Linguistic Redundancy and its Effects on Younger and Older Adults' Real-Time Comprehension and Memory.

Redundant modifiers can facilitate referential interpretation by narrowing attention to intended referents. This is intriguing because, on traditional accounts, redundancy should impair comprehension. Little is known, however, about the effects of redundancy on older adults' comprehension. Older adults may show different patterns due to age-related decline (e.g., processing speed and memory) or their greater proclivity for linguistic redundancy, as suggested in language production studies. The present study explores the effects of linguistic redundancy on younger and older listeners' incremental referential processing, judgments of informativity, and downstream memory performance. In an eye tracking task, gaze was monitored as listeners followed instructions from a social robot referring to a unique object within a multi-object display. Critical trials were varied in terms of modifier type ("…closed/purple/[NONE] umbrella") and whether displays contained another object matching target properties (closed purple notebook), making modifiers less effective at narrowing attention. Relative to unmodified descriptions, redundant color modifiers facilitated comprehension, particularly when they narrowed attention to a single referent. Descriptions with redundant state modifiers always impaired real-time comprehension. In contrast, memory measures showed faster recognition of objects previously described with redundant state modifiers. Although color and state descriptions had different effects on referential processing and memory, informativity judgments showed participants perceived them as informationally redundant to the same extent relative to unmodified descriptions. Importantly, the patterns did not differ by listener age. Together, the results show that the effects of linguistic redundancy are stable across adulthood but vary as a function of modifier type, visual context, and the measured phenomenon.

Pragmatic inferences in aging and human-robot communication.

Despite the increase in research on older adults' communicative behavior, little work has explored patterns of age-related change in pragmatic inferencing and how these patterns are adapted depending on the situation-specific context. In two eye-tracking experiments, participants followed instructions like "Click on the greenhouse", which were either played over speakers or spoken live by a co-present robot partner. Implicit inferential processes were measured by exploring the extent to which listeners temporarily (mis)understood the unfolding noun to be a modified phrase referring to a competitor object in the display (green hat). This competitor was accompanied by either another member of the same category or an unrelated item (tan hat vs. dice). Experiment 1 (no robot) showed clear evidence of contrastive inferencing in both younger and older adults (more looks to the green hat when the tan hat was also present). Experiment 2 explored the ability to suppress these contrastive inferences when the robot talker was known to lack any color perception, making descriptions like "green hat" implausible. Younger but not older listeners were able to suppress contrastive inferences in this context, suggesting older adults could not keep the relevant limitations in mind and/or were more likely to spontaneously ascribe human attributes to the robot. Together, the findings enhance our understanding of pragmatic inferencing in aging.

Gesture and reference to objects in the here-and-now: Listeners' use of gesture cues in quiet and in noise.

In face-to-face interaction, speakers spontaneously produce manual gestures that can facilitate listeners' comprehension of spoken language. The present study explores the factors affecting the uptake and influence of gesture cues in situations where a speaker is referring to objects visible to the listener. In this context, the listener's attention must be distributed across various scene regions, potentially reducing the ability to draw on and apply gesture cues in real time. In two experiments, the instruction provided by a speaker (e.g., "pick up the candy") was accompanied by an iconic grasp gesture (produced alongside the verb) that reflected the size/shape of the intended target. Effects on listeners' comprehension were compared with a no-gesture condition. Experiment 1 (audiovisual gating task) showed that, under simplified processing circumstances, gesture cues allowed earlier identification of intended targets. Experiment 2 (eye tracking) explored whether this facilitation is found in real-time comprehension, and whether attention to gesture information is influenced by the acoustic environment (quiet vs. background noise). Measures of gaze position showed that although the speaker's gesturing hand was rarely fixated directly, gestures did facilitate comprehension, particularly when the target object was smaller relative to alternatives. The magnitude of the gesture effect was greater in quiet than in noise, suggesting that the latter did not provoke listeners to increase attention to gesture to compensate for the challenging auditory signal. Together, the findings clarify how situational factors influence listeners' attention to visual information during real-time comprehension. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The use of disfluency cues in spoken language processing: Insights from aging.

Past research suggests listeners treat disfluencies as informative cues during spoken language processing. For example, studies have shown that child and younger adult listeners use filled pauses to rapidly anticipate discourse-new objects. The present study explores whether older adults show a similar pattern, or if this ability is reduced in light of age-related declines in language and cognitive abilities. The study also examines whether the processing of disfluencies differs depending on the talker's age. Stereotyped ideas about older adults' speech could lead listeners to treat disfluencies as uninformative, similar to the way in which listeners react to disfluencies produced by non-native speakers or individuals with a cognitive disorder. Experiment 1 used eye tracking to capture younger and older listeners' real-time reactions to filled pauses produced by younger and older talkers. On critical trials, participants followed fluent or disfluent instructions referring to either discourse-given or discourse-new objects. Younger and older listeners treated filled pauses produced by both younger and older talkers as cues for reference to discourse-new objects despite holding stereotypes regarding older adults' speech. Experiment 2 further explored listeners' biased judgments of talkers' fluency, using auditory materials from Experiment 1. Speech produced by an older talker was rated as more disfluent and slower than a younger talker even though these features were matched across recordings. Together, the findings demonstrate (a) older listeners' effective use of disfluency cues in real-time processing and (b) that listeners treat both older and younger talkers' disfluencies as informative despite biased perceptions regarding older talkers' speech. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Real-time communicative perspective taking in younger and older adults.

One core question in studies of language processing is the extent to which interlocutors engage in real-time communicative perspective-taking. Current evidence suggests that both children and young adult listeners are able to draw on common ground (shared knowledge) to guide referential interpretation. However, less is known about older listeners, who are often described as experiencing age-related cognitive declines that could affect their capacity to integrate perspective cues online. In the present study, we examined the extent to which younger and older listeners used common ground to guide the interpretation of temporarily ambiguous descriptions. Participants followed instructions from a Director to click on displayed objects. The target object (e.g., hat with blue feathers) was accompanied by a competitor (e.g., hat with pink feathers) or a control object (e.g., stapler). We manipulated whether the competitor/control was mutually visible (common ground) or not (privileged ground). The results revealed that, although listeners used perspective information to differentiate the target from the competitor in the common ground condition, this pattern was notably weaker in older adults. Whereas measures of executive function showed significant group differences in inhibitory control and working memory, no differences were found in theory of mind. Thus, age-related changes in communicative perspective-taking are not likely due to general declines in mentalizing ability. Furthermore, strict screening criteria for vision and hearing ability allowed us to rule out explanations involving age-related sensory decline. Together, the results advance our understanding of how younger and older adults integrate common ground during real-time referential processing. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Age-related differences in referential production: A multiple-measures study.

Contemporary research on aging has provided mixed evidence for whether older adults are less effective than younger adults at designing and delivering spoken utterances. However, most of these studies have focused on only specific aspects of this process. In addition, they tend to vary significantly in terms of the degree of complexity in their chosen stimuli or task. The present study compares younger and older adults' performance using a referential production paradigm involving simple everyday objects. We varied referential context such that a target object was either unique in its category (e.g., one shirt), or was accompanied by a same-category object (e.g., two shirts). We evaluated whether speakers' descriptions provided listeners with sufficient information for identification, and whether speakers spontaneously adapt their speech for different addressee types (younger adult, older adult, automated dialogue system). A variety of measures were included to provide a comprehensive perspective on adults' performance. Interestingly, the results revealed few or no age differences in measures related to production performance (speech onset latency, speech rate, and fluency). In contrast, consistent differences were observed for measures related to descriptive content, both in terms of informativity and variability in lexical selection: Older adults not only provided more information than necessary for referential success (e.g., superfluous modifiers), but also exhibited greater variability in their selection of modifiers. The results show that, although certain aspects of the production process are well-preserved across the adult lifespan, meaningful age-related differences can still be found in simple referential tasks with everyday objects. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Inattentional Blindness During Driving in Younger and Older Adults.

Age-related changes to perceptual and cognitive abilities have been implicated in an increased risk of collision in older adults. This may be due, in part, to their reduced ability to attend to potentially relevant aspects of their driving environment. An associated general phenomenon of inattentional blindness involves a failure to notice visually presented objects or events when attention is directed elsewhere. Previous studies of inattentional blindness using computer paradigms report higher incidence of this effect in older compared to younger adults. However, little is known about whether these age-related effects are observed during more complex, realistic, everyday tasks, such as driving. Therefore, the goal of this study was to explore whether younger and older adults differ in their awareness of objects in their driving environment when their attention is directed toward another primary driving task. This study took place in a high-fidelity, full field of view, driving simulator. Thirty-two younger (M age = 25.41) and 32 older (M age = 73.41) adults drove through 19 short scenarios and were asked to first judge whether their vehicle could fit between two rows of vehicles parked on either side of the road and then to perform the associated driving maneuver (i.e., drive through or drive around). On four critical trials, objects were placed on the side of the road that differed in terms of animacy. Specifically, animate objects consisted of 3D humans standing by a bus shelter and inanimate objects consisted of photographs of the same individuals on a bus shelter advertisement. Inattentional blindness was measured via a post-drive, tablet-based recognition task immediately following the critical trials. Results revealed high rates of inattentional blindness across both age groups, with significantly lower levels of awareness for inanimate objects compared to animate objects. Further, whereas younger adults demonstrated reduced inattentional blindness following the first critical trial, older adults did not show this immediate improvement in recognition performance. Overall, this study provides unique insights into the factors associated with age-related changes to attention and how they may affect important driving-related outcomes.

Picture perfect: A stimulus set of 225 pairs of matched clipart and photographic images normed by Mechanical Turk and laboratory participants.

The present study provides normative measures for a new stimulus set of images consisting of 225 everyday objects, each depicted both as a photograph and a matched clipart image generated directly from the photograph (450 images total). The clipart images preserve the same scale, shape, orientation, and general color features as the corresponding photographs. Various norms (modal name and verb agreement measures, picture-name agreement, familiarity, visual complexity, and image agreement) were collected separately for each image type and in two different contexts: online (using Mechanical Turk) and in the laboratory. We discuss similarities and differences in the normative measures according to both image type and experimental context. The full set of norms is provided in the supplemental materials.

Mapping language to visual referents: Does the degree of image realism matter?

Studies of real-time spoken language comprehension have shown that listeners rapidly map unfolding speech to available referents in the immediate visual environment. This has been explored using various kinds of 2-dimensional (2D) stimuli, with convenience or availability typically motivating the choice of a particular image type. However, work in other areas has suggested that certain cognitive processes are sensitive to the level of realism in 2D representations. The present study examined the process of mapping language to depictions of objects that are more or less realistic, namely photographs versus clipart images. A custom stimulus set was first created by generating clipart images directly from photographs of real objects. Two visual world experiments were then conducted, varying whether referent identification was driven by noun or verb information. A modest benefit for clipart stimuli was observed during real-time processing, but only for noun-driving mappings. The results are discussed in terms of their implications for studies of visually situated language processing.