Changes in audio-spatial working memory abilities during childhood: The role of spatial and phonological development

Abstract

Working memory is a cognitive system devoted to storage and retrieval processing of information. Numerous studies on the development of working memory have investigated the processing of visuo-spatial and verbal non-spatialized information; however, little is known regarding the refinement of acoustic spatial and memory abilities across development. Here, we hypothesize that audio-spatial memory skills improve over development, due to strengthening spatial and cognitive skills such as semantic elaboration. We asked children aged 6 to 11 years old (n = 55) to pair spatialized animal calls with the corresponding animal spoken name. Spatialized sounds were emitted from an audio-haptic device, haptically explored by children with the dominant hand's index finger. Children younger than 8 anchored their exploration strategy on previously discovered sounds instead of holding this information in working memory and performed worse than older peers when asked to pair the spoken word with the corresponding animal call. In line with our hypothesis, these findings demonstrate that age-related improvements in spatial exploration and verbal coding memorization strategies affect how children learn and memorize items belonging to a complex acoustic spatial layout. Similar to vision, audio-spatial memory abilities strongly depend on cognitive development in early years of life.

Fig 1. Performance analyses.

Data are presented as mean across participants; error bars represent standard error. The left panel shows the results for the score parameter; the right panel represents the results for the number of attempts parameter. In the call-name condition, 6–7 year-olds reached a lower score and employed a greater number of attempts compared to the other two groups and the call-call condition. Asterisks indicate significant differences (see Results section for details). One asterisk (*) represents p < 0.5 Two asterisks (**) represent p < 0.01 and three asterisks (***) p < 0.001.

Fig 2. Audio-anchor.

Data are presented as the mean across participants per each group; error bars represent the standard error. Regardless of the condition, 6–7 year-olds used the Audio-anchor exploration strategy more often compared to the other age groups. Significant comparisons between groups are represented. Two asterisks (**) represent p < 0.01 and three asterisks (***) p < 0.001.

Fig 3. Linear regression analysis.

Linear regression plot with 95% confidence intervals (shaded areas). The box on top of each plot shows the correlation and the significance level. Top row shows the linear regression in the call-name condition for the score (A) and the number of attempts (B). Middle row shows the linear regression in the call-call condition for the score (C) and the number of attempts (D). Bottom row shows the linear regression for both conditions for the Audio-anchor (E).

Fig 4. ARENA.

A) The device measures 50 cm x 50 cm and consists of 25 speakers embedded in blocks covered by tactile sensors. Tactile sensors cover the blocks. B) The cardboard grid placed over the ARENA is represented. The grid is composed of 12 free slots. The feedback sounds were emitted from the speaker indicated by the red dot.

Fig 5. Experimental conditions.

A) In the call-call condition, we asked the child to a couple animal calls. B) In the call-name condition, the animal call and the name of the animal had to be paired.

Fig 6. Example of score calculation.

The score is an index that decreases when the child returns to the speakers previously touched. When the child touches two speakers for the first time, the score equals 0. If they have already touched one or both the speakers, the score decreases by 1 or 2, respectively. When a pair is found, the score increases by 10. In the example, if the starting value were equal to 0, the final score would have been: 0–1–2 + 10 = 7. Depicted animals were downloaded from a royalty-free images web archive (https://publicdomainvectors.org/).

Fig 7. Example of Audio anchor calculation.

The index equals 0 at the beginning of the test. The index increased correlated with more attempts started with the same speaker. In the represented example, the final value would have been: 0+1+1 = 2. Depicted animals were downloaded from a royalty-free images web archive (https://publicdomainvectors.org/).