Age equivalence in switch costs for prosaccade and antisaccade tasks

This study examined age differences in task switching using prosaccade and antisaccade tasks. Significant specific and general switch costs were found for both young and old adults, suggesting the existence of 2 types of processes: those responsible for activation of the currently relevant task set and deactivation of the previously relevant task set and those responsible for maintaining more than 1 task active in working memory. Contrary to the findings of previous research, which used manual response tasks with arbitrary stimulus-response mappings to study task-switching performance, no age-related deficits in either type of switch costs were found. These data suggest age-related sparing of task-switching processes in situations in which memory load is low and stimulus-response mappings are well learned.     

Aging and the strategic control of the fixation offset effect

A study was conducted to examine potential age-related differences in the strategic control of exogenous and endogenous saccades within the context of the fixation offset effect (FOE; i.e., faster saccades when a fixation point is removed than when it is left on throughout a trial). Subjects were instructed to make rapid saccades either on the basis of a suddenly appearing peripheral visual stimulus (exogenous saccade) or in response to a tone (endogenous saccade). On half of the trials the fixation point was removed simultaneously with the occurrence of the cue stimulus. Subjects' preparatory set was varied by manipulating the proportion of saccades generated to a visual and auditory stimulus within a trial block. Young and old adults both produced FOEs, and the FOEs were strategically modulated by preparatory set. The data are discussed in terms of aging and oculomotor control.     

Attentional effects on preattentive vision: spatial precues affect the detection of simple features

Most accounts of visual perception hold that the detection of primitive features occurs preattentively, in parallel across the visual field. Evidence that preattentive vision operates without attentional limitations comes from visual search tasks in which the detection of the presence of absence of a primitive feature is independent of the number of stimuli in a display. If the detection of primitive features occurs preattentively, in parallel and without capacity limitations, then it should not matter where attention is located in the visual field. The present study shows that even though the detection of a red element in an array of gray elements occurred in parallel without capacity limitations, the allocation of attention did have a large effect on search performance. If attention was directed to a particular region of the display and the target feature was presented elsewhere, response latencies increased. Results indicate that the classic view of preattentive vision requires revision.     

Task coordination and aging: explorations of executive control processes in the task switching paradigm.

A number of models of cognitive aging suggest that older adults exhibit disproportionate performance decrements on tasks which require executive control processes. In a series of three studies we examined age-related differences in executive control processes and more specifically in the executive control processes which underlie performance in the task switching paradigm. Young and old adults were presented with rows of digits and were required to indicate whether the number of digits (element number task) or the value of the digits (digit value task) were greater than or less than five. Switch costs were assessed by subtracting the reaction times obtained on non-switch trials from trials following a task switch. Several theoretically interesting results were obtained. First, large age-related differences in switch costs were found early in practice. Second, and most surprising, after relatively modest amounts of practice old and young adults switch costs were equivalent. Older adults showed large practice effects on switch trials. Third, age-equivalent switch costs were maintained across a two month retention period. Finally, the main constraint on whether age equivalence was observed in task switching performance was memory load. Older adults were unable to capitalize on practice under high memory loads. These data are discussed in terms of their implications for both general and process specific cognitive aging models.     

Memory for a dialectical and a nondialectical prose passage in young and older adults

Age differences in adults' processing of a dialectical or nondialectical prose passage were explored. Twenty young and 20 older adults read a dialectical or mechanistic passage and were tested for free recall and recognition after a 30-min delay (filled with vocabulary and paradigm belief scale). Older (vs. young) adults had significantly lower formistic and mechanistic scores and showed greater relative preference for relativistic and dialectical beliefs (paradigm scale). There were no age differences in amount of free recall or number of correct responses (hits) on recognition, but older adults produced more spontaneous dialectical distortions in recall of the mechanistic passage and more paradigm-congruent false alarms on recognition. There was also a move from absolute toward dialectical thinking on the paradigm scale and, among males, on the recognition measure. Dialectical scores (paradigm scale) were positively correlated, and mechanistic scores negatively correlated, with number of dialectical distortions on free recall (mechanistic passage), while dialectical scores were positively correlated with number of dialectical false alarms (dialectical passage).     

The Rorschach M response: a return to its roots

The Exner (1986) system of scoring of the Rorschach results in a human movement response (M), which is far afield from Rorschach's original intent. This divergence can easily lead to faulty interpretations of a record as there is no need for kinesthetic reactions on behalf of the subject in Exner's system. The need to return to a traditional view of the M is demonstrated through a focus on theory and the literature that illustrates Rorschach's intent. The alteration of the M results in a scoring system which, due to its differences, must come up with a separate interpretative system and not consider itself part of the Rorschach system that Rorschach envisioned.     

Searching for faces in crowd chokepoint videos

Investigations of face identification have typically focussed on matching faces to photographic IDs. Few researchers have considered the task of searching for a face in a crowd. In Experiment 1, we created the Chokepoint Search Test to simulate real-time search for a target. Performance on this test was poor (39% accuracy) and showed moderate associations with tests of face matching and memory. In addition, trial-level confidence predicted accuracy, and for those participants who were previously familiar with one or more targets, higher familiarity was associated with increased accuracy. In Experiment 2, we found improvements in performance on the test when three recent images of the target, but not three social media images, were displayed during searches. Taken together, our results highlight the difficulties inherent in real-time searching for faces, with important implications for those security personnel who carry out this task on a daily basis.     

Influence of single and multiple onset distractors on visual search for singleton targets

In three experiments, we examined attentional and oculomotor capture by single and multiple abrupt onsets in a singleton search paradigm. Subjects were instructed to move their eyes as quickly as possible to a color singleton target and to identify a small letter located inside of it. In Experiment 1, taskirrelevant sudden onsets appeared simultaneously on half the trials with the presentation of the color singleton target. Response times (RTs) were longer when onsets appeared in the display regardless of the number of onsets. Eye-scan strategies were also disrupted by the appearance of the onset distractors, although the proportion of trials on which the eyes were directed to the onsets was the same regardless of the number of onsets. In Experiment 2, we manipulated the time of presentation of two taskirrelevant onsets in order to further examine whether multiple onsets would be attended and fixated prior to attending a color singleton target. Again, subjects made a saccade to a task-irrelevant onset on a substantial proportion of trials prior to fixating the target. However, saccades to the second onset were rare. Experiment 3 served as a replication of Experiment 1 but without the requirement for subjects to move their eyes to detect and identify the singleton target. The RT results were consistent with those in Experiment 1; dual onsets had no larger an effect on response speed than single onset distractors. These data are discussed in terms of the interaction between top-down and bottom-up control of attention and the eyes.