Endogenous shifts of covert attention operate within multiple coordinate frames: evidence from a feature-priming task

The locations of visual objects and events in the world are represented in a number of different coordinate frameworks. For example, a visual transient is known to attract (exogenous) attention and facilitate performance within an egocentric framework. However, when attention is allocated voluntarily to a particular visual feature (ie endogenous attention), the location of that feature appears to be variously encoded either within an allocentric framework or in a spatially invariant manner. In three experiments we investigated the importance of location for the allocation of endogenous attention and whether egocentric and/or allocentric spatial frameworks are involved. Primes and targets were presented in four conditions designed to vary systematically their spatial relationships in egocentric and allocentric coordinates. A reliable effect of egocentric priming was found in all three experiments, which suggests that endogenous shifts of attention towards targets defined by a particular feature operate in an egocentric representation of visual space. In addition, allocentric priming was also found for targets primed by their colour or shape. This suggests that attending to targets primed by nonspatial attributes results in facilitation that is localised in more than one coordinate frame of spatial reference.     

It does take a village: nonfamilial environments and children's behavior

Abstract - Family characteristics influence children's behavioral development, but so do variations in schools, neighborhoods, and communities. We documented extrafamilial environmental effects by fitting maximum likelihood models to questionnaire data collected from double dyads consisting of twins and their classmate controls. The classmate controls in each double dyad were genetic strangers living in separate households, but they shared school, neighborhood, and community environments with their yoked twin pair and with one another. At ages 11 to 12, the control classmates showed significant similarities in religious practices and smoking and drinking patterns, demonstrating that environmental influences outside the family affect children's behavioral development. Familial self-selection of residential neighborhoods may have contributed to these results, but direct effects of variation across communities, neighborhoods, and schools cannot be dismissed, and such effects warrant further study.     

Long-term memory formation in the chick requires mobilization of ryanodine-sensitive intracellular calcium stores

Training chicks (Gallus domesticus) on a one-trial passive avoidance task results in transient and time-dependent enhanced increases in N-methyl-d-aspartate- or alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate-stimulated intracellular calcium concentration in synaptoneurosomes isolated from a specific forebrain region, the intermediate medial hyperstriatum ventrale. This increase could result from either calcium entry from the extracellular medium or from mobilization of intracellular calcium stores. We have therefore examined the effects of dantrolene, an inhibitor of calcium release from the intracellular ryanodine-sensitive store, on these processes. Dantrolene, 50 nmol per hemisphere injected intracerebrally 30 min pre- or 30 min posttraining, blocked longer term memory for the passive avoidance task, whereas memory for the task was unaffected when dantrolene was injected at earlier or later times. Preincubation of synaptoneurosomes, isolated from the intermediate hyperstriatum ventrale 10 min after training, with 100 nM dantrolene abolished the enhanced training-induced increase in intracellular calcium concentration elicited by 0.5 mM N-methyl-d-aspartate. By contrast, the training-induced enhancement of the alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionate-stimulated increase in intracellular calcium concentration in synaptoneurosomes prepared 6 h posttraining was unaffected by preincubation with dantrolene, which was not amnestic at this time. Calcium release from ryanodine-sensitive intracellular stores may thus be a necessary stage in the early phase of the molecular cascade leading to the synaptic modulation required for long-term memory storage.     

Can the Media Create Public Opinion? A Social-Identity Approach

The media remains a powerful presence in U.S. culture. It gives people news of world and local events, it entertains, and it may even function as a companion to children. Because it functions as a window to the outside world, what appears across its landscape actually may become people's reality. Thus, the potential for distorting their view of that world is high if the picture provided is unrepresentative of actual events. For example, the prevalence of violent acts on television has been linked to increased aggression and escalating impressions of a dangerous world, and the overrepresentation of youth and beauty may be a causal factor of eating disorders. In this article, we explore the possibility that the media may also serve as a powerful creator of the very public opinions it seeks to reflect in its news. Subtle nonverbal cues of newscasters have been shown to influence voting behavior, and the media's overrepresentation of the proportion of blacks in poverty may decrease whites' support of welfare. By portraying a world in which people's opinions are based on their ethnic or demographic group membership, the media may also subtly but powerfully create the very opinions they seek to reflect.     

Sequence-Specific Impairment of Memory Formation by NCAM Antisense Oligonucleotides

The functional role of NCAM gene expression in memory formation was studied in the one-trial passive avoidance task in day-old chicks by pretraining injections of one of three different 18-mer end-protected oligonucleotides corresponding to positions 190-, 207-, and 332- of the NCAM Ig1 domain. Twenty-four-hour-old chicks were trained by pecking at a bitter-tasting bead and tested for avoidance 30 min, 3, 8, or 24 hr later. Memory retention was significantly reduced only in the group of animals injected with the NCAM antisense corresponding to position 207- (AS-ODN-207), and only if given twice, both immediately after hatching and 12 hr before training. This antisense was without effect on the general behavior of the chicks, training or acquisition, and did not produce observable neurotoxic damage. Under such conditions amnesia was evident by 3 hr after training and lasted until at least 24 hr after training. The two other tested oligonucleotides were without behavioral effect. To control for nonsequence-specific effects of AS-ODN-207, brains from injected and trained animals were processed for Western blotting and probed using anti-NCAM, anti-L1, and anti-actin antibodies. NCAM antisense corresponding to position 207- significantly reduced the level of NCAM, whereas the level of L1 and actin remained unchanged. These results confirm our earlier conclusion that NCAM is necessary for longer term memory retention.     

Frequency judgements: the problem of defining a perceptual event

In four experiments the conditions under which frequency judgments reflect the relative frequency of complex perceptual events were explored. Subjects viewed a series of 4 x 4 grids each containing seven items, which were letters and numbers in one of four typefaces. Later judgments of the relative frequency with which particular letters appeared in particular typefaces were unaffected by a warning about an upcoming frequency judgment task, but were affected by both the time available for processing the stimuli and the nature of the cover task subjects engaged in while viewing the grids. Frequency judgments were poor when exposure durations were less than 2 s and when the cover task directed subjects' attention merely to the locations of the items within the grids. Frequency judgments improved when the cover task directed subjects' attention to the identity of the stimuli, especially to the conjunction of letter and typeface. The results suggest that frequency estimation of complex stimuli may be possible only for stimuli that have been processed as phenomenal objects.     

Book reviews

Hall, G. (1991). Perceptual and associative leaning. Oxfod: Clarendon Press. Pp. xi + 300. ISBN 0-19-8524182-0. £35.00.

Rahmann, H., & Rahmann, M. (1992). The neurobilogical basis of memoy and behavior. New York: Springe Verlag. Pp. 292. ISBN 3-540-97545-4. £53.00.

Iversen, I.H., & Lattal, K.A. (Eds.). (1991). Experimental analysis of behavior, arts 1 and 2. Techniques in the behavioral and neural sciences, volume 6 (series editor: J.P Huston). Amstedam: Elsevier. Pp. 724. ISBN 0-444-8932-2. £50.00 (paperback).

Baudry, M., & Davis, J.L. (Eds.) (1991). Long-tem potentiation: A debate of current issues. Cambridge, Ma & London, England: MIT Press. Pp. xxii + 454. ISBN 0-262-02330-x. £62.95 (Hb).

The Biological Council Animal Reseach and Welfare Panel (1992). Guidelines on the handling and training of laboatory animals. Univer-sities Federation for Animal Welfare. Pp. ISBN 0-900767-77-4. £2.50.     

Sensitive Topics,Missing Data,and Refusal in Social Network Studies: An Ethical Examination

We describe our ethics‐driven process of addressing missing data within a social network study about accountability for racism, classism, sexism, heterosexism, cis‐sexism, ableism, and other forms of oppression among social justice union organizers. During data collection, some would‐be participants did not return emails and others explicitly refused to engage in the research. All refusals came from women of color. We faced an ethical dilemma: Should we continue to seek participation from those who had not yet responded, with the hopes of recruiting more women of color from within the network so their perspectives would not be tokenized? Or, should we stop asking those who had been contacted multiple times, which would compromise the social network data and analysis? We delineate ways in which current discussions of the ethics of social network studies fell short, given our framework and our community psychology (CP ) values. We outline literature that was helpful in thinking through this challenge; we looked outside of CP to the decolonization literature on refusal. Lessons learned include listening for the possible meanings of refusals and considering the level of engagement and the labor required of participants when designing research studies.     

Differential effects of arousal in positive and negative autobiographical memories

Autobiographical memories are characterised by a range of emotions and emotional reactions. Recent research has demonstrated that differences in emotional valence (positive vs. negative emotion) and arousal (the degree of emotional intensity) differentially influence the retrieved memory narrative. Although the mnemonic effects of valence and arousal have both been heavily studied, it is currently unclear whether the effects of emotional arousal are equivalent for positive and negative autobiographical events. In the current study, multilevel models were used to examine differential effects of emotional valence and arousal on the richness of autobiographical memory retrieval both between and within subjects. Thirty-four young adults were asked to retrieve personal autobiographical memories associated with popular musical cues and to rate the valence, arousal and richness of these events. The multilevel analyses identified independent influences of valence and intensity upon retrieval characteristics at the within- and between-subject levels. In addition, the within-subject interactions between valence and arousal highlighted differential effects of arousal for positive and negative memories. These findings have important implications for future studies of emotion and memory, highlighting the importance of considering both valence and arousal when examining the role emotion plays in the richness of memory representation.