Detection of masked patterns in monkeys with inferotemporal, striate or dorsolateral frontal lesions.

Monkeys with lateral striate (LS) lesions, inferotemporal (IT) lesions or dorsolateral frontal (DLF) lesions were trained to discriminate between two visual patterns before and after the patterns were masked with irrelevant stimuli (rings enclosing the patterns). Compared to the DLF monkeys, the IT monkeys and one monkey with LS lesions were retarded in discriminating between the unmasked patterns. Irrespective of their performance with unmasked patterns, the IT and LS monkeys were impaired in discriminating the masked patterns, compared to the DLF monkeys. Analysis of performance in testing suggests that both LS and IT lesions produce an impairment in selective attention to visual stimul