On the status of location in visual attention

The authors propose a distinction between four issues underlying the debate on the status of location in visual selective attention. Three of them concern the representation within which attention operates. The grouping question focuses on whether or not this representation segments the visual field into perceptual groups. The space-invariance question focuses on whether it describes objects in spatio-topic or in space-invariant coordinates. Finally, the feature-coding question concerns whether or not it contains information about objects' non-spatial features. The last issue focuses on whether or not attention can be guided preattentively towards items possessing certain pre-specified physical properties other than location, and is referred to as the attentional-guidance question. A critical survey of the literature within the proposed framework is presented. Based on its conclusions, the status of location in current research is outlined, and avenues for further research are suggested.     

Scene congruency biases Binocular Rivalry

Contextual regularities, that is, objects’ tendency to appear with certain other objects, facilitate the processing of visual scenes and confer contextually incongruent objects with a special attentional status. This study was aimed at investigating the mechanisms underlying this attentional advantage using Binocular Rivalry (BR). In two experiments, congruent and incongruent images (e.g., a man drinking from a glass vs. a man “drinking” from a hairbrush) were pitted against each other, yielding a version of BR in which two objects rival within a given scene. Incongruent objects predominated in awareness longer than congruent ones. This effect stemmed from the fact that their dominance epochs lasted longer on the average than those of congruent objects, suggesting a difficulty to disengage attention from such objects. On the other hand, no support was found for the notion that incongruent objects also attract attention.     

Object-based selection under focused attention: a failure to replicate

In a recent study, Lavie and Driver (1996) reported that object-based effects found with distributed attention disappear when attention is focused on a narrow area of the display. This finding stands in contrast with previous reports of object-based effects under conditions of focused attention (e.g., Atchley & Kramer, 1998; Egly, Driver, & Rafal, 1994). The present study was an attempt to replicate Lavie and Driver's finding, using similar task and stimuli. While Lavie and Driver's object-based effect in the distributed attention condition was replicated, its absence in the focused attention condition was not. In the two experiments reported in this paper, object-based effects were found under conditions of both distributed and focused attention, with no difference in the magnitude of the object-based effects in the two conditions. It is concluded that, in contrast with Lavie and Driver's claim, the initial spatial setting of attention does not influence object-based constraints on the distribution of attention.     

Nature and nurture in own-race face processing

A standard visual preference task was used to examine 3-month-olds' looking times at own-race versus other-race faces as a function of environmental exposure to faces from the two categories. Participants were Caucasian infants living in a Caucasian environment, African infants living in an African environment, and African infants living in a predominantly Caucasian environment. The results indicate that preference for own-race faces is present as early as 3 months of age, but that this preference results from exposure to the prototypical facial environment.     

Implicit learning of a repeated segment in continuous tracking: a reappraisal

Several prior studies (e.g., Shea, Wulf, Whitacre, & Park, 2001; Wulf & Schmidt, 1997) have apparently demonstrated implicit learning of a repeated segment in continuous-tracking tasks. In two conceptual replications of these studies, we failed to reproduce the original findings. However, these findings were reproduced in a third experiment, in which we used the same repeated segment as that used in the Wulf et al. studies. Analyses of the velocity and the acceleration of the target suggests that this repeated segment could be easier to track than the random segments serving as control, accounting for the results of Wulf and collaborators. Overall these experiments suggest that learning a repeated segment in continuous-tracking tasks may be much more difficult than learning from a repeated sequence in conventional serial reaction time tasks. A possible explanation for this difference is outlined.     

When "new" meets "old": configurations of adult attachment representations and their implications for marital functioning

Two studies addressed the implications of concordance versus discrepancy of attachment representations in individuals at 2 stages in their marital relationships. Engaged (n = 157) and dating (n = 101) couples participated in a multimethod 6-year longitudinal study of adult attachment. Individuals completed the Adult Attachment Interview (AAI), the Current Relationship Interview (CRI), and various questionnaires and were observed in interactions with partners. On the basis of AAI and CRI classifications, participants were placed in one of four groups: Secure-sub(AAI)/Secure-sub(CRI), Secure-sub(AAI)/Insecure-sub(CRI), Insecure-sub(AAI)/Secure-sub(CRI), or Insecure-sub(AAI)/Insecure-sub(CRI). Each of the configurations showed a particular pattern of behavior, feelings about relationships and the self, and likelihood of relationship breakup. The findings of the studies address important points about the protective effects of attachment security and have interesting implications for the extension of attachment theory into adulthood.     

Long-term plasticity of intrinsic excitability: learning rules and mechanisms

Spatio-temporal configurations of distributed activity in the brain is thought to contribute to the coding of neuronal information and synaptic contacts between nerve cells could play a central role in the formation of privileged pathways of activity. Synaptic plasticity is not the exclusive mode of regulation of information processing in the brain, and persistent regulations of ionic conductances in some specialized neuronal areas such as the dendrites, the cell body, and the axon could also modulate, in the long-term, the propagation of neuronal information. Persistent changes in intrinsic excitability have been reported in several brain areas in which activity is elevated during a classical conditioning. The role of synaptic activity seems to be a determinant in the induction, but the learning rules and the underlying mechanisms remain to be defined. We discuss here the role of synaptic activity in the induction of intrinsic plasticity in cortical, hippocampal, and cerebellar neurons. Activation of glutamate receptors initiates a long-term modification in neuronal excitability that may represent a parallel, synergistic substrate for learning and memory. Similar to synaptic plasticity, long-lasting intrinsic plasticity appears to be bidirectional and to express a certain level of input or cell specificity. These nonsynaptic forms of plasticity affect the signal propagation in the axon, the dendrites, and the soma. They not only share common learning rules and induction pathways with the better-known synaptic plasticity such as NMDA receptor dependent LTP and LTD, but also contribute in synergy with these synaptic changes to the formation of a coherent engram.     

Structural aspects of face recognition and the other-race effect

The other-race effect was examined in a series of experiments and simulations that looked at the relationships among observer ratings of typicality, familiarity, attractiveness, memorability, and the performance variables ofd’ and criterion. Experiment 1 replicated the other-race effect with our Caucasian and Japanese stimuli for both Caucasian and Asian observers. In Experiment 2, we collected ratings from Caucasian observers on the faces used in the recognition task. A Varimax-rotated principal components analysis on the rating and performance data for the Caucasian faces replicated Vokey and Read’s (1992) finding that typicality is composed of two orthogonal components, dissociable via their independent relationships to: (1) attractiveness and familiarity ratings and (2) memorahility ratings. For Japanese faces, however, we fond that typicality was related only to memorahility. Where performance measures were concerned, two additional principal components dominated by criterion and byd’ emerged for Caucasian faces. For the Japanese faces, however, the performance measures ofd’ and criterion merged into a single component that represented a second component of typicality, one orthogonal to thememorability-dominated component. A measure offace representation quality extracted from an autoassociative neural network trained with a majority of Caucasian faces and a minority of Japanese faces was incorporated into the principal components analysis. For both Caucasian and Japanese faces, the neural network measure related both to memorability ratings and to human accuracy measures. Combined, the human data and simulation results indicate that the memorahility component of typicality may be related to small, local, distinctive features, whereas the attractiveness/familiarity component may be more related to the global, shape-based properties of the face.     

Children as witnesses: A comparison of lineup versus showup identification methods

The goal of this study was to compare children's and adults eyewitness identification accuracy when presented with an array of possible suspects (‘lineup’) versus one suspect (‘showup’). Kindergarten children and adults were shown a slide show of a staged theft and subsequently asked whether, of the photo or photos shown them, the perpetrator was present or not. Children were more likely than adults to identify the perpetrator correctly when that suspect was present in the lineup or showup. Children were also more likely than adults to make an incorrect identification of another person when the perpetrator's photo was not present in the lineup or showup. Because false positive identification errors are more difficult to detect with the showup than the lineup, use of the showup may be less appropriate with child witnesses than with adults due to children's greater tendency to make positive identifications.     

Attending to an object’s color entails Attending to its location: Support for location-special views of visual attention

Van der Heijden, Kurvink, de Lange, de Leeuw, and van der Geest (1996) argued that the results supporting the location-special view obtained by Tsal and Lavie (1988) were due to uncontrollable shifts of fixation, rather than reflecting the properties of the attentional system. In the present study, we present an improved variation of the Tsal and Lavie (1988) paradigm and reassert our claim that location is a special dimension. Subjects were presented with circular arrays of six letters of different colors. Three of the letters were enclosed by (Experiment 1) or superimposed on (Experiments 2,3, and 4) different colored shapes. The subjects were instructed to report the (target) shape with a given color (e.g., report whether the red shape was a square, a circle, or a triangle) and then either freely report letters from the array (Experiments 1, 2, and 4) or identify a prespecified target letter (Experiment 3). In all four experiments, performance was substantially better for the letter that appeared in the location of the to-be-reported shape (location letter) than for the letter that shared its color (color letter). We conclude that attending to the stimulus color entails directing attention to its location.