PORCH INDEX OF COMMUNICATIVE ABILITY (PICA)
Bruce E. Porch, Ph.D.
The PICA continues to be among the most reliable and sensitive measures of communicative ability available to clinicians who assess brain injured adults.
As discussed in Vol. I of the manuals, the PICA has very high inter-scorer agreement, test-retest stability, and internal consistency. These excellent psychometric characteristics result from a powerful binary choice multidimensional scoring system, standardized administration, and homogeneous test items. The test battery has 18 subtests that revolve around ten common objects sampling communicative ability in the modalities of speaking, auditory processing, gesture, writing, reading, copying, and visual matching. The test averages about one hour to administer.
The test scores are used to compare the patient to his pre-morbid communicative levels and the percentiles compare him to a large random sample of patients with similarly localized brain lesions. There are separate norms for patients with damage in the left hemisphere, right hemisphere, or bilateral damage. Discriminant analyses sort aphasia from non-aphasia patterns and left from bilateral/diffuse damage. Scores may be plotted as test profiles by modalities or on ranked response summary graphs that present the subtests in order of difficulty. These profiles offer information about the locus of the lesion(s), the nature of the communicative deficits, and appropriate task selection for treatment. The score sheet yields a variety of prognostic indices as early as one month post onset. It should also be mentioned that the PICA scoring system is widely used for quantifying the patient's responses during treatment. ( Also see: PICA PAD DESCRIPTION)
Training To Use the PICA
As with most complex test instruments the PICA is best mastered through direct training by an experienced PICA user or qualified instructor. Training program availability is discussed in more detail under PICA TRAINING COURSES