One of the primary symptoms of schizophrenia is severely impaired cognitive functioning. Prior to the onset of the illness, during a stage referred to as the prodrome, cognitive abilities, including sensory information processing abilities, can begin to deteriorate. During the prodrome, individuals often exhibit behaviors that differ significantly from their normal behaviors and responses. One domain that is affected in clients with schizophrenia is auditory and visual processing. However, little attention has been focused on the levels of auditory and visual processing in clients at risk for or in the early stages of schizophrenia. Understanding how these domains are affected in the earliest stages of schizophrenia could help clinicians better diagnose and treat the illness. In an attempt to examine this dynamic in early onset and at-risk clients, C. Jahshan of the Mental Illness Research, Education and Clinical Center of the Veterans Affairs Greater Los Angeles Healthcare System led a study that focused specifically on event-related responses (ERP).
Using three response classifications, mismatch negativity responses (MMN), reorienting negativity (RON) responses, and attention shifts (P3a), Jahshan examined the neurocognitive abilities of clients with schizophrenia, clients at-risk for schizophrenia, clients in prodrome, and healthy controls. The study revealed that the clients with schizophrenia had deficits in all three areas, and those in prodrome exhibited less activity in MMN, RON, and P3a than healthy participants. The at-risk group, although showing no outward symptoms of impaired functioning, did have decreased MMN and P3a activity, suggesting that these individuals already had difficulty with sensory processing and attention. The findings also support the theory that auditory processing is affected in a negative way in individuals with schizophrenia as well as those at risk for the illness. This deficit can result in decreased attention and difficulty organizing, which can severely impact how one functions in daily life. This new evidence may enable clinicians to detect individuals who are at risk for schizophrenia and psychosis prior to symptom appearance. Jahshan added, “Additionally, it will be useful to ascertain whether measures derived from the MMN/P3a/RON complex can be used to predict medication adherence, academic or vocational functioning, and other instrumental activities of daily living in affected subjects.”
Jahshan, C., Cadenhead, K. S., Rissling, A. J., Kirihara, K., Braff, D. L., Light, G. A. Automatic Sensory Information Processing Abnormalities across the Illness Course of Schizophrenia. Psychological Medicine 42.1 (2012): 85-97. Print.
© Copyright 2012 GoodTherapy.org. All rights reserved.