Localizing sequential effects in serial choice reaction time with the information reduction procedure.

Patterns of sequential effects in serial 2-choice reaction time (RT) tasks have been explained by 2 processing mechanisms, automatic facilitation and subjective expectancy, depending on the response-to-stimulus interval (RSI) and stimulus-response compatibility. Both mechanisms were localized in stimulus- or response-related processing stages with 4-stimulus 2-response experiments. Stimuli were presented on the corners of a square and keys were left-right or up-down. Subjective expectancy, appearing at long RSI, was systematically response related. Automatic facilitation, appearing with short RSI, shifted toward stimulus-related processes with noncompatible mappings. The results support the idea that automatic facilitation is related to structural bottom-up processes and is mainly located in stages that gain most from a facilitatory effect, whereas subjective expectancy needs a minimum time and therefore appears in late, response-related stages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling aging effects on two-choice tasks: Response signal and response time data.

In the response signal paradigm, a test stimulus is presented, and then at one of a number of experimenter-determined times, a signal to respond is presented. Response signal, standard response time (RT), and accuracy data were collected from 19 college-age and 19 60- to 75-year-old participants in a numerosity discrimination task. The data were fit with 2 versions of the diffusion model. Response signal data were modeled by assuming a mixture of processes, those that have terminated before the signal and those that have not terminated; in the latter case, decisions are based on either partial information or guessing. The effects of aging on performance in the regular RT task were explained the same way in the models, with a 70- to 100-ms increase in the nondecision component of processing, more conservative decision criteria, and more variability across trials in drift and the nondecision component of processing, but little difference in drift rate (evidence). In the response signal task, the primary reason for a slower rise in the response signal functions for older participants was variability in the nondecision component of processing. Overall, the results were consistent with earlier fits of the diffusion model to the standard RT task for college-age participants and to the data from aging studies using this task in the standard RT procedure. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Statistical learning in a serial reaction time task: Access to separable statistical cues by individual learners.

The ability of adult learners to exploit the joint and conditional probabilities in a serial reaction time task containing both deterministic and probabilistic information was investigated. Learners used the statistical information embedded in a continuous input stream to improve their performance for certain transitions by simultaneously exploiting differences in the predictability of 2 or more underlying statistics. Analysis of individual learners revealed that although most acquired the underlying statistical structure veridically, others used an alternate strategy that was partially predictive of the sequences. The findings show that learners possess a robust learning device well suited to exploiting the relative predictability of more than 1 source of statistical information at the same time. This work expands on previous studies of statistical learning, as well as studies of artificial grammar learning and implicit sequence learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Signal recency effects can be distinguished from signal repetition effects in serial CRT tasks.

Reaction time (RT) is reduced in serial choice tasks when a particular signal, as distinct from the response made to it, is repeated on successive trials, N–1 and N. This experiment with 30 undergraduates showed a separate signal recency effect. RT is also reduced when a signal presented on trial N–2 recurs on trial N. In 3 many-to-one signal-to-response mapping tasks (2 responses 4 signals, 2 responses 8 signals, and 2 responses 16 signals), the effects of recent occurrence of signals were shown to be distinct from the effects of recent occurrence of responses made to them. The magnitude of signal recency effects varies directly with set size, but decreases, and may eventually disappear, with practice. The effect decreases with practice faster when signal sets are small than when they are large. A simple model accounts for these results and for earlier data from many-to-one mapping tasks that show that variations in signal entropy cease to affect choice reaction time if practice is sufficiently prolonged. Predictions from this model for changes in component RT distributions with signal set size, signal repetition, signal recency, and practice suggest further experiments. (French summary) (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of immediate stimulus repetition on reaction time and event-related potentials in tasks of different complexity.

Examined the effect of immediate stimulus repetition in lexical decision, face recognition, letter search, face/nonface discrimination, and word/number discrimination tasks using reaction time (RT), accuracy, and event-related brain potential (ERP) measures. Repetition facilitated performance in all tasks and for all stimulus types. However, ERPs were strongly affected by repetition only in lexical decision, face recognition, and letter search, when relatively long stimulus analysis and decision making processes were required. The ERP repetition effect consisted of a significant increase in P300 amplitude and a shortening of its latency. Repetition also resulted in the attenuation of a negative component that was tentatively identified as N400. These results suggest that immediate repetition facilitates stimulus identification and eliminates the need for stimulus analysis processes including access to semantic memory while making categorical decisions. While both factors affected RT, ERPs were modulated primarily by the elimination of the need to access to semantic memory and by the consequent speeding of categorical decision processes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Comparative effects of different test day challenges on performance in the 5-choice serial reaction time task.

The 5-choice serial reaction time task (5-CSRTT) is a valuable cognitive test that permits the simultaneous assessment of several different cognitive modalities, including attention, impulse control, processing speed, and cognitive flexibility. Increasing task difficulty on test days through various challenges can further enhance the versatility of this test by selectively enhancing the cognitive load on different aspects of the task. Systematic comparisons of the effects of different test day challenges on 5-CSRTT performance are essential to verify how these challenges affect different task measures and which manipulations are best suited for future studies of different aspects of cognition. We trained Wistar rats in the 5-CSRTT under standard conditions, then challenged them on the test days by (1) decreasing the duration of the stimulus to be detected, (2) increasing the time interval between trials (intertrial interval, ITI), (3) randomly varying the ITI, or (4) adding a flashing light distractor. All test day challenges produced distinct profiles of performance disruption that reflected differential effects on different cognitive modalities. Decreased stimulus duration selectively impaired attentional performance, while increased ITI increased impulsive-like premature responses and decreased trials completed. Variable ITI induced only mild, nonsignificant disruptions in response inhibition and processing speed, while the flashing light distractor produced comprehensive impairment affecting multiple aspects of 5-CSRTT performance, including disrupted attention and increased premature and timeout responses. This improved understanding of the effects of different test day challenges in the 5-CSRTT will allow researchers to use these manipulations of a valuable cognitive test to their full potential. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Tonic and phasic activation and arousal effects as a function of feedback in repetitive-choice reaction time tasks.

This study examines the effects of positive and negative feedback on performance during choice reaction time tasks to assess whether they differentially affect phasic arousal and tonic activation. Participants (N=96) received either no feedback or signals of reward, punishment, or both during a semantic and a visuospatial repetitive-choice reaction time task. The number of errors made was analyzed both on a trial-by-trial basis and over a continuous series of 80 trials (assessing phasic and tonic feedback effects, respectively). The results show that punishment and reward have different phasic and tonic effects on performance. The data further show that feedback effects interact with the task characteristics: semantic versus visuospatial, and reaction stimulus preceded by a warning signal versus an irrelevant signal. The interaction effects appear to be consistent with the proposed neurological model. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Selective attention and response strategies as factors in serial reversal learning.

3 experiments investigated the basis of serial-reversal improvement in 40 white Carneaux pigeons. In the 1st, Ss trained on either color or position reversals alone performed more accurately than Ss initially trained on interspersed color and position reversals, and then shifted to 1 type of problem only. This suggests that the selective strengthening of attention to a single relevant dimension is 1 factor underlying rapid reversal learning. In 2 further experiments, Ss were trained on delayed conditional discriminations, the requirements of which were similar to those of a win-stay, lose-shift strategy. Ss' poor performance on these problems implies that such strategies do not play an important part in reversal learning in these Ss. (French summary) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Implicit learning in Parkinson''s disease: evidence from a verbal version of the serial reaction time task

Reinvestigation of the root of Rhinacanthus nasutus afforded, in addition to rhinacanthin-A to -D reported previously, two new dimethyldihydropyranonaphthoquinone esters (5, 6) and eight new 2-hydroxy-1,4-naphthoquinone esters (7-14) were isolated. The stereochemistry of rhinacanthin-A was determined as the R configuration. Compounds rhinacanthin-G to -N, belong to a class of 2-hydroxy-3-(3-hydroxy-2,2-dimethylpropyl)-1,4-naphthoquinone esters, and so far have been isolated only in this plant. Their biosynthesis is also discussed.     

Stimulus exposure time as a factor in serial learning in an aged sample.

Stimulus exposure and learning in old (O) and young (Y) Ss was investigated. Lists of 8 words equated for size, association value, and structure were used in a serial rote learning task with a 1-sec. interword interval and a 45-sec. intertrial interval. 3 groups of Y (M = 37.3 yr.) and O (M = 66.5 yr.) men received exposure times of 4, 6, or 8 sec., comprising a 3 X 2 A of V design (N = 81). WAIS Vocabulary scores served as a control. Conclusions are: (a) Y Ss learned better than O (p     

Equivalent effects of grouping by time, voice, and location on response timing in verbal serial memory.

The grouping of list items is known to improve serial memory accuracy and constrain the nature of temporal errors. A recent study (M. T. Maybery, F. B. R. Parmentier, & D. M. Jones, 2002) showed that grouping results in a temporal organization of the participants' responses that mimics the list structure but not the timing of its presentation. Here the authors tested the prediction that the temporal grouping of responses should yield the same pattern of response time (RT) irrespective of the method of grouping at presentation. Comparing temporal, location, and voice grouping, the results show that although these methods impact on recall accuracy to varying degrees, all 3 conditions produce significant and equivalent peaks in RT at the first position of each group. The RT data were accurately simulated through a model based on ACT-R's (J. R. Anderson & M. Matessa, 1997) basic principles. Altogether, the data suggest that the temporal organization of responses in verbal serial recall results from (a) declarative knowledge about the list's structure that is independent of the perceptual means by which grouping is induced at presentation and (b) the level of activation of the items per se. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Paradoxical effects in the reaction time of schizophrenics.

"A reaction-time experiment was carried out, using lights of different intensities, to test Pavlov's suggestion that paradoxical effects are commonly found in schizophrenics. It was predicted that whereas normal persons tend to respond more quickly to more intense stimuli, schizophrenics respond more slowly to such 'ultramarginal' stimuli than to lights of weaker intensity. In 22 out of 24 chronic, nonparanoid schizophrenics, RTs to the brighter stimuli were longer than those to weaker stimuli in a first testing session but not in a second. Convalescent, shore-stay schizophrenics and normal controls showed no paradoxical effects. A tentative hypothesis to explain why the chronic patients did not show paradoxical effects on retest is proposed." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Blocking in rat serial pattern learning.

Both associative and rule-learning theories have been proposed to account for rat serial pattern learning, but individually they are unable to account for a variety of recent behavioral and psychobiological phenomena. The present study examined the role of rule learning versus discriminative learning in rat pattern learning using a classic associative phenomenon: blocking. Rats learned to press levers in an 8-lever circular array according to a rule-based serial pattern, 123–234–345–456–567–678–781–812, where digits indicate the correct lever in the array for each trial. Each pattern presentation contained a chunk with a final element violation, such as 454 instead of 456. Rats learned in a first phase that a noise signaled the violation chunk; then, a concurrent spatial cue was added in a second phase. A test with spatial cues alone showed that blocking occurred. The results suggest that associative learning mediated cuing of violation elements. Taken together with other behavioral and psychobiological evidence already reported in the literature implicating rule learning when rats learn this pattern in this paradigm, these results implicate multiple concurrent learning processes in rat serial pattern learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of concurrent verbal and visual tasks on category learning.

Current theories of category learning posit separate verbal and nonverbal learning systems. Past research suggests that the verbal system relies on verbal working memory and executive functioning and learns rule-defined categories; the nonverbal system does not rely on verbal working memory and learns non-rule-defined categories (E. M. Waldron & F. G. Ashby, 2001; D. Zeithamova & W. T. Maddox, 2006). However, relatively little research has explored the importance of visual working memory or visual processing for either system. The authors investigated the role of working memory (Experiment 1a and 1b), visual processing (Experiment 2), and executive functioning for each system, using a concurrent task methodology. It was found that visual tasks with high executive functioning demands and verbal tasks with high or low executive demands disrupted rule-defined learning, whereas any visual task, regardless of executive functioning demand, disrupted non-rule-defined learning. Taken together, these results confirm the importance of verbal working memory and executive functioning for the verbal system and provide new evidence for the importance of visual processing for the nonverbal system. These results help to clarify understanding of the nonverbal system and have implications for multiple systems theories of category learning (F. G. Ashby, L. A. Alfonso-Reese, A. U. Turken, & E. M. Waldron, 1998). (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Irrelevant sound disrupts order information in free recall as in serial recall

The claim that the sensitivity of free recall to disruption by irrelevant sound is a function of the extent to which rote rehearsal is employed as a mnemonic strategy was investigated in two experiments. The degree of disruption by irrelevant sound in terms of both item and order information was contrasted under serial and free recall instructions. Irrelevant sound was found to disrupt order and item information equally in serial and free recall tasks (Experiment 1). Contrary to previous reports, an effect of irrelevant sound was also demonstrated on free recall of particularly long lists, and the interaction between list length and retention interval in the irrelevant sound effect was examined (Experiment 2). Generally, the results support the view that irrelevant sound disrupts the use of order cues.     

Beyond nonutilization: Irrelevant cues can gate learning in probabilistic categorization.

In probabilistic categorization, also known as multiple cue probability learning (MCPL), people learn to predict a discrete outcome on the basis of imperfectly valid cues. In MCPL, normatively irrelevant cues are usually ignored, which stands in apparent conflict with recent research in deterministic categorization that has shown that people sometimes use irrelevant cues to gate access to partial knowledge encapsulated in independent partitions. The authors report 2 experiments that sought support for the existence of such knowledge partitioning in probabilistic categorization. The results indicate that, as in other areas of concept acquisition (such as function learning and deterministic categorization), a significant proportion of participants partitioned their knowledge on the basis of an irrelevant cue. The authors show by computational modeling that knowledge partitioning cannot be accommodated by 2 exemplar models (Generalized Context Model and Rapid Attention Shifts 'N Learning), whereas a rule-based model (General Recognition Theory) can capture partitioned performance. The authors conclude by pointing to the necessity of a mixture-of-experts approach to capture performance in MCPL and by identifying reduction of complexity as a possible explanation for partitioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Predisposition to fantasy and situational variations as determinants of attention in reaction time tasks.

Predicted the effects of procedural changes and embellished directions on performance in a RT task on the basis of 200 undergraduates' predisposition toward fantasy activity. Ss who had given more Human Movement (M) responses to an inkblot test were found to be more responsive than Ss who had given less M responses to changes in procedures and directions which altered the interest value of the task. However, this effect was primarily found for the female sample. Interpretations regarding the likelihood of task-relevant and task-irrelevant cognitive activity as mediators of the obtained changes in performance and cautions regarding sex differences in attention and fantasy processes are offered. (23 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Detecting multimodality in saccadic reaction time distributions in gap and overlap tasks

This study examined whether the socially anxious show deficits in performance on a social task as well as how their anxiety and competence relate to judgments they make about themselves and others. Ratings from a panel of judges were used to compare men of high and low social anxiety on their performances in a simulated job interview. Participants also viewed videotapes of themselves and others and rated responses for content, fluency, nonverbal, and global competence. Contradicting predictions of a performance deficit model, high levels of social anxiety had no detrimental effect on participants' performance or on their ability to judge their own performance. In contrast, observer-rated competence was related to a number of significant effects for social judgment tasks. Implications for treatment of social anxiety and research on social anxiety are discussed.     

Composition during serial learning: A serial position effect.

Composition is a computational learning mechanism that merges serially performed elementary processes into hierarchically organized knowledge structures. The main goals of this research were to explore (1) the role of serial position in composition and (2) the relation between degree of composition and explicit serial recall in serial learning. In 3 experiments, Ss performed a rule-based serial reaction time (RT) task in which they had to categorize a sequence of 12 stimuli shown simultaneously on a video monitor. A procedure based on the comparison of RTs to random sequences and a repeating sequence identified a serial position effect of composition that was, however, moderated by Ss' explicit, postexperimental recall of the repeating sequence. A production-system-based computational model of composition is described that qualitatively reproduces the empirical findings. Implications for the mechanisms governing serial learning are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Temporal specificity in serial feature-positive discrimination learning.

Two experiments examined the temporal specificity of learning in operant serial feature positive discriminations (feature?→?target+/target–). Test performance was better when the target cues were presented at their customary times after the features than when they were presented at earlier or later times. When features trained with one feature–target interval were combined with targets trained with another interval, performance was best when the test interval was the same as the interval associated with the feature, suggesting that the temporal information was coded with the feature cue. Finally, the temporal specificity of the responding controlled by occasion setters was unaffected by feature extinction. Implications for the nature of learning in occasion setting are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)