"Pessimistic noise effects": The perception of reaction times in noise.

Used a between-group design to examine the effect of loud noise on a 2-choice discrete reaction task and the judgments Ss made about self-produced RTs under these conditions. In Exp I, 70 Ss (aged 26–39 yrs) completed a 2-choice RT task and a concurrent RT rating task of speed. White noise was presented to Ss in the experimental groups. RTs were unexpectedly faster in noise, but Ss used more "slow" categories in describing them. The effect was not apparent when the same RTs were rerated a 2nd time under instructions that indicated that they were random time intervals. Also, the effect was not apparent when a new group of 14 undergraduates in Exp II rated the original RT data, again in noise. Exp III showed that when asked to predict average RTs produced by a hypothetical S in noise, 30 uniformed Ss (aged 26–39 yrs) predicted slow RTs. Results are considered in the light of the hypothesis that pessimistic expectancies about likely effects of noise may be a factor influencing performance. (French abstract) (12 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evidence for higher reaction time variability for children with ADHD on a range of cognitive tasks including reward and event rate manipulations.

Objective: The purpose of the research study was to examine the manifestation of variability in reaction times (RT) in children with attention deficit hyperactivity disorder (ADHD) and to examine whether RT variability presented differently across a variety of neuropsychological tasks, was present across the two most common ADHD subtypes, and whether it was affected by reward and event rate (ER) manipulations. Method: Children with ADHD-combined type (n = 51), ADHD-predominantly inattentive type (n = 53), and 47 controls completed five neuropsychological tasks (Choice Discrimination Task, Child Attentional Network Task, Go/No-Go task, Stop Signal Task, and N-back task), each allowing trial-by-trial assessment of RTs. Multiple indicators of RT variability including RT standard deviation, coefficient of variation and ex-Gaussian tau were used. Results: Children with ADHD demonstrated greater RT variability than controls across all five tasks as measured by the ex-Gaussian indicator tau. There were minimal differences in RT variability across the ADHD subtypes. Children with ADHD also had poorer task accuracy than controls across all tasks except the Choice Discrimination task. Although ER and reward manipulations did affect children's RT variability and task accuracy, these manipulations largely did not differentially affect children with ADHD compared to controls. RT variability and task accuracy were highly correlated across tasks. Removing variance attributable to RT variability from task accuracy did not appreciably affect between-groups differences in task accuracy. Conclusions: High RT variability is a ubiquitous and robust phenomenon in children with ADHD. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Processing deficits in Turner's syndrome.

Exp I compared 31 female 11–28 yr old Turner syndrome (TS) Ss and 31 matched controls on a mental rotation task. Although both groups utilized the some rotation strategy, TS Ss were less accurate and slower than controls in the rotational component of the task. Exp II compared 23 TS Ss and 23 matched controls (mean age 15.4 yrs) on a sentence verification task. No differences were observed between the groups in accuracy, strategy, or processing rates, although RTs of the TS group were significantly longer. Exp III studied a set of 12.5-yr-old dizygotic twins, one of whom had TS. Results replicate the findings of Exps I and II. Also discussed are the specific processing deficits in TS and the role of biological factors that may contribute to them. (67 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Slowness and age: Speed-accuracy mechanisms.

Young and older adults' mechanisms of trial-by-trial control of accuracy and choice reaction times (RTs) were compared in 2,000 trials. With equal mean error rates, the older group's correct and error RT were longer, and their within-subject distribution was a linear function of the younger group's. Conditional accuracy functions (CAFs) were very similar in location and shape, with both groups achieving 95% accuracy at the same RT. Combining RT distributions with CAFs showed that the older group did not track their limits as often as the younger group, and they were more careful, having fewer very fast (near random) responses, more average speed responses in long error-free runs, and more slowing following an error. All participants were faster before an error and slower immediately after, but the older participants had coarser RT control. To compensate for this, the older participants produced slower responding to avoid the very fast, high-error part of the CAF. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response–reinforcer associations after caudate-putamen lesions in the rat: Spatial discrimination and overshadowing–potentiation effects in instrumental learning.

Exp I, with 12 male hooded rats, demonstrated that Ss with caudate-putamen lesions exhibited an impairment in the acquisition and reversal of a spatial maze task when compared with unoperated control Ss. Exp II, with 24 Ss, investigated leverpress responding supported by a VI schedule in 3 groups of Ss: a group with caudate-putamen lesions, a group with lesions of the posterior cortex, and an unoperated control group. The presentation of a 0.5-sec, response-contingent light correlated with reinforcement generated an elevated response rate in the 2 operated groups but tended to suppress responding in the control group, perhaps by overshadowing the response–reinforcer relation. Only the group with cortical lesions maintained the elevated rate when the light was uncorrelated with food delivery. Exp III confirmed for these same Ss that caudate-putamen lesions produced a spatial learning deficit. No deficit was observed in the posterior cortex group. It is suggested that caudate-putamen lesions disrupt the mechanism underlying the response–reinforcer association on which spatial maze learning and free operant responding in part depend. (48 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

L'avantage même-main: effet de la préparation motrice ou de la compatibilité indices-réponses?

Studied the goodness-of-fit of 2 explanations of the same-hand advantage (SHA), i.e., faster reaction time (RT) if responses cued before stimulus presentation are from the same hand as opposed to different hands. Ss were 82 university students (aged 20–40 yrs). Exp 1 consisted of a computerized 4-choice reaction task involving variations in (1) the placement of the fingers on the keyboard, (2) duration of the preparation period, and (3) same-hand vs different-hand preparation. RTs under these experimental variations were compared. Exp 2 involved a greater number of trials than Exp 1 and cued responses either visually or by vibration of the appropriate response keys. Duration of the preparation period and same-hand vs different-hand preparation also were varied. RTs under the different experimental conditions were compared. (English abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Visual sampling after lesions of the superior colliculus in rats.

In 2 experiments with 20 male black-hooded rats, Ss with bilateral lesions of the superior colliculus showed significantly poorer relearning of a horizontal/vertical stripe discrimination than control Ss. In Exp I, all Ss showed disruption of performance when a stimulus–response (S–R) separation was introduced by raising the stimuli above the site of responding. However, colliculectomized Ss were much more disturbed by the S–R separation than were control Ss. In Exp II, all Ss showed lower performance levels when conflicting patterns were introduced into the upper portion of the stimulus doors, but this time Ss with collicular lesions were less disturbed than controls. It is suggested (a) that when the stimulus and response sites are discontinuous, rats must make an appropriate orienting response to effectively sample the visual stimuli and (b) that lesions of the superior colliculus alter performance by interfering with this orienting behavior. The impairment in relearning is attributed to the absence of preoperative overtraining on the discrimination task. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learned helplessness and immunization: Sensitivity to response–reinforcer independence in immunized rats.

Exps I and II, with 62 male Holtzman rats, examined the learned helplessness and immunization effects using a test in which appetitive responding was extinguished by delivering noncontingent reinforcers. Contrary to learned helplessness theory, "immunized" Ss showed performance virtually identical to that of Ss exposed only to inescapable shock and different from that of nonshock controls. Exp II suggested that the helplessness effect and the lack of immunization were not due to direct response suppression resulting from shock. In Exp III, in which the immunization effect was assessed in 28 Ss by measuring the acquisition of a response to obtain food when there was a positive response–reinforcer contingency, immunization was observed. Results cannot be explained on the basis of proactive interference and instead suggest that Ss exposed to the immunization procedure acquired an expectancy of response–reinforcer independence during inescapable shock. Thus, immunization effects may reflect the differential expression of expectancies rather than their differential acquisition as learned helplessness theory postulates. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differential effects of voluntary expectancies on reaction times and event-related potentials: Evidence for automatic and controlled expectancies.

Expectancy has been used to explain the effects of stimulus sequences both on reaction times (RTs) and on the P300 component of the human event-related potential. However, there are conflicting views about the control obtainable over these underlying expectancies. The effects of voluntary expectancies for stimulus changes or repetitions in random tone series on RTs and the P300 were compared. Ss responded according to either stimulus identity (Exp 1) or stimulus sequence (Exp 2). In both experiments, RTs were strongly affected by event expectedness. P300 amplitude, on the other hand, was affected (as a trend) only in Exp 2. Results suggest that there are at least 2 types of "expectancy," one that is largely automatic and inflexible, reflected in P300 amplitude, and a second, controlled process that is reflected mainly in RT. The latter type of expectancy appears to affect processing stages beyond stimulus evaluation and classification. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Dynamics of activation in long-term memory: The retrieval of verbal, pictorial, spatial, and color information.

Tested A. Paivio's (1986) dual code theory in 5 experiments with a new paradigm for the FAN effect that enforced genuine memory recall. Ss had to learn associations between concepts and mediators. The FAN of the concepts in relation to the mediators was varied systematically. Response times (RTs) were measured while Ss had to decide whether 2 concepts were linked to each other or not by a common mediator. In Exp 1, the concepts and mediators were words, whereas in the other experiments the concepts were line drawings. Colors served as mediators in Exp 2 and spatial locations served as mediators in Exps 3, 4, and 5. All of the experiments were equivalent with respect to the FAN, the learning procedure, and the retrieval test. In all of the experiments, RT proved to be a linear function of the FAN. These results suggested that the same dynamics hold for all types of information stored in long-term memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Paleostriatal lesions in the pigeon (Columba livia) potentiate classical conditioning: Evidence from fixed-interval responding, free operant go–no-go discrimination, and alternation.

Explored the existence of behavioral deficits in the paleostriatum augmentatum in 4 experiments in which pigeons were given bilateral electrolytic lesions. Exp I, conducted with 16 Ss, investigated the effects of lesions on keypecking for reinforcement on a 1-min FI schedule. The lesions increased total response rates, but response timing was not disrupted in paleostriatal Ss. In Exp II, 17 naive Ss were given VI baseline training and, in contrast to the results of Exp I, paleostriatal lesions did not increase responding. Go–no-go discrimination, which followed baseline training, revealed enhanced positive behavioral contrast in paleostriatal Ss, which was explained in terms of additivity theory. The results of Exps I and II suggest that potentiated classical conditioning occurred in paleostriatal Ss. In Exp III, 16 naive Ss were given spatial alternation training, and performance was temporarily impaired following paleostriatal lesions. The same paleostriatal Ss showed superior differentiation performance in Exp IV with a classical go–no-go alternation procedure (which also suggested potentiated classical conditioning). It is argued that disruption of (irrelevant) response-produced information may account for paleostriatal superiority. (55 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Influence of adult age on primary and secondary memory search.

Conducted 2 experiments with 25 19–29 yr olds, 26 62–85 yr olds, 30 18–32 yr olds, and 30 61–81 yr olds to compare young and elderly adults on the ability to search lists of words stored in primary memory (PM) and in secondary memory (SM). Exp I indicated that age differences in search performance were greatest under SM conditions. Older Ss, unlike the younger ones, appeared biased toward responding that probe items were not members of the memory sets stored in SM. As a result of this apparent bias, older Ss committed a large number of errors on trials in which the probe was a member of the memorized list (i.e., positive probe trials) yet few errors on the trials in which the probe was not a member of the list ( i.e., negative probe trials). The responses of older Ss to negative probe trials were more rapid than were those to positive probe trials. In Exp II, this pattern of responding was examined. It is concluded that age differences were involved in the ability to encode memory sets and transfer them from PM to SM as well as in the ability to retrieve information from SM prior to conducting a memory search. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention and retrieval from long-term memory.

Conducted 9 experiments with 152 female volunteers (mean age 44.4 yrs) to investigate the disrupting effect of a secondary task on retrieval from long-term memory. Exps I–V studied the influence of concurrent card sorting or digit span on free recall or paired-associate learning of word lists. Exp VI explored recall probability using a recognition paradigm in which accuracy and latency could be measured simultaneously. Exp VII explored the latency effect with a semantic memory paradigm, and Exp VIII required Ss to make semantic category judgments while retaining sequences of 6 digits. Exp IX examined the effect of concurrent digital load on the rate of generating items from semantic categories. Overall findings reveal that a demanding concurrent task did not reduce the probability of retrieving an item from semantic or episodic memory. However, concurrent load during learning substantially effected recall performance. A concurrent task during retrieval did not have a clear effect on latency. The contrast between the pattern shown by errors and by that shown by latencies suggests that attempts to estimate the attentional demands of any task should be interpreted with considerable caution when based on a single measure, such as performance errors, performance latency, or a response to a probe RT signal. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of signaling intertrial unconditioned stimuli in autoshaping.

Context–UCS associations have been suggested as the mediator of the response decrement that occurs when extra UCSs are added to the intertrial intervals (ITIs) of a standard Pavlovian conditioning situation. The present autoshaping experiments were concerned with the effect of signaling those extra UCSs, since such signaling might be expected to lessen their ability to condition the context. In Exp I, 16 female Carneaux pigeons were trained in Skinner boxes before receiving pretraining with the CS to be used as the signal of the ITI UCSs. During the main training, Ss were given autoshaping with a keylight CS. Exp II used a tone CS with 31 Ss. Results show that signaling the ITI UCSs did reduce their detrimental effects in responding to the CS. To determine whether that reduction was due to an impact of signaling on the target-CS/UCS association or on performance to the target-CS, Exp III examined responding to differentially trained CSs in a common context, as well as responding to identically trained CSs in differentially trained contexts with 32 Ss. More responding occurred to the CS trained with signaled, as compared with unsignaled, ITI UCSs; further, there was more responding to that CS in the more highly valued context. Results suggest that contextual value does interact with CS–UCS learning and may also affect performance to the CS. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Attention, unpredictability, and reports of physical symptoms: Eliminating the benefits of predictability.

Conducted 3 experiments with 135 undergraduates to investigate the established finding from the unpredictability literature that exposure to unpredictable noise leads to reports of more severe physical symptoms than does exposure to predictable noise. In Exp I, Ss performed a reaction time (RT) task while they listened to loud bursts of either predictable or unpredictable noise. As expected, RTs were slower when the noise was unpredictable than when it was not. This finding suggests that more attention had been directed to the unpredictable than the predictable noise. In Exp II and III, Ss were exposed to either predictable or unpredictable noise and were instructed to attend to the noise or were given no instructions. In both cases, Ss not instructed to attend to the noise reported more severe symptoms when the noise was unpredictable than when it was not, thus replicating the previous finding. Of greater interest, however, was the fact that equating the amount of attention directed to the unpredictable and predictable noise (by asking Ss to attend to the noise) eliminated the apparent benefits of predictability. (32 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Task construction and persistence as means for self-assessment of abilities.

In Exp I, 80 18–22 yr old Israelis performed 2 tasks and received feedback designed to manipulate independently the uncertainty regarding their standing on 2 abilities. Ss were then allowed to construct new tasks by determining the number of items from these ability domains. As predicted, the number of items chosen from each ability domain was directly related to Ss' uncertainty in that ability, so that the self-constructed tasks were predominantly composed of problems assessing the ability of which Ss were least certain. In Exp II, 80 17–28 yr olds worked as much as they wished on a task varying in diagnostic value and received either success or failure trial-by-trial feedback. It was expected that persistence would decrease with task diagnosticity. Results support this prediction and demonstrate that Ss were equally persistent when succeeding and failing. (26 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Contextual cues and release from proactive inhibition in young and old people.

Three experiments examined whether elderly people perform similarly to Korsakoff amnesics on tests of release from proactive inhibition (PI). In Exp I, with 20 18–36 yr old undergraduates, 20 64–77 yr old university alumni, 20 employed 21–43 yr olds, and 21 institutionalized but healthy 71–92 yr olds, only the latter Ss failed to release from PI, like Korsakoff amnesics, whereas all the other groups of Ss showed the normal release from PI. Exp II, with 12 institutionalized 64–90 yr olds and 12 25–47 yr old controls, showed that release from PI could be induced in institutionalized elderly, as in Korsakoff amnesics, by salient environmental cues that coincided with the category shift. Exp III, with 13 67–89 yr old institutionalized Ss and 12 22–42 yr old controls, demonstrated that even in the absence of a category shift, salient environmental cues could lead to smaller, but noticeable, release from PI in institutionalized elderly, but not in young controls. The similarity in performance between the institutionalized elderly and Korsakoff amnesics suggested that it results from a common neurological deficit. (French abstract) (37 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental changes in processing speed: Influence of speed-accuracy regulation.

We investigated the possibility that marked improvements in speed of information processing from early childhood to adulthood reflect improved speed–accuracy monitoring and regulation. Trial-by-trial examination of reaction time (RT) and accuracy transitions during serial choice RT performance revealed developmental changes in accuracy monitoring and speed regulation; these changes corresponded to the most pronounced age-related changes in average RT. For 5-year-olds, poor control over speed of responding, coupled with inconsistent accuracy monitoring, resulted in less orderly trial-to-trial RT transitions and a consequent failure to constrain responses within fast RT bands just safely above overly fast error RT levels. Control over speed of responding was improved by age 7, but inconsistent accuracy monitoring was still a factor. From age 9 up to adulthood, subjects monitored accuracy consistently and showed quite precise control over speed of responding. These developments were associated with a marked improvement in RT constraint within narrow, fast RT bands. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A violation of pure insertion: Mental rotation and choice reaction time.

Six experiments tested the assumption that the mental rotation process is purely inserted into a mirror–normal discrimination task. In Exp 1, Ss took significantly longer to respond to upright characters in blocks containing rotated stimuli than in blocks containing only upright stimuli. Exps 2 and 3 showed that this rotational uncertainty effect was not caused by the need to determine stimulus orientation, and Exp 4 showed that it was independent of the visual quality of the stimulus. Exp 5 showed that the effect was greatly reduced when Ss performed a go–no-go task rather than choice reaction time (RT), and Exp 6 showed that it was independent of the complexity of the response required in the choice task. Results suggest that response selection in a choice RT mirror–normal discrimination task is altered when mental rotation is added, violating the assumption of pure insertion. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The roles of typicality, instance dominance, and category dominance in verifying category membership.

Examined the relationships between category verification reaction time (RT), exemplar typicality, instance dominance, category selection time (an RT measure of category dominance), and 3 production measures of category dominance in 3 experiments with 122 Ss. The category dominance measures were obtained in Exp I for use in 2 nearly identical category verification experiments. In Exp II, the category name was presented 800 msec before the exemplar name. In Exp III, the exemplar name preceded the category name by 800 msec. Multiple regression analyses of the yes and no category verification RTs indicated that category dominance produced large and highly significant effects in all conditions, whereas instance dominance produced marginally significant and selective effects. Typicality had no effect beyond its shared effect with the dominance measures except as a possible suppressor variable. Category selection time was the best predictor, although all of the category dominance measures were better predictors than typicality or instance dominance. It is concluded that typicality may be an inappropriate independent variable for RT tasks studying the memory representation of natural-world knowledge. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)