Analysis of child and parent behavior during painful medical procedures

Examined (a) the impact of demographic, medical, and psychological factors on overall child distress during an invasive medical procedure required for pediatric cancer treatment and (b) the relationship of individual parent behaviors to child distress across phases of the procedure. Seventy 3- to 10-year-old pediatric cancer patients receiving outpatient venipuncture and their parents participated. Overall distress was greater in younger children who had fewer previous venipunctures and poorer venous access and whose parents rated them prior to the procedure as less likely to be cooperative. Providing explanations regarding the procedure was the parent behavior most clearly associated with child distress. The impact of parent explanation depended on when the explanation was given and on the child's level of distress at the time.     

Human visual short-term memory precision can be varied at will when the number of retained items is low

It has been debated whether human visual working memory is limited by the number of items or the precision with which they are represented. In the research reported here, we show that the precision of working memory can be flexibly and willfully controlled, but only if the number of retained items is low. Electroencephalographic recordings revealed that a neural marker for visual working memory (contralateral delay activity, or CDA) that is known to increase in amplitude with the number of retained items was also affected by the precision with which items were retained. However, willfully enhanced precision increased CDA amplitude only when the number of retained items was low. These results show that both the number and the (willfully controlled) precision of retained items constrain visual working memory: People can enhance the precision of their visual working memory, but only for a few items.     

Superior visual search in autism.

Children with a diagnosis of autism and normally developing children, matched for age and general ability, were tested on a series of visual search tasks in 2 separate experiments. The children with autism performed better than the normally developing children on difficult visual search tasks. This result occurred regardless of whether the target was uniquely defined by a single feature or a conjunction of features, as long as ceiling effects did not mask the difference. Superior visual search performance in autism can be seen as analogous to other reports of enhanced unique item detection in autism. Unique item detection in autism is discussed in the light of mechanisms proposed to be involved in normal visual search performance.     

The boundary conditions of priming of visual search: From passive viewing through task-relevant working memory load

Priming of visual search has a dominating effect upon attentional shifts and is thought to play a decisive role in visual stability. Despite this importance, the nature of the memory underlying priming remains controversial. To understand more fully the necessary conditions for priming, we contrasted passive versus active viewing of visual search arrays. There was no priming from passive viewing of search arrays, while it was strong for active search of the same displays. Displays requiring no search resulted in no priming, again showing that search is needed for priming to occur. Finally, we introduced working memory load during visual search in an effort to disrupt priming. The memorized items had either the same colors as or different colors from the visual search items. Retaining items in working memory inhibited priming of the working memory task-relevant colors, while little interference was observed for unrelated colors. The picture that emerges of priming is that it requires active attentional processing of the search items in addition to the operation of visual working memory, where the task relevance of the working memory load plays a key role.     

Effects of perceived mutual gaze and gender on face processing and recognition memory

Perceived gaze contact in seen faces may convey important social signals. We examined whether gaze perception affects face processing during two tasks: Online gender judgement, and later incidental recognition memory. Individual faces were presented with eyes directed either straight towards the viewer or away, while these faces were seen in either frontal or three-quarters view. Participants were slower to make gender judgements for faces with direct versus averted eye gaze, but this effect was particularly pronounced for faces with opposite gender to the observer, and seen in three-quarters view. During subsequent surprise recognition-memory testing, recognition was better for faces previously seen with direct than averted gaze, again especially for the opposite gender to the observer. The effect of direct gaze was stronger in both tasks when the head was seen in three-quarters rather than in frontal view, consistent with the greater salience of perceived eye contact for deviated faces. However, in the memory test, face recognition was also relatively enhanced for faces of opposite gender in front views when their gaze was averted rather than direct. Together, these results indicate that perceived eye contact can interact with facial processing during gender judgements and recognition memory, even when gaze direction is task-irrelevant, and particularly for faces of opposite gender to the observer (an influence which controls for stimulus factors when considering observers of both genders). These findings appear consistent with recent neuroimaging evidence that social facial cues can modulate visual processing in cortical regions involved in face processing and memory, presumably via interconnections with brain systems specialized for gaze perception and social monitoring.     

The ventriloquist effect does not depend on the direction of deliberate visual attention

It is well known that discrepancies in the location of synchronized auditory and visual events can lead to mislocalizations of the auditory source, so-called ventriloquism. In two experiments, we tested whether such cross-modal influences on auditory localization depend on deliberate visual attention to the biasing visual event. In Experiment 1, subjects pointed to the apparent source of sounds in the presence or absence of a synchronous peripheral flash. They also monitored for target visual events, either at the location of the peripheral flash or in a central location. Auditory localization was attracted toward the synchronous peripheral flash, but this was unaffected by where deliberate visual attention was directed in the monitoring task. In Experiment 2, bilateral flashes were presented in synchrony with each sound, to provide competing visual attractors. When these visual events were equally salient on the two sides, auditory localization was unaffected by which side subjects monitored for visual targets. When one flash was larger than the other, auditory localization was slightly but reliably attracted toward it, but again regardless of where visual monitoring was required. We conclude that ventriloquism largely reflects automatic sensory interactions, with little or no role for deliberate spatial attention.     

Grouping reduces visual extinction: Neuropsychological evidence for weight-linkage in visual selection

Abstract

We tested two subjects following damage to right parietal cortex to see if their failure to detect a left visual stimulus in the presence of a simultaneous right stimulus (visual extinction) could be modulated by perceptual grouping between the left and right stimuli. Subjects performed a simple detection task for brief displays in which items could appear in the left or right visual field, both fields, or neither field. On trials in which items appeared in both fields, we found that left omissions (extinction errors) were dramatically reduced when the two items formed a good perceptual group, either on the basis of Gestalt factors such as similarity and symmetry (Experiment 1). or by forming a familiar configuration (Experiment 2). We suggest that extinction may be a spatially specific exaggeration of a normal attention limitation, in which the contralesional item is disadvantaged in the competition for selection. However, this obstacle to selection can be overcome if, as a result of grouping, ipsilesional and contralesional items become allies rather than competitors for selection.     

Gaze Perception Triggers Reflexive Visuospatial Orienting

This paper seeks to bring together two previously separate research traditions: research on spatial orienting within the visual cueing paradigm and research into social cognition, addressing our tendency to attend in the direction that another person looks. Cueing methodologies from mainstream attention research were adapted to test the automaticity of orienting in the direction of seen gaze. Three studies manipulated the direction of gaze in a computerized face, which appeared centrally in a frontal view during a peripheral letter-discrimination task. Experiments 1 and 2 found faster discrimination of peripheral target letters on the side the computerized face gazed towards, even though the seen gaze did not predict target side, and despite participants being asked to ignore the face. This suggests reflexive covert and/or overt orienting in the direction of seen gaze, arising even when the observer has no motivation to orient in this way. Experiment 3 found faster letter discrimination on the side the computerized face gazed towards even when participants knew that target letters were four times as likely on the opposite side. This suggests that orienting can arise in the direction of seen gaze even when counter to intentions. The experiments illustrate that methods from mainstream attention research can be usefully applied to social cognition, and that studies of spatial attention may profit from considering its social function.