Assessing nonverbal memory with the Biber Figure Learning Test—Extended in temporal lobe epilepsy patients

Archives of Clinical Neuropsychology 17 (2002) 25 – 35 Assessing nonverbal memory with the Biber Figure Learning Test—Extended in temporal lobe epilepsy patients Guila Glossera,*, Lynne Colea, Upama Khatria, Lynn DellaPietraa, Edith Kaplanb,c a Department of Neurology — 3 Gates, University of Pennsylvania Medical Center, 3400 Spruce Street, Philadelphia, PA 19104-4283, USA b Department of Neurology, Boston University, Boston, MA, USA c Department of Psychology, Suffolk University, Boston, MA, USA Accepted 11 September 2000 Abstract Material-specific memory dysfunction was assessed using a nonverbal, visuospatial, supraspan learning test, the Biber Figure Learning Test-Extended (BFLT-E), in 71 left-hemisphere languagedominant epilepsy patients prior to anterior temporal lobectomy (ATL) and in 48 age-matched healthy subjects. Two matched forms of the BFLT-E yielded comparable scores, indicating that this task may be used to track memory performance over time in individual patients. Right temporal lobe epilepsy (RTLE) and left temporal lobe epilepsy (LTLE) patients performed below healthy subjects on all freerecall measures. RTLE, but not LTLE, patients also differed from healthy subjects in recognition memory discrimination. Furthermore, the RTLE patients performed below LTLE patients on measures specific to long-term memory abilities. The BFLT-E appears to be a useful clinical tool for assessing different components of visuospatial memory in patients with lateralized mesial temporal lobe (MTL) dysfunction. The test is sensitive to visuoconstructional problems associated with various types of brain damage, but it also distinguishes material-specific, nonverbal, visuospatial memory impairments in patients with neurological dysfunction in the non language-dominant right temporal lobe. D 2001 National Academy of Neuropsychology. Published by Elsevier Science Ltd. Keywords: Temporal lobe epilepsy; Design memory * Corresponding author. Tel.: +1-215-662-3371; fax: +1-215-349-5579. E-mail address: (G. Glosser). 0887-6177/01/$ – see front matter D 2001 National Academy of Neuropsychology. 0887-6177(00)00093-7 Downloaded PII: from Shttps://academic.oup.com/acn/article-abstract/17/1/25/2081 by guest on 30 June 2018 26 G. Glosser et al. / Archives of Clinical Neuropsychology 17 (2002) 25–35 The importance of mesial temporal lobe (MTL) structures, especially the hippocampus, in long-term memory has been well-established in studies of humans, primates, and rodents (Zola-Morgan & Squire, 1993). It has been proposed further that in humans unilateral MTL lesions disrupt memory in a material-specific fashion. Most of this evidence comes from investigations of patients who have undergone anterior temporal lobectomy (ATL) for treatment of medically refractory epilepsy. These studies have demonstrated an association between ATL in the language-dominant left hemisphere and deficits on verbal memory tasks such as prose recall, word list learning, and supraspan digit learning (Hermann, Wyler, & Somes, 1994; Milner, 1958; Ojemann & Dodrill, 1985; Rausch & Ary, 1990; Saykin et al., 1992). Other studies have shown a relationship between right ATL and impairments on tasks assessing memory using nonverbal materials, primarily visuospatial stimuli such as unfamiliar faces, abstract designs, mazes, and object–space locations (Jones-Gotman, 1986; Kimura, 1963; Majdan, Sziklas, & Jones-Gotman, 1996; Milner, 1965, 1968; Smith & Milner, 1989). Compared to the robust relationship between verbal memory deficits and left ATL, however, findings of visuospatial memory deficits following right ATL have been weaker and less consistent (Chelune, Naugle, Luders, & Awad, 1991; Lee, Loring, & Thomson, 1989; Malec et al., 1992; Novelly et al., 1984). One problem in attempting to define the role of MTL structures of the right or non language-dominant hemisphere in visuospatial long-term memory has been the isolation of memory functions from other aspects of cognition. Since multiple regions in both the right and left cerebral hemispheres are implicated in visuospatial, perceptual, and constructional processes, memory tests that engage these more elementary cognitive operations can be disrupted by lesions of either hemisphere (Butters, Delis, & Lucas, 1995; Heilbronner, 1992; Lezak, 1995). The confounding of visuospatial memory performances with impairments in other aspects of visuospatial processing is demonstrated by factor analyses, which have repeatedly found that scores on many standard tests of visuospatial memory load highly on visuoperceptual and visuospatial constructional factors, but have much lower association with measures more clearly defining learning and memory (Larrabee, Kane, Schuck, & Francis, 1985; Leonberger, Nicks, Larrabee, & Goldfader, 1992). Even when a memory factor has been isolated in these analyses, visuospatial memory functions have not emerged consistently as separate from general aspects of memory (Smith, Malec, & Ivnik, 1992). One way to isolate visuospatial memory processes from other cognitive operations is to design tasks that draw more directly on learning processes. A well-accepted method for assessing various components of long-term memory involves presentation of a supraspan set of stimuli for repeated recall or recognition trials and subsequent testing of delayed retention. This method provides a measure of the capacity for encoding new information into long-term memory by quantifying the degree of improvement in memory over successive presentations of the stimulus set. Problems in memory consolidation are identified by the difference between initial learning performance and delayed retention. Memory retrieval functions are assessed by comparing free-recall and recognition performances. This technique has been adapted for assessing visuospatial memory using designs of moderate complexity that are presented over several learning trials for drawing (Glosser, Goodglass, & Biber, 1989; JonesGotman, 1986b; Majdan et al., 1996; Rey, 1968). G. Glosser et al. / Archives of Clinical Neuropsychology 17 (2002) 25–35 27 Four previous studies using supraspan design learning techniques have demonstrated impaired visuospatial long-term memory in patients following right ATL (Glosser, Fedio, & Ryan, 1993; Jones-Gotman, 1986b; Jones-Gotman et al., 1997; Majdan et al., 1996). In the present investigation, we extend those results. The Biber Figure Learning Test-Extended (BFLT-E), an expanded version of a previously described visuospatial supraspan learning task (Glosser et al., 1989), was used to assess various components of learning, long-term memory, and retrieval in patients with unilateral temporal lobe epilepsy (TLE) prior to resective surgery. We expected to find that among these patients, the majority of whom have primary pathology in the hippocampus (Meencke & Veith, 1991), those with right-sided seizure foci would be selectively impaired in visuospatial long-term memory. (...truncated)