Table 2.
Characteristics of the experimental and control groups.
| Deaf | Hearing | t | p | |||
|---|---|---|---|---|---|---|
| mean (SD) | range | mean (SD) | range | |||
| Non-verbal Intelligence | 84.15 (9.74) | 75–99 | 86.40 (9.88) | 75–99 | 0.73 | 0.47 |
| Reading comprehension | 88.75 (8.81) | 75–99 | 92.90 (7.86) | 75–99 | 1.57 | 0.12 |
| Vocabulary size | 94.58 (5.93) | 78.33–100 | 90.96 (12.93) | 51.66–100 | 1.13 | 0.26 |
Non-verbal intelligence was measured with the Raven Progressive Matrices test69, where participants had to identify the missing item of a sequence of figures. Spanish reading comprehension was assessed through the ECL-264, a standardized reading test consisting of five short paragraphs followed by a total of 27 multiple-choice questions evaluating word meaning, synonyms, antonyms, sentence and text content. Vocabulary size was measured using the Spanish version of the LexTALE70,71, a lexical decision test consisting of 60 real words and 30 nonwords providing a good estimate of language knowledge72. All scores are percentages. Results of two-tailed t-tests are reported for each group comparison.