A landmark and a parcel answer different questions
Orient
A sulcus describes surface shape. A parcel divides cortex according to an atlas method. The two can be anatomically related without sharing the same boundary.
Select each structure to light it on the atlas, then rotate until you can name what lies in front, behind and beneath it.
Targets
4 · precentral
3b · postcentral
Compare
Compare 4 and 3b around the central region. Describe the surface relationship first, then identify what the parcel contour adds.
Read the neighbours
HCP-MMP1 combines several cortical features to define its regions.
A parcel name does not replace a description of gyrus, sulcus, side and surface.
Explain before revealing
Does a parcel contour certify the exact functional edge of an individual gyrus?
Explanation
No. It identifies the atlas boundary on this reference surface. Individual functional localization is a separate observation, and the structural gyrus still needs to be identified on the individual anatomy.
In a surgical discussion
When presenting a lesion, use atlas terminology alongside individual structural anatomy. A template label should not erase a visible anatomical displacement or an uncertain sulcal identification.
HCP-MMP1 parcels identify population cortical subdivisions from multiple features. A parcel is not a whole gyrus, functional localizer or individualized tissue boundary. Its side and atlas identity must accompany its name.
Ask the learner to answer before opening the explanation. Compare the answer with the named structures and the cited method. Teaching point: No. It identifies the atlas boundary on this reference surface. Individual functional localization is a separate observation, and the structural gyrus still needs to be identified on the individual anatomy.
This relationship draws on 2 cited sources.
Relationship 2 of 4 · reconstruction
A plausible course is an anatomical hypothesis
Orient
The CST sample provides a three-dimensional trajectory to inspect. Its appearance can support a comparison with expected anatomy, but it does not verify every connection.
Rotate the atlas until you can name what lies in front, behind and beneath the displayed structures.
Compare
Follow the descending sample and identify one spatial observation you can make directly. Then name one claim that would need additional evidence.
Read the neighbours
A streamline is a reconstruction from diffusion data, not a histological axon.
The tractography validation challenge found plausible-looking false connections under its tested conditions.
Explain before revealing
Which is directly observed here: a rendered descending course or a verified functioning corticospinal connection?
Explanation
A rendered descending course. Verifying the latter needs evidence beyond this display. The distinction does not make the image useless: it defines the spatial question the image can help you investigate.
In a surgical discussion
A neat reconstruction should prompt an anatomical consistency check, including its location and method, rather than ending the assessment.
A group-average cortical surface with a population parcellation, a population-averaged bundle atlas, and gross subcortical meshes. No patient image, no registration, no functional map, no brainstem or thalamic nuclei.
Ask the learner to answer before opening the explanation. Compare the answer with the named structures and the cited method. Teaching point: A rendered descending course. Verifying the latter needs evidence beyond this display. The distinction does not make the image useless: it defines the spatial question the image can help you investigate.
This relationship draws on 4 cited sources.
Relationship 3 of 4 · functional measurement
Put the task beside a functional claim
Orient
A functional observation is tied to a task, modality and population. Saying “this tract is language” discards the distinctions that make an experiment interpretable.
Rotate the atlas until you can name what lies in front, behind and beneath the displayed structures.
Compare
Inspect the left FAT sample, then compare a verbal-fluency correlation with phrase-boundary disruption during stimulation. Neither experiment is being replayed on this brain.
Read the neighbours
A cohort association relates measured variables; it does not reproduce a stimulation experiment.
A stimulation finding is task-specific and localized under the study conditions.
Explain before revealing
Are a fluency correlation and a stimulation-induced planning disruption the same evidence?
Explanation
No. The first is an association between measurements; the second tests a local perturbation under particular task conditions. Both require their population and method to remain attached to the interpretation.
In a surgical discussion
Use precise task descriptions when discussing function near a lesion. A tract name is a starting point for the question, not a replacement for the clinical observation.
A group-average cortical surface with a population parcellation, a population-averaged bundle atlas, and gross subcortical meshes. No patient image, no registration, no functional map, no brainstem or thalamic nuclei.
Ask the learner to answer before opening the explanation. Compare the answer with the named structures and the cited method. Teaching point: No. The first is an association between measurements; the second tests a local perturbation under particular task conditions. Both require their population and method to remain attached to the interpretation.
This relationship draws on 5 cited sources.
Relationship 4 of 4 · schematic
Construct a statement with the correct scope
Orient
Teaching vignette: a report labels a highlighted cortical patch, a nearby tract and a patient’s weakness as one finding. Separate the three observations before interpreting their relationship.
Rotate the atlas until you can name what lies in front, behind and beneath the displayed structures.
Compare
Use the current parcel and pathway to form two separate image descriptions. Add a third sentence stating what an actual clinical examination would contribute.
Read the neighbours
The parcel describes reference identity; the streamlines describe reconstructed geometry.
A clinical deficit is an observation about a person. This reference scene contains no such examination.
Explain before revealing
Complete the three-part account: “The atlas shows…; the reconstruction suggests…; the examination establishes…”
Explanation
The atlas shows a reference parcel; the reconstruction suggests a spatial pathway relationship; the examination establishes the observed clinical deficit. Whether they explain one another is a further question requiring individual localization and supporting evidence.
In a surgical discussion
A useful case discussion keeps anatomy, reconstruction and function connected in the reasoning while making their sources individually clear.
A group-average cortical surface with a population parcellation, a population-averaged bundle atlas, and gross subcortical meshes. No patient image, no registration, no functional map, no brainstem or thalamic nuclei.
Ask the learner to answer before opening the explanation. Compare the answer with the named structures and the cited method. Teaching point: The atlas shows a reference parcel; the reconstruction suggests a spatial pathway relationship; the examination establishes the observed clinical deficit. Whether they explain one another is a further question requiring individual localization and supporting evidence.
This relationship draws on 6 cited sources.
Recap
A highlighted parcel, a nearby tract and weakness appear in one report. What does each actually establish?
Identify whether the object is a surface landmark, parcel label or reconstruction.
Attach a functional statement to its measurement and method.
Keep atlas anatomy, reconstructed course and examination findings distinguishable.
Review the final explanation
The atlas shows a reference parcel; the reconstruction suggests a spatial pathway relationship; the examination establishes the observed clinical deficit. Whether they explain one another is a further question requiring individual localization and supporting evidence.
HCP population reference built from converging cortical features. A parcel boundary here is a group boundary; it does not locate one person’s functional border and it has not been registered to any individual in this viewer.
Challenge dataset with a defined ground truth and many submitted pipelines. Its false-positive findings motivate caution; its error figures belong to that challenge and are not an error estimate for this atlas.
Provenance for the HCP1065 population-averaged bundles rendered here. Every displayed line is an average-space reconstruction sampled for display; it is not a patient’s pathway and carries no direction of conduction.
Provenance for the S1200 group-average surface rendered here. A group-average midthickness surface is a population object; individual gyral and sulcal anatomy differs from it.
Provenance for the Melbourne Subcortex Atlas scale-1 meshes rendered here. Scale 1 is the coarsest level: anterior and posterior thalamus are merged and no brainstem nucleus is included.
Primary progressive aphasia cohorts and controls; diffusion measures related to language tests. A cohort association is not a universal deficit prediction.
One awake-mapping case: stimulation changed phrase-boundary timing without the same effect on intra-word articulation. The measured sites are not installed in this atlas.