Effects of information presentation mode on subjects' hypotheses in a probabilistic inference task

The effects of two modes of information-presentation (visual access to an ordered array of cue values vs. no access) on subjects' performance in a two-cue probability learning (MPL) task were investigated.The results showed that the visual access to an ordered array of cue values led to a larger proportion of correct hypotheses and of optimal selection strategies and to a better learning performance. These results were interpreted as supporting the conjecture that the situational variables may affect the subject's hypotheses about the cue-criterion relations. The results were also discussed with respect to their implications for the theory of MPL.     

Novel popout and familiar popout in a brightness discrimination task

A single novel word among several familiarized words may be localized more effectively than the familiarized words (novel popout). Early demonstrations of novel popout attributed the effect to the capture of attentional resources by novel stimuli. Christie and Klein (1995, 1996) argued that differential recollection of novel versus familiar words could alternatively account for the popout effect. In the present experiments, participants judged which of four locations contained a physically brighter word. A bright novel word was localized significantly better than a bright familiar word in one-novel/three-familiar arrays, inconsistent with a retrievability account of novel popout. However, a bright familiar word was also localized better than a bright novel word in three-novel/one-familiar arrays, inconsistent with the mismatch theory proposed by Johnston and Hawley (1994). The results suggest that familiarity and novelty provide a perceptual segregation of the odd item; superior brightness discrimination at that location may be due either to attentional capture or to locational ambiguity within the larger group.     

Effect of task similarity on transfer performance

Transfer of training was studied using a discrete tracking task which involved aiming at targets on a moving paper strip. The effects of target speed, target size, and task demand, (number of targets aimed at in each trial) were examined separately in three experiments. In Experiment 1, a difference in stimulus input (i.e., target speed) produced large differences in task strategy (i.e., speed vs. accuracy bias). No significant transfer was found. A difference in target size (Experiment 2) involves a change in stimulus input, but this did not result in large strategy differences. Significant transfer was found when transferring from large to small targets. In Experiment 3, a variation in task demand produced different task strategies without a change in stimulus input. Significant transfer was found in all groups. The results were discussed in terms of similarity in perceptual elements and task strategy between transfer and training tasks. Greater similarity overall led to greater transfer.     

Effect of different delayed auditory feedback intervals on a music performance task

The effects of 12 different delay intervals were studied in a musical task involving performance on an electronic organ. Disruption was found to occur to a degree comparable to similar studies involving verbal and rhythmic tasks under DAF. Maximal disruption was found with a delay of 0.27 sec, a value rather greater than that typically found to be most disruptive in speech. Three of the 12 Ss showed speeded performance under part of the range of DAF intervals, as compared with performance under immediate feedback; however, their performance also reached a peak of slowing at a delay of about 0.27 sec. No significant differences were found between male and female Ss’ performance. These findings were discussed without the context of control processes operating in music performance, and compared with the possibly analogous mechanisms of speech.     

Demonstrating how unfamiliar faces become familiar using a face matching task

Two experiments examine a novel method of assessing face familiarity that does not require explicit identification of presented faces. Earlier research (Clutterbuck & Johnston, 2002; Young, Hay, McWeeny, Flude, & Ellis, 1985) has shown that different views of the same face can be matched more quickly for familiar than for unfamiliar faces. This study examines whether exposure to previously novel faces allows the speed with which they can be matched to be increased, thus allowing a means of assessing how faces become familiar. In Experiment 1, participants viewed two sets of unfamiliar faces presented for either many, short intervals or for few, long intervals. At test, previously familiar (famous) faces were matched more quickly than novel faces or learned faces. In addition, learned faces seen on many, brief occasions were matched more quickly than the novel faces or faces seen on fewer, longer occasions. However, this was only observed when participants performed “different” decision matches. In Experiment 2, the similarity between face pairs was controlled more strictly. Once again, matches were performed on familiar faces more quickly than on unfamiliar or learned items. However, matches made to learned faces were significantly faster than those made to completely novel faces. This was now observed for both same and different match decisions. The use of this matching task as a means of tracking how unfamiliar faces become familiar is discussed.     

Time-pressure effects on performance in a base-rate task

Researchers assume that time pressure impairs performance in decision tasks by invoking heuristic processes. In the present study, the authors inquired (a) whether it was possible in some cases for time pressure to improve performance or to alter it without impairing it, and (b) whether the heuristic invoked by base-rate neglect under direct experience can be identified. They used a probability-learning design in 2 experiments, and they measured the choice proportions after each of 2 possible cues in each experiment. In 1 comparison, time pressure increased predictions of the more likely outcome, which improved performance. In 2 comparisons, time pressure changed the choice proportions without affecting performance. In a 4th comparison, time pressure hindered performance. The choice proportions were consistent with heuristic processing that is based on cue matching rather than on cue accuracy, base rates, or posterior probabilities.     

Effect of low-frequency random noises on performance of a numeric monitoring task.

Previous findings indicate that continuous low-frequency noises at moderate sound-pressure levels do not produce decrements in vigilance performance. Such noises are commonly found in urban environments, however; and it is important to explore their effects carefully. This study employed 27 human males in a numeric monitoring task to evaluate the effects of low-frequency (11.5 to 350 Hz) noise at moderate sound-pressure levels (80 db). More numeric signals were missed during noise than during control runs. The effect was small but statistically reliable (P smaller than .033), in disagreement with previous research. The possible environmental impact of these findings is discussed.     

Sense mode and coupling in a vigilance task

Usarmymedical Research Laboratory, Fort Knox, Kentucky This investigation examined the performance of 36 Ss on three 90-min vigilance tasks. As time on task increased, there was a significant decrease in number of detections and false responses and a corresponding significant increase in response latency. The consistent rank order relationship between stimulus conditions suggests that there were uniform trends among these conventional response measures. There was a significant decline in sensitivity (d′) lor the closely coupled tasks, regardless of the sense mode involved. However, d′ remained fairly stable for the loosely coupled visual task. The significant increase in criterion values(β) suggest that Ss adopt a more conservative mode of responding with increasing time on task. Further, these data indicate that a lack of control of coupling effects, rather than sense mode specificity, may have confounded the interpretation of prior research on visualand auditory tasks.     

The effect of a prior presentation on temporal judgments in a perceptual identification task

Subjects read aloud words presented once at the rate of one per second. A perceptual identification task, involving 30- or 50-msec presentations, followed. Some of the words presented for identification had been read previously; others were new. After each presentation, in addition to identifying the word, the subjects judged its duration. The data indicate that a single presentation of a word affects its later perception, as revealed by enhanced perceptual identification, longer duration judgments, and better temporal discrimination. A second experiment showed that a single presentation influenced duration judgments even when identification was not required. The final experiment addressed the issue of what is preserved in memory from a prior presentation. The results from the three experiments indicate that duration judgments provide a valuable dependent measure of memory in the perceptual identification task and support the misattribution hypothesis: A prior presentation enhances perceptual identification, and this increase in relative perceptual fluency is incorrectly attributed to a longer presentation duration.     

Order of a 'uniform random' presentation on contextual interference in a serial tracking task

The purpose of the present study was to examine the effect of order of a 'uniform random' presentation on contextual interference in a serial tracking task. Subjects (N=48) were randomly assigned to either a random condition or a blocked condition in the acquisition phase, in which they learned three patterns of serial tracking tasks. Subjects performed retention and transfer trials either in a blocked or a 'uniform random' order. Analysis indicated, in comparisons of performance among conditions, 'uniform random' presentation in the acquisition phase did not improve learning in retention and transfer phases. The results are discussed with regard to both theoretical significance to contextual interference and the nature of 'uniform random' presentation.     

Task self-efficacy and task interest as a function of performance on a gender-neutral task

This study experimentally investigates several hypotheses about the relationships between performance on a gender-neutral task and gender, self-efficacy, performance attributions, and task interest. Ninety-two subjects were randomly assigned to a success or failure condition and attempted to solve a series of easy or difficult anagrams. Results indicated that changes in self-efficacy expectations as a result of task success or failure were in accordance with predictions from self-efficacy theory; 2 × 2 × 4 ANCOVAs, with the pretest as the covariate, were conducted on self-efficacy strength, level, and task interest. Subjects decreased their ratings of self-efficacy and task interest as a result of the failure experience, and the same ratings increased as a result of the success experience. Few gender differences were found, supporting the hypothesis that the sex linkage of the task significantly influences gender differences in self-efficacy. Analyses of global verbal and mathematical ability ratings resulted in the same trends. Finally, women in the success condition were significantly more likely than men in that condition to attribute their performance to luck; women in the failure condition were significantly more likely than men or women in any other group to attribute their failure to their lack of ability. Implications of these results for future research on career self-efficacy were discussed.     

The Attentional Boost Effect: Transient increases in attention to one task enhance performance in a second task

Recent work on event perception suggests that perceptual processing increases when events change. An important question is how such changes influence the way other information is processed, particularly during dual-task performance. In this study, participants monitored a long series of distractor items for an occasional target as they simultaneously encoded unrelated background scenes. The appearance of an occasional target could have two opposite effects on the secondary task: It could draw attention away from the second task, or, as a change in the ongoing event, it could improve secondary task performance. Results were consistent with the second possibility. Memory for scenes presented simultaneously with the targets was better than memory for scenes that preceded or followed the targets. This effect was observed when the primary detection task involved visual feature oddball detection, auditory oddball detection, and visual color-shape conjunction detection. It was eliminated when the detection task was omitted, and when it required an arbitrary response mapping. The appearance of occasional, task-relevant events appears to trigger a temporal orienting response that facilitates processing of concurrently attended information (Attentional Boost Effect).     

Cuing efficiency in a Stroop-like task with visual half-field presentation

Stroop-like stimuli were presented to either the left or the right visual half-field. Subjects responded to the identity of the words above and below (the target dimension), which appeared above or below a reference point (the cuing dimension). Automatic Stroop-like effects were assessed as the difference in reaction times between congruent trials (e.g., above the reference point) and incongruent trials (e.g., above below the reference point) when both trial types were equally frequent. In blocks in which most trials were of one type (e.g., 80% congruent trials), controlled Stroop-like effects could be assessed. Automatic Stroop-like effects remained unchanged under different task manipulations. In contrast, controlled Stroop-like effects were reduced by lowering cue-response compatibility and by increasing the response alternatives from two to four. Thus, similar to other cuing effects, controlled Stroop-like effects are susceptible to manipulations that affect the response-decision stage and appear to involve response-selection processes. The resources supporting these response-selection decisions were not hemisphere-specific, and were sufficiently nonspecific that interference from a memory-load task was found. When resources were scarce, a consistent bias to attend to stimuli presented or responded to on the right was evident.     

Functional visual field in a rapid serial visual presentation task

Dynamic temporal change in the size of functional visual field was measured using a dual task: a peripheral task in which one square in a background pattern of squares was changed in shape to a dot; and a central task involving the rapid serial visual presentation of a sequence of letters (RSVP task). The temporal lag between the occurrences of the dot and the RSVP target was manipulated. University students were asked to detect the dot and to depress a mouse button as quickly as possible while searching for the RSVP target among a sequence of distracter letters. The abrupt change in the shape of a background square in the peripheral task caused a processing deficit in the RSVP task at relative lags from –3 to –1 (255 ms to 85 ms before presentation of the RSVP target), but the encoding and retaining processes involved in identifying the RSVP target did not impair the detection of the peripheral dot. The functional visual field was found to expand while participants were performing the dual task, suggesting that preattentive detection is affected by general attentional activity.     

Recognition in a visuospatial memory task: The effect of presentation

The influence of the mode of presentation (simultaneous vs. sequential) on accuracy and latency of visuospatial recognition was explored in three experiments. In Experiment 1, two groups were administered a visuospatial task in which a number of positions were shown either simultaneously or sequentially (in a random order); memory was tested using a recognition procedure of visuospatial patterns, either identical or different (a single cell displaced). The results showed that (1) performance was higher in the simultaneous than in the sequential presentation, and (2) decision time increased with complexity in the sequential presentation but not in the simultaneous presentation. In Experiment 2, the same task was used in three conditions of presentation, simultaneous, random sequential, and ordered sequential; at test, a single location, rather than a pattern, was presented for recognition. The results showed that (1) performance was higher in the simultaneous and in the ordered sequential presentations than in the random sequential one, and (2) decision time increased with complexity. In Experiment 3, the same task was used in the same three conditions of presentation, simultaneous, random sequential, and ordered sequential; at test either an identical or a “displaced” pattern was presented for recognition. The results showed that (1) performance was equivalent in the three types of presentation, and (2) decision time increased with complexity for “hit” items; different patterns of linear relations were observed for “correct rejections” items. The results are interpreted in terms of the organisation of visuospatial working memory, and three types of encoding—extrafigural spatial encoding, visual pattern encoding, and spatial path encoding—were proposed.