Behavioral and Electrophysiological Indices of Temporal Processing Dysfunction in Schizophrenia

Deana B. Davalos, Michael A. Kisley, Robert Freedman
2005 The Journal of Neuropsychiatry and Clinical Neurosciences  
Timing deficits in schizophrenia have been noted in several behavioral studies. However, the involvement of mediating factors, such as inattention, has not been ruled out as contributing to these effects. Mismatch negativity (MMN), an electrophysiological measure, may provide a more direct index of stimulus processing ability in individuals with schizophrenia. The current study explored the relationship between behavioral time judgments and a time-based MMN paradigm. Participants were
more » ... ed two MMN paradigms consisting of an "easy" or "difficult" deviant and an analogous behavioral measure of time processing. Matched against a healthy comparison group, patients exhibited decreased MMN amplitude on the "difficult" deviant interval only. However, on the behavioral paradigm, the patients made significantly more errors across all conditions. These results suggest that behavioral measures of time processing may reflect different processes than those captured by preattentive physiological measures in this population. (The Journal of Neuropsychiatry and Clinical Neurosciences 2005; 17:517-525) R esearchers have argued that time processing is a fundamental component of daily goal-oriented behaviors. 1 More specifically, time processing has been associated with the ability to sequence, plan events, and understand "warning signals" that predict later events. 2,3 Navon argued that our perception of the world consists of a hierarchy of dimensions and that time occupies the highest level of that hierarchy. 4 Given the possible impact of temporal processing dysfunction on cognition and daily behavior, researchers have attempted to understand the role of timing dysfunction in clinical populations for a number of years. Early research assessing timing abilities in individuals with schizophrenia provided the first indicators that time estimation may be dysfunctional in this population. 5 More recent findings suggest that individuals with schizophrenia are impaired on both auditory and visual temporal processing tasks. 6,7 Limitations including small sample sizes and disparity in tasks described as "temporal processing" measures have made general assertions about time processing difficult. The degree of nontemporal information that has historically been included in timing tasks is a further limitation. Poynter and Homa point out that temporal perception tasks of-
doi:10.1176/jnp.17.4.517 pmid:16387992 fatcat:2gs6kzbxdbc6hje7ju6gll6a6q