اثر سطح هوش و محل اقامت بر روی توانایی افراد با عقب ماندگی ذهنی برای شناسایی حالات چهره

Abstract This study was designed to investigate the abilities of individuals with mental retardation to recognize and match emotional facial expressions from a series of photographs depicting various facial expressions. There were four groups of participants according to their place of residence (community or institution) and their intelligence level (mild or moderate). Each individual participated in two tasks: (1) recognizing a facial expression from an array of three pictures presented, and (2) matching a facial expression from one picture with a picture depicting a similar emotion from an array of three pictures. All information was presented to the participants in the native language, Hebrew. The six facial expressions used for the study included happiness, sadness, fear, anger, surprise, and disgust. The ability to recognize and match facial expressions was significantly higher for individuals with mild than moderate mental retardation. There was no significant difference for place of residence. Happiness was the easiest feeling to recognize and match for all groups. Fear and anger were the most difficult to recognize, while sadness and anger were most difficult to match.

1. Introduction The ability to recognize facial emotional expressions is a critical skill for understanding the messages conveyed to one another during communication. Distinguishing between various facial expressions and different emotions also appears to be an essential component of social functioning (Simon, Rosen, & Ponpipom, 1996). The ability to decode emotional expressions and interpersonal skills are key elements in the development of social adaptation and socio-emotional competence (Rojahn, Lederer, & Tasse, 1995). While adults with typical abilities are able to identify facial emotions such as happiness, sadness, anger, fear, surprise, and disgust with great accuracy across various cultures (e.g., Ekman & Oster, 1982), this ability has been shown to be impaired in adults with mental retardation (e.g., McAlpine, Kendall, & Singh, 1991; Simon et al., 1996). Children with mental retardation perform well on tasks involving identification of facial expressions when compared to mental age-matched children (McAlpine et al., 1991). However, when older children and adolescents with mental retardation were compared to children with typical abilities, even when matched for age, they were not able to perform as well (Adams & Markham, 1991 and Rojahn et al., 1995). In a study examining age and IQ as factors influencing the ability of adults with mental retardation to identify facial expressions, results indicated that age correlated negatively with performance and the ability to identify expressions increased significantly when IQ was higher (Simon et al., 1996). Thus, IQ predicted the ability to choose pictorial representations of an emotion and the label that corresponded to various facial expressions (Simon et al., 1996). The Ekman and Friesen (1976) facial emotion slides have been used in various studies investigating the ability of individuals with mental retardation to identify facial emotional expressions (e.g., McAlpine et al., 1991; Simon, Rosen, Grossman, & Pratowski, 1995; Simon et al., 1996). These slides have also been used in a study investigating the ability of individuals with mild and moderate mental retardation to recognize facial expressions (McAlpine, Singh, Kendall, & Ellis, 1992). The study involved the use of slides that depicted six sets of emotions: happiness, disgust, sadness, anger, fear, and surprise. No difference was found between the abilities of adults with mild and moderate mental retardation to recognize facial expressions. In an attempt to explain these results, the authors suggested that place of residence could be a cause for the lack of differences. The authors reported that while the individuals with mild mental retardation participating in the study lived in institutions, the individuals with moderate mental retardation lived in the community (McAlpine et al., 1992). Thus, the authors suggested that the type of residence possibly influenced the results. Research examining the level of social skills of people in institutional and community-based settings has found that individuals with mental retardation living in the community demonstrate higher levels of social and adaptive behavior skills when compared to people living in institutions (e.g., Anderson et al., 1992, Heller et al., 1998, Hill et al., 1984 and Spreat et al., 1998). The number of social interactions in institutions is fewer than in the community. This finding may influence experience and exposure to emotional facial expressions. In a longitudinal study investigating the effects of institutionalization on individuals who remained in the institutions, researchers found that adaptive behavior was not affected by intra-institutional moves, although the individuals did experience fewer community interactions (Stancliffe & Hayden, 1998). Thus, it is important to investigate whether institutions have an effect on the ability to identify emotional facial expressions. Recent studies investigating new trends and programs in institutions found no significant differences between persons living in the community and persons remaining in institutions, and that most of the latter stayed in smaller settings (Heinlein & Fortune, 1995). A meta-analysis investigating the impact of de-institutionalization on the adaptive behaviors of adults with mental retardation found that other than self-care, most adaptive behavior measures, such as socialization gains were modest (Lynch, Kellow, & Willson, 1997). The authors suggested that physical integration did not translate to social integration (Lynch et al., 1997). Thus, the importance of investigating the effect of place of residence as a factor influencing the ability of individuals with mental retardation remains unresolved. The purpose of this study was to examine the relationship between level of mental retardation and place of residence on the ability to identify different facial expressions. The level of mental retardation was represented by adults with mild and moderate mental retardation, the place of residence were presented by the community and by institutions. Facial expressions were assessed by two recognition-matching tasks between pictorial representations of six feelings

. Results Frequencies of the number of correctly identified and matched photos and expressions were calculated to evaluate the ease of identification of the facial expressions across both parts of the study. Fig. 1 depicts the results, which indicate that happiness was the emotion most frequently identified and matched. Frequency (in %) of the number of correct identifications of emotional facial ... Fig. 1. Frequency (in %) of the number of correct identifications of emotional facial expressions across parts I and II. Figure options There was no significant difference for age between groups [F(18,312)=.9, p>.05 for part I and F(18,312)=.1, p>.05 for part II). No significant differences were found for gender for part I of the study [F(6,110)=1.4, p>.05] and part II of the study [F(6,110)=.3, p>.05]. To investigate the effect of place of residence, a MANOVA was performed on the number of correct responses across feelings for each part of the study. The place of residence did not show any significant difference for part I of the study [F(6,110)=1.5, p>.05] and part II of the study [F(6,110)=1.4, p>.05]. ANOVA for each separate feeling also revealed no significant difference for place of residence (see Table 2). A linear regression procedure was performed to investigate the effects of the number of years in residence on the results of parts I and II of the study. The number of years in residence was calculated for all participants that were not living at home. No significant differences were found for the number of years for part I of the study [F(1,92)=.8, p>.37] and part II of the study [F(1,92)=.1, p>.69]. An additional analysis performed on the both parts of the study also revealed no significant difference in the study [F(1,92)=.5, p>.47]. Table 2. Results of correct identification and matching of facial expressions across place of residence Facial expression Happiness Sadness Fear Anger Surprise Disgust Part I Mean Community 2.72 1.83 1.66 1.96 2.23 2.49 Institution 2.65 2.15 1.82 1.88 2.38 2.38 F value .14 4.55 1.18 .15 1.20 .20 Part II Mean Community 2.81 1.96 2.11 1.75 2.55 2.53 Institution 2.79 2.32 2.21 1.80 2.51 2.47 F value .01 6.58 .52 .16 .01 .08 Table options To investigate the differences between the two levels of IQ in the ability to identify and match emotional facial expressions, a MANOVA was performed. There was a significant difference between individuals who have mild and moderate levels of mental retardation in part I [F(6,110)=4.3, p<.01] and part II [F(6,110)=3.7060, p<.01] of the study. Separate ANOVA’s conducted for each feeling in both parts of the study also revealed significant differences between mild and moderate mental retardation (see Table 3). Table 3. Results of correct identification and matching of facial expressions across mild and moderate mental retardation Facial expression Happiness Sadness Fear Anger Surprise Disgust Part I Mean Mild 2.88 2.24 1.94 2.09 2.56 2.62 Moderate 2.43 1.72 1.51 1.70 2.00 2.19 F value 11.83** 10.27** 8.37** 7.68** 11.47** 5.14** Part II Mean Mild 2.94 2.41 2.35 1.95 2.67 2.68 Moderate 2.62 1.85 1.94 1.57 2.36 2.26 F value 10.00** 15.90** 6.53* 5.65* 4.73* 8.46** * p<.05. ** p<.01. Table options To investigate the differences between levels of difficulty in both parts of the study, t-tests were used. The only significant difference between scores in parts I and II was found for fear [F(6,110)=18.3, p<.01]. MANOVA conducted revealed no significant differences for place of residence [F(6,110)=.3, p>.05], IQ level [F(6,110)=.4, p>.05] or gender [F(6,110)=1.5, p>.05].