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Compares first-order encoding-retrieval transfer with second-order geometry preservation using matched variance-partition models. The model builds item-level prototypes in a source state (`dataset$train_data`) and a target state (`dataset$test_data`), then estimates how much variance is uniquely explained by same-item transfer and by source-state geometry after optional nuisance pair models.

Usage

era_partition_model(
  dataset,
  design,
  key_var,
  distfun = cordist(method = "pearson"),
  rsa_simfun = c("pearson", "spearman"),
  first_order_nuisance = NULL,
  second_order_nuisance = NULL,
  item_block_enc = NULL,
  item_block_ret = NULL,
  item_time_enc = NULL,
  item_time_ret = NULL,
  item_category = NULL,
  include_procrustes = TRUE,
  procrustes_center = TRUE,
  min_procrustes_train_items = 3L,
  return_matrices = FALSE,
  ...
)

Arguments

dataset

An `mvpa_dataset` with `train_data` and `test_data`.

design

An `mvpa_design` with train/test design tables.

key_var

Column name or formula giving the item key shared across source and target states.

distfun

Distance function used for within-state RDMs.

rsa_simfun

Correlation method for the raw geometry summary.

first_order_nuisance

Optional named list of `K x K` matrices or length `K^2` vectors for cross-state similarity nuisance regressors. Matrices are interpreted as target rows by source columns.

second_order_nuisance

Optional named list of `K x K` matrices or lower-triangle vectors for geometry nuisance regressors.

item_block_enc, item_block_ret

Optional item-level block labels for source and target states. Named vectors are matched to item keys.

item_time_enc, item_time_ret

Optional item-level time/order values for source and target states. Named vectors are matched to item keys.

item_category

Optional item-level category labels used to add a same-category nuisance model to both first- and second-order regressions.

include_procrustes

Logical; compute leave-one-item-out orthogonal Procrustes cross-decoding metrics.

procrustes_center

Logical; center source and target prototypes using only alignment-training items before fitting Procrustes maps.

min_procrustes_train_items

Minimum number of paired items allowed for each leave-one-item-out Procrustes alignment.

return_matrices

Logical; store prototype/similarity matrices in each ROI result for diagnostics.

...

Additional fields stored on the model spec.

Value

A model spec of class `era_partition_model` for `run_regional()` or `run_searchlight()`.