Common region wins the competition between extrinsic grouping cues: Evidence from a task without explicit attention to grouping

The competition between perceptual grouping factors is a relatively ignored topic, especially in the case of extrinsic grouping cues (e.g., common region or connectedness). Recent studies have examined the integration of extrinsic cues using tasks that induce selective attention to groups based on different grouping cues. However, this procedure could generate alternative strategies for task performance, which are non-related to the perceptual grouping operations. In the current work, we used an indirect task, i.e. repetition discrimination task, without explicit attention to grouping cues to further examine the rules that govern dominance between competing extrinsic grouping factors. This procedure allowed us to obtain an unbiased measure of the competition between common region and connectedness cues acting within the same display. The results corroborate previous data showing that grouping by common region dominated the perceived organization of the display, even though the phenomenological strength of the grouping cues was equated for each participant by means of a preliminary scaling task. Our results highlight the relevance of using indirect tasks as an essential tool for the systematic study of the integration of extrinsic grouping cues.     

New indirect measures of “inattentive” visual grouping in a change-detection task

It has often been suggested that Gestalt-like visual grouping processes may operate preattentively, but Mack and Rock (1998) suggested that no visual grouping takes place under “inattention.” We introduced a new method to assess this. While participants performed a demanding change-detection task on a small matrix at fixation, task-irrelevant background elements were arranged by color similarity into columns, rows, or pseudorandomly. Independent of any change in the target matrix, background grouping could also change or remain the same on each trial. This influenced accuracy of change judgments for the central task, even though background grouping or its change usually could not be explicitly reported when probed with surprise questions as in Mack and Rock. This suggests that visual grouping may arise implicitly under inattention and provides a new method for testing the boundaries of this processing. Here we extended the initial result to changes in background grouping remote from the target and to those occurring across an intervening saccade.     

New indirect measures of "inattentive" visual grouping in a change-detection task

It has often been suggested that Gestalt-like visual grouping processes may operate preattentively, but Mack and Rock (1998) suggested that no visual grouping takes place under "inattention." We introduced a new method to assess this. While participants performed a demanding change-detection task on a small matrix at fixation, task-irrelevant background elements were arranged by color sinilarity into columns, rows, or pseudorandomly. Independent of any change in the target matrix, background grouping could also change or remain the same on each trial. This influenced accuracy of change judgments for the central task, even though background grouping or its change usually could not be explicitly reported when probed with surprise questions as in Mack and Rock. This suggests that visual grouping may arise implicitly under inattention and provides a new method for testing the boundaries of this processing. Here we extended the initial result to changes in background grouping remote from the target and to those occurring across an intervening saccade.     

The influence of degree of expertise and objective task complexity on perceived task complexity and performance

Research on expertise has shown that nonexperts may sometimes outperform experts. Some researchers have suggested that superior performance by experts depends on the match between the experts' cognition and the demands of the task. The authors explored this issue using a quasi-experiment set in an organization. They examined how 3 sets of similar tasks that differ in their type of complexity can lead to differences in task perceptions and performance among experts, intermediates, and novices. The results suggest that experts and novices pay attention to different aspects of a task and that this affects both their perceptions of task complexity (i.e., task analyzability and variability) and their performance on the task.     

Perceptual grouping and distance estimates in typical and atypical development: comparing performance across perception, drawing and construction tasks

Perceptual grouping is a pre-attentive process which serves to group local elements into global wholes, based on shared properties. One effect of perceptual grouping is to distort the ability to estimate the distance between two elements. In this study, biases in distance estimates, caused by four types of perceptual grouping, were measured across three tasks, a perception, a drawing and a construction task in both typical development (TD: Experiment 1) and in individuals with Williams syndrome (WS: Experiment 2). In Experiment 1, perceptual grouping distorted distance estimates across all three tasks. Interestingly, the effect of grouping by luminance was in the opposite direction to the effects of the remaining grouping types. We relate this to differences in the ability to inhibit perceptual grouping effects on distance estimates. Additive distorting influences were also observed in the drawing and the construction task, which are explained in terms of the points of reference employed in each task. Experiment 2 demonstrated that the above distortion effects are also observed in WS. Given the known deficit in the ability to use perceptual grouping in WS, this suggests a dissociation between the pre-attentive influence of and the attentive deployment of perceptual grouping in WS. The typical distortion in relation to drawing and construction points towards the presence of some typical location coding strategies in WS. The performance of the WS group differed from the TD participants on two counts. First, the pattern of overall distance estimates (averaged across interior and exterior distances) across the four perceptual grouping types, differed between groups. Second, the distorting influence of perceptual grouping was strongest for grouping by shape similarity in WS, which contrasts to a strength in grouping by proximity observed in the TD participants.     

Sorting food labels and describing properties of categories: stability of results between and within subjects

The purpose of this research is to improve understanding of the consistency of the categorization process in cognitive psychology. To investigate the temporal stability of the categorization process between and within subjects, 100 participants (M = 22.1 yr., SD = 2.1) were required to sort 65 food labels into groups and to explain their grouping. The sorting and property generation of food labels were compared by conducting two sessions (with a 15-day interval) to assess within-subject variability. Two groups of participants were compared to assess between-subjects variability. The results from the sorting task showed excellent stability between and within subjects. Conversely, the property generation task showed high variability. It is concluded that the tasks involved different types of knowledge. The sorting task appeared to generate good agreement and to involve more stable knowledge. The task of producing properties may involve other mechanisms. This paper discusses the results in light of cognitive and pragmatic theories.     

Forecasting outcomes of the World Cup 2006 in football: Performance and confidence of bettors and laypeople

ObjectivesMotivated by a paucity of research on sports forecasting, this paper examines how well individuals with varying degrees of relevant knowledge predict football (soccer) and how much confidence they have in their predictions.Design and procedureThree groups of participants (110 art students, 81 sports students, and 85 bettors) representing three levels of knowledge (poor, moderate, and expert) performed five forecasting tasks with relation to the outcome of the first round of the World Cup 2006. The tasks were assumed to reflect different degrees of complexity. About half of the participants obtained relevant information (world rankings). The participants stated their confidence in connection to conducting those tasks.ResultsWhereas the groups had roughly similar levels of performance in three tasks (i.e., predicting the teams qualifying for the second round as well as two types of match statistics), the knowledgeable and expert participants were better at predicting scores and percentage of ball possession in the matches than the naïve participants. Relatively few participants performed better than the simple rule that followed world rankings. Regardless of task complexity, the knowledgeable and expert participants were found to be significantly more confident about their forecasts than the naïve participants. Access to information had limited influence on forecasting performance and confidence.ConclusionThe present study shows that the forecasting performance of football experts and laypeople varies dependent on task. For easy tasks, they tend to predict equally well, partly because laypeople might use well-adapted heuristics. Once the prediction tasks become more difficult, the experts may take advantage of their domain-specific skills and produce forecasts that excel those of the laypeople.     

Visual recognition of biological motion is impaired in children with autism

Autistic children and typically developing control children were tested on two visual tasks, one involving grouping of small line elements into a global figure and the other involving perception of human activity portrayed in point-light animations. Performance of the two groups was equivalent on the figure task, but autistic children were significantly impaired on the biological motion task. This latter deficit may be related to the impaired social skills characteristic of autism, and we speculate that this deficit may implicate abnormalities in brain areas mediating perception of human movement.     

Grouping of Pupils in Secondary School Classrooms: Possible Links between Pedagogy and Learning

Pupil groupings within classrooms are a constant social pedagogic factor which effect participation and learning. The grouping of pupils provides a dynamic relationship between learning tasks and the classroom context within which learning takes place. This paper explores types of pupil groupings found in secondary school classrooms related to themes of group size and composition, learning task, group interaction and teacher presence. The paper questions how classroom groupings may be related to the circumstances that promote or inhibit school learning. Previous studies concerning classroom grouping in secondary schools have been dominated by ability or attainment level of the child. The approach and review presented in this study advances a new and more extensive understanding of social pedagogic activity within classrooms. Empirically, a novel classroom “mapping” method with follow-up questions for teachers was used to identify within-class grouping characteristics of children aged 12 and 15 years (in school Years 7 and 10), across curriculum subjects (English, mathematics, science and humanities) in secondary schools. Maps were drawn for 250 classrooms and explained by teachers from 47 schools in England. Results identified that a variety of groupings were found in most classes. Use of particular groupings related to phase of lesson and, to some extent, curriculum. The results showed: little pedagogic association with learning task or interaction; teacher presence associated with control of knowledge; and group composition dominated by stereotypical adolescent friendships. Discussion considers the social pedagogic potential of grouping (with regard to relational capital), control of knowledge and social structure of the classroom attributed to the teacher, and patterns of grouping that may be associated with polarisation in the classroom. *Research reported was part of the GRIS (The Nature and Use of Within Class Groupings in Secondary Schools) project funded by the ESRC, grant number R000238172.     

Color categories and color appearance

We examined categorical effects in color appearance in two tasks, which in part differed in the extent to which color naming was explicitly required for the response. In one, we measured the effects of color differences on perceptual grouping for hues that spanned the blue-green boundary, to test whether chromatic differences across the boundary were perceptually exaggerated. This task did not require overt judgments of the perceived colors, and the tendency to group showed only a weak and inconsistent categorical bias. In a second case, we analyzed results from two prior studies of hue scaling of chromatic stimuli (De Valois, De Valois, Switkes, & Mahon, 1997; Malkoc, Kay, & Webster, 2005), to test whether color appearance changed more rapidly around the blue-green boundary. In this task observers directly judge the perceived color of the stimuli and these judgments tended to show much stronger categorical effects. The differences between these tasks could arise either because different signals mediate color grouping and color appearance, or because linguistic categories might differentially intrude on the response to color and/or on the perception of color. Our results suggest that the interaction between language and color processing may be highly dependent on the specific task and cognitive demands and strategies of the observer, and also highlight pronounced individual differences in the tendency to exhibit categorical responses.     

Improved intertask coordination after extensive dual-task practice

This study examines whether an improved intertask coordination skill is acquired during extensive dual-task training and whether it can be transferred to a new dual-task situation. Participants practised a visual–manual task and an auditory–vocal task. These tasks were trained in two groups matched in dual-task performance measures before practice: a single-task practice group and a hybrid practice group (including single-task and dual-task practice). After practice, the single-task practice group was transferred to the same dual-task situation as that for the hybrid practice group (Experiment 1), both groups were transferred to a dual-task situation with a new visual task (Experiment 2), and both groups were transferred to a dual-task situation with a new auditory task matched in task difficulty (Experiment 3). The results show a dual-task performance advantage in the hybrid practice group over the single-task practice group in the practised dual-task situation (Experiment 1), the manipulated visual-task situation (Experiment 2), and the manipulated auditory-task situation (Experiment 3). In all experiments, the dual-task performance advantage was consistently found for the auditory task only. These findings suggest that extended dual-task practice improves the skill to coordinate two tasks, which may be defined as an accelerated switching operation between both tasks. This skill is relatively robust against changes of the component visual and auditory tasks. We discuss how the finding of task coordination could be integrated in present models of dual-task research.     

Improved intertask coordination after extensive dual-task practice

This study examines whether an improved intertask coordination skill is acquired during extensive dual-task training and whether it can be transferred to a new dual-task situation. Participants practised a visual-manual task and an auditory-vocal task. These tasks were trained in two groups matched in dual-task performance measures before practice: a single-task practice group and a hybrid practice group (including single-task and dual-task practice). After practice, the single-task practice group was transferred to the same dual-task situation as that for the hybrid practice group (Experiment 1), both groups were transferred to a dual-task situation with a new visual task (Experiment 2), and both groups were transferred to a dual-task situation with a new auditory task matched in task difficulty (Experiment 3). The results show a dual-task performance advantage in the hybrid practice group over the single-task practice group in the practised dual-task situation (Experiment 1), the manipulated visual-task situation (Experiment 2), and the manipulated auditory-task situation (Experiment 3). In all experiments, the dual-task performance advantage was consistently found for the auditory task only. These findings suggest that extended dual-task practice improves the skill to coordinate two tasks, which may be defined as an accelerated switching operation between both tasks. This skill is relatively robust against changes of the component visual and auditory tasks. We discuss how the finding of task coordination could be integrated in present models of dual-task research.     

Task bias and the accuracy of judgment: Setting a baseline for expected group performance

When a judgment task evokes unbiased estimates (i.e. the errors in individual judgments are distributed randomly around the true value), mathematical aggregation of individual estimates, even by a simple arithmetic mean, often will outperform all group members. However, when a task evokes biased estimates, mathematical aggregation does not perform so well. In this study, simulated data were accumulated to specify the expected' accuracy of mathematical aggregation relative to the accuracy of observed judgment of individual group members under varying conditions of task bias. Three types of judgment tasks were employed: (1) single-estimate, holistic tasks, (2) multiple-estimate, ranking tasks, and (3) multi-cue, decomposed tasks. Findings indicated across all task types that a large percentage of judgment-making group estimates formed strictly by computing the arithmetic mean of individual estimates performed better than their most capable members when a judgment task evoked little or no bias, a result particularly pronounced for ranking tasks. When the task was more greatly bias-evoking, a large percentage of parallel groups performed more poorly than average (or median) members, again a pattern more starkly evident for ranking tasks. These results suggest that the extent to which a judgment task evokes bias in a population of prospective group members is an important explanatory variable deserving much greater attention in the study of group performance. For example, an assertion about the efficacy of a particular group intervention based on a reliable demonstration of group performance as accurate as the most capable members may be unfounded when a task evokes no bias, since the baseline standard under such conditions should be much higher. By selecting tasks and populations that jointly produced highly biased estimates, researchers can lower the performance floor enough to detect (with reasonably small samples of groups) experimental effects should they occur.     

Cognitive task transformations

The difficulty facing an agent performing a familiar task is one of satisfactory performance rather than one of figuring out how the task is to be performed. In this paper I describe and exemplify a number of principal ways in which the physical form of tools and working environments can reduce the cognitive burden of performing routine tasks. Starting from the commonly held assumption that tools transform the structure of the tasks in which they figure, I explore some basic ways in which tools can reshape tasks to circumvent excessive demands on attention, working memory and motor control, and the need to perform the kinds of cognitive operations at which we lack proficiency. The principal task transformations that are identified include: removing superfluous actions; delegating problematic parts of a task to other people or artefacts; substituting less demanding parts of a task for parts that are cognitively difficult; rearranging a task to avoid conflict between actions; and increasing the tolerance of a task environment to sub-optimal task performance. For each transformation an account is given of the change to the task from the perspective of an agent and how this improves the cognitive congeniality of the task. For each transformation I also give an example drawn from the everyday experience of the reader of a particular tool that may be said to bring about or facilitate the transformation in question, and explain in what way the tool is able to achieve the transformation whilst still ensuring that task demands are met.     

Task preparation based on precues versus memory: Precues lead to superior performance with two tasks but not with four tasks

There is considerable evidence that task switching proceeds more efficiently with preparation based on explicit precues than on the basis of a learned sequence of tasks. However, this evidence stems almost exclusively from experiments in which participants switched between only two tasks. In two experiments stronger preparation effects with explicit precues compared to memory-based preparation was replicated with two tasks. With four tasks, however, preparation based on memory was at least as efficient as preparation based on precues. A third experiment ruled out the possibility that this latter finding was due to increased difficulty of cue processing with two-dimensional cues. These findings question the generalisability of observations regarding preparation effects that are based on two-task situations. It is suggested that one crucial factor regarding the relative efficiency of precue-based and memory-based preparation pertains to the fact that with two tasks, the relevant task can be determined by knowing only the previous task and whether a switch is required or not. This is not possible with four tasks that require a more elaborated task representation at the outset, which in turn may be more apt to support memory-based preparation.     

Comparison of patients with Parkinson's disease or cerebellar lesions in the production of periodic movements involving event-based or emergent timing

We have hypothesized a distinction between the processes required to control the timing of different classes of periodic movements. In one class, salient events mark successive cycles. For these movements, we hypothesize that the temporal goal is a requisite component of the task representation, what we refer to as event-based timing. In the other class, the successive cycles are produced continuously. For these movements, alternative control strategies can optimize performance, allowing timing to be emergent. In a previous study, patients with cerebellar lesions were found to be selectively impaired on event-based timing tasks; they were unimpaired on a continuously produced task. In the present study, patients with Parkinson's disease were tested on repetitive movement tasks in which timing was either event-based or emergent. Temporal variability on either type of task did not differ between on- and off-medication sessions for the Parkinson's patients nor did patient performance differ from that of controls. These results suggest that the basal ganglia play a minimal role in movement timing and that impairments on event-based timing tasks are specific to cerebellar damage.     

The effect of correlated linguistic dimensions on speeded classification of visually presented trigrams

The influence of two types of linguistic dimensions, word-nonword and consonant pronunciation, on classification speed of trigrams in card-sorting tasks of two levels of complexity was examined. In complex grouping tasks, which required the evaluation of more than one letter to classify each stimulus, sorting times were faster when the linguistic dimension was correlated with, rather than orthogonal to, the response categories. For tasks in which each stimulus could be classified on the basis of a single letter, no effect of the correlated vs orthogonal linguistic dimension was observed, even when performance was degraded by visual noise. These results provide further evidence that, while linguistic properties of visual stimuli may influence classification time in complex tasks, they are of little importance in the performance of tasks only requiring the discriminalion of a single visual feature.     

Visual attention and perceptual grouping.

Perceptual organization is thought to involve an analysis of both textural discontinuities and perceptual grouping. In earlier work, we found that textural discontinuities were detected normally even when visual attention was engaged elsewhere. Here we report how perceptual grouping is affected when visual attention is engaged by a concurrent visual task. To elicit perceptual grouping, we used the Gestalt demonstrations of grouping on the basis of proximity and of similarity. Four tasks were investigated, some requiring the observer to discriminate between horizontal and vertical grouping, and some requiring the observer to merely detect the presence or absence of grouping. Visual attention was engaged at the center of the display by a form identification task. The detection of a textural discontinuity served as a control task. Concurrent form identification conflicted with all four grouping tasks, resulting in a significant reduction of grouping performance in each case. No performance reduction was observed when either form identification or grouping discrimination was combined with the detection of a textural discontinuity. These results suggest that perceptual grouping and form identification compete for visual attention, whereas the detection of a textural discontinuity does not.     

The use of visual and name codes in scanning and classifying colors

The effect of incongruent color words on speed of classifying ink colors was measured in visual scanning tasks and in card sorting tasks. In both cases, little or no interference effects were noted when the classification allowed focusing on a single ink color or a set of highly similar colors (adjacent hues). Substantial interference occurred when the task required grouping of three dissimilar colors (nonadjacent hues). These findings suggest that the relative efficiency of name and visual codes in making perceptual classifications is largely dependent upon the memory requirements imposed by the task.     

Measuring Creativity with Planned Missing Data

This paper introduces a method for the assessment of creativity that relies on creativity tasks, a subjective evaluation procedure, and a planned missing data design that offers a drastic reduction in the overall implementation costs (administration time and scoring procedure). This method was tested on a sample of 149 people, using three creativity tasks as a basis. Participants were instructed to produce several ideas in each task and then to select what they considered to be their best two ideas (i.e., “Top 2” procedure; Silvia, Winterstein, Willse, Barona, et al., Psychology of Aesthetics, Creativity, and the Arts, 2 , 2008 and 68). These ideas were then evaluated by a panel of peers and experts. Creativity ratings were analyzed with structural equations; measurement models were estimated for each task and correlations between factor-scores across the three tasks were investigated. Further insights regarding validity are provided through systematic investigation of the relationship between fluency scores, creativity ratings, intelligence tasks, self-reported idea generation abilities, and creative activities and achievements. Overall, the results support the viability of this new approach, providing evidence of convergent and discriminant validity. They are discussed in relation to past research and avenues for further extension are proposed.