[Differential effects of dual tasks on emotional processing in non-medicated patients with Parkinson's disease]

Previous research has shown that correct identification of emotional facial expressions (EFE) depends on the cognitive resources that are available. In this study, we examine whether the capacity to identify EFE in a dual task paradigm is affected in Parkinson's disease (PD).

To investigate the interference generated by introducing a secondary task in EFE processing during the encoding and recovery of the facial expression in non-medicated PD patients.

A total of 14 patients with de novo PD and 28 healthy adults identified 24 EFE under two conditions: simultaneous encoding along with a secondary task and introduction of the secondary task between the time that spans the encoding of the primary task and the response time latency.

Results showed that identification of EFE by patients with PD was significantly worse than by healthy adults in the simultaneous encoding condition. In contrast, no differences were found when the interference of the secondary task took place in the phase involving recovery of information of the primary task.

Patients with PD only display specific deficits in processing EFE when the task consumes high levels of the resources required for divided attention, as occurs in everyday situations.