义相关判断发现, 物体形状变化隐含的“先前/后来”的时间概念与“左/右”的空间概念亦存在着对应关系, 而且物体形状变化类型影响对物体图片对语义相关判断的速度和准确性, 被试对渐进式变化物体的语义相关判断显著快于对断裂式变化物体的语义相关判断, 错误率亦低。整个研究表明, 在物体形状变化内隐时间概念的表征中, 既存在着抽象的符号表征, 又存在着具体的形状知觉表征。研究结果支持概念双加工理论的预言。     

Sex differences in cerebral laterality of language and visuospatial processing

Sex differences on language and visuospatial tasks are of great interest, with differences in hemispheric laterality hypothesized to exist between males and females. Some functional imaging studies examining sex differences have shown that males are more left lateralized on language tasks and females are more right lateralized on visuospatial tasks; however, findings are inconsistent. Here we used functional magnetic resonance imaging to study thirty participants, matched on task performance, during phonological and visuospatial tasks. For each task, region-of-interest analyses were used to test differences in cerebral laterality. Results indicate that lateralization differences exist, with males more left lateralized during the phonological task and showing greater bilateral activity during the visuospatial task, whereas females showed greater bilateral activity during the phonological task and were more right lateralized during the visuospatial task. Our data provide clear evidence for differences in laterality between males and females when processing language versus visuospatial information.     

A Possible Connection between Categorical and Coordinate Spatial Relation Representations

Kosslyn (1987) theorized that the visual system uses two types of spatial relations. Categorical spatial relations represent a range of locations as an equivalence class, whereas coordinate spatial relations represent the precise distance between two objects. Data indicate a left hemisphere (LH) advantage for processing categorical spatial relations and a right hemisphere (RH) advantage for processing coordinate spatial relations. Although generally assumed to be independent processes, this article proposes a possible connection between categorical and coordinate spatial relations. Specifically, categorical spatial relations may be an initial stage in the formation of coordinate spatial relations. Three experiments tested the hypothesis that categorical information would benefit tasks that required coordinate judgments. Experiments 1 and 2 presented categorical information before participants made coordinate judgments and coordinate information before participants made categorical judgments. Categorical information sped the processing of a coordinate task under a range of experimental variables; however, coordinate information did not benefit categorical judgments. Experiment 3 used this priming paradigm to present stimuli in the left or right visual field. Although visual field differences were present in the third experiment, categorical information did not speed the processing of a coordinate task. The lack of priming effects in Experiment 3 may have been due to methodological changes. In general, support is provided that categorical spatial relations may act as an initial step in the formation of more precise distance representations, i.e., coordinate spatial relations.     

Increased spatial salience in the social Simon task: A response-coding account of spatial compatibility effects

A spatial compatibility effect (SCE) is typically observed in forced two-choice tasks in which a spatially defined response (e.g., pressing a left vs. a right key) has to be executed to a nonspatial feature of a stimulus (e.g., discriminating red from green) that is additionally connoted by a spatial feature (e.g., the stimulus points to the left or the right). Responses are faster and more accurate when the response side and the spatial stimulus feature are compatible than when they are incompatible. Previous research has demonstrated that SCEs are diminished when stimuli from only one response category are responded to in individual go/no-go tasks, whereas SCEs reemerge when two participants work jointly on two complementary, individual go/no-go tasks in a joint go/no-go task setting. This social Simon effect has been considered evidence for shared task representations. We show that SCEs emerge in individual go/no-go tasks when the spatial dimension is made more salient, whereas SCEs are eliminated in joint go/no-go tasks when the spatial dimension is made less salient. These findings are consistent with an account of social Simon effects in terms of spatial response coding, whereas they are inconsistent with an account of shared task representations. The relevance of social factors for spatial response coding is discussed.     

Sugar ingestion and dichotic listening: Increased perceptual capacity is more than motivation

Participants ingested a sugar drink or a sugar-free drink and then engaged in a pair of dichotic listening tasks. Tasks presented category labels then played a series of word pairs, one in the left ear and one in the right. Participants attempted to identify pairs containing a target category member. Target category words were homonyms. For example, arms appeared as a target in the “body parts” category. Nontargets that played along with targets were related to a category-appropriate version of the target (e.g., sleeves), a category-inappropriate version (e.g., weapons), or were unrelated to either version of the target (e.g., plant). Hence, an effect of nontarget type on number of targets missed was evidence that participants processed nontargets for meaning. In the divided attention task, participants monitored both ears. In the focused attention task, participants monitored the left ear. Half the participants in each group had the divided attention task before the focused attention task; the other half had the focused attention task before the divided attention task. We set task lengths to about 12 min so working on the first task would give sufficient time for metabolizing sugar from the drink before the start of the second task. Nontarget word type significantly affected targets missed in both tasks. Drink type affected performance in the divided attention task only after sufficient time for converting sugar into blood glucose. The result supports an energy model for the effect of sugar ingestion on perceptual tasks rather than a motivational model.     

Habitual reading biases in the allocation of study time

Item order can bias learners’ study decisions and undermine the use of more effective allocation strategies, such as allocating study time to items in one’s region of proximal learning. In two experiments, we evaluated whether the influence of item order on study decisions reflects habitual responding based on a reading bias. We manipulated the order in which relatively easy, moderately difficult, and difficult items were presented from left to right on a computer screen and examined selection preference as a function of item order and item difficulty. Experiment 1a was conducted with native Arabic readers and in Arabic, and Experiment 1b was conducted with native English readers and in English. Students from both cultures prioritized items for study in the reading order of their native language: Arabic readers selected items for study in a right-to-left fashion, whereas English readers largely selected items from left to right. In Experiment 2, native English readers completed the same task as participants in Experiment 1b, but for some participants, lines of text were rotated upside down to encourage them to read from right to left. Participants who read upside-down text were more likely to first select items on the right side of an array than were participants who studied right-side-up text. These results indicate that reading habits can bias learners’ study decisions and can undermine agenda-based regulation.     

Transfer of response codes from choice-response to go/no-go tasks

The present study investigated the conditions for observing the Simon effect in go/no-go tasks. The Simon effect denotes faster and more accurate responses when irrelevant stimulus location and response location correspond than when they do not correspond. In four experiments, participants performed both in a choice-response task (CRT) and in a go/no-go task, and we varied the order and the similarity of the tasks. In the CRT, participants pressed a left key to one stimulus colour and a right key to another stimulus colour; in the go/no-go task, participants pressed one (e.g., left) key to one stimulus colour and refrained from responding to the other stimulus colour. As expected, Simon effects were consistently observed in the CRT. In contrast, Simon effects in the go/no-go task were only observed when it followed the CRT and when the mapping of stimulus colours to response locations was preserved between tasks (i.e., in Experiment 4). Results suggest that transfer of a particular S–R rule including response location from the CRT to the go/no-go task was responsible for the Simon effect in the latter task. In general, results are consistent with a response-discrimination account of the Simon effect.     

The impact of object type on the spatial analogies in Korean preschoolers

We tested young children’s spatial reasoning in a match-to-sample task, manipulating the objects in the task (abstract geometric shapes, line drawings of realistic objects, or both). Korean 4- and 5-year-old children (N = 161) generalized the target spatial configuration (i.e., on, in, above) more easily when the sample used geometric shapes and the choices used realistic objects than the reverse (i.e., realistic-object sample to geometric-shape choices). With within-type stimuli (i.e., sample and choices were both geometric shapes or both realistic objects), 5-year-old, but not 4-year-old, children generalized the spatial relations more easily with geometric shapes than realistic objects. In addition, children who knew more locative terms (e.g., “in”, “on”) performed better on the task, suggesting a link to children’s spatial vocabulary. The results demonstrate an advantage of geometric shapes over realistic objects in facilitating young children’s performance on a match-to-sample spatial reasoning task.     

Elimination of the enhanced Simon effect for older adults in a three-choice situation: Ageing and the Simon effect in a go/no-go Simon task

In a Simon task, participants show better performance when the irrelevant stimulus location corresponds with the response location than when it does not, and this effect is typically greater for older adults than for younger adults. To study the effect of cognitive ageing in the Simon task, we compared young and old adults using two versions of the Simon task: (a) a standard visual Simon task, for which participants respond with left and right key-presses to the red and green colours of stimuli presented in left and right locations; (b) a go/no-go version of the Simon task, which was basically the same, except that the shape of the stimulus in one third of the trials indicates that no response is to be made. In both tasks, both age groups showed the Simon effect. The magnitude of the effect for the standard Simon task was greater for the older adults than for the younger adults. Nevertheless, the two groups showed an equivalent Simon effect in the go/no-go version of the Simon task. Reaction time distribution analyses revealed basically similar functions for both age groups: a decreasing pattern of the Simon effect in the standard task and an increasing pattern of the effect in the go/no-go version of the task. The results suggest that older adults find it more difficult to suppress an automatic activation of the corresponding response, though this automatic activation was reduced in situations where the response was frequently inhibited.     

Choosing to switch: Spontaneous task switching despite associated behavioral costs

The literature shows that switching among simple cognitive tasks is difficult and involves a performance cost. Accordingly, cost-benefit considerations seem to predict that task switching would not occur spontaneously. Here we show that spontaneous task switching is a robust phenomenon, despite its costs. In Experiment 1, participants had to judge shapes according to one of three possible dimensions. Importantly, they were given the option to choose another relevant dimension or let the computer program change the dimension for them, but only if they wanted to do so. The results showed that spontaneous task switching was prevalent, despite robust switching costs. Experiment 2 extended this finding in showing spontaneous switching from an easy task to a more difficult task. The authors provide two possible explanations for the phenomenon that posit that spontaneous switching may be unpreventable or even advantageous.     

Post‐Learning Verbal Information Changes Visual and Motor Memory for Hand‐Manipulative Tasks

Many instructions of a motor task include visual and verbal information. However, verbal information presented after a visual event has been shown to influence memory. This study examined whether this effect applies for hand‐manipulative motor tasks such as knot tying. Eighty‐six naive participants learned to tie the archaic bowline. Subsequently, half of the participants received misleading verbal information about the cowboy bowline, which differs from the originally instructed archaic bowline in one central detail: At a certain point, the rope crosses from left to right instead of from right to left. The remaining half of the participants received no misinformation. Dependent variables measured visual and motor memory for the knot. Results showed that misleading verbal information influenced visual and motor memory for knot‐tying tasks. More specifically, the misleading information changed memory at exactly this point to which it referred. This study suggests new avenues for our understanding and design of learning environments. Copyright © 2014 John Wiley & Sons, Ltd.     

Task-order coordination in dual-task performance and the lateral prefrontal cortex: an event-related fMRI study

A crucial demand in dual tasks suffering from a capacity limited processing mechanism is task-order scheduling, i.e. the control of the order in which the two component tasks are processed by this limited processing mechanism. The present study aims to test whether the lateral prefrontal cortex (LPFC) is associated with this demand. For this, 15 participants performed a psychological refractory paradigm (PRP) type dual task in an event-related functional magnetic resonance (fMRI) experiment. In detail, two choice reaction tasks, a visual (response with right hand) and an auditory (response with left hand), were presented with a temporal offset of 200 ms, while the participants were required to respond to the tasks in the order of their presentation. Importantly, the presentation order of the tasks changed randomly. Based on previous evidence, we argue that trials in which the present task order changed as compared to the previous trial (different-order trials) impose higher demands on task coordination than same-order trials do. The analyses showed that cortical areas along the posterior part of the left inferior frontal sulcus as well as the right posterior middle frontal gyrus were more strongly activated in different-order than in same-order trials, thus supporting the conclusion that one function of the LPFC for dual-task performance is the temporal coordination of two tasks. Furthermore, it is discussed that the present findings favour the active scheduling over the passive queuing hypothesis of dual-task processing.     

Decisions about the axes of disoriented shapes

Subjects were timed as they made decisions about the location of an asterisk placed to the left, right, top, or bottom of disoriented shapes, and their reaction times were plotted as a function of the angular departure of the shapes from the upright. In Experiment 1, the shapes were letters, and the functions suggested that the subjects generally mentally rotated some internal representation of each letter to the upright in order to decide whether the asterisk was to the left or the right, regardless of whether the letters were vertically symmetrical (A, T, U, V), horizontally symmetrical (B, C, D, E), or asymmetrical (F, G, R, L). For decisions about top and bottom, mental rotation rarely occurred, although there was some evidence for it in the case of horizontally symmetrical letters. Experiment 2 showed that mental rotation was not involved when subjects made one response if the asterisk was to the left or right, and another if it was at the top or bottom. In Experiment 3, the shapes were relatively unfamiliar architectural symbols, and in this case mental rotation was most strongly induced by those decisions requiring mirror-image discrimination, that is, left-right decisions for vertically symmetrical shapes and top-bottom decisions for horizontally symmetrical ones. Taken overall, the results suggest that there are two task ingredients that may induce mental rotation: One is the labeling of the left and right sides of a disoriented shape, and the other is the discrimination of mirror images.     

Neural correlates of stimulus response and stimulus outcome shifting in healthy participants and MS patients

Introduction

Adaptation to changing situations can be mediated by two strategies: (1) Evaluation of a response and (2) Evaluation of outcome values in relation to objects. Previous studies indicate that response shifting is associated with a network comprising the left frontal cortex and parietal cortex connected by the superior longitudinal fascicle, whereas outcome evaluation is associated with a network consisting of the orbitofrontal cortex, amygdala and uncinate fascicle. However, these studies rarely compared both kinds of adaptation directly and existing fMRI studies with healthy subjects are not informative about the role of the two fiber systems.

Methods

We analyzed stimulus response shifting and stimulus outcome shifting in two studies, one fMRI-study on healthy participants and one study on patients with MS involving structural MRI (Diffusion Tensor Imaging, Voxel Based Morphometry, Ventricular volumetry). Two tasks were used, identical in presentation but different in instruction, controlling for effects of lower level processing. In the SRS task, participants had to perform a “Go” or “NoGo” response depending on a stimulus change: if the stimulus remained the same, they had to continue with the former type of response, if it changed they had to adapt their response pattern. In the SOS task they had to perform a “Go” response only if the presented stimulus corresponded to that of an internal alternating series.

Results

fMRI findings showed that SRS is related to a bilateral parietal-premotor network. In the left hemisphere the prefrontal cortex was also involved. SOS was lateralized to the right hemisphere, particularly to the anterior temporal pole and amygdala, and the inferior parietal cortex. MS patients impaired on this task suffered from lesions in the right uncinate fascicle and showed an enlarged right frontal lateral ventricle.

Conclusion

With physically identical tasks, a functional neuronal segregation can be demonstrated for stimulus response shifting (bilateral activations with a focus in the left prefrontal cortex) and stimulus outcome shifting (right anterior temporal lobe and right supramarginal gyrus).     

Lateral biases and reading direction: a dissociation between aesthetic preference and line bisection

Perceptual asymmetries for tasks involving aesthetic preference or line bisection can be affected by asymmetrical neurological mechanisms or left/right reading habits. This study investigated the relative contribution of these mechanisms in 100 readers of Japanese and English. Participants made aesthetic judgments between pairs of mirror-reversed pictures showing: (a) static objects, (b) moving objects and (c) landscapes. A line bisection task was also administered. There was a strong effect of reading direction for static and mobile objects whereby Japanese readers preferred objects with a right-to-left directionality (and vice versa for English readers). In contrast, similar patterns were observed for the Japanese and English readers for the landscape and line bisection tasks. The results show that reading habits affect aesthetic judgments for static and moving object tasks, but not the landscape and line bisection tasks. The difference between the tasks may be related to the horizontal/vertical geometry of the stimuli, which makes the landscape and line bisection tasks more prone to universal effects related to cerebral dominance.     

关于条件推理的ERP研究

以抽象的条件命题作为实验材料,测定13名大学生在完成MP、AC、DA、MT推理（推测判断任务）和基线任务（记忆判断任务）时的事件相关电位（ERP）,初步探讨不同推理类型的脑内时程动态变化。这是使用ERP技术来研究条件推理脑机制的初步尝试。结果发现,五种任务所诱发的ERP早成分均不存在显著差异,在头皮前部的左外侧额区和左颞区,MP与DA推理与基线任务相比,均诱发一个更明显的晚期正成分（450-1100ms）,在右外侧额区则诱发一个更明显的晚期负成分（450~1100ms）;与之相反,MT与AC推理与基线任务相比,在左侧诱发一个更明显的晚期负成分（450~1100ms）,在右侧诱发一个更明显的晚期正成分（450~1100ms）,这一结果可能是由于左右脑在推理中的认知功能以及四种推理类型之间存在的差异所致,同时也表明推测过程主要激活了左右侧的前额部、颞叶等区域,基本支持Goel等人的双加工理论     

Differential effects of cast shadows on perception and action

In two experiments we investigated the effects of cast shadows on different real-life tasks. In experiment 1, participants were required to make a speeded verbal identification of the target object (perceptual task), whereas in experiment 2 participants were required to reach for and grasp the target object (motor task). In both experiments real three-dimensional (3-D) objects were presented, one at a time, either with their own natural cast shadow (congruent condition) or with the cast shadow of a different object (incongruent condition). Shadows were cast either to the left or to the right of the object. We asked whether the features of the shadow (ie whether it is congruent or incongruent with the object, and whether it is cast to the left or to the right of the object) could influence perception and action differently. Results showed that cast shadows did not influence identification of real 3-D objects (experiment 1), but they affected movement kinematics, producing distractor-like interference, particularly on movement trajectory (experiment 2). These findings suggest a task-dependent influence of cast shadows on human performance. In the case of object-oriented actions, cast shadows may represent further affordances of the object, and as such compete for the control of the action.