Memory for different aspects of complex visual scenes after unilateral temporal- or frontal-lobe resection

Delayed recognition memory for different aspects of complex visual scenes was examined in 65 patients with unilateral temporal- or frontal-lobe excisions and 15 normal control subjects. Right anterior temporal lobectomy, irrespective of the extent of hippocampal removal, impaired memory for figurative detail (the visual characteristics of the objects in a scene) and spatial composition (the arrangement of the filled and unfilled space in a scene). In contrast, only patients with right temporal-lobe lesions that included extensive hippocampal removal were impaired at detecting changes in the spatial location of specific objects. A subsequent study provided no evidence that right temporal lobectomy impairs the immediate recognition of these types of visual information, suggesting that the impairments observed after a delay represent a failure of retention or retrieval rather than of encoding.