Sandro Franceschini, Simone Gori, Milena Ruffino, Simona Viola, Massimo Molteni, and Andrea Facoetti

Transcription

1 Current Biology, Volume 23 Supplemental Information Action Video Games Make Dyslexic Children Read Better Sandro Franceschini, Simone Gori, Milena Ruffino, Simona Viola, Massimo Molteni, and Andrea Facoetti Table S1. Descriptive Statistics of the Two Groups, Related to Figure 1 Action Video Non-Action Video t (18) p Gamers (n=10) Gamers (n=10) value Age (months) (±17.35) (±17.15).40 Full IQ (±10.23) 98.4 (±9.94).63 Clinical words reading speed (z-scores) (±3.62) (±2.66).85 Clinical words reading errors (z-scores) (±3.14) (±1.26).30 Clinical pseudo-words reading speed (z-scores) -1.5 (±1.32) (±2.69).15 Clinical pseudo-words reading errors (z-scores) -2.6 (±1.72) (±.86).37 Phonemic blending (number of correct phonemes) 32.6 (±12.52) 30.9 (±16.1).80 Mean (and SD) of the two samples of video game players: Age (in months), IQ [1S] and words and pseudo-words reading severities (speed and errors in z-scores) measured by the clinical tasks [2S]. The two treated groups were carefully matched for chronological age, full IQ, reading severity and phonological skill. 1

2 Table S2. Reading Inefficiency Indexes of the Two Groups, Related to Figure 1 Action Video Gamers (n=10) t (9) p Action Video Gamers (n=6) Non-Action Video Gamers (n=10) t (9) p T1 T2 T3 T1 T2 Clinical pseudo-words list Experimental pseudo-words list (±67.1) 57.1 (±20) (±49.5) 47.5 (±14.3) (±60.1) (±173) (±14.2) 70.7 (±33.8) (±213.4) 81.3 (±34.4) Experimental pseudo-words text (±36.8) 92.6 (±23.1) (±28.8) 156 (±74.6) (±88.6).48 Experimental words text (±173.5) (±97.7).04 // (±93.2) (±110.2).53 T1, T2 and T3 inefficiency indexes (i.e., speed/accuracy, the higher is the index, the higher are the reading difficulties) in Action Video Gamers and Non-Action Video Gamers was used to control speed-accuracy trade-off. Significant within-subject t-test between T1 and T2 in two trained groups are reported in bold. The two groups did not differ at T1 in reading measurements. 2

3 Table S3. Reading Speed and Accuracy of the Two Groups, Related to Figure 1 Action Video Gamers (n=10) Action Video Gamers (n=6) Non-Action Video Gamers (n=10) T1 T2 T3 T1 T2 Clinical pseudo-words (speed) (±39) 99.8 (±30.4) (±45.5) (±83.5) (±78) Clinical pseudo-words (accuracy).69 (±.11).69 (±.09).83 (±.07).71 (±.11).68 (±.15) Experimental pseudo-words list (speed) 35.5 (±9.5) 30.4 (±8.5) 33.1 (±9.7) 47.6 (±20.8) 45.8 (±17.6) Experimental pseudo-words list (accuracy).65 (±.14).67 (±.15).77(±.12).70 (±.13).61 (±.21) Experimental pseudo-words text (speed) 82.5 (±22.2) 71 (±13.4) 70.7 (±26.2) (±39.9) (±59.4) Experimental pseudo-words text (accuracy).78 (±.13).79 (±.13).93 (±.05).78 (±.12).75(±.13) Experimental words text (speed) (±126.5) (±80.6) (± 79) (±95.2) Experimental words text (accuracy).93 (±.08).95 (±.05).93 (±.04).95 (±.04) Speed (in seconds) and accuracy mean (and SD) of the two samples of Video Game Players in the different reading tasks administered at T1, T2 and T3. 3

4 Table S4. Attentional Tasks Performances of the Two Groups, Related to Figures 2 and 3 Action Video Gamers Non-Action Video Gamers Distributed and Focused Attention tasks Crossmodal temporal attention task Distributed spatial Attention (accuracy) Focused spatial Attention (accuracy) First cue-target interval RT (ms) Second cue-target interval RT (ms) First cue-target interval accuracy Second cue-target interval accuracy T1 T2 T1 T2.24 (±.11).38 (±.14).26 (±.10).28 (±.18).29 (±.13).49 (±.17).29 (±.20).36 (±.25) 375 (90) 361 (100) 435 (141) 401 (82) 377 (107) 320 (74) 420 (162) 402 (100).98 (.03).98 (.03).96 (.05).96 (.05).96 (.04).95 (.04).97 (.03).98 (.05) In the upper part: mean accuracy (and SD) of the two samples of video game players in the Distributed and Focused Attention tasks at T1 and T2. The two groups did not differ at T1 in distributed and focused spatial attention measurements. In the lower part: AVG and NAVG players reaction time (RT) and accuracy (mean and SD) at first (50 ms) and second (100 ms) cue-target interval in the cross-modal temporal attention task for T1 and T2 are showed. The two groups did not differ at T1 in the temporal attention measurements. 4

5 Table S5. Measure Used in the Multiple Regression Analysis, Related to Figures 1, 2 and 3 n=20 Mean SD T1 general reading inefficiency (speed/accuracy) T2 general reading inefficiency (speed/accuracy) General reading abilities improvement T1 age (months) T1 IQ T1 phonemic blending (number of correct phoneme) T2 phonemic blending (number of correct phoneme) Phonetic blending improvement (T2-T1) T1 spatial attention (accuracy) T2 spatial attention (accuracy) Spatial attention improvement (T2-T1) T1 temporal attention (ms) T2 temporal attention (ms) Temporal attention improvement (T2-T1) Mean and SD of raw data at T1 and T2, and measure of improvements (T2-T1) used in the multiple regression analysis. 5

6 Table S6. Multiple Regression Analysis, Related to Figure 1, 2, and 3 General Reading Improvements R 2 Change p 1 Age and full IQ Phonological changes Spatial and temporal attentional improvements To more stringently determine the predictive relationships between attentional and reading improvements induced by video game training in all treated children with dyslexia (n=20), we performed a three-step, fixed-entry, multiple regression analysis in which the dependent variable was general reading abilities improvements (inefficiency mean reduction between the pseudo-words decoding and the word text reading task). To control for age, general cognitive functioning and changes in phonological skill, the predictors entered at the three step were: (1) chronological age and full IQ, (2) T1 T2 accuracy changes in phonemic blending, and (3) spatial (mean between focused and distributed attention) and temporal attentional T1 T2 improvements. Importantly, visual-spatial and cross-modal temporal attention enhancements, entered last, accounted for a significant portion of unique variance in general reading improvements (r 2 change=.48) induced by video game treatments. 6

7 Supplemental Experimental Procedures Participants Participants were 20 children with dyslexia (mean age=9.8 yrs, SD=1.4, range 7 13 yrs) recruited in the Scientific Institute E. Medea of Bosisio Parini, Lecco, Italy. Children were diagnosed with dyslexia based on standard exclusion and inclusion criteria [3S]. The reading performance (errors and/or speed) of each individual was at least 2 SDs below the age-standardized norm in at least one of the 4 clinical measures [2S]. Full IQ scores were computed using the WISC III [1S]. Other inclusion criteria for this study were normal full IQ ( 85), normal or corrected-tonormal vision, absence of attention deficit disorder with hyperactivity, based on standard exclusion and inclusion criteria [3S], and no experience with AVGs. Information about video game experience was collected in interviews of parents during pre-informative briefing about the experimental treatment. Dyslexic children did not know the aim of the treatment. Children who participated in the treatment and had less efficient results will be re-contacted to participate in other training. Although our group size could be considered a limitation, it was large enough to show reliable significant differences between the two trainings. Treatments Apparatus, stimuli and procedure Participants were tested at 3 to 5 days before the start of treatment and re-tested between one and three days after the end of treatment. Stimuli were presented on a 15.4-in LCD screen, 40 cm from the observer. Video games were played at 200 cm from a 27-in TV screen. A commercial Wii video game from Ubisoft (deemed suitable for children age 7 and older by the Pan European Game Information) called Rayman Raving Rabbids was used. Single mini-games were selected from the overall game and categorized as AVG or NAVG. In order to 7

8 classify the mini-games, we followed the checklist developed by Green et al. [4S], reporting that all action video games share a set of qualitative features, including: 1) extraordinary speed both in terms of very transient events and in terms of the velocity of moving objects; 2) a high degree of perceptual, cognitive, and motor load in the service of an accurate motor plan; 3) unpredictability both temporal and spatial; 4) an emphasis on peripheral processing. Based on the description of the AVG characteristics a possible distinction between the two treatments could be that the AVG stimulate more the Magnocellular-Dorsal or Action stream in comparison with the NAVG as suggested by Vydiasagar and Pammer [6]. We labeled action video games only the mini-games that presented all the four characteristics listed above, whereas the non action video-games presented not more then one of them. All the authors of the manuscript evaluated the single mini-games using this checklist. When the agreement among the authors was over 67% the mini-games were labeled as action or nonaction video games. The NAVG participants did not see the mini games used by the AVG player and vice versa. Each child was individually treated, we trained children for 9 sessions of 80 minutes per day distributed in a period of two weeks (usually parents did not bring their children in the hospital during the weekend). Action Video Game Training This treatment was composed by the Bunny Hunt and Shake your Booty sections. In the Bunny Hunt sections the player had to shoot plungers at rabbits avoiding to be hit by them, rabbits will appear in any possible position of the screen. The Shake your Booty sections are dancing games where both hands have to be moved at rhythm when rabbits appear from left or right. From the section Sport-Workout we employed: Bunnies are Addicted to Carrot Juice in which the player had to shoot carrot juice at rabbits avoiding to be hit by them, Bunnies Can t Shear Sheep in which the player had to shear sheep, the mechanic is similar to the previous game; Bunnies Rarely Leave Their Burrows (1, 2) consisted a whac-a-mole game; Bunnies are Bad at Peek-a- 8

9 Boo is a typical red-light green-light game. From the section Sport-Precision we used: Bunnies are A-mazing which is a fast paced labyrinth; Bunnies Have a Great Ear for Music which is basically a visual and auditory search task; Bunnies Don t Use Toothpaste (1, 2) consisted a whaca-mole game; Bunnies Like to Stuff Themselves (1,2) in which the player has to trace objects very fast. From the section Sport-Skill we used: Bunnies are Slow to React (1, 2, 3) which is a fast paced three-dimensional labyrinth; Bunnies Don t Like Being Shot At in which the player has to shoot to moving objects; Bunnies Never Close Doors (1, 2) which is a kind of a visual search task; Bunnies Can t Jump in which the player has to let jump a rope to his/her character at different speeds. The mini-games of the family Bunny Hunt were played more often than the other in the AVG training because they were more similar to the action video games reported in the previous literature [4S]. Non-action Video Game Training This treatment was composed by the following mini-games: from the section Sport-Workout : Bunnies Don t Give Gifts which is a is a race against the clock; Bunnies Like Surprises in which the player has to guide a blind character into several objects; Bunnies Can t Fly (1, 2) which is a cart run; Bunnies Have Natural Rhythm (1, 2) in which the player has to touch different characters with the same color; Bunnies Don t Milk Cows (1, 2) in which the player has to do the same simple movement as fast as he/she can; Bunnies Can t Play Soccer in which the player has to do simple movements as precise as he/she can. From the section Sport-Precision we used: Bunnies are Heartless with Pigs (1, 2) in which the player has to walk through a maze guided by sounds feedbacks; Bunnies Can t Slide (1, 2) in which the player has to aim to a static target. From the section Sport-Skill we employed: Bunnies are Not Ostriches in which the player has to carefully control a flying character; Bunnies Don t Understand Bowling which is basically a bowling game; Bunnies Have a Poor Grasp of Anatomy which is a memory game for shapes; Bunnies Don t Know What to Do with Cows in which the player has to do a simple sequence of movements. 9

10 Focused Spatial Attention Task Stimuli The fixation mark was a green square (0.3 x 0.3 ). A string of six black, non-verbal symbols (1.1 x 1.8 ), three for each half of the visual field (eccentricity 1.1, 3.6 and 6.1 ), were displayed simultaneously. The target was the non-verbal symbol indicated by a red dot (0.3 ) that appeared before the string, and a post-mask (six 8-like red figures string, 1.1 x 1.8 ) was displayed after six black, non-verbal symbols. All the stimuli were presented on a white background and had a luminance of 24 cd/m 2. Procedure Participants were instructed to keep their eyes on the fixation point for the duration of the trial. Eye movements were monitored by a video camera system. Each trial started with the display of the fixation point, and after 1000 ms, the red dot focused attention on the target location, appearing for 34 ms before the string of six black, non-verbal symbols. A blank screen for 100 ms was presented. A post-mask was displayed for 50 ms, and a blank screen for 1000 ms. Participants were instructed to identify the target as accurately as possible without time limit. Responses were pointed by the participant and entered by the experimenter who pressed the corresponding key on the computer keyboard. The accuracy was recorded by the computer. No feedback was provided. The experimental session consisted of 48 trials. Distributed Spatial Attention Task Stimuli The stimuli were the same employed for the focused spatial attention task. 10

11 Procedure The procedure was the same described for the focused spatial attention task, except the red dot appeared after the string of non-verbal symbols disappeared. This experimental session was mixed with those of the focused spatial attention task. Cross-modal Attention Task Stimuli Two circles (5.7 ) were displayed peripherally (16.4 of eccentricity) on the left and right of the fixation point, which was a stylized bone (2.9 x 2.1 ). The auditory spatial cue consisted of a single pure tone of 1000 Hz presented in the left, right, or both loudspeakers placed 4.5 cm from the two circles. The target stimulus was a stylized dog (4.3 x 3.6 ) that could appear in the center of either circle. All the stimuli were black on a white background and had a luminance of 24 cd/m 2. Procedure Participants were instructed to keep their eyes on the fixation point for the duration of the trial. Eye movements were monitored by a video camera system. Each trial started with the display of the fixation point and two lateral circles. The spatial auditory cue was presented after 500 ms in the left, right, or both loudspeakers. The cue (duration 40 ms) was followed by the target (duration 100 ms) after a SOA (cue-target interval) of 50 or 100 ms. In the response trials, the probability that the target would appear in the cued location (valid) or in the other location (invalid) was 50% (cue location was uninformative). In the neutral condition, the target was presented inside the left (50%) and the right (50%) circle an equal amount of times. In contrast, in the catch trials, the target was not displayed, and participants did not have to respond. Catch trials were randomly interspersed with response trials. Participants were instructed to respond as quickly as possible to the display of 11

12 the visual targets by pressing the correct button on the computer keyboard to localize the position of the target. Choice reaction times and accuracy were recorded. The time limit for responding was 1500 ms. The experimenter controlled the inter-trial interval. The experimental session consisted of 56 trials: 8 valid, 8 invalid, 8 neutral, and 4 catch trials (for each cue-target interval). Auditory and Speech-sound Tasks Syllabic blending measured the ability to blend several spoken segmented phonemes into a pseudo-word (10 pseudo-words for a total of 76 phonemes; e.g., N + O + S + I + T + R + A = nositra ). Accuracy was recorded for each pseudo-word single phoneme. Reading Tasks Reading tasks were administered by three experimenters that did not know the aims of the study. Word Reading In T1, the ability to read aloud was measured using a clinical standardized Italian test composed by 112 words (separated into 4 lists) [2S]. This clinical test was used as an index of reading severity (see Table S1). Pseudo-words Reading Phonological decoding ability was measured using: (i) 3 standardized clinical lists of 48 Italian pseudo-words [2S], employed also to test the reading severity in T1 (see Table S1), (ii) 2 experimental lists of 15 pseudo-words, and (iii) 2 experimental texts of 46 pseudo-words, counterbalanced in T1 and T2. 12

13 Word Text Reading Reading fluency and errors in age-standardized prose passages from Italian clinical tests [5S] were used to measure ecological-context reading. Supplemental Results Speed Improvements in Reading Tasks Speed improvements in word text reading and pseudo-words decoding for both treated groups were compared with the developmental trend in syllables per second for children [6S]. The Italian children with dyslexia increased their word text reading speed by an average of.3 syllables/second (for each grade), while their pseudo-words decoding speed by.15 syllables/second [6S]. Speed reading improvements for AVG training (12 hours) was.39 syllables per second, resulting bigger than those obtained in estimated 12 hours by the stressful and repetitive traditional phonological (.06 syllables per second) and orthographic treatments (.29 syllables per second) [7S] and equal to the letter-to-speech integration training (.40 syllables per second) [8S]. Video Games Improvements To measure the improvement in the video game abilities of the two training methods, both groups were evaluated before every session (except for the first practice day) on a single mini-game ( Bunnies Don't Like Being Disturbed on Holiday for the AVG and Bunnies Don t Understand Bowling for the NAVG training). The z-scores from the video game scores were calculated. A mixed ANOVA, in which the within-subject factor was Time (performance recorded each day of treatment) and the between-subject factor Group (AVG and NAVG), was calculated. The time main effect was significant (F (7,126) =3.51, p<.001, η 2 p=.16). Importantly, the Time*Group interaction was not significant, indicating that the two groups of children with dyslexia similarly improved their 13

14 video game abilities during the two treatments. Planned comparisons (paired sample t-tests), indeed, reveal a significant improvement (i.e., mean z-score for day two versus day nine) in both AVG (from SD±2.07 to SD±1,51; t (9) =5.55, p<.001) and NAVG players (from -1.1 SD±2,39 to SD±2.88; t (9) =2.93, p=.02). Cross-modal Temporal Attention Task A 2 (Time: T1 and T2) *2 (cue-target interval: 50 and 100 ms) *3 (Cue Type: Valid, Neutral, and Invalid) *2 (Group: AVG and NAVG) mixed ANOVA performed on accuracy revealed no significant main effects or interactions (see Table S4). Finally, a 2 (Time: T1 and T2) *2 (cue-target interval: 50 and 100 ms) *2 (Group: AVG and NAVG) mixed ANOVA performed on accuracy in catch trials revealed no significant main effects or interactions. 14

15 Author Contributions S.F., S.G., and A.F. designed the experiments, performed the data analyses, and wrote the paper. S.F., M.R., and S.V. performed the experiments. M.R. and M.M. selected the clinical population. This research constitutes part of S.F. s PhD thesis. Supplemental References [1S] Wechsler, D. (2006). Wechsler Intelligence Scale for Children III (WISC-III), (Firenze: Organizzazioni Speciali). [2S] Sartori, G., Job, R., and Tressoldi, P.E. (1995). Batteria per la Valutazione della Dislessia e della Disortografia Evolutiva (Firenze: Organizzazioni Speciali). [3S] American Psychiatric Association. (1994). Diagnostic and Statistical Manual of Mental Disorders 4th Ed. (Washington, DC: American Psychiatric Association). [4S] Green, C.S., Li, R., and Bavelier, D. (2009). Perceptual learning during action video game playing. Top. Cogn. Sci., 2, [5S] Cornoldi, C., Colpo, G., and Gruppo M.T. (1998). Prove di Lettura MT (Firenze: Organizzazioni Speciali). [6S] Tressoldi, P.E., Stella, G., and Faggella, M. (2001). The development of reading speed in Italians with dyslexia: A longitudinal study, J. Learn. Disabil., 34, [7S] Lorusso, M.L., Facoetti, A., Paganoni, P., Pezzani, M., and Molteni, M. (2006). Effects of visual hemisphere-specific stimulation versus reading-focused training in dyslexic children, Neuropsychol. Rehabil., 16, [8S] Tressoldi, P.E., Lorusso, M.L., Brenbati, F., and Donini, R. (2008). Fluency remediation in dyslexic children: Does age make a difference? Dyslexia, 14,