Elsevier

Psychiatry Research

Volume 217, Issue 3, 30 July 2014, Pages 163-170
Psychiatry Research

Multitasking capacities in persons diagnosed with schizophrenia: A preliminary examination of their neurocognitive underpinnings and ability to predict real world functioning

https://doi.org/10.1016/j.psychres.2014.03.026Get rights and content

Abstract

Difficulties in everyday life activities are core features of persons diagnosed with schizophrenia and in particular during multitasking activities. However, at present, patients׳ multitasking capacities have not been adequately examined in the literature due to the absence of suitable assessment strategies. We thus recently developed a computerized real-life activity task designed to take into account the complex and multitasking nature of certain everyday life activities where participants are required to prepare a room for a meeting. Twenty-one individuals diagnosed with schizophrenia and 20 matched healthy controls completed the computerized task. Patients were also evaluated with a cognitive battery, measures of symptomatology and real world functioning. To examine the ecological validity, 14 other patients were recruited and were given the computerized version and a real version of the meeting preparation task. Results showed that performance on the computerized task was significantly correlated with executive functioning, pointing to the major implication of these cognitive processes in multitasking situations. Performance on the computerized task also significantly predicted up to 50% of real world functioning. Moreover, the computerized task demonstrated good ecological validity. These findings suggest the importance of evaluating multitasking capacities in patients diagnosed with schizophrenia in order to predict real world functioning.

Introduction

Difficulties in everyday life activities (real world functioning) are core features of persons diagnosed with a psychiatric disorder and in particular with schizophrenia (American Psychiatric Association, 1994, Bowie et al., 2006, Leifker et al., 2009, Tandon et al., 2009). A number of everyday life activities, such as cooking a meal, are complex and require multitasking abilities. According to Burgess (2000), multitasking refers to performing activities where the person has to: carry out and alternate between different activities that vary in terms of priority, difficulty and duration; define the tasks׳ targets; and where the person is faced with unexpected problems during the realization of these tasks.

Patients with schizophrenia, in particular, seem to have problems with activities of everyday life of a multitasking nature. In the only study that has (albeit indirectly) examined this issue, Semkovska et al. (2004) compared the performance of patients diagnosed with schizophrenia with healthy controls during the realization of 3 tasks of everyday life where participants had to: (1) choose a 3-set menu, (2) shop for the missing ingredients in a local supermarket, and (3) cook a meal within an hour. Other measures included cognitive functioning and severity of symptomatology. Results showed that patients performed worse than controls for all three tasks and, in particular, for the multitasking cooking task. Moreover, in the patient group, performance on this task was significantly correlated with executive functions (i.e. cognitive flexibility and planning) and negative symptom severity.

The capacity to deal with two tasks at a time is a main characteristic of multitasking, for example when keeping an eye on the sausages frying in the pan while at the same time reading the next steps of the recipe. Studies that have used the dual task paradigm where the person is asked to deal with the realization of two simple tasks after a training phase (automatization) for the first task, have found that persons diagnosed with schizophrenia demonstrate an impaired performance compared to healthy controls (Granholm et al., 1996, Serper et al., 1990, van Raalten et al., 2008). Moreover, this impairment was not related to a failure in automatization of information processing, suggesting reduced resource availability in patients.

However, at present, patients׳ multitasking capacities have not been adequately examined due to the absence of appropriate assessment strategies. To date, the most suitable test has been developed by Shallice and Burgess (1991), who created a multiple sub-goal task – the Multiple Errands Test. Here, participants have to acquire items (e.g., buy a packet of throat pastilles) and information (e.g., the price of a pound of tomatoes) in an unfamiliar pedestrian precinct while at the same time respecting certain rules (e.g., participants cannot enter a shop other than to buy something). However, the rules that participants need to respect are artificially constraining and explicit, which is not in line with many multitasking activities of everyday life where task objectives often need to be defined and completed by the persons themselves while facing environmental constraints (Chevignard et al., 2006).

Moreover, in general, there are a number of limits related to the fact that data is obtained based on qualitative observations (as is the case, for example, in the Multiple Errands Test and in the task used in Semkovska et al. (2004)). For instance, only a limited number of variables can be encoded and calculated as there are constraints as to how much the observer can note down. It is difficult to obtain precise measures in observer-based tasks. A series of variables that may affect performance (e.g., the amount of noise and other distractors) cannot be controlled. Such a test is difficult to carry out due to practical constraints (e.g., finding the opportunity to observe patients) and human resource limits (e.g., having the available personnel that can leave the clinical setting). Finally, participants may find it particularly stressful to be observed during the realization of an activity in a real life situation, which could influence participants׳ performance.

Others have created instruments that assess specific activities of everyday life, such as a shopping task (Josman et al., 2009, Larøi et al., 2010) or a cooking task (Zhang et al., 2003, Semkovska et al., 2004). However, one major limit with such an approach is that performance on such tasks may be mediated by the participant׳s level of task familiarity. Thus, a person who is more familiar with doing the shopping/cooking in everyday life will have fewer difficulties performing the task and will not be relying on his/her executive functions as much in order to perform the task efficiently compared to someone who has only rarely done the shopping/cooking previously. Moreover, such tasks are frequently simplified in order to facilitate assessment but, as a result, unfortunately, end up not resembling the actual everyday life activity itself in that many of the characteristics of multitasking activities, such as those defined by Burgess (2000), are lost.

In this context, a new computerized task was created, which was directly based on everyday life activities – and that was particularly designed (a) to reflect the complex, multitasking nature of everyday life activities and (b) which places the participant in a new situation in order to emphasize the implication of executive functions and in order to reduce the influence of level of task familiarity on task performance. Furthermore, there are several advantages with computerized tasks in general: the environment is controlled (i.e., every participant interacts in the same environment), characteristics of the task (e.g., level of difficulty) can be modulated, a large number of variables can be measured in a precise manner, the task is easy to administer in a clinical context and, finally, performing a computerized task may be less stressful for patients compared to being observed in a real setting.

The main objective of the present study was to investigate the multitasking capabilities of a group of persons diagnosed with schizophrenia with a newly developed computerized task: the Computerized Meeting Preparation Task (CMPT). Furthermore, the nature of the cognitive processes implicated in multitasking capabilities was also examined. We also wished to assess the task׳s ability to predict real world functioning. Finally, the ecological validity of the CMPT was assessed by examining relations between performance on the computerized version and a real version of the meeting preparation task.

It was hypothesized that performance on the CMPT would significantly differentiate the group of patients from healthy controls. Moreover, we expected significant correlations between patients׳ performance on the CMPT and cognitive (in particular with executive functions) and clinical (in particular with real world functioning) measures. We also hypothesized that the CMPT would be a good predictor of real world functioning. Finally, it was hypothesized that performance on both versions (computerized and real) of the task would be significantly correlated.

Section snippets

Participants

Twenty-one persons diagnosed with schizophrenia according to DSM-IV criteria (American Psychiatric Association, 1994) were included. Patients were recruited from local psychiatric services. Diagnosis was made by experienced psychiatrists based on DSM-IV criteria for schizophrenia and was furthermore confirmed by an experienced clinical psychologist in light of information from the Positive And Negative Syndrome Scale (PANSS; Kay et al., 1987) interview. Patients with schizo-affective or

Results

Patients and healthy controls were compared (t-test) in regard to their performance on the learning phase and the meeting preparation phase of the CMPT (Table 3). A Benjamini–Hochberg–Yekutieli correction revealed a critical value (alpha) of 0.018. Results demonstrated that performance on the computerized task significantly differentiated patients and healthy controls for the following variables: Total time to complete the learning phase, Total number of incorrect actions in the learning phase,

Discussion

We created a novel computerized task (CMPT) that takes into account the multitasking nature of real world activities and where participants find themselves in a novel and complex situation. The main objective of this study was to investigate the multitasking capacities of a group of persons diagnosed with schizophrenia with this newly developed computerized task. Furthermore, the nature of the cognitive processes implicated was also examined. Finally, we wished to examine the task׳s ability to

Acknowledgments

This work was supported in part by an unrestricted Grant from Janssen-Cilag Belgium.

The authors would like to thank Sleiman Azar for his help in programming the CMPT.

References (37)

  • T.R. van Raalten et al.

    Automatization and working memory capacity in schizophrenia

    Schizophrenia Research

    (2008)
  • D.I. Velligan et al.

    The reliability and validity of the Test of Adaptive Behavior in Schizophrenia (TABS)

    Psychiatry Research

    (2007)
  • L. Zhang et al.

    A virtual reality environment for evaluation of a daily living skill in brain injury rehabilitation: reliability and validity

    Archives of Physical Medicine and Rehabilitation

    (2003)
  • American Psychiatric Association

    Diagnostic and Statistical Manual for Mental Disorders

    (1994)
  • Army Individual Test Battery

    Manual of Directions and Scoring

    (1944)
  • Y. Benjamini et al.

    Controlling the false discovery rate: a practical and powerful approach to multiple testing

    Journal of the Royal Statistical Society: Series B

    (1995)
  • Y. Benjamini et al.

    The control of the false discovery rate in multiple testing under dependency

    The Annals of Statistics

    (2001)
  • M.-J. Boily et al.

    Comment évaluer la charge anticholinergique?

    Pharmactuel

    (2008)
  • Cited by (15)

    • Serial multitasking

      2021, Encyclopedia of Behavioral Neuroscience: Second Edition
    • A direct examination of the cognitive underpinnings of multitasking abilities: A first study examining schizophrenia

      2018, Psychiatry Research
      Citation Excerpt :

      There is thus a need for standardized tools that are accessible in a clinical setting and that are closely related to real world activities – but that at the same time place participants in an unfamiliar situation. Recently, Laloyaux et al. (2014) developed a pilot version of a computerized task that takes into account certain characteristics of multitasking activities and places participants in an unfamiliar situation. In this task – the Computerized Meeting Preparation Task (CMPT) – participants are required to prepare a room for a meeting for 5 guests with the help of a list of instructions (e.g., containing the names of the guests, the required objects and participants’ desired drinks).

    • Clinical utility of the Multiple Errands Test in schizophrenia: A preliminary assessment

      2016, Psychiatry Research
      Citation Excerpt :

      Some authors have suggested using more “ecological” EF assessment approaches in SZ (Semkovska et al., 2004; Zimmermann et al., 2014), and new assessment models have emerged. For example, Laloyaux and colleagues investigated a novel computerized real-life activity task reflecting the complex and multitasking nature of everyday life activities in patients with SZ (Laloyaux et al., 2014). Ability to follow rules was found to be the main predictor of the real-world functioning.

    View all citing articles on Scopus
    View full text