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Joana Sampaio, Bobrowicz-Campos, E., Rui André, Inês Almeida, Pedro Faria, Januário, C....Miguel Castelo-Branco (2011). Specific impairment of visual spatial covert attention mechanisms in Parkinson's disease. Neuropsychologia. 49 (1), 34-42

J. Sampaio et al.,  "Specific impairment of visual spatial covert attention mechanisms in Parkinson's disease", in Neuropsychologia, vol. 49, no. 1, pp. 34-42, 2011

@article{sampaio2011_1741675195102,
	author = "Joana Sampaio and Bobrowicz-Campos, E. and Rui André and Inês Almeida and Pedro Faria and Januário, C. and António Freire and Miguel Castelo-Branco",
	title = "Specific impairment of visual spatial covert attention mechanisms in Parkinson's disease",
	journal = "Neuropsychologia",
	year = "2011",
	volume = "49",
	number = "1",
	doi = "10.1016/j.neuropsychologia.2010.11.002",
	pages = "34-42"
}

TY  - JOUR
TI  - Specific impairment of visual spatial covert attention mechanisms in Parkinson's disease
T2  - Neuropsychologia
VL  - 49
IS  - 1
AU  - Joana Sampaio
AU  - Bobrowicz-Campos, E.
AU  - Rui André
AU  - Inês Almeida
AU  - Pedro Faria
AU  - Januário, C.
AU  - António Freire
AU  - Miguel Castelo-Branco
PY  - 2011
SP  - 34-42
SN  - 0028-3932
DO  - 10.1016/j.neuropsychologia.2010.11.002
AB  - Visual deficits in early and high level processing nodes have been documented in Parkinson’s disease
(PD). Non-motor high level visual integration deficits in PD seem to have a cortical basis independently
of a low level retinal contribution. It is however an open question whether sensory and visual attention
deficits can be separated in PD. Here, we have explicitly separated visual and attentional disease related
patterns of performance, by using bias free staircase procedures measuring psychophysical contrast sensitivity across visual space under covert attention conditions with distinct types of cues (valid, neutral
and invalid). This further enabled the analysis of patterns of dorsal–ventral (up–down) and physiological
inter-hemispheric asymmetries. We have found that under these carefully controlled covert attention
conditions PD subjects show impaired psychophysical performance enhancement by valid attentional
cues. Interestingly, PD patients also show paradoxically increased visual homogeneity of spatial per-
formance profiles, suggesting flattening of high level modulation of spatial attention. Finally we have
found impaired higher level attentional modulation of contrast sensitivity in the visual periphery, where
mechanisms of covert attention are at higher demands. These findings demonstrate a specific loss of attentional mechanisms in PD and a pathological redistribution of spatial mechanisms of covert attention.
ER  -