Selective attention and target search with brief visual displays

In a series of four experiments, subjects were presented with eight item arrays tachistoscopically. In two tasks, the subject was required to recall a digit presented among seven letters or a letter among seven digits. The remaining tasks required the subject to detect the presence of a specific letter either in the context of seven random letters or seven digits. An examination of the effects of a masking stimulus for various target positions suggested that subjects could attend selectively when the target was a different category than its context but had to process the entire array when the target was the same category as the context. The effects of selective attention and masking are explained in terms of parallel and sequential identification processes.     

Shared attention in pigeons

Two pigeons performed a three-key matching-to-sample task. The comparison (side key) stimuli were either solid colors or white lines. The sample (center key) stimuli were either compounds (white lines on colored grounds) or elements (white lines on black grounds on some trials, and solid colors on other trials). Sample stimuli were presented for nine sample stimulus durations ranging between 0.04 and 5.00 sec. Within each daily session, both compound and element samples were presented at each sample duration in a random sequence. Compound samples controlled matching responses less effectively than did element samples at all sample stimulus durations.     

Visual search asymmetry in pigeons

Pigeons received an odd-item search task that involved an array of 12 patterns containing 11 similar distractors and a single target. Pecks to the target resulted in the delivery of food. Accuracy was greater on trials when a distinctive feature was located in the target but not in the distractors, rather than when the feature was in the distractors but not in the target. This search asymmetry was influenced by the similarity of the target to the distractors. The results are similar to those obtained with humans.     

Feature-based search asymmetries in pigeons and humans

Pigeon and human subjects searched for one target item amidst a number of identical distractors. Simple line forms were used. The target differed from the distractors only in terms of the presence or absence of a feature (a line or a gap); in some experimental series, the feature was present in the target; in others, the feature was in the distractors. The pigeons pecked at the target; the human subjects either reported the presence of the target or pointed to it with a light pen. The time between display onset and this response was recorded. Varied across experimental conditions were the number of distractors in the display, the nature of the stimulus forms, and certain procedural parameters; five conditions were run with pigeons and three with humans. Under all test conditions, the results from the human subjects replicated the previously reported search-asymmetry effect. That is, search speed was greater and decreased less with display size when the target bore the feature (line or gap) than when the distractors bore the feature; both yes/no and localization-response conditions yielded this effect. However, pigeons failed to show search asymmetry; neither line nor gap in a target facilitated search. The results suggest that early visual processing differs for pigeons and humans, that pigeon features differ from human features, or that search asymmetry was eliminated by the long practice given the pigeons.     

Attentional priming and visual search in pigeons

Advance information about a target's identity improved visual search efficiency in pigeons. Experiments 1 and 2 compared information supplied by visual cues with information supplied by trial sequences. Reaction times (RTs) were lower when visual cues signaled a single target rather than two. RTs were (Experiment 1) or accuracy improved (Experiment 2) when a sequence of trials presented a single target rather than a mixture of 2. Experiments 3, 4, and 5 considered the selectivity of visual priming by introducing probe trials that reversed the usual cue-target relationship. RT was higher following such miscues than following the usual 1- or 2- target cuing relationships (Experiment 3); the miscuing effect persisted over variations in the target's concealment (Experiments 4 and 5), but did not occur when the target was presented alone (Experiment 4). The findings indicate that priming modifies an attentional mechanism and suggest that this effect accounts for search images.     

Selective attention and relevance-irrelevance in recall

Abstract.— Recall of relevant and irrelevant items was examined under different types of set, where selection was procured either by a figural or a cognitive attribute of the items. Letters and digits were differentiated by their colour or position (S-set), or by their mutual class (R-set). Recall of irrelevant items proved consistently poorer with selection based on S-set than on R-set. the effect beeing enhanced, the greater the number of items involved. Response latency increased with number of items, being greatest under R-set. The differentiation between relevant and irrelevant categories thus appeared more effective with selection procured by figural attributes, which suggests different levels of information processing of these categories under the two types of set.     

Selective attention in obsessive-compulsive disorder

Recent information-processing studies have suggested that a selective attention deficit may be involved in the symptomatology of obsessive-compulsive disorder (OCD). In this study, individuals diagnosed with OCD were distinguished from those with panic disorder and from control participants by their relatively poorer performance on a series of psychometric tasks of selective attention. These results are interpreted as supporting the hypothesis of a diminished ability of people with OCD to selectively ignore competing external (sensory) and internal (cognitive) stimuli, especially intrusive thoughts.     

Odd-item search in pigeons: display size and transfer effects

Pigeons searched arrays of small forms displayed on computer monitors. On each trial, a single target form appeared together with two or more identical distractor forms. A set of six different forms was used in each of three experiments. All possible combinations of these forms, paired as target and distractor, appeared in each experimental session. Both the accuracy and speed of search increased with the number of distractors displayed. When both targets and distractors were new, accuracy was above chance only for the large (24 item) display, where transfer was highly significant. The experiments do not support the attribution to pigeons of a general "oddity concept." Rather, the results suggest that odd-item performance depends in part on a perceptual isolation of the target and in part on familiarity with target-distractor combinations.     

Discrimination of contour-deleted images by pigeons.

Three experiments attempted to determine which properties of pictorial representations of objects control their discrimination by pigeons. A particular focus was whether the representation mediating such discriminations could be described by the simple viewpoint-invariant primitive volumes of Biederman's (1987) recognition-by-components theory of object recognition or by Cerella's (1990) particulate features. In all 3 experiments, pigeons were first trained to discriminate drawings of 4 stimulus objects with half of the contour deleted but with the component geons postulated by Biederman's theory recoverable. Discrimination accuracy was then compared for test items containing the original particulate features, affording the retrieval of the original component geons, or having neither of these properties of the training stimuli. Although response accuracy was significantly greater when the component geons of the original objects were retrievable, measurable control over recognition by the particulate features of the objects and by their specific locations was also found. The results are consistent with the idea of component geon recognition as one of the important factors in object discrimination.     

Selective attention and visual search: revision of an allocation model and application to age differences.

The present experiments examined a revised version of the Eriksen and Yeh model of attentional allocation during visual search. The results confirmed the assumption of the model that performance represents a weighted combination of focused- and distributed-attention trials, although Ss relied on focused attention more than was predicted. Consistent with the model, predictions on the basis of the assumption of a terminating search fit the data better than predictions on the basis of an exhaustive search. The effects of varying cue validity favored an interpretation of focused attention in terms of a processing gradient rather than a zoom lens. Although the allocation of attention across trials was similar for young and older adults, there was an age-related increase in the time required to allocate attention within individual trials.     

Selective attention and changes in clinical state

Thirty inpatients of a psychiatric unit were given the Mini-Mult and a series of auditory selective attention tasks in order to test the hypotheses that (1) impaired attention is related to degree of pathology, and (2) improvement in clinical state leads to improved ability to selectively attend. The results showed that the relationship between the Mini-Mult and the listening tasks is significant only when the subjects had to exclude irrelevant stimuli (interference condition). The results also indicated that the relationship between clinical changes and changes in attentional performance is significant. The findings were discussed in terms of a quantitative theory of attention.     

Selective visual attention and perceptual coherence

Conscious perception of the visual world depends on neural activity at all levels of the visual system from the retina to regions of parietal and frontal cortex. Neurons in early visual areas have small spatial receptive fields (RFs) and code basic image features; neurons in later areas have large RFs and code abstract features such as behavioral relevance. This hierarchical organization presents challenges to perception: objects compete when they are presented in a single RF, and component object features are coded by anatomically distributed neuronal activity. Recent research has shown that selective attention coordinates the activity of neurons to resolve competition and link distributed object representations. We refer to this ensemble activity as a "coherence field", and propose that voluntary shifts of attention are initiated by a transient control signal that "nudges" the visual system from one coherent state to another.     

Selective attention and subjective confidence calibration

In the present experiments, failures of selective visual attention were invoked using the B. A. Eriksen and C. W. Eriksen (1974) flanker task. On each trial, a three-letter stimulus array was flashed briefly, followed by a mask. The identity of the two flanking letters was response congruent, neutral, or incongruent with the identity of the middle target letter. On half of the trials, confidence ratings were obtained after each response. In the first three experiments, participants were highly overconfident in the accuracy of their responding to incongruent flanker stimulus arrays. In a final experiment, presenting a prestimulus target location cue greatly reduced both selective attention failure and overconfidence. The findings demonstrate that participants are often unaware of such selective attention failures and provide support for the notion that, in these cases, decisional processing is driven largely by the identities of the incongruent flankers. In addition, responding was invariably slower and sometimes more accurate when confidence was required than when it was not required, demonstrating that the need to provide posttrial confidence reports can affect decisional processing. Moreover, there was some evidence that the presence of neutral contextual flanking information can slow responding, suggesting that such nondiagnostic information can, indeed, contribute to decisional processing.     

Selective attention to words and colours

In the Stroop test it is found that the presence of words interferes with the task of naming colours. The usual account of this phenomenon is that the names of words are more readily obtained than are the names of colours and that the production of the latter is interfered with by the spontaneous occurrence of the former. Treisman and Fearnley (1969) have suggested a modification of the usual account such that stress is laid on the correspondence between the nature of the response (“verbal”) and that feature of a stimulus which will dominate. The present experiments seem to demonstrate that the data which Treisman and Fearnley use in support of their claim can be attributed to the strategy which their subjects adopted in their task. Some further observations are made concerning the different levels at which comparisons can be made between two stimuli.     

Selective attention in animal discrimination learning

The traditional approach to the study of selective attention in animal discrimination learning has been to ask if animals are capable of the central selective processing of stimuli, such that certain aspects of the discriminative stimuli are partially or wholly ignored while their relationships to each other, or other relevant stimuli, are processed. A notable characteristic of this research has been that procedures involve the acquisition of discriminations, and the issue of concern is whether learning is selectively determined by the stimulus dimension defined by the discriminative stimuli. Although there is support for this kind of selective attention, in many cases, simpler nonattentional accounts are sufficient to explain the results. An alternative approach involves procedures more similar to those used in human information-processing research. When selective attention is studied in humans, it generally involves the steady state performance of tasks for which there is limited time allowed for stimulus input and a relatively large amount of relevant information to be processed; thus, attention must be selective or divided. When this approach is applied to animals and alternative accounts have been ruled out, stronger evidence for selective or divided attention in animals has been found. Similar processes are thought to be involved when animals search more natural environments for targets. Finally, an attempt is made to distinguish these top-down attentional processes from more automatic preattentional processes that have been studied in humans and other animals.     

Selective attention in cerebral palsied and normal children

Noninstitutionalized, educable retarded, spastic cerebral palsied children of two mental age (MA) levels were compared with normal MA controls on a task measuring selective attention and were not found deficient in selective attention. For both the cerebral palsied and the normals there was an increase in selective attention efficiency with an increase in MA. The results support the position that MA rather than chronological age or IQ is the important variable in determining selective attention performance. The results do not support the attention-deficit theory; they do support the argument that institutionalization has a negative affect on attention. The effects of brain damage and retardation on selective attention ability were discussed.Thanks are expressed to Eleanor Rennie, Head Teacher, Robert Massie, Supervisor of Special Education, and E. F. DeFord, Assistant Director, Department of Research for the Richmond Public Schools, Richmond, Virginia. Appreciation is also given to Scott Hamrick, Principal, Jackson Via Elementary School, Charlottesville, Virginia. Susan Autrey is also thanked for assistance in data collection.     

Selective attention and stimulus-reinforcer interactions in the pigeon

The study supplies further evidence that non-associative effects and temporal-spatial similarities between certain combinations of cue and consequence cannot explain all instances of stimulus-reinforcer interactions. Pigeons were trained to press a treadle in the presence of a discriminative compound stimulus either to avoid shock or to obtain a food reinforcer. The compound stimulus was composed of diffuse tone and light cues which had identical temporal patterns of onset, duration and offset. With the avoidance schedule the auditory cue acquired more control than the visual cue; however, when food was the reinforcer, the visual cue exerted more control. This pattern of stimulus control on the appetitive schedule did not change if random shocks were also added, even though these shocks were equal in density to the food presentations and equal in magnitude to those used for the avoidance schedule. Other changes in the appetitive procedure, such as making the tone spatially contiguous with food and removing the light in the food hopper, also failed to alter the relative control by the different cues. Prior training with a food reinforcer did not produce any change in the relative control by the two cues when the birds were retrained on the shock-avoidance schedule. The results suggest that some frequently stated alternatives to selective associability are not adequate explanations of this instance of a stimulus-reinforcer interaction.     

Selective attention modulates implicit learning

The effect of selective attention on implicit learning was tested in four experiments using the contextual cueing paradigm (Chun & Jiang, 1998, 1999). Observers performed visual search through items presented in an attended colour (e.g., red) and an ignored colour (e.g., green). When the spatial configuration of items in the attended colour was invariant and was consistently paired with a target location, visual search was facilitated, showing contextual cueing (Experiments 1, 3, and 4). In contrast, repeating and pairing the configuration of the ignored items with the target location resulted in no contextual cueing (Experiments 2 and 4). We conclude that implicit learning is robust only when relevant, predictive information is selectively attended.     

Selective attention and attention switching: towards a unified developmental approach

We review and relate two literatures on the development of attention in children: one concerning flexible attention switching and the other concerning selective attention. The first is a growing literature on preschool children’s performances in an attention‐switching task indicating that children become more flexible in their attentional control during the preschool years. The second literature encompasses a large and robust set of phenomena for the same developmental period that indicates a protracted course of development for selective attention in children. We ask whether developmental changes in processes of selective attention may contribute to more flexible attention switching. We consider the two sets of phenomena with respect to this question and propose an empirical agenda for their joint study that may lead ultimately to a unified account of the development of selective attention and attention switching.     

Selective attention,diffused attention,and the development of categorization

How do people learn categories and what changes with development? The current study attempts to address these questions by focusing on the role of attention in the development of categorization. In Experiment 1, participants (adults, 7-year-olds, and 4-year-olds) were trained with novel categories consisting of deterministic and probabilistic features, and their categorization and memory for features were tested. In Experiment 2, participants’ attention was directed to the deterministic feature, and in Experiment 3 it was directed to the probabilistic features. Attentional cueing affected categorization and memory in adults and 7-year-olds: these participants relied on the cued features in their categorization and exhibited better memory of cued than of non-cued features. In contrast, in 4-year-olds attentional cueing affected only categorization, but not memory: these participants exhibited equally good memory for both cued and non-cued features. Furthermore, across the experiments, 4-year-olds remembered non-cued features better than adults. These results coupled with computational simulations provide novel evidence (1) pointing to differences in category representation and mechanisms of categorization across development, (2) elucidating the role of attention in the development of categorization, and (3) suggesting an important distinction between representation and decision factors in categorization early in development. These issues are discussed with respect to theories of categorization and its development.