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Auditory working memory for objects vs. features.

Joseph S, Kumar S, Husain M, Griffiths TD - Front Neurosci (2015)

Bottom Line: Memory recall was more accurate when the objects had to be maintained as a whole compared to the individual features alone.Additionally a feature extraction cost was associated with maintenance and recall of individual features, when extracted from bound object representations.The results have implications for feature-integration theory in the context of WM in the auditory system.

View Article: PubMed Central - PubMed

Affiliation: Institute of Cognitive Neuroscience, University College London London, UK ; Institute of Neurology, University College London London, UK.

ABSTRACT
This work considers bases for working memory for non-verbal sounds. Specifically we address whether sounds are represented as integrated objects or individual features in auditory working memory and whether the representational format influences WM capacity. The experiments used sounds in which two different stimulus features, spectral passband and temporal amplitude modulation rate, could be combined to produce different auditory objects. Participants had to memorize sequences of auditory objects of variable length (1-4 items). They either maintained sequences of whole objects or sequences of individual features until recall for one of the items was tested. Memory recall was more accurate when the objects had to be maintained as a whole compared to the individual features alone. This is due to interference between features of the same object. Additionally a feature extraction cost was associated with maintenance and recall of individual features, when extracted from bound object representations. An interpretation of our findings is that, at some stage of processing, sounds might be stored as objects in WM with features bound into coherent wholes. The results have implications for feature-integration theory in the context of WM in the auditory system.

No MeSH data available.


Related in: MedlinePlus

Accuracy varies by memory load and experimental condition. Overall accuracy (percentage correct) for every memory load (1, 2, and 4 auditory objects presented within a sequence). The plot shows how accuracy decreases with an increase in memory load for each experimental condition: single feature spectral condition (in rose), single feature temporal condition (in orange) and object condition (in black).
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Figure 3: Accuracy varies by memory load and experimental condition. Overall accuracy (percentage correct) for every memory load (1, 2, and 4 auditory objects presented within a sequence). The plot shows how accuracy decreases with an increase in memory load for each experimental condition: single feature spectral condition (in rose), single feature temporal condition (in orange) and object condition (in black).

Mentions: A Two-Way ANOVA was employed to test for the effects of factor 1, memory load, and factor 2, experimental condition, on accuracy. This analysis revealed a significant main effect of memory load [F(2, 32) = 31.94, p < 0.001] and a significant main effect of experimental condition on accuracy [F(2, 32) = 67.13, p < 0.001], as well as an interaction [F(4, 32) = 2.72, p = 0.035], (see Figure 3). All post hoc comparisons between individual memory loads across conditions were significant at p < 0.001. Memory recall was more accurate when the object had to be maintained as a whole compared to its individual features. This result cannot be explained based on the level of difficulty: it would be expected that monitoring a single feature should be easier than two. Features therefore may be represented as bound units. Participants had more accurate recollection on the dimension of the spectral passband compared to the temporal AM rate.


Auditory working memory for objects vs. features.

Joseph S, Kumar S, Husain M, Griffiths TD - Front Neurosci (2015)

Accuracy varies by memory load and experimental condition. Overall accuracy (percentage correct) for every memory load (1, 2, and 4 auditory objects presented within a sequence). The plot shows how accuracy decreases with an increase in memory load for each experimental condition: single feature spectral condition (in rose), single feature temporal condition (in orange) and object condition (in black).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4321563&req=5

Figure 3: Accuracy varies by memory load and experimental condition. Overall accuracy (percentage correct) for every memory load (1, 2, and 4 auditory objects presented within a sequence). The plot shows how accuracy decreases with an increase in memory load for each experimental condition: single feature spectral condition (in rose), single feature temporal condition (in orange) and object condition (in black).
Mentions: A Two-Way ANOVA was employed to test for the effects of factor 1, memory load, and factor 2, experimental condition, on accuracy. This analysis revealed a significant main effect of memory load [F(2, 32) = 31.94, p < 0.001] and a significant main effect of experimental condition on accuracy [F(2, 32) = 67.13, p < 0.001], as well as an interaction [F(4, 32) = 2.72, p = 0.035], (see Figure 3). All post hoc comparisons between individual memory loads across conditions were significant at p < 0.001. Memory recall was more accurate when the object had to be maintained as a whole compared to its individual features. This result cannot be explained based on the level of difficulty: it would be expected that monitoring a single feature should be easier than two. Features therefore may be represented as bound units. Participants had more accurate recollection on the dimension of the spectral passband compared to the temporal AM rate.

Bottom Line: Memory recall was more accurate when the objects had to be maintained as a whole compared to the individual features alone.Additionally a feature extraction cost was associated with maintenance and recall of individual features, when extracted from bound object representations.The results have implications for feature-integration theory in the context of WM in the auditory system.

View Article: PubMed Central - PubMed

Affiliation: Institute of Cognitive Neuroscience, University College London London, UK ; Institute of Neurology, University College London London, UK.

ABSTRACT
This work considers bases for working memory for non-verbal sounds. Specifically we address whether sounds are represented as integrated objects or individual features in auditory working memory and whether the representational format influences WM capacity. The experiments used sounds in which two different stimulus features, spectral passband and temporal amplitude modulation rate, could be combined to produce different auditory objects. Participants had to memorize sequences of auditory objects of variable length (1-4 items). They either maintained sequences of whole objects or sequences of individual features until recall for one of the items was tested. Memory recall was more accurate when the objects had to be maintained as a whole compared to the individual features alone. This is due to interference between features of the same object. Additionally a feature extraction cost was associated with maintenance and recall of individual features, when extracted from bound object representations. An interpretation of our findings is that, at some stage of processing, sounds might be stored as objects in WM with features bound into coherent wholes. The results have implications for feature-integration theory in the context of WM in the auditory system.

No MeSH data available.


Related in: MedlinePlus