Biomedical subjects

Richard L Bryck

Publications and source records attributed to Richard L Bryck.

4 recordsLinked to original sources

PubMed2005

Outsourcing control to the environment: effects of stimulus/response locations on task selection.

Response-time and accuracy costs as assessed in the context of the task-switching paradigm are usually thought to represent processes involved in the selection of abstract task sets. However, task sets are also applied to specific stimulus and response constellations, which in turn may become associated with task-set representations. To explore the consequence of such associations, we used a task-switching paradigm in which subjects had to select between two tasks (color or orientation discrimination) that were either associated with shared or unique stimulus/response locations on a touchscreen. When each task was associated with unique locations, error switch costs, stimulus-response congruency effects, as well as the characteristic task-switch x repetition-priming interaction were eliminated, and global selection costs were substantially reduced. These results demonstrate that to understand standard task-switching phenomena it is critical to consider links between lower level stimulus/response parameters and task sets.

Choice Behavior↗

PubMed2005

Sticky rules: integration between abstract rules and specific actions.

The authors manipulated repetitions and/or changes of abstract response rules and the specific stimulus- response (S-R) associations used under these rules. Experiments 1 and 2, assessing trial-to-trial priming effects, showed that repetition of complete S-R couplings produced only benefits when the rule also repeated (i.e., rule-S-R conjunctions) but costs when identical S-R couplings repeated while rules changed. In Experiments 3 and 4, the authors manipulated amount of experience with specific rule-S-R conjunctions and demonstrated integration between rules and S-R couplings in terms of cumulative practice effects. However, unlike short-term priming effects, cumulative practice supported generalization of experience with specific S-R couplings across rule boundaries (Experiment 4). Results are discussed in terms of constraints on models of hierarchical control and in terms of qualitatively different ways in which people profit from very recent experiences (i.e., all-or-none access to working memory representations) versus cumulative experience (i.e., similarity-based retrieval from long-term memory).

Choice Behavior↗

PubMed2005

On the role of verbalization during task set selection: switching or serial order control?

Recent task-switching work in which paper-and-pencil administered single-task lists were compared with task-alternation lists has demonstrated large increases in task-switch costs with concurrent articulatory suppression (AS), implicating a crucial role for verbalization during switching (Baddeley, Chincotta, & Adlam, 2001; Emerson & Miyake, 2003). Experiment 1 replicated this result, using computerized assessment, albeit with much smaller effect sizes than in the original reports. In Experiment 2, AS interference was reduced when a sequential cue (spatial location) that indicated the current position in the sequence of task alternations was given. Finally, in Experiment 3, switch trials and no-switch trials were compared within a block of alternating runs of two tasks. Again, AS interference was obtained mainly when the endogenous sequencing demand was high, and it was comparable for no-switch and switch trials. These results suggest that verbalization may be critical for endogenous maintenance and updating of a sequential plan, rather than exclusively for the actual switching process.

Choice Behavior↗

PubMed2003

The mind's eye, looking inward? In search of executive control in internal attention shifting.

In studies of mental counting, participants are faster to increment a count that was just incremented (no-switch trial) than to increment a different count (switch trial). Investigators have attributed the effect to a shift in the internal focus of attention on switch trials. Here we report evidence for other bottom-up and top-down contributions. Two stimuli were mapped to each of two counts. The no-switch facilitation was greater when stimuli repeated than when they were different. Event-related potential (ERP) activity associated with repetitions was anterior to that associated with switching. Runs of no-switch trials elicited faster responses and frontal ERP activity. Runs of switches and large counts both elicited slow responses and reduced P300 amplitudes. Bottom-up processes may include priming on no-switch trials and conflict on switch trials. Top-down processes may control conflict, subvocal rehearsal, and the contents of working memory.

Adolescent↗