Self-paced and reprogrammed saccades: differences between melancholic and non-melancholic depression.
Motor disturbances in major depressive disorder (MDD) are increasingly recognized and may differentiate melancholic, from non-melancholic depression. Motor impairments in melancholic depression have been likened to Parkinson's disease and proposed to have a frontostriatal basis. This study investigated self-pacing and reprogramming skills, thought to rely on frontostriatal functioning, in groups of healthy individuals (n=15), non-melancholic depression patients (n=10) and melancholic depression patients (n=9) using ocular motor tasks. Self-paced saccades were requested to be performed at a rhythm of 1 Hz between two continuously illuminated targets, before and after external cueing. Saccade reprogramming, for direction and amplitude, was explored using a saccadic "oddball" task. Results indicated no group differences for accuracy, intersaccadic intervals (during the self-paced task), latency or peak velocity. However, the melancholic group showed greater intrasubject variability of latencies than the control group, lower peak saccade velocities compared to the non-melancholic group, and reduced accuracy of the primary saccade when compared to the control and the non-melancholic groups. These findings provide further support for distinct motor impairments associated with melancholia that may reflect frontostriatal abnormalities.
Winograd-Gurvich
Caroline
C
Experimental Neuropsychology Research Unit, School of Psychology, Psychiatry and Psychological Medicine, Monash University, Clayton, Victoria 3800, Australia. caroline.winograd@med.monash.edu.au <caroline.winograd@med.monash.edu.au>
Georgiou-Karistianis
Nellie
N
Fitzgerald
Paul B
PB
Millist
Lyn
L
White
Owen B
OB
D000328:Adult; D000704:Analysis of Variance; D003463:Cues; D003863:Depression / Q000503:physiopathology*; D003866:Depressive Disorder / Q000503:physiopathology*; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008609:Mental Status Schedule; D008875:Middle Aged; D009483:Neuropsychological Tests; D010775:Photic Stimulation / Q000379:methods; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012438:Saccades / Q000502:physiology*