Stimulus devaluation by backward inhibition exceeds any emotional impact of cognitive conflict: Evidence from task switching

Ignoring or withholding a response from a stimulus causes it to become affectively devalued. Leading accounts posit that this is due to negative affect elicited by neurocognitive inhibition when it is applied to resolve conflict from distracting or otherwise inappropriate stimulus/response representations. Other research, however, suggests that stimulus/response conflict may itself elicit negative affect and devalue stimuli, raising questions about whether effects previously attributed to inhibition may instead reflect the emotional impact of conflict, per se. To address this, we measured affective ratings of art-like patterns that previously appeared on critical trials of a task-switching paradigm (ABA vs. CBA task sequences) known for its capacity to distinguish behavioural effects of inhibition and conflict. Stimuli from the ABA-sequence experimental condition showing behavioural evidence of backward inhibition (n-2 repetition costs) received more negative ratings than those from the CBA-sequence control condition. This stimulus-devaluation effect was not impacted by the level of conflict associated with high uncertainty or low uncertainty about upcoming task order. Moreover, the response-time index of inhibition was larger on ABA trials in which the associated stimuli later received negative ratings than on trials preceding relatively positive ratings. Inhibition therefore appears to have negative affective consequences that exceed any emotional impact of conflict, with fluctuations in inhibition linked to subsequent stimulus evaluations.

Decreased inhibitory control after partial sleep deprivation in individuals reporting binge eating: preliminary findings

Background Poor executive functions are associated with dysregulated eating and greater caloric intake in healthy samples. In parallel, findings suggested that sleep deprivation impairs executive functions. Methods We investigated whether partial sleep deprivation impairs executive functions in individuals reporting binge eating (BE, N = 14) and healthy controls (C, N = 13). Switch cost and backward inhibition were measured using the Task Switching Paradigm after a habitual night of sleep and after a night of partial sleep deprivation. Results Results showed a Night by Group interaction on the backward inhibition. The two groups differed in the habitual night, evidencing higher inhibitory control in BE compared to C. Additionally, after partial sleep deprivation, compared to the habitual night, backward inhibition decreased in BE group. This preliminary study was the first to explore the impact of sleep deprivation on executive functions in participants reporting binge eating and healthy controls, thus highlighting their potential role in influencing eating behavior.

Task cues lead to item-level backward inhibition with univalent stimuli and responses

Backward inhibition may aid our ability to switch between tasks by counteracting the tendency to repeat a recently performed task. Current theory asserts that conflict between tasks during performance plays a key role in inducing the effect. However, a study by Costa and Friedrich suggests that backward inhibition might occur without this type of conflict being present. To better understand the mechanisms underlying backward inhibition, we investigated the roles of between-task conflict, task-based instructions, and task cues. Experiment 1 tentatively supported the view that conflict between tasks is not necessary for backward inhibition to be present, and suggested that either the use of task-based instructions or the provision of specific task cues might be sufficient to generate the effect. Experiment 2 ruled out task-based instruction as a likely cause of backward inhibition in this context. Experiment 3 showed that the provision of task cues was sufficient to drive a significant backward inhibition effect, but only when stimuli and responses (as well as tasks) repeated. Overall, these results indicate that between-task conflict during performance is not necessary for backward inhibition to be applied, and that task cues have a key role in generating the effect.