Article

Encoding and representation of simultaneous and sequential arrays in visuospatial working memory.

Colorado State University, Fort Collins, CO, USA.
Quarterly journal of experimental psychology (2006) (Impact Factor: 1.73). 03/2010; 63(5):856-62. DOI: 10.1080/17470211003690680
Source: PubMed

ABSTRACT The effect of presentation type on organization in visuospatial working memory (VSWM) was examined. Stimuli were presented sequentially or simultaneously at study, and participants made same/different judgements at test. The test array varied in four different spatial configuration conditions: one featuring no changes from study, one in which two items switched, one in which the same array repeated but in a different location, and one in which a completely novel test stimulus appeared. Results indicated the use of a global configuration for both simultaneous and sequential presentations and showed increased impairment of item-level knowledge with sequential presentations. Overall, these results support the use of a global configuration organization as a fundamental aspect of VSWM processing.

0 Followers
 · 
118 Views
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: This study examines how normal aging affects the occurrence of different types of incorrect responses in a visual short-term memory (VSTM) object-recall task. Seventeen young (Mean = 23.3 years, SD = 3.76), and 17 normally aging older (Mean = 66.5 years, SD = 6.30) adults participated. Memory stimuli comprised two or four real world objects (the memory load) presented sequentially, each for 650 ms, at random locations on a computer screen. After a 1000 ms retention interval, a test display was presented, comprising an empty box at one of the previously presented two or four memory stimulus locations. Participants were asked to report the name of the object presented at the cued location. Errors rates wherein participants reported the names of objects that had been presented in the memory display but not at the cued location (non-target errors) vs. objects that had not been presented at all in the memory display (non-memory errors) were compared. Significant effects of aging, memory load and target recency on error type and absolute error rates were found. Non-target error rate was higher than non-memory error rate in both age groups, indicating that VSTM may have been more often than not populated with partial traces of previously presented items. At high memory load, non-memory error rate was higher in young participants (compared to older participants) when the memory target had been presented at the earliest temporal position. However, non-target error rates exhibited a reversed trend, i.e., greater error rates were found in older participants when the memory target had been presented at the two most recent temporal positions. Data are interpreted in terms of proactive interference (earlier examined non-target items interfering with more recent items), false memories (non-memory items which have a categorical relationship to presented items, interfering with memory targets), slot and flexible resource models, and spatial coding deficits.
    Frontiers in Aging Neuroscience 01/2014; 6:346. DOI:10.3389/fnagi.2014.00346 · 2.84 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: The relationship between working memory (WM) and attention is a highly interdependent one, with evidence that attention determines the state in which items in WM are retained. Through focusing of attention, an item might be held in a more prioritized state, commonly termed as the focus of attention (FOA). The remaining items, although still retrievable, are considered to be in a different representational state. One means to bring an item into the FOA is to use retrospective cues ("retro-cues") which direct attention to one of the objects retained in WM. Alternatively, an item can enter a privileged state once attention is directed towards it through bottom-up influences (e.g., recency effect) or by performing an action on one of the retained items ("incidental" cueing). In all these cases, the item in the FOA is recalled with better accuracy compared to the other items in WM. Far less is known about the nature of the other items in WM and whether they can be flexibly manipulated in and out of the FOA. We present data from three types of experiments as well as transcranial magnetic stimulation (TMS) to early visual cortex to manipulate the item inside FOA. Taken together, our results suggest that the context in which items are retained in WM matters. When an item remains behaviorally relevant, despite not being inside the FOA, re-focusing attention upon it can increase its recall precision. This suggests that a non-FOA item can be held in a state in which it can be later retrieved. However, if an item is rendered behaviorally unimportant because it is very unlikely to be probed, it cannot be brought back into the FOA, nor recalled with high precision. Under such conditions, some information appears to be irretrievably lost from WM. These findings, obtained from several different methods, demonstrate quite considerable flexibility with which items in WM can be represented depending upon context. They have important consequences for emerging state-dependent models of WM.
    Frontiers in Human Neuroscience 11/2014; 8:853. DOI:10.3389/fnhum.2014.00853 · 2.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Williams syndrome (WS) is a neurodevelopmental disorder associated with an impaired capacity for visuospatial representation. Individuals with WS have a specific weakness in spatial processing, while visual components are relatively well preserved. This dissociation is apparent in working memory function too. The present study aimed to further investigate spatial working memory performance in individuals with WS, analyzing whether their impaired WM performance regards both simultaneous and sequential spatial formats, and whether presenting configurations differently might reduce their difficulties. These issues were examined by administering simultaneous and sequential spatial tasks, in which the information to be recalled was presented in random or arranged configurations.Our results showed that individuals with WS performed less well than typically developing (TD) children in the spatial-simultaneous task, but not in the spatial-sequential one. The presence of a pattern enhanced the performance of both groups, but the difference between the two groups’ performance in the spatial simultaneous task remained, albeit to a lesser degree.
    Research in Developmental Disabilities 11/2014; 37. DOI:10.1016/j.ridd.2014.10.031 · 3.40 Impact Factor

Full-text (2 Sources)

Download
74 Downloads
Available from
May 20, 2014