Chad S. Rogers

Expectation and entropy in spoken word recognition: effects of age and hearing acuity.

Background/Study Context: Older adults, especially those with reduced hearing acuity, can make good use of linguistic context in word recognition. Less is known about the effects of the weighted distribution of probable target and nontarget words that fit the sentence context (response entropy). The present study examined the effects of age, hearing acuity, linguistic context, and response entropy on spoken word recognition. Methods: Participants were 18 older adults with good hearing acuity (M age = 74.3 years), 18 older adults with mild-to-moderate hearing loss (M age = 76.1 years), and 18 young adults with age-normal hearing (M age = 19.6 years). Participants heard sentence-final words using a word-onset gating paradigm, in which words were heard with increasing amounts of onset information until they could be correctly identified. Degrees of context varied from a neutral context to a high context condition. Results: Older adults with poor hearing acuity required a greater amount of word onset information for recognition of words when heard in a neutral context compared with older adults with good hearing acuity and young adults. This difference progressively decreased with an increase in words’ contextual probability. Unlike the young adults, both older adult groups’ word recognition thresholds were sensitive to response entropy. Response entropy was not affected by hearing acuity. Conclusion: Increasing linguistic context mitigates the negative effect of age and hearing loss on word recognition. The effect of response entropy on older adults’ word recognition is discussed in terms of an age-related inhibition deficit.

Learning to diminish the effects of proactive interference: reducing false memory for young and older adults.

Results from two experiments revealed that prior experience with proactive interference (PI) diminished PI’s effects for both young and older adults. Participants were given two rounds of experience, with different materials, in a situation that produced PI. Comparisons with a control condition showed that the effects of PI on accuracy and on high-confidence intrusion errors (false memory) were reduced on the second round, as compared with those on the first. Also, the ability of confidence to diagnose accuracy of responding improved across rounds. Effects of prior experience with PI depended on feedback given at the time of test (Experiment 1). At least in part, the diminishment of PI resulted from participants’ allocating more attention to interference items during study in the second round than in the first (Experiment 2). Implications of the results for interpreting age differences in PI and false memory are discussed.

Effects of Age, Acoustic Challenge, and Verbal Working Memory on Recall of Narrative Speech

Background/Study Context: A common goal during speech comprehension is to remember what we have heard. Encoding speech into long-term memory frequently requires processes such as verbal working memory that may also be involved in processing degraded speech. Here the authors tested whether young and older adult listeners’ memory for short stories was worse when the stories were acoustically degraded, or whether the additional contextual support provided by a narrative would protect against these effects. Methods: The authors tested 30 young adults (aged 18–28 years) and 30 older adults (aged 65–79 years) with good self-reported hearing. Participants heard short stories that were presented as normal (unprocessed) speech or acoustically degraded using a noise vocoding algorithm with 24 or 16 channels. The degraded stories were still fully intelligible. Following each story, participants were asked to repeat the story in as much detail as possible. Recall was scored using a modified idea unit scoring approach, which included separately scoring hierarchical levels of narrative detail. Results: Memory for acoustically degraded stories was significantly worse than for normal stories at some levels of narrative detail. Older adults’ memory for the stories was significantly worse overall, but there was no interaction between age and acoustic clarity or level of narrative detail. Verbal working memory (assessed by reading span) significantly correlated with recall accuracy for both young and older adults, whereas hearing ability (better ear pure tone average) did not. Conclusion: The present findings are consistent with a framework in which the additional cognitive demands caused by a degraded acoustic signal use resources that would otherwise be available for memory encoding for both young and older adults. Verbal working memory is a likely candidate for supporting both of these processes.

Older adults show impaired modulation of attentional alpha oscillations: Evidence from dichotic listening.

Auditory attention is critical for selectively listening to speech from a single talker in a multitalker environment (e.g., Cherry, 1953). Listening in such situations is notoriously more difficult and more poorly encoded to long-term memory in older than in young adults (Tun, O’Kane, & Wingfield, 2002). Recent work by Payne, Rogers, Wingfield, and Sekuler (2017) in young adults demonstrated a neural correlate of auditory attention in the directed dichotic listening task (DDLT), where listeners attend to one ear while ignoring the other. Measured using electroencephalography, differences in alpha band power (8–14 Hz) between left and right hemisphere parietal regions mark the direction to which auditory attention is focused. Little prior research has been conducted on alpha power modulations in older adults, particularly with regard to auditory attention directed toward speech stimuli. In the current study, an older adult sample was administered the DDLT and delayed recognition procedures used by Payne et al. (2017). Compared to young adults, older adults showed reduced selective attention in the DDLT, evidenced by a higher rate of intrusions from the unattended ear. Moreover, older adults did not exhibit attention-related alpha modulation evidenced by young adults, nor did their event-related potentials (ERPs) to recognition probes differentiate between attended or unattended probes. Older adults’ delayed recognition did not reveal a pattern of suppression of unattended items evidenced by young adults. These results serve as evidence for an age-related decline in selective auditory attention, potentially mediated by age-related decline in the ability to modulate alpha oscillations.

Semantic priming, not repetition priming, is to blame for false hearing

Contextual and sensory information are combined in speech perception. Conflict between the two can lead to false hearing, defined as a high-confidence misidentification of a spoken word. Rogers, Jacoby, and Sommers (Psychology and Aging, 27(1), 33–45, 2012) found that older adults are more susceptible to false hearing than are young adults, using a combination of semantic priming and repetition priming to create context. In this study, the type of context (repetition vs. sematic priming) responsible for false hearing was examined. Older and young adult participants read and listened to a list of paired associates (e.g., ROW–BOAT) and were told to remember the pairs for a later memory test. Following the memory test, participants identified words masked in noise that were preceded by a cue word in the clear. Targets were semantically associated to the cue (e.g., ROW–BOAT), unrelated to the cue (e.g., JAW–PASS), or phonologically related to a semantic associate of the cue (e.g., ROW–GOAT). How often each cue word and its paired associate were presented prior to the memory test was manipulated (0, 3, or 5 times) to test effects of repetition priming. Results showed repetitions had no effect on rates of context-based listening or false hearing. However, repetition did significantly increase sensory information as a basis for metacognitive judgments in young and older adults. This pattern suggests that semantic priming dominates as the basis for false hearing and highlights context and sensory information operating as qualitatively different bases for listening and metacognition.

Online testing for assessing speech intelligibility

The use of online testing in the behavioral sciences is increasing due to the potential for lower cost and faster completion than traditional in-person laboratory testing. Online testing presents a special challenge for speech research due to the variety of listeners’ acoustic environments. For example, listeners may use headphones or speakers of various types, complete the task in different levels of background noise, or vary in their hearing abilities. Here we presented spoken sentences in speech-shaped noise to participants from the United States recruited online using Amazon Mechanical Turk at SNRs of -2, -5, and -8 dB (n≥50 per SNR). We compared these online results to normative data collected using these same sentences in the lab (SNR of -5 dB; n = 30). Preliminary results suggest a reasonable correspondence between average intelligibility scores for individual sentences presented using the two methods (Spearman rho = 0.79). Standard deviations suggest greater variability in the online responses (av...