A multimodal analysis of sustained attention in younger and older adults.

Age-related cognitive decline has been attributed to processing speed differences, as well as differences in executive control and response inhibition. However, recent research has shown that healthy older adults have intact, if not superior, sustained attention abilities compared to younger adults. The present study used a combination of reaction time (RT), thought probes, and pupillometry to measure sustained attention in samples of younger and older adults. The RT data revealed that, while slightly slower overall, older adults sustained their attention to the task better than younger adults, and did not show a vigilance decrement. Older adults also reported fewer instances of task-unrelated thoughts and reported feeling more motivated and alert than younger adults, despite finding the task more demanding. Additionally, older adults showed larger, albeit later-peaking, task-evoked pupillary responses (TEPRs), corroborating the behavioral and self-report data. Finally, older adults did not show a shallowing of TEPRs across time, corroborating the finding that their RTs also did not change across time. The present findings are interpreted in light of processing speed theory, resource-depletion theories of vigilance, and recent neurological theories of cognitive aging. (PsycInfo Database Record (c) 2022 APA, all rights reserved).

The effect of context on mind-wandering in younger and older adults.

Older adults report less mind-wandering (MW) during tasks of sustained attention than younger adults. The control failure × current concerns account argues that this is due to age differences in how contexts cue personally relevant task-unrelated thoughts. For older adults, the university laboratory contains few reminders of their current concerns and unfinished goals. For younger adults, however, the university laboratory is more directly tied to their current concerns. Therefore, if the context for triggering current concerns is the critical difference between younger and older adults' reported MW frequencies, then testing the two groups in contexts that equate the salience of self-relevant cues (i.e., their homes) should result in an increase in older but not younger adults' MW rates. The present study directly compared rates of MW and involuntary autobiographical memories (IAMs) in the home versus in the lab for younger and older adults using a within-subjects manipulation of context. Inconsistent with the control failure × current concerns account, no significant reduction in the age-gap in MW was found. Suggesting a lack of cues rather than an abundance of cues elicits MW, participants in both age groups reported more MW in the lab than at home. The number of IAMs recalled did not differ across contexts but was lower in older than younger adults. These findings suggest that a cognitive rather than an environmental mechanism may be behind the reduction in spontaneous cognition in aging.

Boundary conditions for the influence of spatial proximity on context-specific attentional settings.

Flexibility of cognitive control is illustrated by the context-specific proportion compatibility (CSPC) effect, the now well-documented pattern showing that compatibility effects are reduced in mostly incompatible relative to mostly compatible locations. The episodic-retrieval account attributes the CSPC effect to location-specific representations that include the attentional settings formed via experience within a given location (e.g., a "focused" attentional setting becomes bound to a location with frequent conflict, whereas a "relaxed" setting becomes bound to one with infrequent conflict). However, Diede and Bugg (Attention, Perception, & Psychophysics, 78, 1255-1266, 2016) demonstrated that the attentional setting associated with a given location can be based on experiences that accumulate across multiple "grouped" locations-namely, those that are proximal to each other, relative to other (distal) locations. This spatial grouping effect supported the relative-proximity hypothesis, which we further tested in the present study. Experiment 1 replicated the spatial grouping effect and showed that it could be disrupted by a horizontal line dividing the otherwise grouped locations. Experiments 2 through 4 suggested that grouping might be a form of "chunking"-that is, the spatial grouping effect did not occur when the proximal locations were few enough in number (two) to represent independently, but it did occur when there were six locations. When there were eight proximal locations (and ten locations overall), the CSPC effect disappeared entirely. These findings suggest important boundary conditions for the relative-proximity hypothesis and inform our understanding of how past experiences with conflict are organized in the form of episodic representations that enable on-the-fly adjustments in cognitive control.

The flexibility of cognitive control: Age equivalence with experience guiding the way.

Prior research has shown that aging is accompanied by changes in cognitive control. Older adults are less effective in maintaining an attentional bias in favor of goal-relevant information and are less flexible in shifting control relative to younger adults. Using a novel variant of the Stroop color-naming task, we tested the hypothesis that age-related differences in the flexible shifting of control may be small or absent when control is guided by experience (i.e., environmental input guiding attention). Younger and older adults named the color of color words in abbreviated lists of trials. In Experiment 1, experience within the early segment of the list was manipulated to encourage adoption of more (mostly congruent condition) or less (mostly incongruent condition) attention toward the word. More important, the middle and late portions were 50% congruent in both conditions. Older adults, like younger adults, demonstrated flexible acquisition and shifting of control settings (i.e., relative attention to word vs. color information). In Experiment 2 we replicated this finding. Additionally, we found that both age groups flexibly acquired and shifted control settings for "transfer" items (i.e., items that were 50% congruent in all lists and list segments), pointing to a generalizable (i.e., global) form of control rather than an item-specific mechanism. Discussion focuses on the role of experience-guided control in enabling flexible performance in older adults. (PsycINFO Database Record

The effects of awareness and secondary task demands on Stroop performance in the pre-cued lists paradigm.

Prior research has demonstrated that explicit pre-cues informing participants of the proportion congruence of an upcoming list of Stroop trials affect performance in mostly congruent lists but not mostly incongruent lists. This pattern suggests a limited role for expectations in influencing Stroop performance. An alternative explanation, however, is that the effects of pre-cues may be masked by a bleed-over of awareness (of the proportion congruence manipulation) from cued to uncued lists given use of a within-subjects manipulation of cueing in prior research. One aim of the current study was to test this explanation by examining patterns of cueing effects when cueing is manipulated between subjects. A second aim was to examine the effects of a secondary, stimulus detection task on expectation and experience-driven effects in the pre-cued lists paradigm. Countering the bleed-over of awareness account, the prior finding of a selective effect of expectations in mostly congruent lists was again observed in the current experiments, and post-experimental assessments of awareness in the uncued condition were unrelated to Stroop performance. Additionally, it was demonstrated that the secondary task did not disrupt experience-driven control but did disrupt the expectation-driven use of pre-cues especially when participants did not know that secondary task stimuli would appear in advance of a list. These findings advance our understanding of the role of awareness in patterns of Stroop performance, and raise interesting questions about the types of advance knowledge that can be integrated in an expectation-driven fashion to optimize Stroop performance.

Cognitive effort is modulated outside of the explicit awareness of conflict frequency: Evidence from pupillometry.

Classic theories of cognitive control conceptualized controlled processes as slow, strategic, and willful, with automatic processes being fast and effortless. The context-specific proportion compatibility (CSPC) effect, the reduction in the compatibility effect in a context (e.g., location) associated with a high relative to low likelihood of conflict, challenged classic theories by demonstrating fast and flexible control that appears to operate outside of conscious awareness. Two theoretical questions yet to be addressed are whether the CSPC effect is accompanied by context-dependent variation in effort, and whether the exertion of effort depends on explicit awareness of context-specific task demands. To address these questions, pupil diameter was measured during a CSPC paradigm. Stimuli were randomly presented in either a mostly compatible location or a mostly incompatible location. Replicating prior research, the CSPC effect was found. The novel finding was that pupil diameter was greater in the mostly incompatible location compared to the mostly compatible location, despite participants' lack of awareness of context-specific task demands. Additionally, this difference occurred regardless of trial type or a preceding switch in location. These patterns support the view that context (location) dictates selection of optimal attentional settings in the CSPC paradigm, and varying levels of effort and performance accompany these settings. Theoretically, these patterns imply that cognitive control may operate fast, flexibly, and outside of awareness, but not effortlessly. (PsycINFO Database Record

Spatial proximity as a determinant of context-specific attentional settings.

People implicitly encode the history of conflict associated with particular contexts and use this information to modulate attention to distractors. This manifests as a reduction in the compatibility effect in mostly incompatible locations compared to mostly compatible locations, a difference termed the context-specific proportion compatibility (CSPC) effect. CSPC effects are explained by an episodic retrieval account positing that abstract attentional settings bind to contextual cues-allowing rapid, context-driven modulation of attention. The current study interrogated this binding process by testing the influence of relative spatial proximity on the association of attentional settings with particular locations. In Experiment 1, like typical CSPC paradigms, biased locations appeared near top (e.g., mostly compatible) and bottom (e.g., mostly incompatible) edges of the screen. A novel feature was the addition of two mostly compatible (above fixation) and two mostly incompatible (below fixation) locations placed within close proximity at the middle of the screen. A CSPC effect was found for outer but not middle mostly compatible and mostly incompatible locations, suggesting the attentional setting bound to the middle locations reflected the average history of conflict (i.e., 50 % compatible) for the group of middle locations. In Experiment 2, distance between middle locations was increased, allowing middle locations to group with outer locations. The CSPC effect was found for outer and middle mostly compatible and mostly incompatible locations. Results support the relative proximity hypothesis, positing that attentional settings bound to a particular location are influenced by experience within a location and relatively close neighboring locations.

Expectations and experience: Dissociable bases for cognitive control?

Classic theories emphasized the role of expectations in the intentional control of attention and action. However, recent theorizing has implicated experience-dependent, online adjustments as the primary basis for cognitive control--adjustments that appear to be implicit (Blais, Harris, Guerrero, & Bunge, 2012). The purpose of the current study was to evaluate whether explicit expectations play any role in cognitive control above and beyond experience. In a novel precued lists paradigm, participants were administered abbreviated lists of Stroop trials. For half of the lists, precues led participants to validly expect lists of varying proportion congruency (e.g., mostly congruent [MC], mostly incongruent [MI]; Experiments 1 to 4). The Stroop effect was greater in cued MC relative to uncued MC lists. By contrast, the Stroop effect was equivalent in cued MI and uncued MI lists. Only when preparation was encouraged via a speed manipulation (Experiment 3) or incentives (Experiment 4) did we find evidence of heightened control when an MI list was expected, in the form of a short-lived reduction in the Stroop effect on the first (experience-free) trial. These patterns suggest (a) expectations play a role in the relaxation of cognitive control, independent of experience (as also shown in Experiment 5, wherein expectations were varied while holding experience constant across lists), but (b) experience is the dominant basis for the sustained heightening of cognitive control (after the first trial). Theoretical implications of dissociating the contributions of expectations and experience to cognitive control are discussed, including interpretations of the list-wide proportion congruence effect.

Cognitive function predicts neural activity associated with pre-attentive temporal processing.

Temporal processing, or processing time-related information, appears to play a significant role in a variety of vital psychological functions. One of the main confounds to assessing the neural underpinnings and cognitive correlates of temporal processing is that behavioral measures of timing are generally confounded by other supporting cognitive processes, such as attention. Further, much theorizing in this field has relied on findings from clinical populations (e.g., individuals with schizophrenia) known to have temporal processing deficits. In this study, we attempted to avoid these difficulties by comparing temporal processing assessed by a pre-attentive event-related brain potential (ERP) waveform, the mismatch negativity (MMN) elicited by time-based stimulus features, to a number of cognitive functions within a non-clinical sample. We studied healthy older adults (without dementia), as this population inherently ensures more prominent variability in cognitive function than a younger adult sample, allowing for the detection of significant relationships between variables. Using hierarchical regression analyses, we found that verbal memory and executive functions (i.e., planning and conditional inhibition, but not set-shifting) uniquely predicted variance in temporal processing beyond that predicted by the demographic variables of age, gender, and hearing loss. These findings are consistent with a frontotemporal model of MMN waveform generation in response to changes in the temporal features of auditory stimuli.