Endogenous visuospatial precuing effects as a function of age and task demands

Age-Related Differences in the Perception of Robotic Referential Gaze in Human-Robot Interaction

There is an increased interest in using social robots to assist older adults during their daily life activities. As social robots are designed to interact with older users, it becomes relevant to study these interactions under the lens of social cognition. Gaze following, the social ability to infer where other people are looking at, deteriorates with older age. Therefore, the referential gaze from robots might not be an effective social cue to indicate spatial locations to older users. In this study, we explored the performance of older adults, middle-aged adults, and younger controls in a task assisted by the referential gaze of a Pepper robot. We examined age-related differences in task performance, and in self-reported social perception of the robot. Our main findings show that referential gaze from a robot benefited task performance, although the magnitude of this facilitation was lower for older participants. Moreover, perceived anthropomorphism of the robot varied less as a result of its referential gaze in older adults. This research supports that social robots, even if limited in their gazing capabilities, can be effectively perceived as social entities. Additionally, this research suggests that robotic social cues, usually validated with young participants, might be less optimal signs for older adults.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12369-022-00926-6.

Predictivity and Manifestation Factors in Aging Effects on the Orienting of Spatial Attention

OBJECTIVE

Prior attention research has asserted that endogenous orienting of spatial attention by willful focusing may be differently influenced by aging than exogenous orienting, the capture of attention by external cues. However, most such studies confound factors of manifestation (locational vs symbolic cues) and the predictivity of cues. We therefore investigated whether age effects on orienting are mediated by those factors.

METHOD

We measured accuracy and response times of groups of younger and older adults in a discrimination task with flanker distracters, under three spatial cueing conditions: nonpredictive locational cues, predictive symbolic cues, and a hybrid predictive locational condition.

RESULTS

Age differences were found to be related to the factor of cue predictivity, but not to the factor of spatial manifestation. These differences were not modulated by flanker congruency.

DISCUSSION

The results indicate that the orienting of spatial attention in healthy aging may be adversely affected by less effective perception or utilization of the predictive value of cues, but not by the requirement to voluntarily execute a shift of attention.

Age-related changes in Bayesian belief updating during attentional deployment and motor intention

Predicting upcoming events using past observations is a crucial component of an efficient allocation of attentional resources. Therefore, the deployment of attention is sensitive to different types of cues predicting upcoming events. Here we investigated probabilistic inference abilities in spatial and feature-based attentional, as well as in motor-intentional subsystems, focusing specifically on the age-related changes in these abilities. In two behavioral experiments, younger and older adults (20 younger and 20 older adults for each experiment) performed three versions of a cueing paradigm, where spatial, feature, or motor cues predicted the location, color, or motor response of a target stimulus. The percentage of cue validity (i.e., the probability of the cue being valid) changed over time, thereby creating a volatile environment. A Bayesian hierarchical model was used to estimate trial-wise beliefs concerning the cue validity from reaction times and to derive a subject-specific belief updating parameter ω in each task version. We also manipulated task difficulty: participants performed an easier version of the task in Experiment 1 and a more difficult version in Experiment 2. Results from Experiment 1 suggested a preserved ability of older adults to use the three different cues to generate predictions. However, the increased task demands of Experiment 2 uncovered a difference in belief updating between the two age groups, indicating moderate evidence for a reduction of the ability to update predictions with motor intention cues in older adults. These results point at a distinction of attentional and motor-intentional subsystems, with age-related differences tackling especially the motor-intentional subsystem.

Specificity of Age-Related Differences in Eye-Gaze Following: Evidence From Social and Nonsocial Stimuli

BACKGROUND

Eye-gaze following is a fundamental social skill, facilitating communication. The present series of studies explored adult age-related differences in this key social-cognitive ability.

METHOD

In Study 1 younger and older adult participants completed a cueing task in which eye-gaze cues were predictive or non-predictive of target location. Another eye-gaze cueing task, assessing the influence of congruent and incongruent eye-gaze cues relative to trials which provided no cue to target location, was administered in Study 2. Finally, in Study 3 the eye-gaze cue was replaced by an arrow.

RESULTS

In Study 1 older adults showed less evidence of gaze following than younger participants when required to strategically follow predictive eye-gaze cues and when making automatic shifts of attention to non-predictive eye-gaze cues. Findings from Study 2 suggested that, unlike younger adults, older participants showed no facilitation effect and thus did not follow congruent eye-gaze cues. They also had significantly weaker attentional costs than their younger counterparts. These age-related differences were not found in the non-social arrow cueing task.

DISCUSSION

Taken together these findings suggest older adults do not use eye-gaze cues to engage in joint attention, and have specific social difficulties decoding critical information from the eye region.

Reflexive orienting in response to short- and long-duration gaze cues in young, young-old, and old-old adults

Shifting visual focus on the basis of the perceived gaze direction of another person is one form of joint attention. In the present study, we investigated whether this socially relevant form of orienting is reflexive and whether it is influenced by age. Green and Woldorff (Cognition 122:96-101, 2012) argued that rapid cueing effects (i.e., faster responses to validly than to invalidly cued targets) were limited to conditions in which a cue overlapped in time with a target. They attributed slower responses following invalid cues to the time needed to resolve the incongruent spatial information provided by the concurrently presented cue and target. In the present study, we examined the orienting responses of young (18-31 years), young-old (60-74 years), and old-old (75-91 years) adults following uninformative central gaze cues that overlapped in time with the target (Exp. 1) or that were removed prior to target presentation (Exp. 2). When the cue and target overlapped, all three groups localized validly cued targets more quickly than invalidly cued targets, and validity effects emerged earlier for the two younger groups (at 100 ms post-cue-onset) than for the old-old group (at 300 ms post-cue-onset). With a short-duration cue (Exp. 2), validity effects developed rapidly (by 100 ms) for all three groups, suggesting that validity effects resulted from reflexive orienting based on the gaze cue information rather than from cue-target conflict. Thus, although old-old adults may be slow to disengage from persistent gaze cues, attention continues to be reflexively guided by gaze cues late in life.

Timing of reflexive visuospatial orienting in young, young-old, and old-old adults

This study examined adult age differences in reflexive orienting to two types of uninformative spatial cues: central arrows and peripheral onsets. In two experiments using a Posner cuing task, young adults (ages 18-28 years), young-old adults (60-74 years), and old-old adults (75-92 years) responded to targets that were preceded 100-1,000 ms earlier by a central arrow or a peripheral abrupt onset. In Experiment 1, the cue remained present upon target onset. Facilitation effects at short cue-target stimulus onset asynchronies (SOAs) were prolonged in duration for the two older groups relative to the young adults. At longer cue-target SOAs, inhibition of return (IOR) that was initiated by peripheral onset cues was observed in the performance of young adults but not in that of the two older groups. In Experiment 2, the cue was presented briefly and removed prior to target onset. The change in cue duration minimized age differences (particularly for young-old adults) in facilitation effects and led to IOR for all three age groups. The findings are consistent with the idea that attentional control settings change with age, with higher settings for older adults leading to delayed disengagement from spatial cues.

Effects of aging on visual attentional focusing

BACKGROUND

Visual attentional performance is affected by aging, but there are methodological barriers to the understanding of this phenomenon that are due, above all, to the concomitant deterioration of sensory or central factors such as visual acuity and information processing speed.

OBJECTIVE

The aim of the present study was to verify the effects of aging on visual attentional focusing by analyzing the space- and object-based components as well as the exogenous and endogenous dimensions of the attentional allocation.

METHODS

Focusing of visual attention was investigated in 14 youngsters, 14 younger adults and 14 older adults (age ranges 12-15, 24-38 and 60-75 years, respectively). In two discrimination reaction time (RT) experiments, attention was cued by means of spatial cues of different size followed by compound stimuli at a shorter (150 ms) and a longer (500 ms) stimulus-onset asynchrony (SOA). The compound stimuli contained a predefined target letter at a local or global level.

RESULTS

Older adults showed generally slower RTs and higher rates of delayed responses than younger individuals and reduced discrimination speed of local objects at 150-ms SOA, particularly when attention was invalidly cued to focus at a larger spatial scale.

CONCLUSIONS

This pattern of results suggests that aging causes a dysfunction of the space-based and the object-based components of the attentional 'zooming in'. Such information may be of practical relevance for developing attentional training programs for older adults.

Spatial shifts in visual attention in normal ageing and dementia of the Alzheimer type

Using a spatial-cueing paradigm, we assessed the ability of Alzheimer's disease patients, age-matched controls and younger participants to use cues to guide attention to the location indicated by the cue. In separate experiments, we attempted to isolate cues that attract attention automatically (exogenous cueing) and those that require the wilful movement of attention (endogenous cues). We found significant cueing effects for all three groups of participants for both types of cue. However, the group with Alzheimer's disease showed far greater cueing effects when using an exogenous cue, whilst no difference between group's ability to use the cue was found for the endogenous cue. No differences in cueing were found for either cue type as a function of normal ageing. We further tested whether the differences in cueing found in the group with Alzheimer's disease was due to a generalised slowing of function. After transforming the data to take account of the overall slowing of all responses in this group, we still found significant differences between this group and the control groups. We conclude that patients with Alzheimer's disease have an abnormality in automatic, but not controlled visuospatial attention.

Visuospatial attention: the role of target contrast and task difficulty when assessing the effects of cues

Cueing paradigms have become popular in assessing the processes of attention. In two experiments we manipulated (i) the contrast of the target, and (ii) the similarity between the targets discriminated. We used a cue that would isolate the exogenous component of attention. Both a reduction in target contrast and an increase in target similarity raised overall reaction times by a similar amount; however, the target contrast manipulation produced a much greater cueing effect compared with the target similarity manipulation. The results suggest that manipulation of target contrast changes the attention cueing effect at a stage of attracting attention to a location of the target (the 'move' stage), rather than at a later processing stage.

Age-related changes in motor control during articulator visuomotor tracking

The present study provides normative data on changes in visuomotor control of the oral-facial system across the lifespan. Control of the lower lip, jaw, and larynx (i.e., fundamental frequency) was examined using a nonspeech visuomotor tracking (VMT) task, where subjects move the articulator of interest to track a moving target on an oscilloscope screen. This task examines articulator motor control during movements that are similar to speech but that do not impose linguistic units or the demands of coordinating multiple structures. Accuracy and within- and between-subject variability in tracking performance were measured by cross correlation, gain ratio, phase shift, and target-tracker amplitude difference. Cross-correlation analyses indicated that performance of children (aged 8;2 to 17;0 [years;months]) and older adults (aged 45;1 to 84;3) is poorer than that of younger adults (aged 17;1 to 45;0). Accuracy of movement amplitude tended to increase during development and decline with aging, whereas age did not appear to influence accuracy of temporal parameters in lip and jaw tracking. In contrast, age tended to influence individual variability in temporal but not amplitude parameters. Differences were noted between articulators. The data complement previous studies that considered accuracy and variability of articulator movement during speech. The VMT method and the data provided may be applied to assessment of impairments in the motor speech system and to differential diagnosis of motor speech versus linguistically based disorders.

Effects of aging on visuospatial attention: an ERP study

The effects of aging on visuospatial attention were investigated with event-related brain potentials (ERPs). A central arrow pointed towards (75% valid cues) or away from (25% invalid cues) the location of upcoming visual targets to which subjects made two choice discriminations. Young and older adults responded faster following valid than invalid cues. The absolute magnitude of the cueing effect was larger for older than young subjects, but cueing effects were similar between groups when estimated proportionally to overall response time. Under the present conditions, the electrophysiological manifestations of visuospatial attention were similar for young and older adults. Early ERP components following the target stimulus (P1, N1, Nd1) were slower for older than young subjects, but amplitude was similarly affected by cueing in each group. The temporal correspondence between component latencies and the observed cueing effects are consistent with theories positing that attention amplifies the sensory gain of early perceptual processes. The observation that aging slowed latency of the ipsilateral but not the contralateral P1, is consistent with age differences in interhemispheric transfer times. A broadly distributed 200-400 ms validity effect on ERP amplitude was similar between groups in timing, spatial distribution, and magnitude. The 200-400 ms attention effect appeared to be a modulation of the P3 in younger subjects, as earlier observed. However, the present study dissociated the 200-400 ms attention effects from the P3 component because the P3 did not peak until 526 ms in older subjects.

Basic response time tools for studying general processing capacity in attention, perception, and cognition

One of the more important constructs in the study of attention, perception, and cognition is that of capacity. The authors reviewed some of the common meanings of this construct and proposed a more precise treatment. They showed how the distribution of response times can be used to derive measures of process capacity and to further illustrate how these measures can be used to address important hypotheses in cognition.