The role of spatial uncertainty in the context-specific proportion congruency effect.

The prime-probe version of the Stroop task has been predominantly used to demonstrate the context-specific proportion congruency (CSPC) effect. In this version, the location of the color is not known until its presentation, creating a spatial uncertainty for the color dimension. We propose that spatial uncertainty plays an important role in observing the CSPC effect. In this study, we investigated the role of spatial uncertainty with two experiments. In Experiment 1 (N = 53), we used a spatially separated version of the Stroop task having spatial uncertainty on the color dimension, and observed a significant CSPC effect. For Experiment 2, we conducted a preregistered prime-probe CSPC experiment with a considerably large sample (N = 128), eliminating the uncertainty of only the color dimension in one condition and both the color and the word dimensions in the other. Results showed that the CSPC effect was not observed in the first condition, while it was very small yet significant in the second condition. The Bayesian approach confirmed frequentist analyses of Experiment 1 and the first condition of Experiment 2. However, in the second condition of Experiment 2, there was no evidence regarding the existence of the CSPC effect. These findings support our claim that the spatial uncertainty of the color dimension, inherent in the prime-probe version Stroop task, contributed to the CSPC effect.

Does survival context enhance memory for source? A within-subjects comparison.

Nairne, Thompson, and Pandeirada [2007. Adaptive memory: Survival processing enhances retention. Journal of Experimental Psychology: Learning, Memory, and Cognition, 33, 263-273] demonstrated that processing words according to their relevance to a survival scenario enhanced their subsequent retrieval in recall and recognition tasks compared to a variety of control scenarios. From an adaptive perspective, it is maintained that processing words in a survival context should also enhance memory for source; however, evidence in the literature is rather mixed regarding a survival context advantage for source memory. In the current study, we conducted four experiments to systematically investigate the survival advantage in source memory, when the context itself is the source, with both recall (Experiments 1A and 1B) and recognition tests (Experiments 2A and 2B). Results showed a survival advantage for item memory over the control contexts in all experiments. The survival context advantage was not extended to source memory performance in Experiment 1A. Results from all other experiments, however, indicated a survival context advantage for both item and source memory. Findings are discussed in relation to possible proximate mechanisms underlying the survival processing effect.

Repetition or alternation of context influences sequential congruency effect depending on the presence of contingency.

The sequential congruency effect (SCE) is defined as the decrease in the congruency effect following incongruent trials compared to congruent trials. The effect of context repetition on the SCE was investigated in four experiments. In all the experiments, dynamic visual white noise was used as the contextual feature, and the number of congruent and incongruent trials was equal. In Experiments 1 and 2, by using eight-value Flanker and Stroop tasks, and excluding stimulus- and response-feature repetitions from the analysis, a SCE was observed in both context repetition and alternation conditions. In Experiment 3, using a two-value Flanker task, all trials consisted of stimulus- and response-feature repetitions, and a SCE was only observed in the context repetition condition. In Experiment 4, we used a four-value Flanker task, which enabled half of the trials to be partial/complete repetitions and the other half to be complete alternations. A SCE was observed in both context repetition and alternation conditions irrespective of the stimulus- and response-feature repetitions. This pattern of results suggested that the effects of context repetition on the SCE are subject to a number of factors including stimulus- and response-feature repetitions and contingency biases. When contingency information exists, the presence of stimulus- and response-feature repetitions was no longer effective in yielding effects of context repetition on the SCE. These findings suggest that the usage of information registered in episodic event representations including stimulus-, response- and contextual-features, control parameters and contingency biases results from interactions of a complex pattern of mechanisms, yet to be further explored.

Cognitive function in chronic obstructive pulmonary disease: relationship to global initiative for chronic obstructive lung disease 2011 categories.

BACKGROUND AND OBJECTIVE: Recently, comorbidities such as impaired cognitive function have been attracting more focus when considering the management of chronic obstructive pulmonary disease (COPD). Here we investigated the relationship between cognitive function and the categories given in the Global Initiative for Chronic Obstructive Lung Disease (GOLD) guidelines in 2011. Specifically, after controlling for non-COPD covariates, we assessed the clinical features that may be predictive of cognitive impairment in patients with COPD. METHODS: We recruited 119 stable patients with mild to very severe COPD. We administered a broad array of standardized neuropsychological tests that assessed cognitive functions in the domains of attention, memory, psychomotor coordination and language. RESULTS: Cognitive scores were significantly different between patients falling within GOLD 2011 categories. Scores were lower in patients with high future risk compared with low future risk. In parallel, there were significant differences in cognitive function between COPD patient subgroups when patients were grouped according to the forced expiratory volume in 1 s, exacerbation history and C-reactive protein levels. After controlling for non-COPD predictors, only exacerbation history remained a significant predictor of cognitive scores. CONCLUSIONS: The number of exacerbation events in a year may be used as a predictor of cognitive impairment in patients with COPD.

Attentional control is partially impaired in obstructive sleep apnea syndrome.

Obstructive sleep apnea syndrome is associated with executive cognitive impairment. An important question is whether impairment in executive functioning in obstructive sleep apnea syndrome is independent of dysfunction in attention. Attentional control is a subcomponent of executive functioning that is mediated by frontal lobe processing. In the current study, we investigated whether attentional control is deficient in obstructive sleep apnea syndrome. Attentional control processes were investigated through conflict adaptation and conflict frequency paradigms. These neuropsychological paradigms were assessed by using the Simon, Flanker and Stroop tasks. We additionally analysed post-error slowing data within these tasks. Error processing is another index of cognitive control that is mediated by frontal lobe functioning. Our sample consisted of 14 healthy adults and 24 patients with untreated moderate-severe obstructive sleep apnea syndrome. Results indicated that attentional control is partially dysfunctional among patients with obstructive sleep apnea syndrome. Attentional control processes were deficient when focal attention (Flanker task) processes were involved, but were intact when observed using the Simon and Stroop tasks. A non-significant trend in post-error slowing data suggested that error processing, assessed with the Flanker task, was diminished among patients with obstructive sleep apnea syndrome. These results support the view that obstructive sleep apnea syndrome leads to some amount of frontal lobe dysfunction, and that attentional control and error processing might be particularly affected by obstructive sleep apnea syndrome.

Can contingency learning alone account for item-specific control? Evidence from within- and between-language ISPC effects.

The item-specific proportion congruence (ISPC) manipulation (Jacoby, Lindsay, & Hessels, 2003) produces larger Stroop interference for mostly congruent items than mostly incongruent items. This effect has been attributed to dynamic control over word-reading processes. However, proportion congruence of an item in the ISPC manipulation is completely confounded with response contingency, suggesting the alternative hypothesis, that the ISPC effect is a result of learning response contingencies (Schmidt & Besner, 2008). The current study asks whether the ISPC effect can be explained by a pure stimulus-response contingency-learning account, or whether other control processes play a role as well, by comparing within- and between-language conditions in a bilingual task. Experiment 1 showed that contingency learning for noncolor words was larger for the within-language than the between-language condition. Experiment 2 revealed significant ISPC effects for both within- and between-language conditions; importantly, the effect was larger in the former. The results of the contingency analyses for Experiment 2 were parallel to that of Experiment 1 and did not show an interaction between contingency and congruency. Put together, these sets of results support the view that contingency-learning processes dominate color-word ISPC effects.