Geometric determinants of human spatial memory

Geometric alterations to the boundaries of a virtual environment were used to investigate the representations underlying human spatial memory. Subjects encountered a cue object in a simple rectangular enclosure, with distant landmarks for orientation. After a brief delay, during which they were removed from the arena, subjects were returned to it at a new location and orientation and asked to mark the place where the cue had been. On some trials the geometry (size, aspect ratio) of the arena was varied between presentation and testing. Responses tended to lie somewhere between a location that maintained fixed distances from nearby walls and a location that maintained fixed ratios of the distances between opposing walls. The former were more common after expansions and for cued locations nearer to the edge while the latter were more common after contractions and for locations nearer to the center. The spatial distributions of responses predicted by various simple geometric models were compared to the data. The best fitting model was one derived from the response properties of 'place cells' in the rat hippocampus, which matches the 'proximities' 1/(d+c) of the cue to the four walls of the arena, where d is the distance to a wall and c is a global constant. Subjects also tended to adopt the same orientation at presentation and testing, although this was not due to using a view matching strategy, which could be ruled out in 50% of responses. Disoriented responses were most often seen where the cued location was near the center of the arena or where the long axis of a rectangular arena was changed between presentation and testing, suggesting that the geometry of the arena acts as a weak cue to orientation. Overall, the results suggest a process of visual landmark matching to determine orientation, combined with an abstract representation of the proximity of the cued location to the walls of the arena consistent with the neural representation of location in the hippocampus.     

What do you get when you cross a scapegoat with a trojan horse: A special edition?

Any short commentary is necessarily going to be partial in the various senses in which that can be understood. Here, partiality will be owned as the concentration upon limited aspects of a multifaceted phenomenon. To find a special edition on ‘Qualitative Social Psychology’ is an event. The focus here will be on two analytic moments of that event: concept and actualization.     

Creating false memories of infancy with hypnotic and non‐hypnotic procedures

This study was designed to test the conditions under while false memory reports are likely to be elicited from hypnotic and non‐hypnotic participants. Low, medium and high hypnotizables were administered either a hypnotic or non‐hypnotic suggestion for regression to the day after birth. False memories of infancy were generated in 68 of 78 age‐regressed participants, nearly half of whom reported strong beliefs in the reality of their recovered ‘memories’. Non‐hypnotic participants were slightly but significantly more likely to report infancy experiences than were hypnotic participants. However, hypnotizability did not have a significant effect on the classification of these experiences as memories or as fantasies. Implications for the experimental and clinical contexts are discussed. Copyright © 1999 John Wiley & Sons, Ltd.     

Changes in Feeling States Following Aquatic Exercise During Pregnancy

Forty-four pregnant women participated in water aerobics 2 times per week for a period of 6 weeks, with each session lasting approximately 45 min. The hypothesis that participants would report greater feelings of positive well-being and less psychological distress and fatigue during the 6-week program as compared to preprogram reports was supported. Also supporting our hypothesis, similar improvements were noted following a single bout of exercise during each week of the program. Taken together, the results of the present study suggest that regular engagement in an aquatic exercise program is associated with improvements in positive feeling states and reductions in negative feeling states and fatigue for women during pregnancy.     

Social rejection and ADHD in young adults: an analogue experiment

Poor outcomes in ADHD may be related to problematic social functioning and consequences of social rejection. This study examines how ADHD symptom expression affects mood and social rejection. Working from findings in depression that describe maintenance through negative interpersonal interactions, the authors seek to examine this theory's applicability to poor outcomes in ADHD. In a completely randomized design, 130 participants are exposed to one of several videotape segments that include displays of ADHD, depression, and social anxiety. A normal control is also used. All abnormal videotapes are met with greater rejection than the control. Displays of ADHD elicit similar levels of rejection to those elicited by displays of depression. Additionally, ADHD elicits greater levels of hostile mood, whereas depression elicits high levels of depression and fatigue. Implications for an interpersonal theory of vulnerability in ADHD are discussed along with implications for future research, prevention, and intervention.     

Affective personality differences in neural processing efficiency confirmed using fMRI

To test for a relation between individual differences in personality and neural-processing efficiency, we used functional magnetic resonance imaging (fMRI) to assess brain activity within regions associated with cognitive control during a demanding working memory task. Fifty-three participants completed both the self-report behavioral inhibition sensitivity (BIS) and behavioral approach sensitivity (BAS) personality scales and a standard measure of fluid intelligence (Raven’s Advanced Progressive Matrices). They were then scanned as they performed a three-back working memory task. A mixed blocked/ event-related fMRI design enabled us to identify both sustained and transient neural activity. Higher BAS was negatively related to event-related activity in the dorsal anterior cingulate, the lateral prefrontal cortex, and parietal areas in regions of interest identified in previous work. These relationships were not explained by differences in either behavioral performance or fluid intelligence, consistent with greater neural efficiency. The results reveal the high specificity of the relationships among personality, cognition, and brain activity. The data confirm that affective dimensions of personality are independent of intelligence, yet also suggest that they might be interrelated in subtle ways, because they modulate activity in overlapping brain regions that appear to be critical for task performance.     

Infant-directed speech produced by fathers with symptoms of depression: effects on infant associative learning in a conditioned-attention paradigm

Infant-directed (ID) speech produced by fathers who varied in their number of self-reported symptoms of depressed was analyzed for differences its ability to promote infant voice-face associative learning. Infants of fathers with elevated scores on the Beck Depression Inventory-II (BDI-II) showed significantly poorer learning than did infants of fathers with non-elevated BDI-II scores when their fathers' ID speech served as a conditioned stimulus for a face reinforcer in a conditioned-attention paradigm. Fathers with elevated BDI-II scores produced ID speech with marginally significantly lower F0 variability than fathers with non-elevated BDI-II scores. However, F0-related cues were uncorrelated with infant learning. Overall, fathers' ID speech contained significantly less F0 modulation than did mothers' ID speech. These findings show that paternal depression, like maternal depression, adversely affects infant learning in a conditioned-attention paradigm.     

The newsworthiness of suicide

There is a paucity of studies examining which suicides are considered news-worthy. By combining data on media reports of individuals' suicides with routinely collected suicide data, it was found that 1% of Australian suicides were reported over a 1-year period. There was evidence of over-reporting of suicides by older people and females, and those involving dramatic methods. Reported suicides fell into three groups: suicides reported in a broader context; suicides by celebrities; and suicides involving unusual circumstances/methods. The data suggest a need for media professionals and suicide experts to work together to balance newsworthiness against the risk of copycat behavior.     

An Evaluation of the Two-Factor Model of Emotion: Clinical Moderators Within a Large,Multi-Ethnic Sample of Youth

The two-factor model of emotion clarifies the complexities of the relationship between anxiety and depression through their varying associations with positive and negative affect. Although this model’s structure has been validated in community samples of children, little research has evaluated the model among clinically referred youth. The present investigation aimed to confirm the two-factor model of emotion within a sample of clinically-referred children (N?=?879) and to investigate potential moderators of the model’s relationships within that group. Structural equation modeling demonstrated excellent fit for the two-factor model, and moderating effects for the model structure were found related to age and diagnostic category. These results support the model’s usefulness in describing patterns of psychopathology and temperament for clinically referred children and suggest the potential for a unified treatment approach to internalizing psychopathology.