Automatic aftereffects in two-choice reaction time: a mathematical representation of some concepts

A mathematical model is developed to describe sequential effects in two-choice reaction time experiments with a short response-stimulus interval. Evidence is briefly discussed that in conditions with short response-stimulus intervals, automatic aftereffects dominate sequential effects, and the influence of subjective expectancy can be neglected. In these conditions the model premises three components of automatic aftereffects--facilitation, inhibition, and noise, with a common decay factor. Influence of response-stimulus interval and practice on sequential effects are examined and related to parameter changes in the proposed single-decay model. The decrease of automatic aftereffects with increasing response-stimulus interval is primarily ascribed to an increasing decay factor. The parameter representation of the model also clarifies the issue of the disappearance of automatic aftereffects with practice. It shows a gradual fading of inhibition in the initial stages of practice, together with a slower decrease of the facilitation effect. The single-decay model provides a satisfactory explanation for the processes involved in compatible two-choice reaction time with short response-stimulus interval.     

Sequential effects on speeded information processing: a developmental study

Two experiments were performed to assess age-related changes in sequential effects on choice reaction time (RT). Sequential effects portray the influence of previous trials on the RT to the current stimulus. In Experiment 1, three age groups (7-9, 10-12, and 18-25 years) performed a spatially compatible choice task, with response-to-stimulus intervals (RSIs) of 50 and 500 ms varied between trial blocks. In Experiment 2, three age groups (7-9, 15-16, and 18-25 years) performed the task with spatial stimulus-response (S-R) mappings (compatible versus incompatible) varied between participants. For adults, the experiments yielded a pattern of sequential effects suggestive of "automatic facilitation" (i.e., a first-order repetition effect and a higher order benefit-only pattern for short RSIs) and "subjective expectancy" (i.e., a first-order alternation effect and a higher order cost-benefit pattern for long RSIs). Automatic facilitation was more pronounced for incompatible responses than for compatible responses. Both experiments showed the anticipated decrease in automatic facilitation with advancing age. Finally, the first-order alternation effect showed the predicted age-related increase, but the cost-benefit pattern revealed an opposite trend, suggesting that the first-order and higher order indexes of subjective expectancy may relate to dissociable mechanisms.     

Is the binding of visual features in working memory resource-demanding?

The episodic buffer component of working memory is assumed to play a role in the binding of features into chunks. A series of experiments compared memory for arrays of colors or shapes with memory for bound combinations of these features. Demanding concurrent verbal tasks were used to investigate the role of general attentional processes, producing load effects that were no greater on memory for feature combinations than for the features themselves. However, the binding condition was significantly less accurate with sequential rather than simultaneous presentation, especially for items earlier in the sequence. The findings are interpreted as evidence of a relatively automatic but fragile visual feature binding mechanism in working memory. Implications for the concept of an episodic buffer are discussed.     

Sequential effects in two-choice reaction time: Subjective expectancy and automatic after- effect at short response-stimulus intervals

Between three serial two-choice reaction-time tasks, the response-stimulus interval (RSI), stimulus-response compatibility, and practice were varied in order to examine two determinants of sequential effects — subjective expectancy and automatic aftereffect. It appears that subjective expectancy is absent when the RSI is below a critical minimum. In an incompatible task, however, this minimum is greater. This is interpreted in support of the single-channel hypothesis: the subject only builds up expectancies when the “central processor” is unoccupied. The automatic aftereffect increases as the RSI decreases. The decay of the aftereffect seems to take place mainly during the RSI and only to a minor degree during the reaction process. Normally, a strong aftereffect operates in a general way, but after extensive practice it becomes stimulus specific. A model is presented, which assumes that only at the initial stages of practice is the unused “neural pathway” inhibited each time the stimulus is an alternation.     

Response-specific slowing in older age revealed through differential stimulus and response effects on P300 latency and reaction time

Older age produces numerous changes in cognitive processes, including slowing in the rate of mental processing speed. There has been controversy over the past three decades about whether this slowing is generalized or process-specific. A growing literature indicates that it is process-specific and suggests it is most dramatic at the interface where a stimulus input is translated into a response output. We tested this hypothesis using a task in which young and older adult males made either compatible or incompatible responses to the word LEFT or RIGHT shown briefly and variously located in a 4 row × 6 column matrix surrounded by # signs or by letters chosen randomly from the sets A-G or A-Z. Processing speed was measured using P300 latency and reaction time. Experimental effects on these two measures provided support for the hypothesis in revealing that stimulus identification processes were preserved, whereas processes related to translating a stimulus input into a designated response output and then selecting that response were compromised in the elderly.     

Cognitive efficiency modes in old age: performance on sequential and coordinative verbal and visuospatial tasks

In an experiment using a large set of verbal and spatial tasks requiring low or high degrees of executive control, 3 distinct age-related effects were found. The smallest effect (no slowing) was tied to lexical tasks with low executive involvement, the largest deficit (age-related slowing factor of 2.2) was tied to visuospatial tasks with high executive involvement, an intermediate level of deficit (slowing factor of 1.7) was found for visuospatial tasks with low executive load and verbal tasks with high executive load. These age-related dissociations were incompatible with any "common cause" formulation. The mechanism responsible for the dissociation between verbal and visual tasks, and between low and high executive load remains to be determined. The latter may reflect capacity limits.     

Outcome expectancy and not accuracy determines posterror slowing: ERP support

A considerable number of studies have recently used event-related potentials (ERPs) to investigate the mechanisms underlying error processing. Nevertheless, how these mechanisms are associated with behavioral adjustments following errors remains unclear. In the present study, we investigated how posterror slowing is linked to outcome expectations and error feedback. We used an adaptive four-choice reaction time task to manipulate outcome expectancy. Behaviorally, the results show posterror slowing when errors are unexpected and postcorrect slowing when correct responses are unexpected, indicating that outcome expectancy is crucial for posterror slowing. ERP analyses revealed that the error-related negativity and the feedback-related negativity were not correlated with the behavioral reaction time pattern, whereas the P3 was. The results support the hypothesis that posterror slowing is caused by attentional orienting to unexpected events.     

Age-specific problems in rhythmic timing

The authors investigated performance in 2 rhythm tasks in young (M = 23.8 years) and older (M = 71.4 years) amateur pianists to test whether slowing of a central clock can explain age-related changes in timing variability. Successive keystrokes in the rhythm tasks were separated by either identical (isochronous) time intervals or varying (anisochronous) intervals. Variability was comparable for young and older adults in the isochronous task; pronounced age effects were found for the anisochronous rhythm. Analyses of covariances between intervals rule out slowing of a central clock as an explanation of the findings, which instead support the distinction between target specification, timekeeper execution, and motor implementation proposed by the rhythm program hypothesis (D. Vorberg & A. M. Wing, 1996). Age stability was found at the level of motor implementation, but there were age-related deficits for processes related to target-duration specification.     

Age effects may be global, not local: comment on Fisk and Rogers (1991)

A series of analyses of variance on target search times allowed Fisk and Rogers (1991) to reject the null hypothesis that age had a uniform, additive effect across search conditions. It does not, however, follow that age affected some conditions in an exceptional way, as Fisk and Rogers concluded. Age may have had a uniform but nonadditive effect across conditions. In this article, it is shown that age had a uniform linear, or perhaps slightly curvilinear, effect on search times. This "null hypothesis" adequately accounted for the age effects in all 27 search conditions. Indeed, it accounted for the age effects in 107 conditions abstracted from other visual search studied and for the age effects in 154 conditions abstracted from a miscellaneous collection of nonsearch processing-time studies. The only variation in age outcomes across studies was consistent with sampling error, given the known variance in response times. It is concluded that age is experienced as a generalized slowing of the central nervous system uniformly affecting all information processes.     

Achievement motivation and problem solving

Abstract.— The relationships between achievement motivation and problem solving were discussed. It was suggested that problem solving may be differentially related to achievement motivation in high and low ability groups. In a group of 46 male students, scoring high on a test of intellectual flexibility, a positive relationship was found between a projective measure of fear of failure and solution of the Hatrack Problem. In a group of 49 male subjects with low flexibility scores, fear of failure was negatively related to problem solving. The results were taken to indicate that the ability measure represented general self confidence and expectancy. Thus subjects with high self confidence might attempt to avoid failure by trying hard to succeed, while a more probable strategy for subjects with low expectancy would be to exert little effort. A test of this hypothesis was made by analyzing a measure of overt activity in the Hatrack situation across high/low motivational and ability groups. Whereas in the high ability group subjects with high fear of failure showed a high level of activity, high fear of failure subjects in the low ability group showed a low level of activity, thus supporting the hypothesis.     

Dissociating controlled from automatic processing in temporal preparation

The aim of the present study was to investigate the controlled versus the automatic nature of temporal preparation. If temporal preparation involves controlled rather than automatic processing, it should be reduced by the addition of a concurrent demanding task. This hypothesis was tested by comparing participants' performance in a temporal preparation task that measured two main effects of temporal preparation (temporal orienting and sequential effects) between a single-task and a dual-task condition. In the single-task condition, participants responded to a visual target presented after symbolic cues that were highly predictive of the moment of target onset. In the dual-task condition, the temporal preparation task was performed concurrently with a working memory task. The results showed that sequential effects survived to dual-task interference, while temporal orienting was reduced as a function of the competition for executive resources required by both working memory and temporal preparation tasks. These findings provide direct behavioural evidence that temporal orienting and sequential effects involve dissociable cognitive processes.     

Semantic congruity and expectancy in symbolic judgments

These experiments assess the degree to which the semantic-congruity effect in comparative judgment can be explained by such expectancy effects as priming, perceptual "set," or strategies used in the task. The first experiment mixed a lexical-decision task with the comparative-judgment task and showed that neither automatic semantic priming nor deliberate preparation can account for the congruity effect. Experiments 2-4 assessed expectancy effects in a different way by presenting the instructions for comparative judgment either before or after the pair to be judged. These experiments included, among other things, a number of safeguards against artifacts in this paradigm. In these three experiments the congruity effect was obtained with both orders of stimuli and instructions, contrary to the prediction of an expectancy hypothesis. The results indicate that when stimuli are not degraded. The semantic-congruity effect depends largely on the relation between the stimuli and the instructions and only to a small degree, if at all, on expectancy.     

Conflict adaptation: It is not what you expect

In two studies, a vocal Stroop task with eight different colours was employed in order to put two core assumptions of the original interpretation of the Gratton effect to the test. We verified whether top-down control processes can elicit conflict adaptation when episodic memory effects are controlled for and to what extent proactive adjustments driven by the subjects' expectancy for congruency level repetition contribute to this effect. Therefore, we presented Stroop stimuli without feature repetitions and investigated whether the induced expectancy manipulation of raising the amount of either congruency level repetitions or alternations in a training phase transferred to an unmanipulated test phase. Over the two experiments, a sequential modulation of the Stroop effect was found in the absence of stimulus feature repetitions, strongly confirming a share for top-down control processes in bringing about the Gratton effect. In the condition where congruency level repetitions were raised, a strong Gratton effect was found. When congruency level alternations outnumbered repetitions, the Gratton effect disappeared completely. However, this difference seemed mainly due to cumulative effects of local, dynamic, trial-to-trial control adjustments rather than expectancy-induced attentional shifting. Once the transition probability changed back to 50% in the test phase of each experiment, a similar Gratton effect was found in both conditions. Taken together, these results are best explained in terms of dynamic reactive control.     

Integrating the Automatic and the Controlled: Strategies in Semantic Priming in an Attractor Network With Latching Dynamics

Semantic priming has long been recognized to reflect, along with automatic semantic mechanisms, the contribution of controlled strategies. However, previous theories of controlled priming were mostly qualitative, lacking common grounds with modern mathematical models of automatic priming based on neural networks. Recently, we introduced a novel attractor network model of automatic semantic priming with latching dynamics. Here, we extend this work to show how the same model can also account for important findings regarding controlled processes. Assuming the rate of semantic transitions in the network can be adapted using simple reinforcement learning, we show how basic findings attributed to controlled processes in priming can be achieved, including their dependency on stimulus onset asynchrony and relatedness proportion and their unique effect on associative, category‐exemplar, mediated and backward prime‐target relations. We discuss how our mechanism relates to the classic expectancy theory and how it can be further extended in future developments of the model.     

Alcohol intoxication alters cognitive skills mediated by frontal and temporal brain regions

Alcohol intoxication affects frontal and temporal brain areas and may functionally impair cognitive processes mediated by these regions. This study examined this hypothesis by testing the effects of alcohol on sustained attention, impulsivity, and verbal memory. Sober and placebo control groups were used to distinguish pharmacological from expectancy effects of alcohol. One hundred nine university students were assigned to an alcohol (low, medium, or high dose), placebo or sober group. Moderate and high doses of alcohol impaired all cognitive measures. A gender effect was revealed in that alcohol impaired sustained attention in males, but not females. Both sustained attention and verbal memory exhibited a U-shaped pattern, in that the medium-dose alcohol group showed the greatest impairment. This study adds to knowledge about the effects of alcohol intoxication on frontally- and temporally-mediated cognitive function. These findings have specific relevance for heavy-drinking undergraduate populations, particularly in light of the fact that repeated alcohol administration produces persistent changes in brain neurocircuitry.     

Introversion,inhibition, and displayed anxiety: The role of error reactivity processes

Three studies involving 176 undergraduates examined the personality-related correlates of tendencies to slow down following errors in choice reaction time tasks. Such tendencies were hypothesized to tap individual differences in threat reactivity processes and therefore be relevant to the prediction of phobic-like fear (Study 1) and displayed anxiety as rated by informants (Studies 2 and 3). However, on the basis of the idea that high levels of extraversion may suppress threat reactivity processes, it was hypothesized that extraversion and post-error slowing tendencies would interact in predicting the dependent measures. The studies supported the latter interactive hypothesis in that post-error slowing tendencies were predictive of displayed anxiety at low, but not high, levels of extraversion. The discussion focuses on the respective roles of error-reactivity processes and extraversion in predicting behavioral inhibition and displayed anxiety.     

Attentional switching in the sequential flanker task: age, location, and time course effects

The sequential flanker task was developed to study sequential performance using methodology borrowed from studies of task switching. We investigated age differences in backward inhibition [BI: Mayr, U., & Keele, S. W. (2000). Changing internal constraints on action: The role of backward inhibition. Journal of Experimental Psychology: General, 129, 4-26] during a sequential category search task. Participants learned four animal categories in a fixed order, and then searched for exemplars from those categories in runs of mis-ordered exemplars. Across three experiments, we observed robust BI facilitation effects. However, the magnitude of BI effects did not differ across age groups. This age-invariance held despite manipulations of distractibility (Experiment 2), and interstimulus interval (Experiment 3), suggesting that BI processes may be relatively automatic and obligatory in the context of sequential tasks. The findings are discussed in terms of the attentional mechanisms that underlie task set switching and sequential performance.     

Synergistic Effects of Expectancy and Value on Homework Engagement: The Case for a Within-Person Perspective

Historically, expectancy–value models of motivation assumed a synergistic relation between expectancy and value: motivation is high only when both expectancy and value are high. Motivational processes were studied from a within-person perspective, with expectancies and values being assessed or experimentally manipulated across multiple domains and the focus being placed on intraindividual differences. In contrast, contemporary expectancy–value models in educational psychology concentrate almost exclusively on linear effects of expectancy and value on motivational outcomes, with a focus on between-person differences. Recent advances in latent variable methodology allow both issues to be addressed in observational studies. Using the expectancy–value model of homework motivation as a theoretical framework, this study estimated multilevel structural equation models with latent interactions in a sample of 511 secondary school students and found synergistic effects between domain-specific homework expectancy and homework value in predicting homework engagement in 6 subjects. This approach not only brings the “×” back into expectancy–value theory but also reestablishes the within-person perspective as the appropriate level of analysis for latent expectancy–value models.     

Numerical representation: abstract or nonabstract?

Until now it has been a commonly held view that numbers are represented abstractly in the human brain. However, a recent imaging study challenged the existence of an abstract representation at least of digits and number words, at the brain level, and argued that previous studies and paradigms were not sensitive enough to detect deviations from abstract representation at the behavioural level. The current study addressed this issue with an analysis of distance and sequential effects in magnitude classification. Previous studies that used this paradigm did not find deviation from abstract representation for digits and number words (e.g., Dehaene, 1996; Schwarz & Ischebeck, 2000). However, in the current study a short stimulus-response interval was used, which reduced subjective expectancy and increased automatic processing. The current results showed deviation from abstract representation in both reaction time and accuracy and therefore support the idea that nonabstract representations of numbers do exist.     

Sequence effects by non-predictive arrow cues

Previous studies have found that attention orienting is influenced by the orienting processes of previous trials in a spatial cueing paradigm. This study mainly investigated whether this sequence effect could happen for a non-predictive arrow cue and whether it was influenced by the cue-target SOAs in previous and current trials. A significant sequence effect was observed for arrow cues even when voluntary control was not required, and it was significantly influenced by the SOAs of previous trials. The present results support the automatic memory check hypothesis and may reflect some temporal characteristics of the memory mechanism in sequential processes. In addition, contrary to the previous findings, we found an overall response facilitation following a catch trial, suggesting that the influence of preceding catch trials may be sensitive to experimental contexts.