The Spatial Learning Task of Lhermitte and Signoret (1972) is an object-location arbitrary associative learning task. Since its introduction, it has been used in a variety of clinical conditions to assess elementary levels of mnestic function. It has most commonly been employed in case studies of amnesia (Lhermitte and Beauvois, 1973; Ponsford and Donnan, 1980; Duyckaerts et al., 1985; Vighetto et al., 1991; Haslam et al., 1997), or in paediatric studies of the developing memory system (Anderson and Lajoie, 1996; Skuy et al., 2001; Anderson et al., 2001a; Pentland et al., 2003) and central nervous system insults during the developmental period (Northam et al., 1995; Anderson et al., 1997a,b, 2001b, 2004, 2005; Lindgren et al., 2004; Brunsdon et al., 2007; Aragón et al., 2008). The task differentiates severe (Lhermitte and Signoret, 1972), but not mild (Ponsford et al., 1980), mnestic disturbances.

In addition to its utility in individuals with low mnestic abilities (Walsh, 1985, 1994), the Spatial Learning Task has a number of other desirable features. It is simple to explain to patients and can be completed based solely on pointing responses, making it useful in a range of otherwise difficult to assess populations (non-English speaking, aphasic, learning disorders, visuoconstructional deficits, etc.). With nine stimulus elements, it is ‘supraspan’ for most individuals without being overwhelming. It also has a number of practical benefits including the use of simple, readily transportable stimulus materials and objective scoring.

The utility of any psychometric instrument is, however, limited by the availability of normative data. Norms for the Spatial Learning Task have been developed for paediatric cohorts (Anderson and Lajoie, 1996) and for older adults (Wardill et al., 2009); however, norms covering young to middle adulthood are not, to the authors’ knowledge, available. Such norms would be very useful given the range of clinical situations in which evaluation of rudimentary mnestic abilities is required in this age band (e.g. traumatic brain injury, hypoxic brain injury and neurosurgical evaluation).

The purpose of the present study is to obtain normative data on the Spatial Learning Task of Lhermitte and Signoret (1972) for adults aged 18–45. We also aim to evaluate the relationship between performance on the Spatial Learning Task and clinical/demographic variables such as age, overall intellectual ability, years of education, gender and other measures of mnestic function. We hypothesise that performance will be independent of these variables, given previous findings in older adults (Wardill et al., 2009) and the suggestion that this elementary mnestic task can be successfully performed via a range of cognitive strategies (e.g. verbal and/or nonverbal; Pentland et al., 2003).

The purpose of this study was to collect adult normative data on the Spatial Learning Task of Lhermitte and Signoret (1972). Ninety percent of participants achieved perfect scores on two successive trials (T2Cr) within five or fewer trials. Our data indicate that a T2Cr score of 6 is suggestive of impairment and a T2Cr score of 7 or more is statistically abnormal. At a practical level, we observed that roughly 10% of participants obtain an imperfect score after their first perfect score. Thus, we recommend continuing administration of the task until two successive perfect scores have been obtained, thereby demonstrating stable memory for the object-location associations.

The lack of dependence of Spatial Learning Task performance on age, gender, level of education or IQ is a desirable property that simplifies test interpretation and widens the utility of the instrument. Typically, when interpreting a particular test score obtained from a given individual these demographic factors must be accounted for, often through stratified normative data or prediction equations. Our data imply this is not the case for the Spatial Learning Task, at least across the demographic range of our cohort.

Previous research has highlighted the importance of individual differences (Waller, 2000; Lopez et al., 2020), especially gender differences (Silverman and Eals, 1992), in measures of object-location learning. For instance, the meta-analysis of Voyer et al. (2007) reported an overall effect favouring women on Object-Location Memory tasks. This gender effect was age dependent, emerging over the age of 13, and was greater for recall (versus recognition) and for categorical (e.g. top/bottom, left/right; versus coordinate, e.g. distance displacement error) formats, though was not apparent in all studies (see ‘Discussion’ in Rahman et al., 2011). Our own results using the Spatial Learning Task, which can be considered a categorical recall task, did not reveal a gender effect. This could reflect the simplicity of the Spatial Learning Task itself (i.e. ceiling effects in the normal population precluding the presence of a gender effect) and its multidetermined nature (i.e. that it is not a ‘pure’ spatial learning task, as considered further below).

The ceiling effect that we observed, with the majority of participants attaining perfect performance across the first few trials, is expected of measures that sample the low end of functional ability (Kaplan and Saccuzzo, 2017), as the Spatial Learning Task does for memory (Walsh, 1985). In clinical practice, the assessment of such basic mnestic abilities is often carried out informally. Typical examples include asking patients to recall a short list of unrelated words or to learn the identity and location of a small number of objects hidden around the room by the examiner, with ‘rules of thumb’ guiding the interpretation of performance (Strub and Black, 2000; Lezak et al., 2012). The Spatial Learning Task affords the opportunity to evaluate such basic mnestic abilities quantitatively, and the normative data reported here extend the utility of this measure to the adult population.

It is important to note that while poor performance on the Spatial Learning Task provides evidence of significant mnestic compromise, normal performance cannot be taken to reflect unimpaired mnestic function. The authors’ clinical experience is that individuals can exhibit subtle to moderate declines on measures such as the Rey Auditory Verbal Learning Test without showing any compromise on the Spatial Learning Test. Thus, the Spatial Learning Test should not be used or interpreted in isolation, but rather considered alongside other measures of memory ability. A dense amnestic picture would, by definition, be expected to show poor performance across multiple measures of anterograde memory.

Among the other cognitive tasks that we administered, the only significant relationship with T2Cr that we observed was with the RAVLT (total words recalled across learning trials and delayed recall). This relationship was weak, only accounting for between 5 and 7% of variance in Spatial Learning Task scores. This suggests, as has been posited previously (Pentland et al., 2003), that while the task is notionally a visuospatial associative learning task, verbal learning and memory can contribute to task performance. The use of simple, familiar objects in conjunction with an orderly grid arrangement of locations makes the task performable via a range of strategies, from purely verbal (e.g. by approaching the task as one of verbal associate learning: ‘Chair – Middle’, ‘Kitten – Top Left’ and ‘Banana – Southeast’) to purely nonverbal and varying combinations thereof (see also Helmstaedter et al., 1995). This again points to the importance of considering performance on the Spatial Learning Task relative to other measures of memory ability.

A range of ‘purer’ measures of spatial memory have been developed, many with normative data available, such as the Brief Visuospatial Memory Test—Revised (Benedict et al., 1996); the Brown Location Test (Brown et al., 2007); the Location Learning Test (Bucks and Willison, 1997; Bucks et al., 2000); the modified Location Learning Test (Kessels et al., 2004, 2006); the Spatial Array Memory Test (Meador et al., 1990); the Spatial Location Test (Sanchez et al., 1997); the Visual Spatial Learning Test (Malec et al., 1992); and the 7/24 Spatial Recall Test (Gontkovsky et al., 2004; see also references cited in discussion of spatial memory and hemispheric lateralisation below). Such measures however are best suited to addressing the question of differences relative to typical performance in the normal population rather than the assessment of elementary levels of mnestic function, the principal question of interest in the present study.

When considered next to other published norms, our data suggest that performance on the Spatial Learning Task improves between age 13 and the youngest individuals in our adult cohort. Inspection of the normative data reported in Anderson and Lajoie (1996; e.g. Figure 3 therein) suggests that even in paediatric cohorts performance approaches ceiling, and hence that the improvement in the adult population is modest. This improvement likely reflects maturation of executive and metacognitive abilities brought to bear on the task over this developmental period (Anderson and Lajoie, 1996). For instance, Huizinga et al. (2006), using a latent variable analysis applied to a battery of executive tasks administered to a range of age groups, have shown that elements of executive function continue to develop throughout adolescence. There is also a large body of literature showing that the availability and effective deployment of memory strategies increases throughout childhood (Schneider and Bjorklund, 2002). Such metacognitive memory strategies emerge relatively early in childhood and continue to develop into early adolescence and beyond (Bjorklund et al., 2008; Roebers, 2014).

The normative values derived from our data are comparable to the older adult data of Wardill et al. (2009), implying that once adult performance levels on the task are attained they remain stable throughout adulthood. Our data are also consistent with the observations of Walsh, who stated that ‘Subjects of normal intelligence will almost invariably reach a perfect score in six trials or less’ (Walsh, 1985, p. 240). Ninety percent of participants in our cohort had returned at least one perfect score within four trials or less, and by the 6th trial, all 101 participants had returned at least one perfect score (Table 3).

Combing our own observations with those of others (Walsh, 1985; Wardill et al., 2009) suggests that poor performance in an adult can be considered a reliable marker of memory dysfunction that can be interpreted free of confounds from other demographic variables such as age, level of education and IQ. Further research targeting specific clinical populations is required to expand the clinical utility of the task. For instance, does the lack of dependence on IQ extend beyond the lower end of the IQ range sampled here to include those with mild to moderate ID? It would also be useful to relate performance on the task to real world metrics, to explore the ecological validity of the task for day-to-day memory functions (e.g. ratings from carers; prognostic value with respect to skill acquisition in clinical cohorts with severe memory impairment).

Further research is also required to determine whether unilateral temporal lobe compromise is sufficient to disrupt task performance, or whether bitemporal dysfunction is required. In our clinical experience, patients with evidence of bilateral mesial temporal dysfunction perform poorly on the Spatial Learning Task. This includes individuals with degenerative disease, such as Alzheimer’s disease, and also focal epilepsy patients with evidence of bitemporal disease (e.g. bilateral hippocampal sclerosis). However, the question remains, can performance be affected in the presence of unilateral disease/pathology. Considerable debate surrounds the question of hemispheric asymmetries and spatial learning (Saling, 2009). Clinically, we have seen individual cases of unilateral, right temporal lobe epilepsy who are impaired on the Spatial Learning Task, and the weight of published evidence does appear to suggest at least a right hemisphere bias for object-location memory more broadly (Smith and Milner, 1981, 1989; Abrahams et al., 1997; Baxendale et al., 1998; Bohbot et al., 1998; Nunn et al., 1998, 1999; Incisa della Rocchetta et al., 2004; Kessels et al., 2004; Stepankova et al., 2004; Crane and Milner, 2005; Glikmann-Johnston et al., 2008; Frisch and Helmstaedter, 2014; see also the meta-analysis by Kessels et al., 2001). A systematically collected, prospective case series would be required to address the question of potential lateralising significance (uni- versus bilateral; left versus right) of the Spatial Learning Task.

A limitation of the present study was reliance upon self-report of neurological and psychiatric history. Self-report, while time and resource efficient, is not as sensitive and specific as ‘gold standard’ approaches such as structured clinical interview, medical records review or re-examination (e.g. mood: (Coyne et al., 2001; Stuart et al., 2014); stroke: (Engstad et al., 2000; Woodfield et al., 2015); and hospitalisation: (Bergmann et al., 1998)). Additionally, the participants in this study comprise a sample of convenience rather than being actively matched to population demographics, and as a group are relatively high functioning (mean level of education = 15.3 years; mean IQ =115.5).

We have obtained normative data for the Spatial Learning Task (Lhermitte and Signoret, 1972) from a sample of 101 participants aged 18–45. We have shown that performance is not influenced by age, gender, the number of years of education or overall IQ, and less than 10% of the variance in learning scores is associated with variability in verbal memory. Our data provide the basis for normative comparisons in adults: 90% of participants achieved perfect scores on two successive trials (T2Cr) within five or fewer trials; a T2Cr score of 6 is suggestive of impairment and a T2Cr score ≥ 7 is statistically abnormal. These data expand the clinical utility of the Spatial Learning Task in the adult population.

The raw data supporting the conclusions of this article will be made available by the authors, without undue reservation.

The studies involving human participants were reviewed and approved by the University of Melbourne Human Research Ethics Committee. The patients/participants provided their written informed consent to participate in this study.

CT, MS, and SW planned and designed the study and coordinated recruitment and data collection. AC and CT analysed the data and drafted the manuscript. All authors contributed to the article and approved the submitted version.

The Florey Institute of Neuroscience and Mental Health acknowledges the strong support from the Victorian Government and in particular the funding from the Operational Infrastructure Support Grant.

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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