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RESEARCH PRODUCT

Impairments in top down attentional processes in right parietal patients: Paradoxical functional facilitation in visual search

Daniela SmirniPatrizia TurrizianiLisa CipolottiLisa CipolottiMassimiliano OliveriLi ZhaopingGiuseppa Renata Mangano

subject

AdultMaleTop-down attentiongenetic structuresmedicine.medical_treatmentPosterior parietal cortexbehavioral disciplines and activities050105 experimental psychologyParietal cortexTask (project management)03 medical and health sciences0302 clinical medicineParietal LobemedicineHumans0501 psychology and cognitive sciencesAttentionVisual searchParietal patientsSettore M-PSI/02 - Psicobiologia E Psicologia FisiologicaBrain NeoplasmsVisual search05 social sciencesCognitive neuroscience of visual object recognitionTop-down and bottom-up designMiddle AgedSensory SystemsTranscranial magnetic stimulationStrokeOphthalmologyFeature (computer vision)Case-Control StudiesParadoxical functional facilitationFacilitationVisual PerceptionFemalePsychologyNeuroscience030217 neurology & neurosurgeryPhotic Stimulationpsychological phenomena and processesCognitive psychologyBottom-up attention

description

AbstractIt is well known that the right posterior parietal cortex (PPC) is involved in attentional processes, including binding features. It remains unclear whether PPC is implicated in top-down and/or bottom-up components of attention. We aim to clarify this by comparing performance of seven PPC patients and healthy controls (HC) in a visual search task involving a conflict between top-down and bottom-up processes. This task requires essentially a bottom-up feature search. However, top-down attention triggers feature binding for object recognition, designed to be irrelevant but interfering to the task. This results in top-down interference, prolonging the search reaction time. This interference was indeed found in our HCs but not in our PPC patients. In contrast to HC, the PPC patients showed no evidence of prolonged reactions times, even though they were slower than the HCs in search tasks without the conflict. This finding is an example of paradoxical functional facilitation (PFF) by brain damage. The PFF effect enhanced our patients’ performance by reducing the top down interference. Our finding supports the idea that right PPC plays a crucial role in top-down attentional processes. In our search tasks, right PPC induces top-down interference either by directing spatial attention to achieve viewpoint invariance in shape recognition or by feature binding.

yearjournalcountryeditionlanguage
2014-04-01Vision Research
10.1016/j.visres.2014.02.002http://dx.doi.org/10.1016/j.visres.2014.02.002