Reference frames in mental rotation

Four experiments are reported that investigate whether images or reference frames are transformed during a mental rotation task. In all experiments a display of four identical letters (P1) was presented at either +90 degrees or -90 degrees from upright, and subjects had to decide whether the letters were normal or mirror-image reflections. A single letter (P2) was then presented 100 ms later in a variable orientation with the same task instructions. Reaction times to P2 were assessed to determine whether an image of P2 was rotated to upright or whether an internal reference frame was rotated into congruence with P2 from the orientation of P1. The results as a whole suggest that transformations of P2 can be initiated either relative to upright or relative to the orientation of P1. They further indicate that the probability of using each reference orientation can be changed by procedural variations. The findings are most parsimoniously interpreted as suggesting that mental rotation involves the transformation of reference frames rather than the transformation of template-like representations.     

Effects of experimenter and mother presence on the attentional performance and activity of hyperactive boys

The attentional performance, activity, and off-task behavior of hyperactive boys with and without conduct problems and normal boys were compared on a cancellation task under three conditions: when performing the task alone, with mother present, and with experimenter present. Results indicated that both the hyperactive groups achieved poorer attentional scores than normal subjects in the alone and mother present conditions, but improved in the experimenter present condition. The performance of the hyperactive boys with conduct problems was particularly affected by this condition. The activity and off-task behavior scores of both the hyperactive groups were higher than controls in all conditions, although the hyperactive boys with conduct problems decreased in off-task behavior when the experimenter was present. Attention and behavior scores were not significantly correlated. The implications of these findings for assessment of hyperactivity, and the role of noncompliance in the attentional behavior of hyperactive children, are discussed.This study is based in part on the first author's Ph.D. thesis in the Department of Psychology, University of Melbourne.     

Attention and probabilistic sequence learning

Limitations of using fixed sequences of events in studies of learning in the sequential reaction-time task led us to develop a probabilistic version of the task. When sequences occur probabilistically, transitions usually follow a sequence, but with some small probability, events occur out of sequence. This variation on the paradigm provides new evidence associated with manipulations of attentional load. Most notably, single-task learning leads to particularly high error rates on improbable transitions, suggesting anticipation of the sequence. Dual-task learning shows sensitivity to the sequence (by reaction-time differences to probable and improbable transitions), but without inflated errors on improbable transitions. Sensitivity to the sequence and anticipatory errors disappeared when participants transferred from single-task learning to dual-task conditions, suggesting that what is learned with single-task practice cannot be applied under conditions of limited attention. When learners transferred from dual- to single-task conditions, sensitivity of RT to the sequence increased but anticipation errors remained the same, suggesting that attentional load limits performance, but not learning. Qualitative differences in performance result from variations in attentional resources, which may reflect different learning processes. Received: 17 February 1997 / Accepted: 5 January 1998     

The filled-duration illusion: The function of temporal and nontemporal set

Studies of the perception of time have demonstrated that large visual stimuli presented for the same duration as small stimuli will appear to have been presented longer. Two theoretical approaches have been offered to explain this effect. Both have emphasized the absolute amount of information in the stimulus. Thus, both would predict the effect when size is varied between sessions. The present study found no effect of size when size was held constant within sessions, but a substantial effect resulted when size was varied within sessions. Also examined was the range of stimulus durations used within a session. In one condition, patterns of various sizes were presented at 15, 30, or 45 msec, while in a second condition, the same patterns were presented to a different group of subjects at 15, 85, or 155 msec. The size effect was significantly reduced when longer time intervals were presented. A third group of subjects was shown patterns at even longer times but with a reduced range (155, 170, and 185 msec). Here the size effect was of equal magnitude to that of the 15-msec interval condition. The implications of these results are that current theoretical explanations of the filled-duration illusion rely on incorrect assumptions.     

The inter-relations of mother and father attachment, self-esteem and aggression during late adolescence

This study examined three models depicting the relations between mother and father attachment, self-esteem and aggression. A total of 385 participants (173 males and 212 females), aged from 18 to 20 years, completed self-rating questionnaires covering mother and father attachment, self-esteem and aggression. Results showed that self-esteem had additive and mediation effects on both the father attachment-aggression and mother attachment-aggression relationships, and also moderated the mother attachment-aggression relation. These findings are discussed in terms of different models for the inter-relations of mother and father attachment, self-esteem and aggression in late adolescence.     

Relationships between musical structure and psychophysiological measures of emotion

Psychophysiological studies with music have not examined what exactly in the music might be responsible for the observed physiological phenomena. The authors explored the relationships between 11 structural features of 16 musical excerpts and both self-reports of felt pleasantness and arousal and different physiological measures (respiration, skin conductance, heart rate). Overall, the relationships between musical features and experienced emotions corresponded well with those known between musical structure and perceived emotions. This suggests that the internal structure of the music played a primary role in the induction of the emotions in comparison to extramusical factors. Mode, harmonic complexity, and rhythmic articulation best differentiated between negative and positive valence, whereas tempo, accentuation, and rhythmic articulation best discriminated high arousal from low arousal. Tempo, accentuation, and rhythmic articulation were the features that most strongly correlated with physiological measures. Music that induced faster breathing and higher minute ventilation, skin conductance, and heart rate was fast, accentuated, and staccato. This finding corroborates the contention that rhythmic aspects are the major determinants of physiological responses to music.     

Weight-related words associated with figure silhouettes

Antifat attitudes and obesity bias are prevalent in Western society; however, little is known about the social meanings and connotations of weight-related words such as fat, overweight, and obese (e.g., Robison & Erdman, 1998). The purpose of this study was to explore college students' perceptions of weight-related terminology. Participants (n=131) completed a modified figure rating scale in which they identified male and female figure silhouettes most associated with a variety of weight-related words and personal characteristics. Additionally, participants completed a word association task and provided definitions of five weight terms. Results indicated that participants grouped weight terms into two groupings (i.e., "slender" and "heavy" weight terms) both in the figure rating task and in the word association and definition tasks. Both male and female participants selected smaller female figure silhouettes for the weight terms overweight, large, fat, and normal weight than for the male figure silhouettes. Moreover, associations between weight-related words and personal characteristics, including normal weight -physically fit and overweight -lazy, were found. The results suggest that weight-related words carry with them social meanings and values that reflect an "ideology of blame."     

Bicuculline infusion into the accessory olfactory bulb facilitates the induction of maternal behavior in rats

The GABAA antagonist bicuculline, intracranially infused into the accessory olfactory bulb (AOB), facilitated the expression of maternal behavior (MB) in virgin Wistar female rats. Behavioral effects were observed 24 hours after infusion and were injection dependent. Pheromonal stimuli, generated by the pups, are thought to exert an inhibitory effect on vomeronasal nuclei involved in MB in virgin rats. The present study investigated the possibility that a decrement in AOB output, resulting from long-term compensatory synaptic changes to chronic bicuculline infusion, would facilitate the expression of MB. The implications of our findings for the mechanisms involved in the induction of MB and the maternal experience effect are discussed.