Separation of the systems for color and spatial manipulation in working memory revealed by a dual-task procedure

The manipulation of different kinds of content is fundamental to working memory. It has been suggested that the mere maintenance of color and spatial information occurs in parallel, but little is known about whether this holds true for manipulation as well. Using a dual-task delayed-response paradigm that required the manipulation of color and angles, this study finds that the two functions do not interfere. Conversely, interference did occur when both components of a dual-task tapped into the spatial system. Thus, color and spatial information are manipulated in parallel. A concurrent phonological task did not interfere with either maintenance or manipulation, whereas a task requiring central executive processes interfered with manipulation only. We speculate that the ventral–dorsal dissociation of visual processing is conserved for manipulation processes and that manipulation differs from maintenance in the extent to which is relies on central executive resources

Neural Signatures of Stimulus Features in Visual Working Memory—A Spatiotemporal Approach

We examined the neural signatures of stimulus features in visual working memory (WM) by integrating functional magnetic resonance imaging (fMRI) and event-related potential data recorded during mental manipulation of colors, rotation angles, and color–angle conjunctions. The N200, negative slow wave, and P3b were modulated by the information content of WM, and an fMRI-constrained source model revealed a progression in neural activity from posterior visual areas to higher order areas in the ventral and dorsal processing streams. Color processing was associated with activity in inferior frontal gyrus during encoding and retrieval, whereas angle processing involved right parietal regions during the delay interval. WM for color–angle conjunctions did not involve any additional neural processes. The finding that different patterns of brain activity underlie WM for color and spatial information is consistent with ideas that the ventral/dorsal “what/where” segregation of perceptual processing influences WM organization. The absence of characteristic signatures of conjunction-related brain activity, which was generally intermediate between the 2 single conditions, suggests that conjunction judgments are based on the coordinated activity of these 2 streams

Uneven integration for perception and action cues in children’s working memory

We examined the development of visual cue integration in a desktop working-memory task using boxes with different visual action cues (opening actions) and perceptual surface cues (colours, monochromatic textures, or images of faces). Children had to recall which box held a hidden toy, based on (a) the action cue, (b) the surface cue, or (c) a conjunction of the two. Results from three experiments show a set of asymmetries in children's integration of action and surface cues. The 18–24-month-olds disregarded colour in conjunction judgements with action; 30–36-month-olds used colour but disregarded texture. Images of faces were not disregarded at either age. We suggest that 18–24-month-olds' disregard of colour, seen previously in reorientation tasks (Hermer & Spelke, 1994), may represent a general phenomenon, likened to uneven integration between the dorsal and ventral streams in early development

Better Together? The Cognitive Advantages of Synaesthesia for Time, Numbers and Space

Synaesthesia for time, numbers and space (TNS synaesthesia) is thought to have costs and benefits for recalling and manipulating time and number. There are two competing theories about how TNS synaesthesia affects cognition. The ‘magnitude’ account predicts TNS synaesthesia may affect cardinal magnitude judgements, whereas the ‘sequence’ account suggests it may affect ordinal sequence judgements and could rely on visuospatial working memory. We aimed to comprehensively assess the cognitive consequences of TNS synaesthesia and distinguish between these two accounts. TNS synaesthetes, grapheme-colour synaesthetes and non-synaesthetes completed a behavioural task battery. Three tasks involved cardinal and ordinal comparisons of temporal, numerical and spatial stimuli; we also examined visuospatial working memory. TNS synaesthetes were significantly more accurate than non-synaesthetes in making ordinal judgements about space. This difference was explained by significantly higher visuospatial working memory accuracy. Our findings demonstrate an advantage of TNS synaesthesia which is more in line with the sequence account

Working memory, map learning, and spatial orientation: The effects of gender and encoding interference on the acquisition of survey knowledge

The present experiment investigated the effects of gender and encoding interference on the retrieval of spatial knowledge in a group of 24 male and 29 female students aged 18 to 43 (M = 23.33; SD = 5.78), with 12 to 20 years of education (M = 14.33; SD = 1.76). Each participant was tested individually on their ability to study a map containing 14 labelled landmarks in 1 of 3 interference conditions (i.e., no interference, articulatory suppression, and spatial interference). Then, the participant was blindfolded and asked to point to different aspects of the environment, varying in degrees of familiarity. Specifically, they were asked to indicate the orientation of 4 familiar cardinal directions (over-learned), 4 obscure cardinal directions (intermediate), and 10 landmarks (novel); the latter were cued verbally or visually. Response latency and accuracy were measured. Mixed ANOVAs were conducted with gender (2) and interference (3) as between-subjects factors and cue modality (2) or level of exposure (3) to the environment as within-subjects factors. The results revealed a marked decrease in orientation error and response latency with increasing degrees of familiarity (exposure). In addition, landmarks cued verbally yielded faster and more accurate responses than landmarks cued visually. Also, the presence of any encoding interference during the map study phase resulted in lower accuracy (higher error), especially in the recall of novel information. Lastly, verbal interference affected the accuracy of females to orient to landmarks more than males and the spatial interference yielded the opposite pattern. The findings are discussed in terms of models of working memory, spatial cognition, and gender differences.Dept. of Psychology. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2005 .M37. Source: Masters Abstracts International, Volume: 44-03, page: 1521. Thesis (M.A.)--University of Windsor (Canada), 2005

Exploring intermediate phenotypes with EEG: Working memory dysfunction in schizophrenia

This review brings together two strands of investigation in the neuropsychology and neurophysiology of schizophrenia that have been particularly productive over the last 20 years. We review the literature on working memory deficits, particularly in the visual domain, and changes in oscillatory neural activity as measured with electroencephalography (EEG) and magnetoencephalography (MEG). We argue that recent results suggest a link between these two phenomena, in that altered oscillations underlie some of the working memory deficits. We furthermore argue that early sensory mechanisms contribute more to working memory (and other) deficits than previously thought. The final part of our review suggests links between working memory, oscillations, and their alterations in schizophrenia and the dopamine, GABA, glutamate and acetylcholine system. These links have already resulted in the development of new remediation strategies, which have some translational potential

Designing Instruction For Recovering Alcoholics: The Role Of Executive Function And Levels Of Guidance In Learning From Visually Complex Simulations

The present study examines the design of visually complex science simulations. Building upon an earlier study by Homer and Plass (2014), the current research determines under which circumstances adult learners, and alcoholics in recovery, would perform better from while learning with different levels of guidance. It was predicted that alcoholic adults in recovery would have impaired Executive Function (EF) as compared to controls selected from the general population and that EF would affect learning. An experiment investigated whether levels of EF predict learning from simulations that offered higher or lower levels of instructional guidance. Participants were 76 adults, half of which were alcoholics in recovery. They were randomly assigned to a treatment condition that taught about the Ideal Gas Laws from either a simulation that allowed them to freely explore the controls or one that used guided animation. Analyses of variance revealed that the control group scored significantly better than the experimental group in EF on tests of processing speed (Stroop S). The experimental group performed slightly better than controls on tests of interference (Stroop I) and scored better on the Stroop (I) as their length of sobriety increased, but there was no significant difference on either. Age had a significant effect on the results of the Stroop. Both groups scored worse with age on the speed tests, but better with age on the interference test. Using a stepwise linear regression analysis it was shown that the best predictor of performance on both tests of comprehension and transfer was the card rotation test (ETS S-1). There was no significant difference between groups on this measure. Results suggest that after a significant time away from a drink there is no difference in learning capabilities between recovering alcoholics and controls when level of education is controlled

The role of visual short-term memory in object-based attentional selection

The present study investigated the relationship between object-based attention and visual short-term memory (VSTM). Three claims were investigated: (a) spatial attention and spatial STM share similar processing resources; (b) object-based attention and object STM share similar processing resources; and (c) both sets of processing resources are dissociable. Although the first claim is well established, the latter two claims are less established due to limited empirical evidence in the literature. Specifically, studies that provided evidence for the latter two claims (Matsukura & Vecera, 2008; Tan, 2008) employed an object-based attention task (Duncan, 1984) with no spatial component that heavily engaged object STM. These issues were addressed in the present study using a dual-task paradigm with different combinations of attention tasks and memory tasks. The different attention tasks used could engage spatial attention, object-based attention, or both. Similarly, the different memory tasks used could engage spatial STM, object STM or both. Experiment 1 was designed to address the issue of a lack of spatial component in the object-based attention task by including a spatial version of the object-based attention task used in previous studies. The results in Experiment 1 were consistent with all three claims that were investigated. Experiment 2 was designed to address the issue of heavy engagement of object STM by the object-based attention task by using a different object-based attention task (Egly et al., 1994). The results in Experiment 2 were not entirely consistent with all three claims. Specifically, while there was some support for the first two claims, the third claim was not supported. Overall, the findings in the present study suggest that the interaction between object-based attention and VSTM is complex and further studies are required to fully describe the relationship