The HED Task Catalog is under development. IDs are not stable until formal release. Comments are welcome at github.com/hed-standard/hed-task/issues.

Serial Reaction Time Task

HED task ID: hedtsk_serial_reaction_time

Family: Conditioning, reinforcement and implicit learning tasks (also Motor performance and speeded response tasks)

Also known as: SRTT, Serial RT, Serial Reaction Time

Sequential key-press responses to cued locations; RT speedup on repeating vs random sequences indexes implicit sequence learning.

Description

The SRTT measures implicit motor sequence learning. Visual stimuli appear sequentially at different spatial locations, each corresponding to a response button. Participants respond as quickly as possible, unaware that stimuli follow a repeating sequence interspersed with random blocks. Learning is inferred from decreasing RT for the repeating sequence relative to random sequences. The dissociation between improved performance and lack of conscious awareness of the sequence structure is a hallmark of implicit learning and provides evidence for procedural memory systems.

Inclusion test

An experiment is an instance of this task when its procedure matches, it manipulates at least one of the listed variables, and it records at least one of the listed measures.

Procedure

Stimuli appear at one of several spatial locations in a repeating (but covert) sequence; participants respond to each location with a spatially mapped keypress. Sequence awareness is typically not disclosed.

Manipulation

Sequence length and complexity; sequence vs. random blocks; explicit vs. implicit instruction; secondary task (dual-task interference).

Measurement

RT slowing when sequence is replaced by random order (sequence learning effect); explicit sequence knowledge (generation task, recognition); offline consolidation gains.

Variations

Named versions that change what the participant experiences or does. The identifier of a variation is hedvar_<task>__<variation>.

Variation

Description

Justification

Deterministic SRTT

hedvar_serial_reaction_time__deterministic_srtt

Fixed repeating sequence (e.g., 10-element) embedded in random blocks.

Fixed repeating sequence; canonical implicit sequence learning

Probabilistic SRTT

hedvar_serial_reaction_time__probabilistic_srtt

Transition probabilities rather than fixed sequences; tests statistical learning.

High-probability sequence structure; tests learning under uncertainty

Alternating Serial Reaction Time (ASRT)

hedvar_serial_reaction_time__alternating_serial_reaction_time_asrt

Pattern and random elements alternate in fixed schedule.

Alternating random and patterned elements; tests learning of alternating structure

SRTT with Awareness Assessment

hedvar_serial_reaction_time__srtt_with_awareness_assessment

Post-task sequence generation, recognition, or verbal report tests.

Explicit sequence knowledge probed after implicit learning; adds awareness component

Second-Order Conditional (SOC) Sequences

hedvar_serial_reaction_time__second_order_conditional_soc_sequences

Sequence structure based on triplet dependencies rather than simple transitions.

Each response depends on two preceding; different sequence order

Arm-Reaching/Foot-Stepping SRTT

hedvar_serial_reaction_time__arm_reaching_foot_stepping_srtt

Non-finger responses to test effector-specific learning.

Full-limb movements instead of finger presses; different motor effector

Cross-Modal SRTT

hedvar_serial_reaction_time__cross_modal_srtt

Stimuli in different modalities (visual positions, auditory tones) to test modality specificity.

Auditory sequence instead of visual; different sensory modality

Cognitive processes

This task is designed to engage the following processes:

Key references

  • Nissen, M. J., & Bullemer, P. (1987). Attentional requirements of learning: Evidence from performance measures. Cognitive Psychology, 19(1), 1-32. (DOI)

  • Robertson, E. M. (2007). The serial reaction time task: Implicit motor skill learning? Journal of Neuroscience, 27(38), 10073-10075. (DOI, PubMed)

  • Grafton, S. T., Hazeltine, E., & Ivry, R. B. (1995). Functional mapping of sequence learning in normal humans. Journal of Cognitive Neuroscience, 7(4), 497-510. (DOI, PubMed)

Further references

  • Janacsek, K., & Nemeth, D. (2012). Predicting the future: From implicit learning to consolidation. International Journal of Psychophysiology, 83(2), 213–221. (DOI, PubMed)

  • Abrahamse, E. L., Jiménez, L., Verwey, W. B., & Clegg, B. A. (2010). Representing serial action and perception. Psychonomic Bulletin & Review, 17(5), 603–623. (DOI, PubMed)

  • Siegert, R. J., Taylor, K. D., Weatherall, M., & Abernethy, D. A. (2006). Is implicit sequence learning impaired in Parkinson’s disease? A meta-analysis. Neuropsychology, 20(4), 490–495. [Updated: Clark, G. M., Lum, J. A., & Ullman, M. T. (2014). A meta-analysis and meta-regression of serial reaction time task performance in Parkinson’s disease. Neuropsychology, 28(6), 945–958.] (DOI, PubMed)