Is there an affective working memory deficit in patients with chronic schizophrenia?

j o u r n a l h o m e p a g e : w w w . e l s e v i e r . c o m / l o c a t e / s c h r e s Is there an affective working memory deficit in patients with chronic schizophrenia? Nicola Mammarella ,, Beth Fairfield Valeria De Leonardis , Barbara Carretti , Erika Borella Elisa Frisullo Alberto Di Domenico a Department of Neuroscience and Imaging, University of Chieti, Italyb Department of General Psychology, University of Padua, Italy Research interest in affective working memory has rapidly grown in the last decade. In this study we investigated working memory functions for affective and neutral words in a group of 22 patients with chronic schizophrenia and 22 healthy controls. In particular, participants were administered the operation working memory span task in which affective and neutral words had to be remembered. Results showed that patients made significantly more intrusion errors, recalling off-goal information, and showed poorer long-termmemory performance than controls. In addition, affective trials showed the largest number of intrusion errors. These results suggest that a general attentional control deficit, especially over affective information, may underly failures to remember in chronic schizophrenia patients.
2012 Elsevier B.V. All rights reserved.
storage demands coupled with an attentional control component (thatmight be indexed by the number of intrusion errors) to limit Emotion regulation skills are fundamental for many everyday interference between processing and storage.
activities since all individuals typically interact with valenced Accordingly, in this study we compared WM performance in a environments. Schizophrenia patients show remarkable impairments group of chronic schizophrenia and healthy controls using an in Working Memory (WM) in both verbal and visuo-spatial domains adaptation of the classical operation WM span task ( (e.g., ) as well as in the integration between the two widely used in clinical settings, in which affective words were used. The interesting methodological aspect of this work was to these studies used neutral valenced information. Recently, a series of ensure active maintenance of affective to-be-remembered stimuli in studies showed that schizophrenia patients are also impaired in the WM by making participants process a series of arithmetic operations short maintenance and control over affective informantion. A study by and remember only final target words (affective and neutral ones). In for instance, found that schizophrenia patients had line with a well-established deficit in cognitive control (e.g., difficulties maintaining the intensity of previously presented emotional ), we expect schizophrenia patients to show a greater pictures in WM and that this occurred for both positive and negative number of intrusion errors especially for affective stimuli compared pictures, while showed that schizophrenia patients to controls. In addition, a series of studies on healthy participants had difficulties controlling negative emotional information during a n-back WM task (but see for a different result), where ) found that positive emotions generally broad the focus of negative pictures intefered with the participants'ability to compare attention during the execution of a cognitive task, leading to target stimuli with preceeding ones. Nevertheless, the available data do processing of both relevant and irrelevant information. If so, intrusion not help to directly investigate the effect of affective information on errors should be particularly pronounced with positive trials.
WM performance, and to date, as far as we know, no studies have used a However, no studies, to our knowledge, have investigated this effect classical WM span task procedure to investigate affective information in schizophrenia patients. Therefore our work is an exploratory study processing in schizophrenia. In typical WM span tasks (e.g., aimed at verifying whether the same pattern of intrusion errors to process (read and judge) a series of sentences, words or operations,and remember final words/digits in their correct serial order. These tasks have been shown to entail concurrent processing and short-term ⁎ Corresponding author at: Department of Neuroscience and Imaging, University of Demographic and clinical data are summarized in . This study Chieti, Italy. Tel.: + 39 0871 355 4204; fax: + 39 0871 355 4163.
included 22 patients with chronic schizophrenia spectrum disorder and 0920-9964/$ – see front matter 2012 Elsevier B.V. All rights reserved.
doi: N. Mammarella et al. / Schizophrenia Research 138 (2012) 99–101 affective word database of 200 words developed in our lab and Demographic and clinical characteristics of patients and controls according to mean judged by an independent group of 100 students in terms of valence scores and standard deviations in parentheses.
and arousal on a 9-point scale. The 28 positive words had a mean valence of 7.8 (1.5) and a mean arousal level of 5.9 (2.8); the 28negative words had a mean valence of 2.4 (1.8) and a mean arousal level of 5.9 (2.7). Finally the 28 neutral words had a mean valence of5.5 (1.9) and a mean arousal level of 2.7 (2.3). All valenced sets were presented to participants, that is, all span levels were administered. The order of the valenced set was counterbalanced across participants.
Following the WM phase, an unexpected yes–no recognition memory task was presented. For the recognition memory test, working memory words were intermixed with new words. A total of 126 words were presented (28 old negative, 28 old positive, 28 old neutral and 42 new items with comparable valence and arousal levels as the target items used in the WM span: 14 negative, 14 positive and 14 neutral).
Participants were asked to respond “yes” on a prepared grid if they remembered having experienced the word or “no” if they did not.
Test data were analyzed using Statistica 6.0 (Statsoft). We used mean proportional numbers of correct recalled words and mean proportional numbers of intrusions errors (i.e., number of recalled words from trials within the same set) as a function of valence as dependent WM measures. The correction criterion was correspon- dence between seen word and recalled word, in the correct position.
p b .05; the forward and backward digit span are from WAIS-R ); the PANAS (Positive and Negative Affective Scale) is from the Therefore, if a participant made a mistake in calculating the sum of an PANSS (Positive and Negative Syndrome Scale) is from .
arithmetic operation but correctly recalled the seen word at the endof the trial, it was counted as a correct response unless the number oferrors was above 15% of the total operations. For the recognition 22 non-psychiatric comparison participants. Patients were recruited memory task, accuracy scores were computed as HITs − FAs. HITs are from a chronic psychiatric unit. Diagnoses were made according to the the proportion of old stimuli correctly recognized as old, while FAs DSM-IV criteria, as determined by the structured Clinical Interview for are the proportion of new stimuli recognized as old. Results are Diagnostic and Statistical Manual of Mental Disorders, fourth edition presented in Between-subjects comparisons within the (DSM-IV) (SCID), by a board-certified attending research team of patients's group did not reveal any significant differences linked to psychiatrists. Twenty-two healthy adults were matched to patients for the type of schizophrenia in any considered measures. Accordingly, age, education and gender. They were recruited through University we collapsed patients' data. Lastly, it must be underlined that these advertisements. No participants had a history of traumatic brain injury, data should be taken with caution as the number of participants does epilepsy, alcoholism or substance abuse, other diagnosable neurological conditions or organic mental disorder, nor were they being treated withantidepressants, benzodiazepines or lithium. Additionally, controls were excluded if they reported past or present psychiatric disorders,as well as if a first-degree relative had sought psychiatric diagnosis or The effect of group was not significant F(1,42) = 1.59 p = .20 as treatment. Before the experimental task, both groups received the the number of correct words was .78 in the control group and .80 in PANAS to evaluate their baseline subjective mood. Schizophrenia the schizophrenia patients group. The valence effect was also not patients reported a greater number of positive compared to negative significant, F b 1, as both groups recalled a comparable number of emotions (p b .05), while no differences were detected between positive affective (positive .80, negative .79) and neutral words (.79). Finally, and negative mood in the control group.
the two-way interaction was not significant, F b 1.
The operation span task requires participants to solve a series of There was a significant effect of group F(1,42) = 47.42 p b .001, math operations while remembering a set of unrelated words.
η2=.53, as schizophrenia patients made more intrusions (.15) Participants were presented with one math operation at a time, compared to controls (.04). The effect of valence was also significant, centered on a computer screen followed by a target word. Theysolved the math problem and read the target word aloud. The operation-word strings were presented in sets of two to five items.
Mean proportional scores of correct recalled words and intrusions in the emotion Following each complete set, participants were cued to recall target operation working memory span task as a function of group and valence. Standard words in the correct order of presentation (e.g. a two item set: (2 + 5) − 2 = 5, T/F? JOY; (7 − 2) + 3 = 6, T/F? LOVE, Recall: JOY, LOVE). Four sets of 4 different lengths (from 2 to 5) were constructed for each affective valence (positive, negative and neutral). Stimuliitems for the operation span task consisted in 84 arithmetic operations and 84 target words. Words were selected from an N. Mammarella et al. / Schizophrenia Research 138 (2012) 99–101 F(2,84) = 3.61 p b .01, η2 = .10 as intrusions were typically more positive than neutral (p b .05). The two-way interaction was not Authors Mammarella, Fairfield, Carretti and Borella all contributed to drafting the manuscript. Author Mammarella was both principal investigator and project director of the study. Authors Carretti and Borella designed the experimental protocol. AuthorsBorella and Frisullo were involved in experiment programming. Authors Di Domenico and Frisullo undertook statistical analyses. Authors De Leornardis and Fairfield wereinvolved in data collection and data management. All authors have contributed to andhave approved the final manuscript.
There was a significant effect of group F(1,42)=45.79 pb .001 η2=.52, as controls were more accurate (.61) than patients (.31). The effect of valence was also significant, F(2,84)=4.31 pb .05, η2=.09: All authors declare that they have no conflicts of interest.
negative words (.53) were recognized better than positive (.43) andneutral words (.42). Finally, the two-way interaction was not The authors are grateful to all those who participated in our research study.
Burglen, F., Marczewski, P., Mitchell, K.J., van der Linden, M., Johnson, M.K., Danion, One of the goals of the present study was to further clarify J.M., Salamé, P., 2004. Impaired performance in a working memory binding task in affective WM performance in chronic schizophrenia since interven- patients with schizophrenia. Psychiatry Res. 125 (3), 247–255.
Daneman, M., Carpenter, P.A., 1980. Individual differences in WM and reading. J. Verbal tion that can increase emotional WM may be beneficial as training for Learn. Verbal Behav. 19 (4), 450–466.
emotion regulation abilities. We found comparable recall of final Diaz, M.T., He, G., Gadde, S., Bellion, C., Belger, A., Voyvodic, J.T., McCarthy, G., 2011. The target words across both groups when we considered the number of influence of emotional distraction on verbal working memory: an fMRI investigation correctly recalled words. However, our data highlighted impaired comparing individuals with schizophrenia and healthy adults. J. Psychiatr. Res. Mar15. [Epub ahead of print].
WM performance in our affective operation span task in terms of a Dreisbach, G., 2006. How positive affect modulates cognitive control: the costs and greater number of intrusion errors confirming the well-documented benefits of reduced maintenance capability. Brain Cogn. 60 (1), 11–19.
general attentional control and WM impairments in schizophrenia Dreisbach, G., Goschke, T., 2004. How positive affect modulates cognitive control: reduced perseveration at the cost of increased distractibility. J. Exp. Psychol. Learn.
(e.g., The second important goal of our study was to investigate the role of valence within this WM paradigm. Thus, Engle, R.W., Kane, M.J., 2004. Executive attention, working memory capacity, and a valence was manipulated in order to observe how schizophrenia two-factor theory of cognitive control. In: Ross, B.H. (Ed.), The Psychology ofLearning and Motivation, Vol. 44. Academic Press, New York, pp. 145–199.
patients control affective words. In line with previous studies (e.g., Gard, D.E., Cooper, S., Fisher, M., Genevsky, A., Mikels, J.A., Vinogradov, S., 2011.
our results support the role of valence in their short- Evidence for an emotion maintenance deficit in schizophrenia. Psychiatry Res. 187 term forgetting. In fact, although both groups showed valenced Habel, U., Pauly, K., Koch, K., Kellermann, T., Reske, M., Backes, V., Stöcker, T., Amunts, intrusion errors, these were particularly marked for schizophrenia.
K., Shah, N.J., Schneider, F., 2010. Emotion–cognition interactions in schizophrenia.
Retention in long-term memory also showed a unique contribution of World J. Biol. Psychiatry 11 (8), 934–944.
valence as participants were more accurate in recognizing negative Hall, J., Harris, J.M., McKirdy, J.W., Johnstone, E.C., Lawrie, S.M., 2007. Emotional memory in schizophrenia. Neuropsychologia 45, 1152–1159.
words compared with the other types of words and this was Hasher, L., Lustig, C., Zacks, R., 2007. Inhibitory mechanisms and the control of particularly true for schizophrenia patients. These long-term memory attention. In: Conway, A.R.A., Jarrold, C., Kane, M.J., Miyake, A., Towse, J.N. (Eds.), data are consistent with the WM data as deficient inhibitory Variation in working memory. Oxford University Press, New York, pp. 227–249.
attentional control over positive words later favored recognition for Kay, S.R., Fiszbein, A., Opler, L.A., 1987. The positive and negative syndrome scale (PANSS) for schizophrenia. Schizophr. Bull. 13, 261–276.
negative words In part, our findings are in line Lee, J., Park, S., 2005. Working memory impairments in schizophrenia: a meta-analysis.
J. Abnorm. Psychol. 114 (4), 599–611.
Quee, P.J., Eling, P.A., van der Heijden, F.M., Hildebrandt, H., 2011. Working memory in schizophrenia: a systematic study of specific modalities and processes. Psychiatry distracted by positive rather than negative emotions. Our additional interpretation is that the greater number of positive intrusion errors Rowe, G., Hirsh, J.B., Anderson, A.K., 2007. Positive affect increases the breadth of in the patients group may be also due to their tendency to maintain a attentional selection. Proc. Natl. Acad. Sci. U. S. A. 104 (1), 383–388.
Smith, E.E., Eich, T.S., Cebenoyan, D., Malapani, C., 2011. Intact and impaired cognitive- positive affective state. In fact, we found that patients reported more control processes in schizophrenia. Schizophr. Res. 126 (1), 132–137.
positive than negative moods. Altogether, our overall results are in Turner, M.L., Engle, R.W., 1989. Is working memory capacity task dependent? J. Mem.
line with a general attention control deficit in chronic schizophrenia, Watson, D., Clark, L.A., Tellegen, A., 1988. Development and validation of brief and suggest that affective information may increase their forgetting measures of positive and negative affect: the PANAS scales. J. Pers. Soc. Psychol. 54 Wechsler, D., 1981. The Wechsler Adult Intelligence Scale—Revised. Psychological No funding sources were involved in this study.

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