The impact of extrafoveal information on visual short-term memory for object position

The role of extrafoveal information in visual short-term memory has been investigated relatively little, and, in most existing studies, using verbalisable stimuli susceptible to the recruitment of long-term memory (LTM). In addition, little is known about the impact of extrafoveal information available pre- and posttarget foveation, as it is typical to provide extrafoveal information prior to the foveation of memory targets. In this study, two object-position recognition experiments were conducted (each with two conditions) to establish the impact of extrafoveal information provided before and after the foveation of memory targets. Stimuli comprised 1/f noise discs that minimised the recruitment of LTM by eliminating verbal and semantic cues. Overall, a greater hit rate was found where extrafoveal information was available; however, performance analyses in which extrafoveal information was considered relative to the temporal lag at which target stimuli were foveated reveals both costs and benefits. A beneficial effect arose only where extrafoveal information was provided after the target had been foveated, but not prior to target foveation. Findings are discussed in terms of recency and extrafoveal perception effects, incorporating a postfoveation object-file refresh mechanism.     

The impact of object working memory on timing

Nontemporal information processing involving short-term memory requirements disturbs time estimation. Previous studies mostly used letters or digits, which are maintained in working memory by phonological loops. Since verbal and nonverbal information are processed by separate working-memory subsystems, how do nonverbal, object-based memory tasks affect time estimation? We manipulated visual object memory load using the magic cube materials. Participants were divided into three groups, who completed a reaction-time task (control task), a memory-recognition task interposed by an attempt to produce a 2500-ms time interval (active processing), and a memory-recognition task following time interval production (passive retention). The produced time increased with increasing memory-object size under both the active processing and passive retention conditions; mean produced time interval did not significantly differ between the two experimental conditions. By comparing the reaction times and error rates of a relevant task, we excluded any speed–accuracy tradeoff during timing. This result suggests that when the working-memory information to be processed includes objects requiring attention for retention, the production of time intervals is also affected by memory item maintenance.     

EEG decoding of semantic category reveals distributed representations for single concepts

Achieving a clearer picture of categorial distinctions in the brain is essential for our understanding of the conceptual lexicon, but much more fine-grained investigations are required in order for this evidence to contribute to lexical research. Here we present a collection of advanced data-mining techniques that allows the category of individual concepts to be decoded from single trials of EEG data. Neural activity was recorded while participants silently named images of mammals and tools, and category could be detected in single trials with an accuracy well above chance, both when considering data from single participants, and when group-training across participants. By aggregating across all trials, single concepts could be correctly assigned to their category with an accuracy of 98%. The pattern of classifications made by the algorithm confirmed that the neural patterns identified are due to conceptual category, and not any of a series of processing-related confounds. The time intervals, frequency bands and scalp locations that proved most informative for prediction permit physiological interpretation: the widespread activation shortly after appearance of the stimulus (from 100 ms) is consistent both with accounts of multi-pass processing, and distributed representations of categories. These methods provide an alternative to fMRI for fine-grained, large-scale investigations of the conceptual lexicon.     

Split identity: intransitive judgments of the identity of objects

Identity is a transitive relation, according to all standard accounts. Necessarily, if x = y and y = z, then x = z. However, people sometimes say that two objects, x and z, are the same as a third, y, even when x and z have different properties (thus, x = y and y = z, but x ≠ z). In the present experiments, participants read stories about an iceberg that breaks into two icebergs, one to the east and the other to the west. Many participants (32–54%, in baseline conditions across experiments) decided that both successors were the original iceberg, despite the different spatial locations of the successors. Experiment 1 shows that this tendency is not due to participants failing to understand both to mean both are simultaneously the original. Similarly, Experiment 2 demonstrates that the tendency is not solely due to their interpreting the question to be about properties of the icebergs rather than about the icebergs themselves. Experiments 3 and 4 suggest, instead, that participants may understand Which is the original? to mean Which, in its own right, is entitled to be the original? Emphasizing entitlement increases the number of seemingly intransitive responses, whereas emphasizing the formal properties of identity decreases them.     

Vicarious goal satiation

A signature feature of self-regulation is that once a goal is satiated, it becomes deactivated, thereby allowing people to engage in new pursuits. The present experiments provide evidence for vicarious goal satiation, a novel phenomenon in which individuals experience “post-completion goal satiation” as a result of unwittingly taking on another person's goal pursuit and witnessing its completion. In Experiments 1 and 2, the observation of a goal being completed (vs. not completed) led to less striving by the observer on the same task. Given that an actor's strength of commitment affects goal contagion, we hypothesized that such commitment would be an important boundary condition for vicarious goal satiation. The results of Experiment 2 showed that observing stronger (vs. weaker) goal commitment lowered accessibility of goal-related words, but only when the goal being observed was completed. Implications of vicarious goal satiation for goal pursuit in everyday environments are discussed.     

Infants' representations of three-dimensional occluded objects

Infants' ability to represent objects has received significant attention from the developmental research community. With the advent of eye-tracking technology, detailed analysis of infants' looking patterns during object occlusion have revealed much about the nature of infants' representations. The current study continues this research by analyzing infants' looking patterns in a novel manner and by comparing infants' looking at a simple display in which a single three-dimensional (3D) object moves along a continuous trajectory to a more complex display in which two 3D objects undergo trajectories that are interrupted behind an occluder. Six-month-old infants saw an occlusion sequence in which a ball moved along a linear path, disappeared behind a rectangular screen, and then a ball (ball-ball event) or a box (ball-box event) emerged at the other edge. An eye-tracking system recorded infants' eye-movements during the event sequence. Results from examination of infants' attention to the occluder indicate that during the occlusion interval infants looked longer to the side of the occluder behind which the moving occluded object was located, shifting gaze from one side of the occluder to the other as the object(s) moved behind the screen. Furthermore, when events included two objects, infants attended to the spatiotemporal coordinates of the objects longer than when a single object was involved. These results provide clear evidence that infants' visual tracking is different in response to a one-object display than to a two-object display. Furthermore, this finding suggests that infants may require more focused attention to the hidden position of objects in more complex multiple-object displays and provides additional evidence that infants represent the spatial location of moving occluded objects.     

The case of the magic bones: Dogs’ memory of the physical properties of objects

Dogs’ memory for properties of occluded objects was assessed using a looking-time procedure. The looking-time procedure has been used to indicate that a change in expectation has been observed, with longer looking times associated with change as compared with no change. In our experiments, a bone-shaped dog biscuit (bone) was placed behind a horizontal screen that then rotated up to occlude the object before the screen returned to its horizontal position. Dogs were shown one of two test events. In one (congruent) event, the screen rotated up to obscure the bone and then rotated back down to reveal the unchanged bone. In the other (incongruent) event, the screen rotated up to obscure the bone and then rotated back down to reveal a bone that had changed in size (Experiment 1) or color (Experiment 2). Looking times were measured to assess which events represented the detection of a change. Increased looking time on incongruent trials indicated that the dogs remembered the size and color of the occluded object.     

Addiction as a functional representation

This study examined how perceptions of the addicted state vary as a function of social conditions, personal circumstances and type of substance. University students (n = 144) were presented with portrayals of drug users in which sex, drug type and social setting were varied. A questionnaire determined the degree to which participants thought that the person portrayed was (i) addicted, (ii) prone to use drugs due to his/her personality, and (iii) perceived as a problem to society. The pattern of results fitted a functional model of the addiction concept rather than an attempt to describe an ‘objective’ state. Copyright © 2001 John Wiley & Sons, Ltd.     

‘The threat of the Other’: Using mixed quantitative and qualitative methods to elucidate racial and cultural dynamics in the counselling process

This paper examines the use of mixed quantitative and qualitative methods in the study of racial and cultural dynamics in the counselling process. The approach is illustrated by the author's own research which combined quantitative survey instruments with a blend of qualitative methods. Emphasis is given to complex racial and cultural phenomena arising from the qualitative methods of data collection and data analysis, particularly the pervasive experience of ‘threat of the Other’. These phenomena were seen to permeate the counselling interactions both explicitly and implicitly. The emerging racial dynamics are discussed with reference to theoretical concepts which stress the interrelationship between intrapsychic development and sociopolitical issues. The effectiveness of employing pluralistic methods in this field of enquiry is also evaluated.