Monday, 25 October 2010
Alexa Tullett and Michael Inzlicht had 37 undergrads perform the Go/No Go task. Briefly, this involved one on-screen symbol indicating that a button should be pressed as quickly as possible (the Go command) whilst another indicated that the button press should not be performed (No Go). Because the Go symbol was far more common, participants tended to find it difficult to suppress making a button press on the rare occasions when a No Go command was given. People with more self-control would be expected to make fewer errors of this kind.
Crucially, Tullett and Inzlicht also had the participants perform a secondary task at the same time - either repeating the word 'computer' with their inner voice, or drawing circles with their free hand. The central finding was that participants made significantly more errors on the Go/No Go task (i.e. pressing the button at the wrong times) when they also had to repeat the word 'computer' to themselves, compared with when they had the additional task of drawing circles. This difference was exacerbated during a more difficult version of the Go/No Go task in which the command symbols were periodically switched (so that the Go command became the No Go command and vice versa). It seems that the participants' self-control was particularly compromised when their inner voice was kept busy saying 'computer' so that it couldn't be used to aid self-control.
'By examining performance on a classic self-control task, this study provides evidence that when we tell ourselves to "keep going" on the treadmill, or when we count to ten during an argument, we may be helping ourselves to successfully overcome our impulses in favour of goals like keeping fit, and preserving a relationship,' the researchers said.
Tullett AM, and Inzlicht M (2010). The voice of self-control: Blocking the inner voice increases impulsive responding. Acta psychologica, 135 (2), 252-6 PMID: 20692639