Sensory Organization Test (SOT) equilibrium and sensory-ratio scoring

Computes NeuroCom-style Sensory Organization Test equilibrium scores, composite score, and the four sensory-analysis ratios from either per-trial equilibrium scores or per-trial peak-to-peak anteroposterior sway angles.

Usage

sensoryOrganizationTest(
  scores = NULL,
  sway_angle = NULL,
  theta_limit = 12.5,
  fall_as_zero = TRUE
)

Arguments

scores

A 6-row (conditions 1-6) numeric matrix / data.frame of equilibrium scores, columns = trials; or a list of 6 numeric vectors. NA entries (e.g. a fall) are treated as a fall with score 0 when fall_as_zero = TRUE.

sway_angle

Alternatively, peak-to-peak AP sway angles (degrees) in the same shape as scores; converted to equilibrium scores.

theta_limit

Theoretical AP stability limit in degrees (default 12.5).

fall_as_zero

Logical; treat NA trials as falls scored 0 (default TRUE).

Value

A sot_result object with per-trial equilibrium, per-condition condition_means, composite, and ratios (SOM/VIS/VEST/PREF).

Details

The equilibrium score for a trial is \(EQ = 100 \times (\theta_{lim} - \theta_{pp}) / \theta_{lim}\), where \(\theta_{pp}\) is the peak-to-peak AP sway angle and \(\theta_{lim}\) the theoretical AP stability limit (12.5 deg). The composite is the mean of the condition-1 and condition-2 average scores together with every individual trial score of conditions 3-6. The sensory ratios use condition average scores: SOM = C2/C1, VIS = C4/C1, VEST = C5/C1, PREF = (C3+C6)/(C2+C5).

References

Nashner LM (1997). "Computerized dynamic posturography."

See also

mCTSIB(), limitsOfStability(), swayMetrics()

Examples

# Three trials per condition, equilibrium scores already computed
sc <- rbind(c(94, 95, 93), c(92, 91, 93), c(88, 90, 89),
            c(85, 84, 86), c(70, 72, 68), c(65, 66, 64))
sensoryOrganizationTest(sc)
#> <sot_result>
#>   condition means: C1=94.0  C2=92.0  C3=89.0  C4=85.0  C5=70.0  C6=65.0 
#>   composite: 79.5
#>   ratios: SOM=0.979  VIS=0.904  VEST=0.745  PREF=0.951