Understanding Sensory Flooding in Schizophrenia
There are several unique symptoms that occur in psychosis and schizophrenia. People with these psychological problems often report being hypersensitive to sounds and scenes. Their cognitive resources become distracted and aroused by seemingly mundane background noise and they have difficulty focusing on visual cues and performing relatively easy cognitive tasks as a result. This aspect of schizophrenia has just now begun to be explored in depth. In an effort to extend the existing research, Jason Smucny of the Neuroscience Program at the University of Colorado recently conducted a study measuring the neurological processes that occur during an easy and difficult task among 21 participants with schizophrenia and 23 with no history of psychosis.
All of the participants underwent magnetic resonance imaging (MRIs) while they performed both easy and difficult tasks that required varying degrees of visual and cognitive attention. While they were completing their tasks, the participants were also exposed to what would be considered normal urban sounds, such as the sound of a train or cars on the streets. The results revealed that the participants with schizophrenia had increased neural activation in specific brain regions that impaired their ability to focus on even the easy tasks. They performed far worse on both sets of tasks than the participants without psychosis. Additionally, the schizophrenic group had slower reaction times as a direct result of the auditory distraction.
Sensory overload, such as the kind evidenced in this study, can have a significant impact on the global functioning and quality of life for people with schizophrenia. They may be unable to perform normal activities, especially in social environments, such as reading street signs, following directions, or communicating with others. These deficits can encroach on other domains required to function at optimal levels, further impairing quality of life. Smucny said, “This work is the first to demonstrate that previously reported auditory processing abnormalities may be associated with neural response changes during cross-modal, visual attention tasks in schizophrenia.” Future work should examine ways to minimize auditory distractions that occur in psychosis and schizophrenia.
Reference:
Smucny J, Rojas DC, Eichman LC, Tregellas JR (2013). Neural effects of auditory distraction on visual attention in schizophrenia. PLoS ONE 8(4): e60606. doi:10.1371/journal.pone.0060606