Inhibitory processing following damage to the parietal lobe

We investigated inhibitory properties of spatial attention in a group of four patients with lesions involving the posterior parietal lobe. In a first experiment, a double cue inhibition of return (IOR) procedure was employed. The parietal patients showed an IOR effect only when they had to detect targets that appeared on the contralesional side. In a second experiment, we combined an IOR procedure with a Stroop task [Psychon. Bull. Rev. 8 (2001) 315] to explore the neural basis of "inhibitory tagging" as described by Fuentes et al. [Q. J. Exp. Psychol. Hum. Exp. Psychol. 52 (1999) 149]. The results from the control participants replicated the findings of Vivas and Fuentes, Stroop interference was reduced at the cued location, relative to the uncued location. The parietal patients showed a similar result, but only for contralesional targets. These findings suggest that IOR is modulated by the parietal lobe, and that, through this process, the parietal cortex influences the application of inhibitory tagging to stimuli.