Visual Perception and Memory Impairments in Children at Risk of Nonverbal Learning Disabilities

Visuospatial working memory (VSWM) and visual perception were examined in two groups aged 11–13, one with children displaying symptoms of nonverbal learning disability (NLD) (n = 18) and the other a control group without learning disabilities (n = 18). The two groups were matched for general verbal abilities, age, gender, and socioeconomic level. The children were presented with VSWM tests involving visual and spatial-simultaneous processes, and also with a classical visual illusion, a classical ambiguous figure, as well as visual perception tests specifically devised for the present study. Results revealed that performance of children at risk of NLD was worse than controls in some VSWM and in visual perception tests without memory involvement; these latter required comparisons of visual stimuli and locations in space with distractors. Moreover, the two groups differed in perceiving the classical ambiguous figure. Findings are discussed in the light of both theoretical and clinical implications.     

Emotion knowledge,emotion regulation,and psychosocial adjustment in children with nonverbal learning disabilities

Nonverbal learning disability is a childhood disorder with basic neuropsychological deficits in visuospatial processing and psychomotor coordination, and secondary impairments in academic and social-emotional functioning. This study examines emotion recognition, understanding, and regulation in a clinic-referred group of young children with nonverbal learning disabilities (NLD). These processes have been shown to be related to social competence and psychological adjustment in typically developing (TD) children. Psychosocial adjustment and social skills are also examined for this young group, and for a clinic-referred group of older children with NLD. The young children with NLD scored lower than the TD comparison group on tasks assessing recognition of happy and sad facial expressions and tasks assessing understanding of how emotions work. Children with NLD were also rated as having less adaptive regulation of their emotions. For both young and older children with NLD, internalizing and externalizing problem scales were rated higher than for the TD comparison groups, and the means of the internalizing, attention, and social problem scales were found to fall within clinically concerning ranges. Measures of attention and nonverbal intelligence did not account for the relationship between NLD and Social Problems. Social skills and NLD membership share mostly overlapping variance in accounting for internalizing problems across the sample. The results are discussed within a framework wherein social cognitive deficits, including emotion processes, have a negative impact on social competence, leading to clinically concerning levels of depression and withdrawal in this population.     

学习困难儿童在工作记忆任务中抑制机制的研究

本研究的目的旨在探讨在WM任务中,LD儿童是否存在抑制机制缺陷。实验程序采用重复启动范式,设计“预期”和“目标”两种启动条件,随后通过间接测量的方式(内隐记忆测验)分别测得LD儿童和NLD儿童对预期词和目标词的启动量。结果表明,LD儿童对预期词的启动分数与目标词没有显著差异,NLD儿童对目标词的启动分数显著高于对预期词的启动分数。我们得出结论:在工作记忆任务中,LD儿童存在抑制机制缺陷。     

分散注意条件下学优生与学困生视空间工作记忆的比较研究

通过控制干扰刺激量 ,研究分散注意对学优生和学困生视空间WM的影响。实验一的结果表明 :在不同干扰条件下 ,学困生视空间WM均比学优生差 ;干扰任务不仅影响学困生视空间WM的加工能力 ,也影响他们的存储能力。这说明学困生不能有效抑制外界干扰可能是他们视空间WM存在缺陷的主要原因之一。实验二的结果表明 :视空间WM有缺陷是各类学困生普遍存在的问题 ;对于学优生来说 ,不同类型学优生视空间WM不同 ,语文学优比数学学优的学生的视空间WM能力更强 ,主要表现在加工功能上。     

语文学习困难儿童的短时记忆、工作记忆和加工速度

短时记忆、工作记忆和加工速度反映了不同的认知加工.采用多因素混合实验设计,在严格控制条件下,比较了语文学习困难和控制组儿童的工作记忆、短时记忆和加工速度的差异.结果发现,与控制组相比,语文学习困难儿童在工作记忆、短时记忆和加工速度方面均存在明显的不足,但短时记忆和加工速度不能解释不同能力组之间的差异,语文学习困难儿童的缺陷在于工作记忆能力的下降.工作记忆的缺陷在于言语工作记忆的不足,与视空间工作记忆能力无关,语文学习困难与特定的工作记忆(言语工作记忆)能力的不足有关.工作记忆缺陷的原因在于存储能力的不足,而不是加工效率的缺陷造成的.     

Mental imagery in a visuospatial working memory task and modulation of activation

Ability to process information during a mental imagery task relying on visuospatial working memory and the advantages offered by the possibility of focusing the activation on specific items were examined in younger and older adults. The mental imagery task used for the study required participants to mentally move on a two-dimensional (5×5) or three-dimensional (3×3×3) matrix, while having to hold in memory either the whole pathway (WP condition) or just the final position reached (FP condition). The results revealed age-related differences in ability to modulate activation of visuospatial information. In particular, older adults, unlike the younger counterparts, did not benefit when the task allowed just part of the presented material to be considered. In particular, they drew less advantage from the three-dimensional matrix than the younger group. The findings are discussed in terms of the importance of processes reducing visuospatial working memory activation of irrelevant information and of the difficulties encountered by older adults in the modulation of activation.     

语文学习困难儿童的工作记忆与加工速度

加工速度和工作记忆反应了不同的认知加工过程,在认知发展研究中,加工速度和工作记忆所起的作用仍存在较大的分歧.采用多因素混合实验设计,在严格控制条件下,比较了语文学习困难和控制组儿童的工作记忆和加工速度.结果发现,与控制组相比,语文学习困难儿童在工作记忆和加工速度方面均存在明显的不足,但加工速度不能解释不同能力组之间的差异,语文学习困难儿童的缺陷在于工作记忆能力的下降.工作记忆的缺陷在于言语工作记忆和中央执行功能的不足,与视空间工作记忆能力无关.语文学习困难既存在一般的工作记忆缺陷(中央执行功能)也存在特定的工作记忆(言语工作记忆)能力的不足.     

学习不良儿童的工作记忆

近年来大量的研究发现：阅读障碍儿童和数学学习不良儿童在言语工作记忆和执行性功能上存在缺陷;数学学习不良儿童在视-空工作记忆上也存在一定的缺陷,但关于阅读障碍儿童是否存在视-空工作记忆缺陷尚存在着争论;关于这种缺陷究竟是一种发展滞后还是发展缺陷尚存在着争论,与所采用的研究方法有一定关系。目前该领域在学习不良与工作记忆的因果关系,工作记忆测量材料的效度及其敏感性,工作记忆与其它认知功能的关系上面临挑战。因此,采用纵向的研究设计、多变量的统计技术,革新工作记忆的评估方法和技术,阐明工作记忆在各学业领域及亚领域中的作用及其内在工作机制是该领域的研究趋势。     

The long-term effects of mild head injury on short-term memory for visual form, spatial location, and their conjunction in well-functioning university students

Research has suggested the presence of subtle long-term cognitive changes in otherwise well-functioning individuals who have previously sustained a mild head injury (MHI). This paper investigated the long-term effects of MHI on visual, spatial, and visual-spatial short-term memory in well-functioning university students. Sixteen students who reported having sustained a MHI were compared to 16 controls on tests of short-term memory (STM) for abstract polygons in haphazardly arranged locations. The three tests differed only in the requirements for recall (shapes for the visual task, locations for the spatial task, and the shapes in their respective locations for the visual-spatial task). MHI participants were selectively impaired on spatial memory, suggesting that tasks of spatial STM may be more sensitive, compared to tasks of visual STM, to the subtle long-term cognitive changes that may be present after a MHI.     

A comparison of backward and forward spatial spans

The standard Corsi blocks task is frequently used to measure the capacity of visuospatial working memory, but the implications of the use of both forward and backward recall are still unclear. In the present study, we showed that the backward Corsi task is particularly powerful in discriminating between low- and high-spatial-ability individuals and involves different processes from those involved in the forward task. From a sample of 425 participants we selected one group of 20 high-spatial-ability participants and one of 20 low-spatial-ability participants. The results demonstrated that a backward spatial span offers specific information not available from a forward spatial span, and that there was no facilitation due to a descending format. In particular, in the low-spatial-ability group, performance was generally poorer, but backward Corsi recall was lower than forward recall, and participants did not show any advantage following the descending presentation format—which in some contexts is considered to reduce proactive interference. We conclude that the backward Corsi task has specific value and that the assumption of fully parallel verbal and visuospatial working-memory systems can lead to a variety of misunderstandings.     

A comparison of backward and forward spatial spans

The standard Corsi blocks task is frequently used to measure the capacity of visuospatial working memory, but the implications of the use of both forward and backward recall are still unclear. In the present study, we showed that the backward Corsi task is particularly powerful in discriminating between low- and high-spatial-ability individuals and involves different processes from those involved in the forward task. From a sample of 425 participants we selected one group of 20 high-spatial-ability participants and one of 20 low-spatial-ability participants. The results demonstrated that a backward spatial span offers specific information not available from a forward spatial span, and that there was no facilitation due to a descending format. In particular, in the low-spatial-ability group, performance was generally poorer, but backward Corsi recall was lower than forward recall, and participants did not show any advantage following the descending presentation format—which in some contexts is considered to reduce proactive interference. We conclude that the backward Corsi task has specific value and that the assumption of fully parallel verbal and visuospatial working-memory systems can lead to a variety of misunderstandings.     

On the Nature of Nonverbal Working Memory Fractionation: A Case of Selective Spatial Short-Term Memory Deficit in a Child

Several lines of research on adult subjects demonstrate a visual/spatial fractionation of nonverbal working memory (WM), while behavioral studies on normal children support the idea of a static/dynamic distinction. In the present paper, we report a child (Z.M.) who failed on nonverbal WM tasks. To verify the nature of his defect, we carried out two experiments: in Experiment 1, Z.M. failed on spatial WM tasks but not on visual WM tasks and was not affected by the static/dynamic format of stimulus presentation; in Experiment 2, this visual/spatial dissociation was extended to the imagery domain. These results are best accounted for within the visual/spatial fractionation of WM and confirmed the role of WM in mental imagery. Clinical and rehabilitative implications of the present findings are also discussed.     

学习困难学生视空间工作记忆提取能力的多指标分析

本实验设计高、低两种加工负载的视空间WM作业,采用WM广度、提取错误值和提取速度三项指标评估学困生视空间WM的提取能力,比较学困生和学优生视空间WM的提取能力间的差异。结果表明：无论在低加工负载条件下还是在高加工负载条件下,学困生视空间WM的提取能力都比学优生差。在不同加工负载条件下,三项指标对评估学困生和学优生视空间WM提取能力间差异的重要程度不同。低加工负载条件下WM容量和提取错误值是较好的指标,而高加工负载条件下WM容量和提取速度是较好的指标。     

Cross-modal and intra-modal binding between identity and location in spatial working memory: The identity of objects does not help recalling their locations

In this study we tested incidental feature-to-location binding in a spatial task, both in unimodal and cross-modal conditions. In Experiment 1 we administered a computerised version of the Corsi Block-Tapping Task (CBTT) in three different conditions: the first one analogous to the original CBTT test; the second one in which locations were associated with unfamiliar images; the third one in which locations were associated with non-verbal sounds. Results showed no effect on performance by the addition of identity information. In Experiment 2, locations on the screen were associated with pitched sounds in two different conditions: one in which different pitches were randomly associated with locations and the other in which pitches were assigned to match the vertical position of the CBTT squares congruently with their frequencies. In Experiment 2 we found marginal evidence of a pitch facilitation effect in the spatial memory task. We ran a third experiment to test the same conditions of Experiment 2 with a within-subject design. Results of Experiment 3 did not confirm the pitch–location facilitation effect. We concluded that the identity of objects does not affect recalling their locations. We discuss our results within the framework of the debate about the mechanisms of “what” and “where” feature binding in working memory.     

Learning a new geometric concept: The role of working memory and of domain-specific abilities

It has been suggested that not only domain-specific factors but also working memory (WM) may play a crucial role in mathematical learning included Geometry, but the issue has not been deeply explored. In the present study, we examined the role of domain-specific factors and of verbal versus visuospatial WM on geometric learning of a new geometrical figure (trapezoid), never presented previously by the teachers participating to the study, after a lecture also involving manipulatives. Results on 105 children in their Year 4 indicated that not only some domain-specific components (geometric declarative knowledge and calculation) but also visuospatial working memory had a significant specific impact on the ability of solving geometric problems requiring to calculate the perimeter and the area of the new figure. On the contrary, verbal WM and geometrical mental imagery did not offer a specific contribution. These findings could have important educational implications, stressing the importance of taking into account the main different aspects supporting the acquisition of geometry.     

Individual differences in visuospatial working memory: benefits from environmental support for rehearsal

ABSTRACT

Previous research has suggested that participants with low working memory spans are less likely than those with high spans to engage in rehearsal and other effective strategies during memory tasks. However, most of this research has been conducted in the verbal domain, and less is known about strategy differences in visuospatial working memory. Therefore, the present experiments investigated potential individual differences in the benefit participants receive from environmental support for visuospatial rehearsal. In Experiment 1, memory spans were significantly larger when support was present (i.e. when the array of possible locations remained on the screen) during long inter-item intervals, but importantly, the observed benefit was larger for high-span participants than low-span participants, suggesting that high spans were more likely to use support to facilitate their rehearsal. Other research has suggested that low spans may benefit more than high spans from rehearsal instructions, and so in Experiment 2, participants also were provided with such instructions. However, the rehearsal instructions did not improve memory spans significantly in either group, suggesting that low spans are not only naturally less strategic than high spans, but they may be less capable of taking advantage of effective rehearsal strategies, even when environmental support is present.     

Spatial and visual working memory ability in children with difficulties in arithmetic word problem solving

Although various studies support the multicomponent nature of visuospatial working memory, to date there is no general consensus on the distinction of its components. A difference is usually proposed between visual and spatial components of working memory, but the individual roles of these components in mathematical learning disabilities remains unclear. The present study aimed to examine the involvement of visual and spatial working memory in poor problem-solvers compared with children with normal level of achievement. Fourth-grade participants were presented with tasks measuring phonological loop, central executive, and visual versus spatial memory. In two separate experiments, both designed to distinguish visual and spatial component involvement, poor problem-solvers specifically failed on spatial—but not visual or phonological—working memory tasks. Results are discussed in the light of possible working memory models, and specifically demonstrate that problem-solving ability can benefit from analysis of spatial processes, which involves ability to manipulate and transform relevant information; instead, no benefit is gained from the analysis of visual pictorial detail.     

The roles of the central executive and visuospatial storage in mental arithmetic: A comparison across strategies

Previous research has demonstrated that working memory plays an important role in arithmetic. Different arithmetical strategies rely on working memory to different extents—for example, verbal working memory has been found to be more important for procedural strategies, such as counting and decomposition, than for retrieval strategies. Surprisingly, given the close connection between spatial and mathematical skills, the role of visuospatial working memory has received less attention and is poorly understood. This study used a dual-task methodology to investigate the impact of a dynamic spatial n-back task (Experiment 1) and tasks loading the visuospatial sketchpad and central executive (Experiment 2) on adults' use of counting, decomposition, and direct retrieval strategies for addition. While Experiment 1 suggested that visuospatial working memory plays an important role in arithmetic, especially when counting, the results of Experiment 2 suggested this was primarily due to the domain-general executive demands of the n-back task. Taken together, these results suggest that maintaining visuospatial information in mind is required when adults solve addition arithmetic problems by any strategy but the role of domain-general executive resources is much greater than that of the visuospatial sketchpad.     

Effects of environmental support on overt and covert visuospatial rehearsal

People can rehearse to-be-remembered locations either overtly, using eye movements, or covertly, using only shifts of spatial attention. The present study examined whether the effectiveness of these two strategies depends on environmental support for rehearsal. In Experiment 1, when environmental support (i.e., the array of possible locations) was present and participants could engage in overt rehearsal during retention intervals, longer intervals resulted in larger spans, whereas in Experiment 2, when support was present but participants could only engage in covert rehearsal, longer intervals resulted in smaller spans. When environmental support was absent, however, longer retention intervals resulted in smaller memory spans regardless of which rehearsal strategies were available. In Experiment 3, analyses of participants’ eye movements revealed that the presence of support increased participants’ fixations of to-be-remembered target locations more than fixations of non-targets, and that this was associated with better memory performance. Further, although the total time fixating targets increased, individual target fixations were actually briefer. Taken together, the present findings suggest that in the presence of environmental support, overt rehearsal is more effective than covert rehearsal at maintaining to-be-remembered locations in working memory, and that having more time for overt rehearsal can actually increase visuospatial memory spans.