Single Letter Cancellation Test (SLCT)

Purpose of the measure

The Single Letter Cancellation Test (SLCT) is used to evaluate the presence and severity of visual scanning deficits, and is used to evaluate unilateral spatial neglect (USN) in the near extrapersonal space (Diller, Ben-Yishay, Gertsman, Goodkin, Gordon, & Weinberg, 1974).

Available versions

The SLCT was published by Diller et al. in 1974.

Features of the measure

There are no actual items for the SLCT.

The test consists of one 8.5″x11″ sheet of paper containing 6 lines with 52 letters per line. The stimulus letter H is presented 104 times. The page is placed at the patient’s midline. The patient is told to put a line through each H that is found on the page. The time taken to complete the test is recorded.

The score is calculated by subtracting the number of omissions (H’s that were not crossed out) from the possible perfect score of 104 (0 to 53 on the left and 0 to 51 on the right). Higher scores indicate better performance. Presence of USN can be inferred by calculating the frequency of errors to the left or to the right from the center of the page. Omissions of 4 or more have been found to be pathological (Zoccolotti, Antonucci, Judica, Montenero, Pizzamiglio, & Razzano, 1989). Commissions are rarely seen and are therefore not included in the analyses.

Normative data has been published by sex and age, based on the results from 341 patients with lesions of the right hemisphere (Gordon, Ruckdeschel-Hibbard, Egelko, Diller, Simmens, & Langer, 1984).

Less than 5 minutes.

None typically reported.



  • 11x 8″-inch page of paper containing 6 lines with 52 letters per line and the stimulus letter H presented 104 times (53 times on left, 51 on right).
  • Pencil
  • Stopwatch
Alternative forms of the SLCT

None typically reported.

Client suitability

Can be used with: Patients with stroke.

  • Patients must be able to hold a pencil to complete the test (the presence of apraxia may impair this ability).
  • Patients must be able to recognize letters of the alphabet to complete the test.

Should not be used with:

  • The SLCT cannot be used to differentiate between sensory neglect and motor neglect because it requires both visual search and manual exploration (Ladavas, 1994).
  • The SLCT cannot be completed by proxy.
In what languages is the measure available?

The SLCT has been used with English and French-speak patients.

A Hebrew version of the SLCT has been used in some studies as part of the Behavioral Inattention Test (e.g. Friedman & Nachman-Katz, 2004).