Generalized lessons about sequence learning from the study of the serial reaction time task

Over the last 20 years researchers have used the serial reaction time (SRT) task to investigate the nature of spatial sequence learning. They have used the task to identify the locus of spatial sequence learning, identify situations that enhance and those that impair learning, and identify the important cognitive processes that facilitate this type of learning. Although controversies remain, the SRT task has been integral in enhancing our understanding of implicit sequence learning. It is important, however, to ask what, if anything, the discoveries made using the SRT task tell us about implicit learning more generally. This review analyzes the state of the current spatial SRT sequence learning literature highlighting the stimulus-response rule hypothesis of sequence learning which we believe provides a unifying account of discrepant SRT data. It also challenges researchers to use the vast body of knowledge acquired with the SRT task to understand other implicit learning literatures too often ignored in the context of this particular task. This broad perspective will make it possible to identify congruences among data acquired using various different tasks that will allow us to generalize about the nature of implicit learning.     

Manipulating attentional load in sequence learning through random number generation

Implicit learning is often assumed to be an effortless process. However, some artificial grammar learning and sequence learning studies using dual tasks seem to suggest that attention is essential for implicit learning to occur. This discrepancy probably results from the specific type of secondary task that is used. Different secondary tasks may engage attentional resources differently and therefore may bias performance on the primary task in different ways. Here, we used a random number generation (RNG) task, which may allow for a closer monitoring of a participant's engagement in a secondary task than the popular secondary task in sequence learning studies: tone counting (TC). In the first two experiments, we investigated the interference associated with performing RNG concurrently with a serial reaction time (SRT) task. In a third experiment, we compared the effects of RNG and TC. In all three experiments, we directly evaluated participants' knowledge of the sequence with a subsequent sequence generation task. Sequence learning was consistently observed in all experiments, but was impaired under dual-task conditions. Most importantly, our data suggest that RNG is more demanding and impairs learning to a greater extent than TC. Nevertheless, we failed to observe effects of the secondary task in subsequent sequence generation. Our studies indicate that RNG is a promising task to explore the involvement of attention in the SRT task.     

Neural correlates of feigned memory impairment are distinguishable from answering randomly and answering incorrectly: an fMRI and behavioral study

Previous functional magnetic resonance imaging (fMRI) studies have identified activation in the prefrontal-parietal-sub-cortical circuit during feigned memory impairment when comparing with truthful telling. Here, we used fMRI to determine whether neural activity can differentiate between answering correctly, answering randomly, answering incorrectly, and feigned memory impairment. In this study, 12 healthy subjects underwent block-design fMRI while they performed digit task of forced-choice format under four conditions: answering correctly, answering randomly, answering incorrectly, and simulated feigned memory impairment. There were three main results. First, six areas, including the left prefrontal cortex, the left superior temporal lobe, the right postcentral gyrus, the right superior parietal cortex, the right superior occipital cortex, and the right putamen, were significantly modulated by condition type. Second, for some areas, including the right superior parietal cortex, the right postcentral gyrus, the right superior occipital cortex, and the right putamen, brain activity was significantly greater in feigned memory impairment than answering randomly. Third, for the areas including the left prefrontal cortex and the right putamen, brain activity was significantly greater in feigned memory impairment than answering incorrectly. In contrast, for the left superior temporal lobe, brain activity was significantly greater in answering incorrectly than feigned memory impairment. The results suggest that neural correlates of feigned memory impairment are distinguishable from answering randomly and answering incorrectly in healthy subjects.     

不同自尊者在赌博情境下的风险规避行为

为了考察不同自尊水平的个体在赌博情境下的风险规避行为,263名大学生被试同时完成外显Rosenberg量表、内隐联想测验和21点赌博游戏。实验结果发现,(1)随着风险的增加,所有被试都表现出风险规避;(2)在高外显自尊水平的个体中,低内隐自尊水平个体比高内隐自尊水平个体表现出更多的风险规避行为;在低内隐自尊的个体中,高外显自尊个体比低外显自尊个体表现出更多的风险规避行为。风险规避行为间接地反映出个体的防御倾向,结果提示,在风险情境中,高外显低内隐自尊个体表现出较高的自我防御倾向。     

Distorted estimates of implicit and explicit learning in applications of the process-dissociation procedure to the SRT task

We investigated potential biases affecting the validity of the process-dissociation (PD) procedure when applied to sequence learning. Participants were or were not exposed to a serial reaction time task (SRTT) with two types of pseudo-random materials. Afterwards, participants worked on a free or cued generation task under inclusion and exclusion instructions. Results showed that pre-experimental response tendencies, non-associative learning of location frequencies, and the usage of cue locations introduced bias to PD estimates. These biases may lead to erroneous conclusions regarding the presence of implicit and explicit knowledge. Potential remedies for these problems are discussed.     

Reinforcement sensitivity theory at work: punishment sensitivity as a dispositional source of job-related stress

Gray's reinforcement sensitivity theory (RST) describes two important personality constructs; sensitivity to reward and sensitivity to punishment. In two studies, we examine whether these constructs can be considered dispositions to work stress. Results of Study 1 (N = 105 employees in different occupations) indicated that employees with strong punishment sensitivity reacted more strongly to work stressors than others. This idea was confirmed in a longitudinal design in Study 2. Reward sensitivity was unrelated to stress in both studies. Overall, results strongly support the idea that punishment sensitivity is a dispositional source of work stress. Results further confirm that RST and its derived personality measures can contribute to theorizing about personality–environment interactions in a highly relevant daily setting, namely the working environment. Copyright © 2007 John Wiley & Sons, Ltd.     

Neural Processing to Visual Stimuli in a Three-Choice Reaction-Time Task

Some authors have suggested that certain components of the event-related potentials (ERPs) reflect underlying stages in the discrimination process. Previous studies have shown that in an auditive three-choice reaction-time task the discrimination is accomplished as a two-stage process, with the more frequently occurring stimulus discriminated at an earlier point than the rarer stimulus and the subjects could be classified as fast and slow responders in function of their response to the most frequent of the three tones. We continuously recorded the electrocerebral activity (EEG) from the scalp and the electromyographic activity (EMG) from the responding muscles in a visual three-choice reaction-time task in 10 strictly right-handed subjects. EEG and EMG responses were subsequently analyzed off-line by aligning them by the onset of either the stimulus (stimulus-synchronized) or the response (response-synchronized). The results suggest that processes of visual stimuli evaluation and response execution are continuously integrated. The discrimination and response systems to visual stimuli is accomplished as a three-stage process, one to frequent tone, another for rare 1, and the last for rare 2. The subjects were classified as fast and slow responders in function of their response to the most frequent of the three tones.     

Resource allocation for visual metaphor processing: A study of political cartoons

ABSTRACT

This paper is a study of visual metaphor processing in political cartoons, while secondary task reaction time was used to assess resource allocation when processing three types of visual metaphors, namely juxtapositions, fusions and replacements. Participants viewed a series of visual metaphors. At various intervals, they were invited to push a button whenever a probe appeared. Reaction times to detect the probes were recorded. Subsequently, participants performed recall and recognition tasks. Results showed that participants reacted faster to each successive probe, while metaphor type had no influence on reaction times. Concerning the recall task, the percentage of correctly recalled items was significantly lower for juxtapositions compared to replacements; results for fusions were in between the two. Recognition scores for juxtapositions and fusions were lower than those for replacements. These findings are discussed in the framework of visual metaphors literature, thus providing empirical support to visual metaphor processing.