Task switching and Parkinson’s disease: The role of articulatory suppression
Yusuf Ali Lalloo
Bangor University
This
study investigated the role of the articulatory loop and Basal Ganglia in
executive functions. A task switching paradigm was employed under separate
conditions, cue verbalisation and articulatory suppression (AS), repeating an
irrelevant syllable. Experiment 1 assessed two types of cues; exogenous cues,
direct representations of task, and endogenous cues, where the words “switch”
and “repeat” were displayed. The results replicated previous findings that AS
enhanced the mixing costs for both conditions and switch cost in the endogenous
condition. Experiment 2 tested for the potential role of Broca-Basal Ganglia
(BBG) connectivity in this effect; comparing 11 Hemiparkinson’s patients (six
left, five right) against eight age-matched controls. While right-side patients were
comparable in pattern to controls, left-side patients exhibited a reversed
pattern, where reading aloud inhibited performance. The results are explained
by, and further support, the role of BBG connection in task control.
