Spatial Proximity as a Determinant of Cognitive Control Context

The speed and flexibility of cognitive control is exemplified by the context-specific proportion congruency (CSPC) effect. Two locations on a computer screen may be biased to present either mostly congruent (MC) stimuli or mostly incongruent (MI) stimuli, necessitating rapid shifts of cognitive control in order to maximize speed and accuracy of responding. The episodic retrieval account has posited that the speed and flexibility of control can be explained by attentional settings being bound with contextual cues (e.g. the location at which a stimulus appears) into an episodic representation—allowing for settings to be retrieved automatically. However, what determines which setting is bound with which location cue has not yet been investigated. The present study posited that relative spatial proximity determines which setting is applied to a given location. In Experiment 1, six locations were arranged to manipulate relative spatial proximity. A biased (e.g., MC) location was placed on the top edge of a screen and a biased (e.g., MI) location was placed at the bottom. At the middle of the screen two MC (above fixation) and two MI (below fixation) locations were placed within close proximity. A CSPC effect was found between outer locations at the edge, while the middle locations were treated as a single 50% congruent location. Experiment 2 separated the middle locations to be closer to the outer locations of their same congruency. A CSPC effect was then found between the middle locations. Results are interpreted within the relative proximity hypothesis that posits multiple locations can influence the formation of an episodic representation when they are placed closer to one another relative to other locations

Mind Wandering in Old Age: Lack of Thoughts or Lack of Resources?

Older adults report mind wandering (MW) less than younger adults, a finding opposite of the predictions of inhibitory deficit theory. The present study attempted to reconcile this finding with inhibitory deficit theory through cognitive control theories of MW that posit separate maintenance and initiation mechanisms of MW. The maintenance mechanism was tested in Experiment 1 where participants completed either a visual or auditory 1-back while reporting instances of inner ear (auditory) or inner eye (visual) MW. It was hypothesized that a specific deficit in inner eye MW in older adults would suggest older adults report less MW due to a lack of resources needed to maintain episodes of MW. The initiation mechanism was tested in Experiment 2 where participants completed a sustained attention to response task and an involuntary autobiographical memory task both at a lab and at their homes. It was hypothesized that a smaller gap in reported MW between age groups in a memory cue rich context (their homes) would suggest older adults report less MW because of the lack of memory cues in lab contexts. Neither hypothesis was supported. Older adults were not found to have a specific deficit of inner eye MW, and instead had a pattern suggesting domain specific resources contributed to MW. Additionally, older adults reported less MW when at home, while the gap between age groups remained unchanged. Implications for inhibitory deficit theory, as well as the component process and the control failure X current concerns theories of MW, are discussed

Experiment 1: Lack of Resources

Experiment 1 of the dissertation. Has not been published beyond the dissertation

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 (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 the location relative to other (distal) locations. This spatial grouping effect supported the relative proximity hypothesis, a hypothesis that was 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 grouping may be a form of “chunking”— the spatial grouping effect did not occur when the number of proximal locations was few enough to represent independently (2) but did occur when there were 6 locations. When there were 8 proximal locations (10 overall), the CSPC effect disappeared entirely. The 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

Experiment 2: Lack of Thoughts

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

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, thought probes, and pupillometry to measure sustained attention in samples of younger and older adults. The reaction time 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, corroborating the behavioral and self-report data. Finally, older adults did not show a shallowing of task-evoked pupillary responses across time, corroborating the finding that their reaction times 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