Temporal Disorders in Left and Right Brain-Damaged Patients

In the MTT task participants are listened to auditory stimuli consisting of brief descriptions of personal and non-personal events. They are required to project themselves in the past (10 years ago), present or future (10 years from now) and to verbally determine whether each event has already happened (relative past event) or is yet to happen (relative future event) with respect to the specific self-location in time (past, present and future).

Error rates and reaction times will be recorded and analyzed. The improvement will be defined as changes in the Inverse Efficiency (IE) ability: reaction times/accuracy.

The Time Estimation task consists of a red square that is displayed for different durations (1400, 1700, 2000, 2300, 2600 ms) on the computer screen. Participants are instructed to verbally judge whether the duration of each stimulus is "short" or "long" with respect to previously acquired pair of reference durations (1400 and 2600 ms).

A psychophysical response function will be created for each participant by calculating the proportion of "long" responses: the Point of Subjective Equality (PSE) is the duration at which a participant is equally likely to classify the stimuli as short or long. An increase of "long" response after treatment, as compared to baseline performance, induces a decreased PSE, reflecting a relative shift towards overestimation of temporal midpoint. Conversely, an increase of "short" responses after treatment, as compared to baseline performance, induces an increased PSE, reflecting a relative shift towards underestimation of temporal midpoint.

The BIT is composed of two scales, the Conventional scale and the Behavioral scale. Participants will be administered the Conventional scale, which includes 6 tasks: line crossing, letter cancellation, star cancellation, figure and shape copying, line bisection and representational drawing. The score ranges from 0 to 146 (cut-off = 129).

The subject is required to cross out the bells that are scattered among several different shapes on a sheet of paper. Two indices of neglect will be calculated: total number of omissions (cut-off < 5) and number of left omissions (cut-off < 5), i.e. the difference between the number of targets crossed out on the right side and the number of targets crossed out on the left side (asymmetry score).

This is a cancellation task in which outline drawings of 150 apples are shown pseudorandomly scattered over a sheet of A4 paper presented in a landscape orientation. All of the apples are presented in an upright position. One-third of the apples are full (targets) and two-thirds are open on either the left or the right side (distractors). Participants are asked to cross out all the full apples and to ignore the distractors. Three scores will be calculated: full apples barrage (cut-off = 45), full apples asymmetry (cut-off = 2), and incomplete apples asymmetry (cut-off = 1).

The full apples asymmetry (the difference between the number of targets selected on the right side and the number of targets selected on the left side) represents the score for egocentric neglect. The incomplete apples asymmetry (total left openings minus total right openings) represents the score for allocentric neglect.

The MMSE is a 30-point questionnaire that examines functions including registration (repeating named prompts), attention and calculation, recall, language, ability to follow simple commands and orientation. The score ranges from 0 to 30 (cut-off = 24).

The Token test is a test of auditory language processing in which participants are asked to manipulate tokens of different shapes, sizes, and colors in response to increasingly complex instructions. One point is credited for a correct performance on the first presentation and 0.5 point if the performance is correct only on the second presentation. The score ranges from 0 to 36 (cut-off = 26,50).

The FAB is a brief battery of six neuropsychological tasks designed to assess frontal lobe function at bedside. The six tasks explore: conceptualization and abstract reasoning, lexical verbal fluency and mental flexibility, motor programming and executive control of action, self-regulation and resistance to interference, inhibitory control, and environmental autonomy.

Each task scores from 0 (pathologic) to 3 (best performance), for a total maximum score of 18.

The test is designed as a list-learning paradigm in which the participant hears a list of 15 nouns and is asked to recall as many words from the list as possible (five repetitions of free-recall). After a 15 min delay, the participant is asked to again recall the words from the list. It provides two scores: immediate (range 0-75) and delayed recall (range 0-15), i.e. the higher the score, the better the performance.

The ability to carry out movements on imitation is assessed with a 24-item test. Each movement is presented for a maximum of 3 times and scores from 0 (pathologic) to 3 (best performance). The total score ranges from 0 to 72 (cut-off = 62).

The STEP assesses aspects of executive functioning related to cognitive estimation ability. The questionnaire is composed of two distinct ten-item sections, focusing on time (e.g., How long does it take to have a shower?) and weight (e.g., How heavy is a pair of jeans?) estimations. Each item scores from 0 (bizarre estimation) to 3 (best estimation), for a total maximum score for each section of 30, with a cut-off value for normality above 20 for each section.

The test comprised 21 questions that required participants to give oral, numerical responses. Two different scoring procedures will be considered: absolute error score and bizarreness. The total score for all 21 items ranges from a best of zero to a worst of 42. The greater the error score, the poorer the performance on the CET (cut-off = 18). The total bizarreness score ranges from 0 and 21 (cu-off = 4). The higher the bizarreness score, the greater the impairment in cognitive estimation.

MTT and Time Estimation Task will be correlated to investigate the relationship between different time processing abilities.