Figure Disembedding: The Gottschaldt’s Hidden Figure Test in Children with Typical Development and Autism

Figure disembedding ability is the capacity to visually locate and detect local elements immersed within a global configural shape (Witkin, 1950; Witkin et al., 1971). It has been classically demonstrated that, when participants are required to search for a simple figure (local level) integrated in a larger one (global level), their task is more difficult if the lines of the simple figure belong perceptually to a different visual configuration within the complex figure, an effect early referred to as “embeddedness” by Gottschaldt (1926, 1929).

Gottschaldt (1926, 1929) introduced the Embedded Figure Test as a suitable measure of the ability to disentangle a figure from the background. The test material is a series of meaningless geometrical patterns in which a simpler geometrical figure is embedded, and the task requirement is to pencil it in. Following the original Gottschaldt’s Hidden Figure Test (GHFT), different versions of the Embedded Figures test have been devised, in which individuals are required to identify a target (simple) shape within complex designs. The most known version is that developed by Witkin et al. (1971).

The ability of disembedding figures undergoes developmental changes across childhood, with younger children being less able to detect embedded figures from the background, as indexed by both time and accuracy measures (Amador-Campos & Kirchner-Nebot, 1997; Cecchini & Pizzamiglio, 1975; Goodenough & Eagle, 1963; Witkin et al., 1967). Moreover, children’s performance seems to be affected by socioeconomic status and sex, with better scores associated to higher socioeconomic status and to male sex, although the results are not entirely consistent (Cakan, 2003; Cecchini & Pizzamiglio, 1975; Forns-Santacana et al., 1993; Karp et al., 1969; Witkin et al., 1967).

Persons with autism are thought to perform better than typical controls in disembedding figures. In a seminal study, Shah and Frith (1983) observed superior performance of children with autism on the Children’s Hidden Figure Test (Witkin et al., 1971) and explained this finding in terms of an enhanced ability to focus on the details within the whole, ignoring the interfering effect of the overall configuration (gestalt). Other studies reported that individuals with autism are as accurate as typical controls in disembedding figures but often show faster response times (Horlin et al., 2016). The inconsistencies in the literature are probably due to methodological reasons such as heterogeneity of task versions, stimuli presentation, and response recording (for a discussion see White & Saldaña, 2011).

To account for the advantage of individuals with autism in disembedding figures, the “Weak Central Coherence” (WCC) model proposed that the perceptual profile in these individuals is characterized by a weakness in global processing of information and a tendency towards local processing (Frith, 1989). Such local processing style would not be intrinsically disadvantageous, but rather it would be related to the specific requirements of the task at hand, for instance being advantageous in tasks requiring a superior ability to process details, such as the Figure Disembedding and the Block Design tests (Happé & Frith, 2006). From another angle, the “Enhanced Perceptual Functioning” (EPF) model posited that individuals with autism would show an enhanced capacity in local processing rather than an impaired ability for global processing (Mottron & Burack, 2001; Mottron et al., 2006).

To address the complex differences between children with typical development and children with autism in figure disembedding ability in the clinical setting, we deemed useful developing a standardized version of the GHFT, with robust normative data available for both time and accuracy parameters. Hence, in the present research, we: (1) assessed developmental changes across childhood in GHFT performance; (2) provided normative data from a large sample of native Italian speaking children; (3) tested a group of children with autism on the standardized version of the GHFT.

To these aims, two studies were conducted. In both, we adopted the GHFT version used by Capitani et al. (1988), in which participants have to complete a first series of stimuli within 15 min and a second series within 5 min. As we assess children, we did not impose any time limit as in adult individuals, but rather recorded the time (s) needed to complete the whole series of patterns.

Study 1 assessed the changes in performance on the GHFT as a function of age and education in a sample of 7–11-year-old typically developing children. This age range was chosen since age consistently affects figure disembedding ability (Amador-Campos & Kirchner-Nebot, 1997; Bigelow, 1971; Cecchini & Pizzamiglio, 1975; Witkin et al., 1967), with a progressive maturation of global and local perceptual abilities, particularly during the early school period (Dukette & Stiles, 2001; Kimchi et al., 2005; Poirel et al., 2008). Response time and accuracy scores of the GHFT were computed using the LMS method (Cole & Green, 1992), which allowed for obtaining normalized growth centile standards.

Study 2 evaluated the GHFT performance of children with autism with respect to the normative data gathered from participants in Study 1, and also compared performance of the autism group with that of closely age-matched typically developing controls.

In the GHFT, participants are presented with 34 complex geometrical figures in which a simple shape is hidden (Capitani et al., 1988; some examples are provided in Fig. 1). Test stimuli are arranged in four tables. In the first three tables containing nine items each, participants need to search for the simple figure (on the left side) within the complex figure (on the right side) and highlight it in by a pencil. In the last table, instead, the simple figure is located at the center of the sheet; the participants have to identify it within seven different complex figures placed above and below the simple shape. Each correct choice is scored 1 (score range 0–34) to obtain the accuracy score. The time needed to solve each of the four tables is recorded and their sum provides the total time score.

The study was conducted according to the standards of the Helsinki Declaration and the study protocol was approved by the local ethical committee of the Department of Psychology of the University of Campania Luigi Vanvitelli (code: N:34/03.11.2020). Written informed consent was obtained from the parents of each participant involved in the study.

The main aims of the present investigation were, first, assessing developmental changes across childhood in GHFT performance and providing normative data on Italian language speaking children (Study 1), and second, assessing a group of children with autism on the standardized version of the GHFT (Study 2).

Results of Study 1 showed that, although a progressive reduction of time scores could be appreciated across all the age ranges, only the two farther age groups were significantly different. These results are in line with Witkin et al.’s (1967) data showing an overall progressive tendency for children to become faster at disembedding, with a levelling off of the trend from about 14 years onward. The accuracy score was statistically lower in 7.0–7.5 and 7.6–7.11 groups with respect to all the other age groups, and in 8.0–8.5 or 8.6–8.11 groups with respect to 10.0–10.5 age groups, thus suggesting a smooth increase of accuracy across childhood. These findings are consistent with previous data on elementary school children (Amador-Campos & Kirchner-Nebot, 1997), with a particular refinement of performance when comparing 7-year-old children with the older ones (Bigelow, 1971; Cecchini & Pizzamiglio, 1975).

Here we did not detect differences due to sex or socioeconomic status. Thus, the normative data only took into account the effect of age. Sex differences have been reported in the literature on figure disembedding but with some inconsistencies partially accounted for by age. In age ranges well comparable with the present one, significant sex differences did not emerge (Bigelow, 1971; Cecchini & Pizzamiglio, 1975; Corah, 1965) although a non-significant advantage of boys over girls was also reported (Amador-Campos & Kirchner-Nebot, 1997). Indeed, until age 10, boys and girls display similar figure disembedding abilities while they tend to diverge during adolescence (Witkin et al., 1967). As for the possible effect of SES on performance, in a review of studies on children aged 4.5–10.5 years Laicardi-Pizzamiglio and Pizzamiglio (1974) found that poorer figure disembedding was related to lower socioeconomic status, but this finding could be related to participant’s general cognitive abilities (Bigelow, 1971; Forns-Santacana et al., 1993). It is possible that in studies on children with a narrow range of general cognitive functioning the differences related to socioeconomic status in figure disembedding could be weakened, consistent with recent findings (Zappullo et al., 2020).

Results of Study 2 showed that children with autism were significantly faster than typical controls whereas the two groups did not differ in accuracy. This finding was also clear with reference to the normative data in Study 1: a substantial proportion of autistic children achieved a time score in the highest centiles of the normative distribution, but only in some of them the accuracy score was at high centiles.

It has been suggested that methodological factors affecting task performance at a behavioral level, rather than a true difference between children with autism and typical development in figure disembedding at a cognitive level, could account for reported group differences on figure disembedding tests (White & Saldaña, 2011). Indeed, several approaches in the analysis of response time differences between children with autism and typical development are available in literature each producing somewhat different data. Some authors computed the average response times for only correct responses (e.g., de Jonge et al., 2006; Morgan et al., 2003), whilst others examined response times to all stimuli, either replacing the maximum time allowed for incorrect trials (e.g., Jolliffe & Baron-Cohen, 1997; Ropar & Mitchell, 2001) or including searching times regardless of whether the response was correct or not (Edgin & Pennington, 2005). Here, we followed the last procedure and recorded the time (in s) needed to complete the whole series of 34 items, irrespectively of the correctness of the responses. The present results were consistent with Edgin and Pennington (2005) and supported the strength of children with autism in disembedding. White and Saldaña (2011) suggested that considering time irrespective of trial accuracy could be affected by different strategies used to detect targets on incorrect trials, as some participants might give up search for the target more quickly than others. However, White and Saldaña’s observations (2011) mainly referred to Witkin’s task or to comparable versions, as the Coates’ (1972) one, in which, for each trial, the participant has to locate a simple target figure (e.g., a triangle) within a complex picture. Such task versions can favor a practice effect, since one or two target figures have to be repeatedly searched within complex images (Gottschaldt, 1926; Ludwig & Lachnit, 2004; Witkin et al., 1967). Moreover, in the Witkin’s task, a small number of items is presented (12 items), thus often leading to a ceiling effect (De Jonge et al., 2006; Jolliffe & Baron-Cohen, 1997). Practice in disembedding could reflect the impact of experience in terms of both perceptual and procedural (searching strategy) factors but can be reduced by varying the stimulus material as in the GHFT (Ludwig & Lachnit, 2004).

In the GHFT, 27 pairs of different images are provided in Tables 1, 2 and 3, whereas in the last table only one target has to be identified within seven different complex images. Hence, this set-up allowed to markedly increase task complexity with respect to other available versions, such as Witkin’s or Coates’ tests, counteracting the impact of practicing. Indeed, we did not find evidence of ceiling in any of the tested populations. Importantly, increased task complexity, and reduced practice effect, are thought to affect response time more than accuracy (Ludwig & Lachnit, 2004; Zoccolotti & Pizzamiglio, 1982), thus favoring the sensitivity of response times in discriminating between participants with autism and typically developing controls. Our results from the comparison of autistic children’s performance with both normative data and individually matched controls consistently showed that GHFT faster time scores significantly relate to the presence of autism, consistent with evidence demonstrating that individuals with autism are able to locate the embedded figures more quickly than controls (de Jonge et al., 2006; Jarrold et al., 2005; Jolliffe & Baron-Cohen, 1997; Morgan et al., 2003; Pellicano et al., 2005).

Both the WCC (Happé & Frith, 2006) and the EPF (Mottron et al., 2006) predict superior disembedding abilities in individuals with autism, albeit hypothesizing different underpinning mechanisms. Comparing the explanatory power of these two models would require more complex paradigms than the one adopted in the present investigation (Horlin et al., 2016). Thus, our findings do not allow to shed light on the reasons why children with autism are faster than typically developing controls in disembedding figures. Moreover, we have to mention that a further limitation of the present study is the reduced possibility to generalize the results to age ranges different from that involved here. Indeed, as recalled above, critical developmental changes occur in global and local perception abilities during the elementary school period, but a progressive refinement of these abilities protracts across adolescence (Mondloch et al., 2003). Hence, future studies should test the GHFT in typically developing adolescents and assess its validity to test figure disembedding abilities in adolescents with autism.

In conclusion, the results of Study 1 on a large sample of typically developing children aged 7–11 demonstrated that GHFT accuracy and time scores differed across age groups, without sex and socioeconomic differences. Thus, we could provide normative data only considering children’s age. In Study 2, children with autism achieved time scores at or above the 50th centile with respect to normative values and significantly differed for time scores from a closely age-matched group of typically developing controls. Taken together, these findings indicate that the GHFT is a valuable tool for assessing developmental changes in children’s figure disembedding ability and tracing the functional cognitive profile of children with autism.