Rehabilitation of endogenous task shift processes in closed head injury patients

Abstract

This paper reports a study that was aimed to rehabilitate executive functions in CHI patients. When a subject is engaged in two speeded tasks, not simultaneously but with some form of alternation, the response is slower to an item of task A if it was preceded by an item of task B, than when it was preceded by an item of task A. This shift cost is small when subjects can prepare in advance for the new task (endogenous task shift), whereas the cost is much greater when preparation is not possible (exogenous task shift). The groups tested comprised 20 severe closed head injury (CHI) patients (10 who underwent treatment and 10 controls), 8 mild CHI patients, and 18 non-brain damaged (NBD) controls. In the present study, the shift cost was greater for severe CHI patients than for NBD controls. Treatment consisted of five sessions, in which an endogenous task shift paradigm was used. A significant reduction of the endogenous shift cost from assessment to retest was found. The reduction remained stable at the 4-month follow-up session. These results are not simply due to retesting, as the control patients did not show any improvement at retest. Interestingly, no reduction of exogenous task shift cost was found. The results showed also that the beneficial effect of the treatment generalises to other executive functions.

Cognitive and psychological flexibility after a traumatic brain injury and the implications for treatment in acceptance-based therapies: A conceptual review

“…Shorter treatment programmes (five sessions) though have also been found to be effective in improving executive function after a TBI using a task shifting exercise (Stablum, Umiltà, Mazzoldi, Pastore, & Magon, 2007). A review of treatments to address impairments in cognitive flexibility in other clinical populations (schizophrenia, pathological gambling, anorexia nervosa) indicates that both pharmacological interventions (Grant, Chamberlain, Odlaug, Potenza, & Kim, 2010;Pardo et al, 2011) and cognitive remediation (Delahunty, Morice, & Frost, 1993;Tchanturia, Davies, & Campbell, 2007;Wykes et al, 2007) can be effective.…”

Rehabilitation of executive disorders after brain injury: Are interventions effective?

“…Stablum, Umilta, Mazzoldi, Pastore, and Magon (2007) purported to improve endogenous (i.e., prepared) task shifting in CHI‐patients. Twenty severe CHI patients were divided in a treatment group and a control group that underwent assessment and retest only.…”

“…However, a general questionnaire does only partially measure generalization as defined in this paper. In the quasi‐experimental group studies (Stablum et al , 2000, 2007), threats to internal validity were controlled by matching subjects on relevant characteristics. Also, care was taken to expose all groups to similar treatment conditions.…”

The effect of computer-based cognitive flexibility training on recovery of executive function after stroke: rationale, design and methods of the TAPASS study

“…Cognitive functions related to the training, in particular cognitive flexibility, were measured by switch cost and dual cost task. These measures were derived from a combined version of a switch task [ 18 ] and a dual task [ 19 ]. These switch and dual tasks were combined to reduce testing time.…”