Identifying the processes underpinning anticipation and decision-making in a dynamic time-constrained task

A novel, representative task was used to examine skill-based differences in the perceptual and cognitive processes underlying performance on a dynamic, externally paced task. Skilled and less skilled soccer players were required to move and interact with life-size, action sequences involving 11 versus 11 soccer situations filmed from the perspective of a central defender in soccer. The ability of participants to anticipate the intentions of their opponents and to make decisions about how they should respond was measured across two separate experiments. In Experiment 1, visual search behaviors were examined using an eye-movement registration system. In Experiment 2, retrospective verbal reports of thinking were gathered from a new sample of skilled and less skilled participants. Skilled participants were more accurate than less skilled participants at anticipating the intentions of opponents and in deciding on an appropriate course of action. The skilled players employed a search strategy involving more fixations of shorter duration in a different sequential order and toward more disparate and informative locations in the display when compared with the less skilled counterparts. The skilled players generated a greater number of verbal report statements with a higher proportion of evaluation, prediction, and planning statements than the less skilled players, suggesting they employed more complex domain-specific memory representations to solve the task. Theoretical, methodological, and practical implications are discussed.     

Knowledge structures of expert-novice gymnasts

Differences in eye movements, problem solving, and verbalization were found for three groups of female gymnasts (N=30) differentiated by skill level (elite, intermediate, novice). In the first study, eye fixations to body parts were recorded during slide presentations of six gymnastic sequences. In a second study, time and error scores were recorded in a problem solving task requiring the resequencing of photographs derived from the sequences used in the eye movement study. In the third study, verbal reports identified the photograph in each sequence and body part thought most important to a successful performance. Consistent differences between groups were recorded in fixations to body parts, time and error scores, and verbal reports; relationships between eye movement and time and error scores, and eye movements and verbal reports were also determined. All three studies supported the general hypotheses that gymnasts with different skill levels are attuned to different type of gymnastic information. These differences are discussed within the context of a knowledge structure of gymnastics, which is defined as an internal representation for a physical skill that is developed in concert with the gymnast's motor system. It is suggested that gymnasts, depending upon skill level, are drawn to perceive certain types of gymnastic information while being oblivious to other equally available types of information. Attunement to gymnastic information appears to be linked up to physical skill level in ways not yet understood.     

Do procedures for verbal reporting of thinking have to be reactive? A meta-analysis and recommendations for best reporting methods

Since its establishment, psychology has struggled to find valid methods for studying thoughts and subjective experiences. Thirty years ago, Ericsson and Simon (1980) proposed that participants can give concurrent verbal expression to their thoughts (think aloud) while completing tasks without changing objectively measurable performance (accuracy). In contrast, directed requests for concurrent verbal reports, such as explanations or directions to describe particular kinds of information, were predicted to change thought processes as a consequence of the need to generate this information, thus altering performance. By comparing performance of concurrent verbal reporting conditions with their matching silent control condition, Ericsson and Simon found several studies demonstrating that directed verbalization was associated with changes in performance. In contrast, the lack of effects of thinking aloud was merely suggested by a handful of experimental studies. In this article, Ericsson and Simon's model is tested by a meta-analysis of 94 studies comparing performance while giving concurrent verbalizations to a matching condition without verbalization. Findings based on nearly 3,500 participants show that the "think-aloud" effect size is indistinguishable from zero (r = -.03) and that this procedure remains nonreactive even after statistically controlling additional factors such as task type (primarily visual or nonvisual). In contrast, procedures that entail describing or explaining thoughts and actions are significantly reactive, leading to higher performance than silent control conditions. All verbal reporting procedures tend to increase times to complete tasks. These results suggest that think-aloud should be distinguished from other methods in future studies. Theoretical and practical implications are discussed.     

Verbal overshadowing of visual memories: some things are better left unsaid

It is widely believed that verbal processing generally improves memory performance. However, in a series of six experiments, verbalizing the appearance of previously seen visual stimuli impaired subsequent recognition performance. In Experiment 1, subjects viewed a videotape including a salient individual. Later, some subjects described the individual's face. Subjects who verbalized the face performed less well on a subsequent recognition test than control subjects who did not engage in memory verbalization. The results of Experiment 2 replicated those of Experiment 1 and further clarified the effect of memory verbalization by demonstrating that visualization does not impair face recognition. In Experiments 3 and 4 we explored the hypothesis that memory verbalization impairs memory for stimuli that are difficult to put into words. In Experiment 3 memory impairment followed the verbalization of a different visual stimulus: color. In Experiment 4 marginal memory improvement followed the verbalization of a verbal stimulus: a brief spoken statement. In Experiments 5 and 6 the source of verbally induced memory impairment was explored. The results of Experiment 5 suggested that the impairment does not reflect a temporary verbal set, but rather indicates relatively long-lasting memory interference. Finally, Experiment 6 demonstrated that limiting subjects' time to make recognition decisions alleviates the impairment, suggesting that memory verbalization overshadows but does not eradicate the original visual memory. This collection of results is consistent with a recording interference hypothesis: verbalizing a visual memory may produce a verbally biased memory representation that can interfere with the application of the original visual memory.     

Automatic guidance of visual attention from verbal working memory

Previous studies have shown that visual attention can be captured by stimuli matching the contents of working memory (WM). Here, the authors assessed the nature of the representation that mediates the guidance of visual attention from WM. Observers were presented with either verbal or visual primes (to hold in memory, Experiment 1; to verbalize, Experiment 2; or merely to attend, Experiment 3) and subsequently were required to search for a target among different distractors, each embedded within a colored shape. In half of the trials, an object in the search array matched the prime, but this object never contained the target. Despite this, search was impaired relative to a neutral baseline in which the prime and search displays did not match. An interesting finding is that verbal primes were effective in generating the effects, and verbalization of visual primes elicited similar effects to those elicited when primes were held in WM. However, the effects were absent when primes were only attended. The data suggest that there is automatic encoding into WM when items are verbalized and that verbal as well as visual WM can guide visual attention.     

Identifying Representational Competence With Multi-Representational Displays

Increasingly, multi-representational educational technologies are being deployed in science classrooms to support science learning and the development of representational competence. Several studies have indicated that students experience significant challenges working with these multi-representational displays and prefer to use only one representation while problem solving. Here, we examine the use of one such display, a multi-representational molecular mechanics animation, by organic chemistry undergraduates in a problem-solving interview. Using both protocol analysis and eye fixation data, our analysis indicates that students rely mainly on two visual–spatial representations in the display and do not make use of two accompanying mathematical representations. Moreover, we explore how eye fixation data complement verbal protocols by providing information about how students allocate their attention to different locations of a multi-representational display with and without concurrent verbal utterances. Our analysis indicates that verbal protocols and eye movement data are highly correlated, suggesting that eye fixations and verbalizations reflect similar cognitive processes in such studies.     

Covert shifts of attention can account for the functional role of “eye movements to nothing”

When trying to remember verbal information from memory, people look at spatial locations that have been associated with visual stimuli during encoding, even when the visual stimuli are no longer present. It has been shown that such “eye movements to nothing” can influence retrieval performance for verbal information, but the mechanism underlying this functional relationship is unclear. More precisely, covert in comparison to overt shifts of attention could be sufficient to elicit the observed differences in retrieval performance. To test if covert shifts of attention explain the functional role of the looking-at-nothing phenomenon, we asked participants to remember verbal information that had been associated with a spatial location during an encoding phase. Additionally, during the retrieval phase, all participants solved an unrelated visual tracking task that appeared in either an associated (congruent) or an incongruent spatial location. Half the participants were instructed to look at the tracking task, half to shift their attention covertly (while keeping the eyes fixed). In two experiments, we found that memory retrieval depended on the location to which participants shifted their attention covertly. Thus, covert shifts of attention seem to be sufficient to cause differences in retrieval performance. The results extend the literature on the relationship between visuospatial attention, eye movements, and verbal memory retrieval and provide deep insights into the nature of the looking-at-nothing phenomenon.     

Capturing and testing perceptual-cognitive expertise: A comparison of stationary and movement response methods

Numerous methods have been used to study expertise and performance. In the present article, we compare the cognitive thought processes of skilled soccer players when responding to film-based simulations of defensive situations involving two different experimental conditions. Participants either remained stationary in a seated position (n = 10) or were allowed to move (n = 10) in response to life-size film sequences of 11 versus 11 open-play soccer situations viewed from a player’s perspective. Response accuracy and retrospective verbal reports of thinking were collected across the two task conditions. In the movement-based response group, participants generated a greater number of verbal report statements, including a higher proportion of evaluation, prediction, and action planning statements, than did participants in the stationary group. Findings suggest that the processing strategies employed during performance differ depending on the nature of the response required of participants. Implications for behavioral methods and experimental design are discussed.     

Scrambled eyes? Disrupting scene structure impedes focal processing and increases bottom-up guidance

Previous research has demonstrated that search and memory for items within natural scenes can be disrupted by "scrambling" the images. In the present study, we asked how disrupting the structure of a scene through scrambling might affect the control of eye fixations in either a search task (Experiment 1) or a memory task (Experiment 2). We found that the search decrement in scrambled scenes was associated with poorer guidance of the eyes to the target. Across both tasks, scrambling led to shorter fixations and longer saccades, and more distributed, less selective overt attention, perhaps corresponding to an ambient mode of processing. These results confirm that scene structure has widespread effects on the guidance of eye movements in scenes. Furthermore, the results demonstrate the trade-off between scene structure and visual saliency, with saliency having more of an effect on eye guidance in scrambled scenes.     

Visual scanning with or without spatial uncertainty and divided and selective attention.

An experiment was conducted to address the relation between theories of selective attention and theories of divided attention by examining the pattern of task interference between visual scanning as a sequential and selective attention process and other concurrent spatial or verbal processing tasks. A distinction is proposed between visual scanning with or without spatial uncertainty regarding their possible differential effects on interference with other concurrent processes. The experiment required the subjects to perform a primary tracking task, which was concurrently performed with a secondary spatial or verbal decision task. The relevant information that was needed to perform the decision tasks was displayed with or without spatial uncertainty. The results provide evidence that visual scanning as a spatial exploratory activity produces greater task interference with concurrent spatial tasks than with verbal tasks. Furthermore, spatial uncertainty in scanning is identified to be the crucial factor in producing this differential effect.     

Methodological issues in judgment and decision-making research: Concurrent verbal protocol validity and simultaneous traces of process

This paper examines two dimensions of concurrent verbal protocol validity. First, whether verbalization affects process and outcome (reactivity) was examined by comparing concurrent verbal protocol traces with those from a computer search process tracing method, the latter being a complete trace of information acquisition from experimental materials. Earlier findings that verbalization affects time were confirmed. However, verbalization did not affect amount and pattern of acquisition or accuracy of judgments. Second, whether concurrent verbal protocols are complete was examined by comparing concurrent verbal protocol and computer traces that were simultaneously obtained in a treatment in which subjects verbalized as they acquired information from the computer. The verbal traces less completely captured information acquisition behavior than computer search. This suggests that, although concurrent verbal protocols provide greater insight into decision behavior than computer search, the latter is a more reliable information-acquisition trace. Thus, if information acquisition is of primary interest and if computer search activities can be naturally integrated into performing the primary task, computer search is preferred to concurrent verbal protocols. However, if information use or retrieval from long-term memory is of primary interest, concurrent verbal protocols are preferred to computer search. Finally, this paper examined whether the simultaneous use of concurrent verbal protocols and computer search provides traces of information acquisition and use that are as complete as when each method is independently applied. Although computer search tended to limit subjects verbalizations of evaluative operators, this effect may be eliminated by practice on the computer prior to collecting data.     

Temporal characteristics of overt attentional behavior during category learning

Many theories of category learning incorporate mechanisms for selective attention, typically implemented as attention weights that change on a trial-by-trial basis. This is because there is relatively little data on within-trial changes in attention. We used eye tracking and mouse tracking as fine-grained measures of attention in three complex visual categorization tasks to investigate temporal patterns in overt attentional behavior within individual categorization decisions. In Experiments 1 and 2, we recorded participants’ eye movements while they performed three different categorization tasks. We extended previous research by demonstrating that not only are participants less likely to fixate irrelevant features, but also, when they do, these fixations are shorter than fixations to relevant features. We also found that participants’ fixation patterns show increasingly consistent temporal patterns. Participants were faster, although no more accurate, when their fixation sequences followed a consistent temporal structure. In Experiment 3, we replicated these findings in a task where participants used mouse movements to uncover features. Overall, we showed that there are important temporal regularities in information sampling during category learning that cannot be accounted for by existing models. These can be used to supplement extant models for richer predictions of how information is attended to during the buildup to a categorization decision.     

A multidimensional approach to skilled perception and performance in sport

Three experiments examined the relative importance of attributes determined largely by the efficiency of the visual/central nervous system versus cognitive domain‐specific skills, in the determination of expertise in soccer. In Experiment 1, expert and intermediate soccer players were assessed on various non‐specific abilities including: processing (simple reaction time, peripheral reaction time, visual correction time), optometric (static, dynamic and mesopic acuity), and perimetric parameters (horizontal and vertical peripheral range). In Experiment 2, domain‐specific variables were assessed including complex decision speed and accuracy, number of visual fixations, fixation duration, and fixation location in solving game problems. Stimuli were initially presented by slides (Experiment 2) and later by 16 mm film (Experiment 3). Eye movements were recorded and analysed. A stepwise discriminant analysis of both non‐specific abilities and soccer‐specific skills revealed an average squared canonical correlation=0.84, with the significant step variables all being domain‐specific skills. Copyright © 1999 John Wiley & Sons, Ltd.     

局部注意干扰效应中的眼动特征

采用眼动追踪范式,本研究通过两个实验探讨局部注意干扰效应（LAI）的注意分配特点和机制。实验一采用搜索时间有限的范式,目标呈现70毫秒后消失,在行为和眼动指标上均发现LAI效应：当两个目标距离较近时,反应时增加,正确率降低,总注视时长增长、注视点增加和眼跳速度加快。实验二增加目标呈现时间至1500毫秒以鼓励搜索,产生了比实验一更强烈的LAI效应,且眼跳速度的模式也有不同,说明增加搜索时间并不利于减轻LAI,从而推断LAI的竞争发生在判断阶段,而非搜索和识别目标阶段。     

Olfactory working memory: exploring the differences in n-back memory for high and low verbalisable odorants

ABSTRACT

We describe four experiments each examining n-back performance for high and low verbalisable odorants. Participants were presented with a sequence of odorants and were required to state if the current odorant was the same or different to the odorant presented two items earlier. Experiment 1 reported superior performance for high, relative to low, verbalisable odorants and was evident despite above-chance memory performance for the low verbalisable odorants. Experiment 2 showed that such superiority persisted with a concurrent articulation condition, suggesting that the memory benefit was not a consequence of verbal recording and rehearsal. Experiment 3 employed metacognitive judgments and showed that correct 2-back responses for high verbalisable odorants received more recollection responses compared to low verbalisable odorants. Experiment 4 compared n-back performance across different stimulus types and showed that, for high verbalisable odorants, performance correlated with both letters and abstract shapes, but such correlations were absent for low verbalisable odorants. Taken together, these findings show differences in n-back performance between high and low verbalisable odorants, and show that high verbalisable odorants exhibit performance similarities with both verbal and visual stimuli. We further argue that n-back performance for low verbalisable odorants operates differently to that of high verbalisable odorants.     

Remembering environmental sounds: The role of verbalization at input

Two experiments investigated the role of verbalization in memory for environmental sounds. Experiment i extended earlier research (Bower & Holyoak, 1973) showing that sound recognition is highly dependent upon consistent verbal interpretation at input and test. While such a finding implies an important role for verbalization, Experiment 2 suggested that verbalization is not the only efficacious strategy for encoding environmental sounds. Recognition after presentation of sounds was shown to differ qualitatively from recognition after presentation of sounds accompanied with interpretative verbal labels and from recognition after presentation of verbal labels alone. The results also suggest that encoding physical information about sounds is of greater importance for sound recognition than for verbal free recall, and that verbalization is of greater importance for free recall than for recognition. Several alternative frameworks for the results are presented, and separate retrieval and discrimination processes in recognition are proposed.     

Measuring the effect of multiple eye fixations on memory for visual attributes.

Because of limited peripheral vision, many visual tasks depend on multiple eye fixations. Good performance in such tasks demonstrates that some memory must survive from one fixation to the next. One factor that must influence performance is the degree to which multiple eye fixations interfere with the critical memories. In the present study, the amount of interference was measured by comparing visual discriminations based on multiple fixations to visual discriminations based on a single fixation. The procedure resembled partial report, but used a discrimination measure. In the prototype study, two lines were presented, followed by a single line and a cue. The cue pointed toward one of the positions of the first two lines. Observers were required to judge if the single line in the second display was longer or shorter than the cued line of the first display. These judgments were used to estimate a length threshold. The critical manipulation was to instruct observers either to maintain fixation between the lines of the first display or to fixate each line in sequence. The results showed an advantage for multiple fixations despite the intervening eye movements. In fact, thresholds for the multiple-fixation condition were nearly as good as those in a control condition where the lines were foveally viewed without eye movements. Thus, eye movements had little or no interfering effect in this task. Additional studies generalized the procedure and the stimuli. In conclusion, information about a variety of size and shape attributes was remembered with essentially no interference across eye fixations.     

Covert visual attention and extrafoveal information use during object identification

Three experiments are reported that examined the relationship between covert visual attention and a viewer's ability to use extrafoveal visual information during object identification. Subjects looked at arrays of four objects while their eye movements were recorded. Their task was to identify the objects in the array for an immediate probe memory test. During viewing, the number and location of objects visible during given fixations were manipulated. In Experiments 1 and 2, we found that multiple extrafoveal previews of an object did not afford any more benefit than a single extrafoveal preview, as assessed by means of time of fixation on the objects. In Experiment 3, we found evidence for a model in which extrafoveal information acquired during a fixation derives primarily from the location toward which the eyes will move next. The results are discussed in terms of their implications for the relationship between covert visual attention and extrafoveal information use, and a sequential attention model is proposed.