Loss and persistence of implicit memory for sound: Evidence from auditory stream segregation context effects

Abstract

An important question is the extent to which declines in memory over time are due to passive loss or active interference from other stimuli. The purpose of the present study was to determine the extent to which implicit memory effects in the perceptual organization of sound sequences are subject to loss and interference. Toward this aim, we took advantage of two recently discovered context effects in the perceptual judgments of sound patterns, one that depends on stimulus features of previous sounds and one that depends on the previous perceptual organization of these sounds. The experiments measured how listeners' perceptual organization of a tone sequence (test) was influenced by the frequency separation, or the perceptual organization, of the two preceding sequences (context1 and context2). The results demonstrated clear evidence for loss of context effects over time but little evidence for interference. However, they also revealed that context effects can be surprisingly persistent. The robust effects of loss, followed by persistence, were similar for the two types of context effects. We discuss whether the same auditory memories might contain information about basic stimulus features of sounds (i.e., frequency separation), as well as the perceptual organization of these sounds.

Neural Correlates of Speech Segregation Based on Formant Frequencies of Adjacent Vowels

“…Our findings are analogous to those of prior research using tonal stimuli27293044. Although different neural mechanisms may underlie stimulus-related (i.e., Δ f 1 ) and perception-related (i.e., one stream vs. two streams) context effects, both context effects recede over time at a similar rate44. Further research is required to determine whether similar mechanisms are responsible for speech sound segregation as in tonal segregation, as well as whether the streaming of speech sounds is affected by factors such as attention and prior knowledge10.…”

“…Our findings are analogous to those of prior research using tonal stimuli27293044. Although different neural mechanisms may underlie stimulus-related (i.e., Δ f 1 ) and perception-related (i.e., one stream vs. two streams) context effects, both context effects recede over time at a similar rate44.…”

How previous experience shapes perception in different sensory modalities

“…The fact that the prior Δf effect generalizes to different frequency ranges (Snyder et al, 2009 ) but less so to different rhythmic patterns (Snyder and Weintraub, 2011 ) points to the recruitment of complex representations that are not arranged according to frequency. The contrastive effect declines over several seconds (Snyder et al, 2008 ; Snyder and Weintraub, 2013 ) and shows a persistent component (Snyder and Weintraub, 2013 ), suggesting the involvement of long auditory memory stores (Cowan, 1984 ; Lu et al, 1992 ). Importantly, the temporal dynamics of TCEs in audition can be strikingly similar to those in vision: for example, contrastive TCEs in visual apparent motion scale with log alternation rate (Anstis et al, 1985 ), as do contrastive effects in auditory stream segregation (Anstis and Saida, 1985 ).…”

Contextual plasticity, top-down, and non-auditory factors in sound localization with a distractor

“…Experiment 2 examined whether contextual plasticity is related to the contextual task difficulty and the strategies adopted by the subjects to cope with it (Snyder and Weintraub, 2013). In the previous study, the distractor location was fixed within a run such that the target array was always to the left or to the right of it.…”