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.

Mirror Tracing Task

HED task ID: hedtsk_mirror_tracing

Family: Motor performance and speeded response tasks

Also known as: MTT, Mirror Drawing, Mirror Tracing

Tracing of a figure viewed only in a mirror; error and completion time across trials index visuomotor adaptation and procedural learning.

Description

The Mirror Tracing Task measures procedural motor learning and sensorimotor adaptation. Participants trace a shape (typically a star outline) while viewing their hand only through a mirror, which reverses the visual feedback left-right. This creates a conflict between visual and proprioceptive information that must be resolved through practice. Performance improves across trials as participants learn to adapt their motor commands to the reversed visual input. Measures include tracing time, number of errors (deviations from the path), and the rate of improvement across trials. The task is a classic demonstration that procedural/implicit memory is preserved in amnesia (H.M. could learn this task despite profound declarative memory loss).

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

Participants trace a path (star, maze) while viewing their hand only through a mirror, which reverses visual-motor mapping. They must stay within path boundaries.

Manipulation

Path complexity; practice blocks; dominant vs. non-dominant hand.

Measurement

Tracing time; number of boundary errors; improvement across trials (learning curve).

Variations

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

Variation

Description

Justification

Star Tracing (Standard)

hedvar_mirror_tracing__star_tracing_standard

Trace a six-pointed star outline viewed in a mirror.

Canonical mirror tracing of star with visuomotor reversal

Circle/Diamond/Complex Shapes

hedvar_mirror_tracing__circle_diamond_complex_shapes

Different contour shapes varying in difficulty.

Different shape complexity and curvature demands

Computerized Mirror Tracing

hedvar_mirror_tracing__computerized_mirror_tracing

Mouse or stylus on tablet with software-reversed cursor; precise error and kinematic recording.

Screen/stylus instead of physical mirror/pencil; per §5.6, loses haptic edge feedback

Left-Right vs. Up-Down Reversal

hedvar_mirror_tracing__left_right_vs_up_down_reversal

Reversing only one axis vs. both to study adaptation components.

Different mirror axis changes visuomotor mapping

Rotation (Non-Mirror) Variants

hedvar_mirror_tracing__rotation_non_mirror_variants

Cursor rotated by varying degrees rather than reflected; parametric visuomotor adaptation.

Rotation rather than mirror reversal; different visuomotor transformation

Prism Adaptation Analog

hedvar_mirror_tracing__prism_adaptation_analog

Wearing prism goggles that shift visual field; aftereffects measure adaptation.

Prismatic displacement of visual field; different mechanism from mirror reversal

Dual-Hand Mirror Tracing

hedvar_mirror_tracing__dual_hand_mirror_tracing

Both hands tracing simultaneously with mirrored feedback.

Both hands trace simultaneously with mirrored feedback; bimanual coordination variant

Mirror Tracing with Delay

hedvar_mirror_tracing__mirror_tracing_with_delay

Delayed visual feedback adds temporal decoupling challenge.

Delay between practice and test; tests retention of visuomotor adaptation

Cognitive processes

This task is designed to engage the following processes:

Key references

  • Gabrieli, J. D. E., Corkin, S., Mickel, S. F., & Growdon, J. H. (1993). Intact acquisition and long-term retention of mirror-tracing skill in Alzheimer’s disease and in global amnesia. Behavioral Neuroscience, 107(6), 899–910. (DOI, PubMed)

  • Sanes, J. N. (2003). Neocortical mechanisms in motor learning. Current Opinion in Neurobiology, 13(2), 225–231. (DOI, PubMed)

Further references

  • Halsband, U., & Lange, R. K. (2006). Motor learning in man: A review of functional and clinical studies. Journal of Physiology-Paris, 99(4-6), 414–424. (DOI, PubMed)

  • Treutwein, B., & Strasburger, H. (1999). Fitting the psychometric function. Perception & Psychophysics, 61(1), 87–106. [Methodological context for motor learning curves] (DOI, PubMed)

  • Hardwick, R. M., Rottschy, C., Miall, R. C., & Eickhoff, S. B. (2013). A quantitative meta-analysis and review of motor learning in the human brain. NeuroImage, 67, 283–297. (DOI, PubMed)

  • Boyd, L. A., & Winstein, C. J. (2004). Cerebellar stroke impairs temporal but not spatial accuracy during implicit motor learning. Neurorehabilitation and Neural Repair, 18(3), 134–143. (DOI, PubMed)