Jana E Ulrich’s research while affiliated with Vanderbilt University and other places

The episodic flanker task is an episodic version of the Eriksen and Eriksen ( Perception & Psychophysics , 16 (1), 143–149, 1974) perceptual flanker task, showing the same compatibility and distance effects. Subjects are presented with a list followed by a probe display in which one item is cued. The task, to indicate whether the probed letter appeared in the same position in the memory list, requires focusing attention on a single item in memory. The probe display contains flanking items to be ignored. They are same as the memory list or different . Same flankers are compatible with “yes” responses and incompatible with “no” responses. Different flankers are incompatible with “yes” responses and compatible with “no” responses. Previously, we presented multiple flankers in the probe, allowing a global matching strategy. Here, we report two episodic flanker experiments with just one flanker in the probe to encourage focusing sharply on the target. We found flanker compatibility effects in both experiments when a single flanker appeared immediately adjacent to the target. Experiment 2 varied the distance between the flanker and the target in the probe and the memory list and found the compatibility effect in response time only when the flanker was immediately adjacent to the target in both the probe and the memory list. The effect in accuracy also appeared when the flanker was two positions away in both the probe and the memory list. These results show that attention is focused sharply on elements of a memory structure during retrieval, suggesting that memory retrieval is perceptual attention turned inward.

We report 10 experiments exploring the proposition that memory retrieval is perceptual attention turned inward. The experiments adapt the Eriksen and Eriksen perceptual flanker effect to a memory task in which subjects must decide whether a cued item in a probe display appeared in the same position in a memory list. Previous research with this episodic flanker task found distance and compatibility effects like those in the perceptual flanker task, suggesting that the same attentional spotlight is turned inward in memory retrieval. The previous experiments used lists of six consonants. The experiments reported here were designed to generalize the results to a broader range of conditions, from letters to words, colors, and pictures, and from set size 6 to set sizes of 4 and 5. Experiments 1–4 varied distance and set size with lists of four, five, or six letters, words, colors, and pictures, respectively. The distance effect was observed with all materials and all set sizes. Experiments 5–8 varied compatibility by presenting context items in the probe that were either the same as the memory list (and therefore compatible with “yes” responses and incompatible with “no” responses) or different from the memory list (and therefore incompatible with “yes” responses and compatible with “no” responses). We found compatibility effects with all materials and all set sizes. These results support the proposition that memory retrieval is attention turned inward. Turned inward or outward, attention is a general process that applies the same computations to different kinds of materials.

Guided by the conjecture that memory retrieval is attention turned inward, we examined serial attention in serial memory, combining the psychological refractory period (PRP) procedure from attention research with cued recall of two items from brief six-item lists. We report six experiments showing robust PRP effects in cued recall from memory (1-4) and cued report from perceptual displays (5-6), which suggest that memory retrieval requires the same attentional bottleneck as "retrieval" from perception. There were strong direction effects in each memory experiment. Response time (RT) was shorter and accuracy was higher when the cues occurred in the forward direction (left-to-right, top-to-bottom, first-to-last), replicating differences between forward and backward serial recall. Cue positions had strong effects on RT and accuracy in the memory experiments (1-4). The pattern suggested that subjects find cued items in memory by stepping through the list from the beginning or the end, with a preference for starting at the beginning. The perceptual experiments (5-6) showed weak effects of position that were more consistent with direct access. In all experiments, the distance between the cues in the list (lag) had weak effects, suggesting that subjects searched for each cue from the beginning or end of the list more often than they moved through the list from the first cue to the second. Direction, distance, and lag effects on RT and inter-response interval changed with SOA in a manner that suggested they affect bottleneck or pre-bottleneck processes that create and execute a plan for successive retrievals. We conclude that sequential retrieval from memory and sequential attention to perception engage the same computations and we show how computational models of memory can be interpreted as models of attention focused on memory.

Guided by the idea that memory retrieval is selective attention turned inward, we report four experiments examining the time-course of focusing attention on memory. We used a novel episodic flanker task that turns the famous perceptual flanker task inward, presenting memory lists followed by probes that asked whether a cued letter had appeared in the same position in the memory list. Like the perceptual flanker task, we manipulated distance to measure the sharpness of the focus of attention on memory, and compatibility to measure the resistance to distraction. To measure the time-course of focusing, we presented a cue indicating the probed position in the interval between the list and the probe and varied the interval between the cue and the probe (0, 250, 500, 750 ms). The main questions were whether the focus would become sharper and resistance to distraction would become stronger as cue–probe delay increased. Experiments 1a and 1b showed strong distance effects and strong cue–probe interval effects but no reliable interaction between them. Experiments 2a and 2b showed robust compatibility effects and cue–probe interval effects but no interaction between them. Thus, there is no evidence that the sharpness of the focus increases and little evidence that the resistance to distraction improves over time. The robust reduction in response time and slight increase in accuracy with cue–probe interval may reflect the time-course of orienting to the cued position in the memory list prior to focusing on the item it contains.

Fine motor skills like typing involve a mapping problem that trades Fitts' law against Hick's law. Eight fingers have to be mapped onto 26 keys. Movement time increases with distance, so Fitts' law is optimized by recruiting more fingers. Choice difficulty increases with the number of alternatives, so Hick's law is optimized by recruiting fewer fingers. The effect of the number of alternatives decreases with consistent practice, so skilled typists achieve a balance between Fitts' law and Hick's law through learning. We tested this hypothesis by comparing standard typists who use the standard QWERTY mapping consistently with nonstandard typists who use fewer fingers less consistently. Typing speed and accuracy were lower for nonstandard typists, especially when visual guidance was reduced by removing the letters from the keys or covering the keyboard. Regression analyses showed that accommodation to Fitts' law (number of fingers) and Hick's law (consistency) predicted typing speed and accuracy. We measured the automaticity of typing in both groups, testing for hierarchical control in 3 tasks: word priming, which measures parallel activation of keystrokes, keyboard recall, which measures explicit knowledge of letter locations, and hand cuing, which measures explicit knowledge of which hand types which letter. Standard and nonstandard typists showed similar degrees of hierarchical control in all 3 tasks, suggesting that nonstandard typists type as automatically as standard typists, but their suboptimal balance between Fitts' law and Hick's law limits their ability to type quickly and accurately. (PsycINFO Database Record

We conducted four experiments to investigate skilled typists' explicit knowledge of the locations of keys on the QWERTY keyboard, with three procedures: free recall (Exp. 1), cued recall (Exp. 2), and recognition (Exp. 3). We found that skilled typists' explicit knowledge of key locations is incomplete and inaccurate. The findings are consistent with theories of skilled performance and automaticity that associate implicit knowledge with skilled performance and explicit knowledge with novice performance. In Experiment 4, we investigated whether novice typists acquire more complete explicit knowledge of key locations when learning to touch-type. We had skilled QWERTY typists complete a Dvorak touch-typing tutorial. We then tested their explicit knowledge of the Dvorak and QWERTY key locations with the free recall task. We found no difference in explicit knowledge of the two keyboards, suggesting that typists know little about key locations on the keyboard, whether they are exposed to the keyboard for 2 h or 12 years.