Frontal lobe damage does not typically produce global amnesia, such as that which is often associated with medial temporal lobe and/or diencephalic lesions (Janowsky et al., 1989; Stuss and Benson, 1986; Squire, 1981). However, it is well known that frontal lobe lesions can cause a variety of impairments on both verbal and visual memory tests, indicating that the frontal lobes are involved, in some manner, in the learning and recall of information. In order to better understand the contributions of the frontal lobes to memory, a number of investigators have examined various aspects of memory functioning in patients with frontal lobe lesions. One manner in which researchers have approached the study of memory impairment in patients with frontal lobe damage is to explore the stage at which memory processing is disrupted, primarily focusing on encoding or retrieval. Gershberg and Shimamura (1995), studied encoding in patients with right and left frontal lobe damage and found impaired use of organizational strategies across three free recall tests in both patient groups. Although the patients’ recall did not improve to the level of the controls, their performances did improve when they were provided with strategic instructions or category cues, suggesting that deficits at encoding might contribute to their impairment. Other studies have also highlighted the encoding deficits observed in frontal lesioned patients, such as poor semantic and subjective organization of to-be-learned verbal material (Eslinger and Grattan, 1994; Stuss et al., 1994). In contrast, Incisa della Rochetta (1986) has argued for a retrieval-deficit explanation of impaired memory in patients with frontal lobe damage. She examined patients with right and left frontal lobe lesions and found evidence for free recall deficits in patients with left frontal lobe damage independent of deficits in their encoding. Impaired retrieval has also been inferred in patients with left, but not right, frontal lobe lesions on tests of part-list cuing – a paradigm thought to interfere with episodic retrieval, rather than encoding or storage mechanisms (Incisa della Rochetta and Milner, 1993). Additional support for a retrieval deficit in frontal lobe patients has come from studies demonstrating that patients with both right and left frontal lobe damage are differentially impaired on tests of free recall relative to recognition (Janowsky et al., 1989; Parkin et al., 1988; Shimamura, 1995). Because free recall places an emphasis on those processes involved in initiating a memory search, whereas recognition does not, some researchers have suggested that the primary memory deficit in frontal lesioned patients is in retrieval processes. However, another possible explanation for the free recall/recognition recall discrepancy in frontal lesioned patients is that recall and recognition rely on different processes. Recall requires the retrieval of complex associative Cortex, (2006) 42, 1080-1092 RESEARCH REPORT EPISODIC MEMORY IN PATIENTS WITH FOCAL FRONTAL LOBE LESIONS Carrie R. McDonald 1,2 , Russell M. Bauer 1 , J. Vincent Filoteo 2 , Laura Grande 1 , Steven N. Roper 3 and Robin Gilmore 4 ( 1 Department of Clinical and Health Psychology, University of Florida, FL, USA; 2 Department of Psychiatry, University of California, and Veterans Administration San Diego Healthcare System, San Diego, CA, USA; 3 Department of Neurological Surgery, University of Florida Brain Institute, FL, USA; 4 Department of Neurology, University of Florida Brain Institute, FL, USA) ABSTRACT Episodic memory was evaluated in patients with unilateral, frontal lobe damage and matched controls using a list- method directed forgetting paradigm. Directed forgetting instructions (forget vs. remember the word), encoding instructions (learn vs. judge the word) and test format (recall vs. recognition) were manipulated in order to explore how variations in encoding and retrieval affect verbal memory. Controls demonstrated a normal directed forgetting effect in recall and less directed forgetting in recognition. Patients with left frontal (LF) damage did not show directed forgetting in either recall or recognition and patients with right frontal (RF) damage showed directed forgetting in recall, but not in recognition. Furthermore, the LF group recalled significantly more of the judge than learn words, suggesting that this group’s performance improves by providing them with an encoding strategy. Conversely, the RF group’s performance did not depend on encoding instructions and their recognition memory was impaired relative to the other two groups when they were instructed to judge the words. Our results suggest that (a) patients with LF damage show deficits in the rehearsal of to-be-remembered information, (b) whereas patients with RF damage show impairments in recognition memory. Furthermore, both patient groups show a lack of directed forgetting when familiarity-based processes guide performance. Key words: frontal lobe damage, episodic memory, directed forgetting, epilepsy