Working memory

Friday, September 30th,   2011 [17:20 - 19:20]

PS_1.076 - Does high work-related stress impair working memory capacity?

Kalakoski, V. , Akila, R. , Vuori, M. & Puttonen, S.

Finnish Institute of Occupational Health. Helsinki, Finland

The ability to perform complex cognitive tasks requires working memory (WM). In work assignments there are several factors that may impair WM functioning. We studied whether long-term exposure to high psychosocial stress, i.e. a combination of high job demands and low job decision latitude, is related to impaired WM capacity. As a part of a large research project, the WM capacity of 99 nurses (n = 43 in High Work Stress Group and n = 56 in Low Work Stress Group) was measured. Visuo-spatial WM span was estimated with a computer-based Symmetry span test consisting of storage of a set of locations, and processing of symmetry information (Kane et al. 2004). Verbal WM span was assessed with an operation span task consisting of word lists to be remembered and arithmetic operation tasks (Turner & Engle, 1989). The High Work Stress group showed a somewhat smaller WM capacity than the Low Work Stress group, suggesting that high work load impairs working memory functioning. We discuss the interaction of workload with other factors, e.g. age, and whether the observed lower performance level in WM tasks is explainable by other cognitive functions, such as inefficiency of visual search or short-term memory encoding.

PS_1.077 - Phonological errors in working memory and speech production

Schweppe, J. ¹ , Grice, M. ² & Rummer, R. ¹

1 Cognitive Psychology, University of Erfurt, Germany
2 Phonetics, University of Cologne, Germany

We test the assumption that verbal working memory and speech production are closely related by having a closer look at how phonological features influence errors in serial recall and in a tongue twister task. In serial list recall, syllables with onset consonants that are acoustically similar (sharing the MANNER feature, e.g. pa-ta) were more frequently confused than syllables with dissimilar consonants, with both auditory and visual input and written and oral output. Articulatorily similar items (with consonants sharing the PLACE feature, e.g. da-za) led to more errors than dissimilar items only with oral recall, that is, only when the task involved overt articulation. For the tongue twister task (paced reading aloud of syllables with incompatible onset and rhyme patterns, e.g. pam-tos-tam-pos), the error pattern resembled that of oral serial recall. The recall data suggest a greater role for input than for output similarity. A comparison between the recall and the tongue twister data indicates that verbal working memory and speech production are similar in that they are similarly influenced by both internal features (acoustic similarity affects serial recall and paced reading in the absence of acoustic input) and by motor codes (articulatory similarity affects those tasks that require overt articulation).

PS_1.078 - Developmental interplay between attentional refreshing and articulatory rehearsal in working memory

Oftinger, A. & Camos, V.

Departement of psychology. University of Fribourg. Fribourg, Switzerland.

Past research in adults shows two mechanisms of maintenance of verbal information in working memory, articulatory rehearsal and attentional refreshing. Rehearsal in Baddeley’s model is already in use at 7 years of age (Tam, Jarrold, Baddeley, & Sabatos-DeVito, 2010). At that age, children also use attentional refreshing mechanism described in time-based resource-sharing (TBRS) model (Barrouillet, & Camos, 2010). The present study evaluated the interplay between these two mechanisms and its changes from 7 to 9.
In a complex span task, children have to maintain letters, while they performed a concurrent task. The opportunity for attentional refreshing was manipulated by varying the attentional demand of the concurrent task. This task was performed either silently or aloud, the latter involving an additional articulatory suppression. As expected, recall performance increased with age. The articulatory suppression had a detrimental effect on recall, but it did not varied across the age groups. Finally, increasing the attention demand of the concurrent task reduced recall, but this effect did not interact with age, or with articulatory suppression. To conclude, the efficiency of the articulatory rehearsal or the attentional refreshing did not improve from 7 to 9, contrary to previous results.

PS_1.079 - Working memory capacity in French-German bilinguals

Perriard, B. & Camos, V.

Department of Psychology, University of Fribourg, Fribourg, Switzerland

It was suggested that bilinguals have advantage on complex non-verbal tasks, because of the superiority of their executive functions (Bialystok et al., 2010). More especially, Bialystok et al. (2004) have shown that bilinguals gave faster answers on trials in a Simon task and concluded that bilinguals had better inhibitory capacity. However, in a replication with children when language and socio-economic status (SES) are controlled, difference between bilinguals and monolinguals disappears (Morton & Harper, 2007). The aim of the present study is to reassess the difference between bilinguals and monolinguals adults while controlling other variables as Morton and Harper did. We then contrasted in a Simon task two groups of young adults with equivalent mean age, French proficiency, SES, and working memory capacity. Contrary to previous findings, our two groups showed no difference in the Simon task. Thus, it could be suggested that previous observed difference relied on impact of other variables like SES. It remains possible that the better inhibitory capacity between monolinguals and bilinguals depends also on the distance between the two languages mastered by the bilinguals. Indeed we contrasted two European languages whereas Bialystok compared Asian population speaking English.

PS_1.080 - Effect of dynamic and static visual noise on the recognition task of color shades

Sant'Anna Pereira, M. & Galera, C.

Department of Psychobiology. University of Sao Paulo. Ribeirao Preto. Brazil

Working memory is involved in an important range of everyday tasks such as learning, reading, comprehension, argumentation, decision making and reasoning. This short term system allows us to perform the storage and manipulation of information simultaneously, while a particular cognitive task is performed. This study aimed to investigate the effects of dynamic visual noise (DVN) and static visual noise (SVN) on visual working memory. The task was to recognize colors and shades. Thus, one color was presented on the center of the screen and after a short interval of time, it was showed a second color. The participants had to judge whether the two showed colors were the same or different. During the interval, the participants stood staring at the screen that could be white (control) or filled by the visual noise (static or dynamic). The partial results showed that participants performance was impaired by the presence of noise. However, there was no difference between the DVN and SVN conditions, suggesting that the noise affected the visual memory task performance, regardless of its nature.

PS_1.081 - Spatial and non-spatial contributions to visual short term memory

Barrett, D.

School of Psychology, College of Medicine and Biological Sciences, University of Leicester, Leicester, UK.

Recent neuroimaging evidence suggests visual short term memory (VSTM) is subserved by separate spatial and non-spatial components. This study uses a change detection task to investigate whether and how these components combine. Observers were presented with memory and probe arrays separated by an ISI of 1500 ms. Memory arrays contained three or four uniquely oriented Gabor patches. Probe arrays contained two Gabor patches randomly selected from the memory array; one identical and one that had changed (target). Targets could change their orientation, location or a combination of both and change in each dimension was manipulated using five equally spaced step sizes. Observers reported the identity of the target on each trial and the probability of a correct response was compared across conditions. The results revealed a linear relationship between step size and target detection in all three conditions. Detection thresholds (P =.75) for orientation targets were smaller than those for location targets. Detection thresholds for combined and orientation targets were equivalent. These findings support independent spatial and non-spatial components in VSTM. When target-change occurs across both components, performance appears to be based upon a winner-takes-all competition between spatial and non-spatial information.