On measuring selective attention to an expected sensory modality

Perceptual judgments can be affected by expectancies regarding the likely target modality. This has been taken as evidence for selective attention to particular modalities, but alternative accounts remain possible in terms of response priming, criterion shifts, stimulus repetition, and spatial confounds. We examined whether attention to a sensory modality would still be apparent when these alternatives were ruled out. Subjects made a speeded detection response (Experiment 1), an intensity or color discrimination (Experiment 2), or a spatial discrimination response (Experiments 3 and 4) for auditory and visual targets presented in a random sequence. On each trial, a symbolic visual cue predicted the likely target modality. Responses were always more rapid and accurate for targets presented in the expected versus unexpected modality, implying that people can indeed selectively attend to the auditory or visual modalities. When subjects were cued to both the probable modality of a target and its likely spatial location (Experiment 4), separable modality-cuing and spatial-cuing effects were observed. These studies introduce appropriate methods for distinguishing attention to a modality from the confounding factors that have plagued previous normal and clinical research.     

Selective attention to multidimensional auditory stimuli

Event-related brain potentials (ERPs) elicited by multidimensional auditory stimuli were recorded from the scalp in a selective-attention task. Subjects listened to tone pips varying orthogonally between two levels each of pitch, location, and duration and responded to longer duration target stimuli having specific values of pitch and location. The discriminability of the pitch and location attributes was varied between groups. By examining the ERPs to tones that shared pitch and/or locational cues with the designated target, we inferred interrelationships among the processing of these attributes. In all groups, stimuli that failed to match the target tone in an easily discriminable cue elicited only transitory ERP signs of selective processing. Tones sharing the "easy" but not the "hard" cue with the target elicited ERPs that indicated more extensive processing, but not as extensive as stimuli sharing both cues. In addition, reaction times and ERP latencies to the designated targets were not influenced by variations in the discriminability of pitch and location. This pattern of results is consistent with parallel, self-terminating models and holistic models of processing and contradicts models specifying either serial or exhaustive parallel processing of these dimensions. Both the parallel, self-terminating models and the holistic models provide a generalized mechanism for hierarchical stimulus selections that achieve an economy of processing, an underlying goal of classic, multiple-stage theories of selective attention.     

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 to the parts of an object

Recent empirical results suggest that there is a decrement in dividing attention between two objects in a scene compared with focusing attention on a single object. However, objects can be made of individual parts. Is there a decrement for dividing attention across different parts of a single object? We addressed this question in two experiments. In Experiment 1, we demonstrated that attention can exhibit part-based selection—that is, the subjects were more accurate in reporting two attributes from the same part of an object than they were in reporting attributes from different parts of an object. In Experiment 2, we demonstrated that part-based attentional decrements occurred simultaneously with object-based attentional decrements. The results from Experiment 2 demonstrated that part-based attention is evident at the same time as objects are processed as coherent wholes. Our results imply that there is an attentional mechanism that can select either objects or their parts.     

Selective attention to elements in working memory

Three experiments with an arithmetic working memory task examine the object switch effect first reported by Garavan (1998), which was interpreted as evidence for a focus of attention within working memory. Experiments 1a and 1b showed object switch costs with a task that requires selective access to items in working memory, but did not involve counting, and did not require updating of working memory contents, thus ruling out two alternative explanations of Garavan's results. Experiment 2 showed object switch costs with a task that required no selective access to working memory contents, but involved updating, thus providing evidence for a second component to the overall object switch costs. Further analyses revealed that the object switch cost increased with memory set size; that there were (smaller) switch costs when the switch was to an item of the same type; that repeating an arithmetic operation does not have the same effect as repeating the object it is applied to; and that object switching is not mediated by backward inhibition of the previously focused object.     

Selective attention in perceptual adjustments to voice

The effects of perceptual adjustments to voice information on the perception of isolated spoken words were examined. In two experiments, spoken target words were preceded or followed within a trial by a neutral word spoken in the same voice or in a different voice as the target. Over-all, words were reproduced more accurately on trials on which the voice of the neutral word matched the voice of the spoken target word, suggesting that perceptual adjustments to voice interfere with word processing. This result, however, was mediated by selective attention to voice. The results provide further evidence of a close processing relationship between perceptual adjustments to voice and spoken word recognition.     

Psychophysical isolation of the modality responsible for detecting multimodal stimuli: a chemosensory example

Multiple sense modalities can be stimulated conjointly by a physically complex item, such as a predator, and also by a physically solitary stimulus that acts on multiple receptor classes. As a prime example of this latter group, l-menthol from mint stimulates taste, smell, and several somatosensory submodalities. In 6 experiments that used a variety of psychometric techniques, the authors experimentally isolated the modality by which l-menthol is detected in the upper airways (the nose and mouth). Interestingly, absolute detection in both the nasal and oral cavities was based on olfaction and not stinging, cooling, or taste. These experiments illustrate how the sensory modality responsible for detecting a multimodal or multisensory stimulus can be psychophysically isolated.     

Top-down control over involuntary attention switching in the auditory modality

We tested the effects of predictability on involuntary attention switching to task-irrelevant sound changes (distraction). Behavioral and neurophysiological evidence are provided, showing that the predictability of task-irrelevant sound changes eliminates effects of distraction even though the automatic auditory change detection system remains responsive. Two indices of distraction, slower task performance and cortical brain responses associated with attention switching, were seen only in the unpredictable condition, in which the irrelevant acoustic changes were unexpected. Attention was not involuntarily drawn away from the primary task when the subjects had foreknowledge of when the irrelevant changes would occur. These results demonstrate attentional control over orienting to sound changes and suggest that involuntary attention switching occurs mainly when an irrelevant stimulus change is unexpected. The present data allowed observation of the temporal dynamics of attention switching in the human brain.     

Selective attention to stimulus features modulates interocular suppression

Psychological and neurophysiological studies have shown that attention modulates various sorts of perceptual processing. Here, we report that attention affects the perceptual dominance of binocular rivalry. Experiments using a dichoptic masking paradigm revealed that when an observer was attending to one of the two orientations of the elements of a monocular texture, a texture briefly presented to the opposite eye suppressed the perception of the elements with the attended orientation, while the elements with the orientation which was ignored sustained their dominance. Moreover, subsequent experiments indicated that the suppression depended on the orientation of the texture elements constituting the mask, but was independent of their locations. These results suggest that attention to specific features modulates interocular suppression in a mode which is different from that found in a previous study [Ooi and He, 1999 Perception 28 551 -574].     

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.     

Selective attention determines emotional responses to novel visual stimuli

Distinct complex brain systems support selective attention and emotion, but connections between them suggest that human behavior should reflect reciprocal interactions of these systems. Although there is ample evidence that emotional stimuli modulate attentional processes, it is not known whether attention influences emotional behavior. Here we show that evaluation of the emotional tone (cheery/dreary) of complex but meaningless visual patterns can be modulated by the prior attentional state (attending vs. ignoring) used to process each pattern in a visual selection task. Previously ignored patterns were evaluated more negatively than either previously attended or novel patterns. Furthermore, this emotional devaluation of distracting stimuli was robust across different emotional contexts and response scales. Finding that negative affective responses are specifically generated for ignored stimuli points to a new functional role for attention and elaborates the link between attention and emotion. This finding also casts doubt on the conventional marketing wisdom that any exposure is good exposure.     

Selective attention to angry faces in clinical social phobia

This study investigated the time course of attentional responses to emotional facial expressions in a clinical sample with social phobia. With a visual probe task, photographs of angry, happy, and neutral faces were presented at 2 exposure durations: 500 and 1250 ms. At 500 ms, the social phobia group showed enhanced vigilance for angry faces, relative to happy and neutral faces, in comparison with normal controls. In the 1250-ms condition, there were no significant attentional biases in the social phobia group. Results are consistent with a bias in initial orienting to threat cues in social anxiety. Findings are discussed in relation to recent cognitive models of anxiety disorders.     

Selective attention to facial identity and emotion in children

Three age groups of participants (6–8 years, 9–11 years, adults) performed two tasks: A face recognition task and a Garner task. In the face recognition task, the participants were presented with 20 faces and then had to recognize them among 20 new faces. In the Garner tasks, the participants had to sort, as fast as possible, the photographs of two persons expressing two emotions by taking into account only one of the two dimensions (identity or emotion). When the sorting task was on one dimension, the other dimension was varied either in a correlated, a constant or an orthogonal way in distinct subsessions. The results indicated an increase in face recognition abilities. They also showed an interference of identity in the emotion-sorting task that was similar in the three age groups. Nevertheless, an interference of emotion in the identity-sorting task was significant only for the children and was more important for the youngest group. These observations suggest that the development in face recognition ability rests on the development of the ability to attend selectively to identity, without paying attention to emotional facial expression.     

Selective attention to facial emotion in physically abused children

The ability to allocate attention to emotional cues in the environment is an important feature of adaptive self-regulation. Existing data suggest that physically abused children overattend to angry expressions, but the attentional mechanisms underlying such behavior are unknown. The authors tested 8-11-year-old physically abused children to determine whether they displayed specific information-processing problems in a selective attention paradigm using emotional faces as cues. Physically abused children demonstrated delayed disengagement when angry faces served as invalid cues. Abused children also demonstrated increased attentional benefits on valid angry trials. Results are discussed in terms of the influence of early adverse experience on children's selective attention to threat-related signals as a mechanism in the development of psychopathology.     

Selective attention to emotional faces following recovery from depression

This study was designed to examine attentional biases in the processing of emotional faces in currently and formerly depressed participants and healthy controls. Using a dot-probe task, the authors presented faces expressing happy or sad emotions paired with emotionally neutral faces. Whereas both currently and formerly depressed participants selectively attended to the sad faces, the control participants selectively avoided the sad faces and oriented toward the happy faces, a positive bias that was not observed for either of the depressed groups. These results indicate that attentional biases in the processing of emotional faces are evident even after individuals have recovered from a depressive episode. Implications of these findings for understanding the roles of cognitive and interpersonal functioning in depression are discussed.     

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.     

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.