Table 1.
Twenty fMRI action observation studies (with 24 experiments) included in the meta-analysis
| Demographic Data | Experimental Design | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Study | Sub-groups | Sample size | Age group | Mean IQ (SD) | Ratio of sex (F:M) | Symptom severity measure | Symptom severity score (SD) | Subject matching criteria | Action observation stimuli | Body part | Social-emotional component | Baseline |
| Bastiaansen(2011) [68] | ASD-HTD | 2121 | Adult | 102.5 (14.81)101.5 (17.4) | 0:210:21 | ADOS (social) | 7.19 (2.46) | Age, IQ, gender | One actor displayed facial expressions (happy, neutral, disgusted) | Face | Yes | Fixation cross |
| Bookheimer (2008) [69] | ASD-HTD | 1212 | Adolescent | N/A | 0:120:12 | ADOS (total) | 11.3 (N/A) | Age, gender | One actor displayed a facial expression (neutral) | Face | Yes | Matching oval shapes |
| Carter (2012) [78] | ASD-HTD | 1213 | Adolescent | 112.1 (15.19)116.6 (10.28) | 3:92:11 | ADOS (social) | 7.25 (1.22) | Age, IQ, gender | Two actors displayed bodily gestures in social situations | Full-body | Yes | Fixation cross |
| Cole (2019) [59] | ASD-HTD | 2020 | Adult | N/A | 8:128:12 | AQ | 37.4 (8.04) | Age, gender, education | One actor manipulated an object (inserting poker chips into a box) | Full-body | No | Fixation cross |
| Critchley (2000) [70] | ASD-HTD | 99 | Adult | 102 (15)116 (10) | 0:90:9 | ADI | N/A | Age, IQ, gender | One actor displayed facial expressions (happy, neutral, angry) | Face | Yes | Observation of neutral face |
| Dalton (2005) [71] | ASD-HTD | 1212 | Adolescent | 94 (19.47)N/A | 0:120:12 | ADI-R | N/A | Age, gender | One actor displayed facial expressions (happy, fear, angry) | Face | Yes | Observation of neutral face |
| Dapretto (2006) [72] | ASD-HTD | 55 | Adolescent | 92.0 (19.4)105.2 (12.8) | 0:50:5 | ADOS (social) | 8.4 (3.1) | Age, IQ, gender | One actor displayed facial expressions (happy, sad, angry, fear, neutral) | Face | Yes | Fixation cross |
| Davies (2011) [73] | ASD-HTD | 1616 | Adolescent | 106.2 (20.3)105.6 (16.0) | 2:142:14 | ADOS (total) | 12 (4) | Age, IQ, gender | One actor displayed facial expressions (happy, angry, fear, neutral) | Face | Yes | Fixation cross |
| Deeley (2007) [74] | ASD-HTD | 99 | Adult | 114 (12)120 (18) | 0:90:9 | ADOS; ADI-R | N/A | IQ, gender | Experiment 1:One actor displayed a facial expression (fear) | Face | Yes | Fixation cross |
| Experiment 2:One actor displayed a facial expression (disgust) | ||||||||||||
| Experiment 3:One actor displayed a facial expression (happy) | ||||||||||||
| Freitag (2008) [60] | ASD-HTD | 1313 | Adolescent | 101.2 (21.2)112.1 (18.0) | 2:132:13 | ADI-R (social) | 11.3 (4.3) | Age, IQ, gender | One point-light walker displayed bodily gesture (walking) | Full-body | No | Scrambled point-light displays |
| Greimel (2010) [75] | ASD-HTD | 1515 | Adolescent | 112.7 (11.3)109.9 (17.3) | 0:150:15 | ADOS, ADI-R | N/A | Age, IQ, gender | One actor displayed facial expressions (happy, sad) | Face | Yes | Neutral faces |
| Grèzes (2009) [61] | ASD-HTD | 1212 | Adult | 102 (20.6)119 (6.6) | 2:100:12 | N/A | N/A | Age, IQ, gender | One actor displayed bodily emotional expression (fear) | Full-body | Yes | Neutral bodily expression |
| Hubbard (2012) [62] | ASD-HTD | 1313 | Adolescent | 110116 | 3:103:10 | ADOS (social) | 7.9 (3) | Age, IQ, gender | Experiment 1:One actor displayed a random hand gesture | Hand | No | Still frame (a kitchen) without presence of hands |
| Experiment 2:One actor (without face) displayed communicative gesture | Hand | Yes | ||||||||||
| Libero (2014) [63] | ASD-HTD | 2122 | Adult | 116.3 (12.8)117.5 (8.8) | 4:175:17 | ADOS, ADI-R | N/A | Age, IQ, gender | One actor manipulated objects (telephone, spoon, camera, cup) | Full-body | No | Fixation cross |
| Marsh (2011) [64] | ASD-HTD | 1819 | Adult | 110.2 (16.0)113.9 (13.8) | N/A | ADOS (social) | 6.17 (3.47) | Age, gender | One actor manipulated an object (a ball) | Hand | No | Moving shapes without hand action |
| Martineau (2010) [66] | ASD-HTD | 78 | Adult | 93.3 (9.5)N/A | 0:70:8 | N/A | N/A | Age, education | One actor displayed hand flexion-extension movement | Hand | No | Picture of a static hand |
| McKay (2012) [67] | ASD-HTD | 1010 | Adult | 125 (7.01)124.8 (6.75) | N/A | N/A | N/A | Age, IQ | One point-light walker displayed bodily gesture (walking) | Full-body | No | Scrambled point-light displays |
| Schneider (2013) [76] | ASD-HTD | 2828 | Adult | 109.1 (9.2)114.0 (9.6) | 13:1513:15 | AQ | 37.69 (7.84) | Age, gender, education | One actor displayed facial expressions (disgust, happy, fear, anger) | Face | Yes | Neutral facial expression |
| Schulte-Ruther (2011) [77] | ASD-HTD | 1818 | Adult | 106.6 (10.5)112.1 (10.4) | 0:180:18 | AQ | 33.6 (10.2) | Age, IQ, gender | One actor displayed facial expressions (happy, sad) | Face | Yes | Neutral facial expression |
| Wadsworth (2018) [65] | ASD-HTD | 1315 | Adolescent | 109 (17.3)102 (16.2) | 2:114:11 | AQ | 72 (34.36) | Age, IQ | Experiment 1:One actor manipulated daily objects (e.g., an iron) | Full-body | No | Fixation cross |
| Experiment 2:More than one actors displayed communicative gestures | Full-body | Yes | ||||||||||
ASD-H High-functioning autism spectrum disorder, TD Typically-developing, ADOS Autism Diagnostic Observation Schedule, ADI-R Autism Diagnostic Interview—Revised, Age chronological age only, IQ full-scale IQ only, Education years of education