Mark D. Lee

Long-term retention of skilled visual search: do young adults retain more than old adults?

Young and old Ss received extensive consistent-mapping visual search practice (3,000 trials). The Ss returned to the laboratory following a 16-month retention interval. Retention of skilled visual search was assessed using the trained stimuli (assessment of retention of stimulus-specific learning) and using new stimuli (assessment of retention of task-specific learning). All Ss, regardless of age group, demonstrated impressive retention. However, age-related retention differences favoring the young were observed when retention of stimulus-specific learning was assessed. No age-related retention differences were observed when task-specific learning was assessed. The data suggest that age-related retention capabilities depend on the type of learning assessed.

Recombination of automatic processing components: the effects of transfer, reversal, and conflict situations

This research was conducted to evaluate the effects of compatible and incompatible automatic processes on performance. Subjects were trained for 8400 trials of consistent mapping practice in a semantic category visual search task and then transferred for 2352 trials to conditions that utilized the trained component processes in various ways. Results indicate that if the components were reused in a compatible fashion (target and distractor transfer), there was positive transfer. Target and distractor reversal resulted in equivalent and severe performance disruption that persisted for the entire retraining period. Target conflict produced disruption equivalent to the reversal conditions. Distractor conflict resulted in less initial disruption, which dissipated before the end of the retraining period. The results are discussed in terms of agreement with strength-theoretic views of visual search and in terms of practical training and retraining issues.

Understanding performance and learning in consistent memory search: an age-related perspective.

This study was conducted to investigate learning in memory search tasks. Young and old participants were trained for 5,640 trials of consistent mapping (CM) and varied mapping (VM) memory search. After training, participants were transferred into New CM and CM Reversal conditions. During training, both young and old adults improved reaction time performance, with more rapid improvement for the young adults. In CM training, both age groups achieved zero comparison slopes, indicating automaticity in CM memory search. VM training maintained a large age-related difference in search times. Age did not moderate the transfer effects, suggesting similar learning mechanisms were responsible for the original CM training gains in both age groups; however, transfer effects were different for CM Reversal and New CM. The pattern of transfer data argues against several possible mechanisms for automaticity in memory search. The data are most compatible with a hypothesis of memory-set unitization as the locus of automaticity in memory search.

Disruption and maintenance of skilled visual search as a function of degree of consistency

The present experiment was conducted to investigate the effects of varying degrees of task consistency on the performance and maintenance of skill in a semanticcategory visual search task. Four groups of participants first received 6000 trials of consistent mapping (CM) training on two different categories. The participants then performed 4000 trials in which one of the previously trained categories remained 100% consistent, whereas the other previously trained category became either 100%, 67%, 50%, or 33% consistent. This second phase of the experiment allowed for the examination of disruption of the search skill as a function of degree of consistency. Subsequent to the degree of consistency manipulation, 100% consistency was restored and participants performed another 4200 CM trials. Results indicate that performance was disrupted by inconsistency and that disruption increased as consistency decreased. On the return of task consistency, performance improved rapidly to predisruption levels, though some performance disruption was evident. Theoretical and practical implications are discussed.

Contextual Change and Skill Acquisition in Visual Search: Does the Rate of Change Affect Performance?

The present investigation examined the effects of training context on the development of a skill in a semantic category visual search task. Thirty-two subjects were trained in a visual search task which allowed the separate examination of feature learning and attention strengthening. Subjects were trained in a Consistently Mapped (CM) condition which allowed both feature learning and attention strengthening, “Attenuated Strength” search conditions which allowed only feature learning, and a Variably Mapped (VM) condition which allowed neither feature learning or attention strengthening. The present experiment also examined the temporal characteristics of feature learning by manipulating the training context which was defined as the number of trials in a row that a particular search condition appeared. There were four different training contexts used (1, 5, 10, and 50) and eight subjects were assigned to each. Each subject performed 11,000 training trials. Analysis of the reaction time (RT) data indicated that within each training context, RT was fastest for the CM condition, intermediate for the Attenuated Strength conditions, and slowest for the VM condition. The results also suggest that 10 trials were sufficient for feature learning to occur. Furthermore, while there was evidence of attention strengthening in the CM condition there was no evidence of attention strengthening in the Attenuated Strength conditions. For inconsistent tasks that allow feature learning, the rate at which the context changes is a critical variable in determining final task performance.

Age-Related Effects in Consistent Memory Search: Performance is the Same but What about Learning?:

Two experiments were conducted to investigate the mechanisms which underlie the learning in consistently mapped (CM) memory search. In Experiment 1, old and young adults were trained in both CM and variably mapped (VM) category search. The training results replicate previous findings by Fisk and Rogers (1991). Even though older adults are initially at a disadvantage relative to young adults, the comparison times of young and old adults are near zero after CM training. For VM, older adults remain at a disadvantage relative to younger adults, even after extensive training. A full reversal manipulation was implemented in Experiment 2 to investigate the learning in memory search. Initially, the young subjects were less affected by the full reversal condition compared to the performance of the older adults. However, older subjects quickly recovered and both young and old were performing at trained CM levels within 60 trials of additional practice. These results suggest: (a) attention is not being trained in CM memory search; (b) automatic category activation does not contribute much, if at all, to the performance improvement in memory search; and (c) age-invariant learning mechanisms account for performance improvement in CM memory search.

Transfer of Automatic Component Processes to Compatible, Incompatible, and Conflict Situations: Issues for Retraining

An experiment was conducted to examine the potential negative effects of automatic task components in situations requiring re-use or inhibition of those components. Participants trained on a category search task for 8,400 trials in three consistent (CM) and one varied mapping (VM) conditions. Following training, 2,352 trials were completed in seven transfer conditions. Results suggest that skill transfers to similar task situations. However, the data demonstrate that if the transfer situations are incompatible or prior learning must be inhibited, performance is disrupted. Although each condition improved after 336 transfer trials, performance did not reach pre-transfer levels in incompatible or inhibited conditions. The present data are useful for predicting transfer performance when skill components are trained to automaticity using a part-task methodology.