Occurrence of imagery and its link with early memories in agoraphobia

Recent cognitive models suggest that mental imagery can help us understand the maintenance of anxiety disorders (e.g., de Silva, 1986; Hackmann, Surawy, & Clark, 1998). However, imagery is relatively unexplored within agoraphobia. Such images are also thought to be useful in uncovering memories that occurred around the onset of a disorder (Hackmann, Clark, & McManus, 2000). A total of 20 patients with agoraphobia and 20 matched controls took part in this investigation. Participants described any recurrent images they experienced in agoraphobic situations, and also any associated memories. All patients with agoraphobia (but no control participants) reported having distinct recurrent images in "agoraphobic situations". Most images involved several sensory modalities and in the majority of cases appeared to be linked with unpleasant memories of events experienced many years previously. While these exploratory findings require replication, potential treatment implications are discussed.     

Chronic stress impairs recall of extinction of conditioned fear

Chronic restraint stress produces retraction of apical dendrites of pyramidal neurons in medial prefrontal cortex. To begin to examine the functional significance of this dendritic reorganization, we assessed the effects of chronic restraint stress on a prefrontally mediated behavior, extinction of conditioned fear. After bar press training to obtain a baseline of activity against which to measure freezing, rats were either unstressed or stressed via placement in a plastic restrainer (3 h/day for 1 week). After an additional day of bar press training, rats underwent fear conditioning and extinction. Rats received five habituation trials to a 30-s tone (4.5 kHz, 80 db) followed by seven pairings of tone and footshock (500 ms, 0.5 mA). One hour later, rats received tone-alone extinction trials to criterion. The next day, rats received 15 additional extinction trials. Percent freezing was assessed during all phases of training. Stress did not significantly affect unconditioned responding to tone, acquisition of conditioned fear, or initial extinction, but significantly increased freezing on extinction day 2. Thus, consistent with the regressive dendritic changes seen in medial prefrontal cortex, one week of restraint stress specifically impaired recall of extinction, a pattern of deficits typical of animals with impaired medial prefrontal function.     

The influence of exploration mode, orientation, and configuration on the haptic Müller-Lyer illusion

We studied the impact of manner of exploration, orientation, spatial position, and configuration on the haptic Müller-Lyer illusion. Blindfolded sighted subjects felt raised-line Müller-Lyer and control stimuli. The stimuli were felt by tracing with the index finger, free exploration, grasping with the index finger and thumb, or by measuring with the use of any two or more fingers. For haptic judgments of extent a sliding tangible ruler was used. The illusion was present in all exploration conditions, with overestimation of the wings-out compared to wings-in stimuli. Tracing with the index finger reduced the magnitude of the illusion. However, tracing and grasping induced an overall underestimation of size. The illusion was greatly attenuated when stimuli were felt with the index fingers of both hands. Illusory misperception was not altered by the position in space of the Müller-Lyer stimuli. No effects of changes in the thickness of the line shaft were found, but there were effects of the length of the wing endings for the smaller, 5.1 cm stimuli. The theoretical and practical implications of the results are discussed.     

Early temperamental traits in an octopus (Octopus bimaculoides)

During their 3rd week of life, 73 Octopus bimaculoides were observed to test whether discrete behaviors could be grouped reliably to reflect dimensions of temperament. Frequencies of behaviors during Week 3 were subjected to principal-components analysis (PCA), resulting in 4 components (active engagement, arousal/readiness, aggression, and avoidance/disinterest) that explain 53% of the variance. Levels of temperamental traits were then evaluated for 37 octopuses using composite scores at 3 time points across the first 9 weeks of life. Profile analysis revealed significant change for the testing group as a whole in trait expression levels from Week 3 to Week 6. Results also suggest a significant effect of relatedness on developing temperamental profiles of octopuses. Discussion focuses on how results apply to the life history of O. bimaculoides and what temperament can reveal about adaptive individuality in a protostome.     

Task switching mediates the attentional blink even without backward masking

When two targets are presented in rapid succession, perception of the second target is impaired at short intertarget lags (100-700 msec). This attentional blink (AB) is thought to occur only when the second target is backward masked. To the contrary, we show that task switching between the targets can produce an AB even without masking (Experiments 1 and 3). Further, we show that task switching produces an AB only when the second target does not belong to a class of overlearned stimuli such as letters or digits (Experiments 1 and 4). When the second target is masked, however, an AB is invariably obtained regardless of switching or overlearning. We propose that task switching involves a time-consuming process of reconfiguration of the visual system, during which the representation of the second target decays beyond recognition, resulting in an AB deficit. We suggest that overlearned stimuli are encoded in a form that, while maskable, decays relatively slowly, thus outlasting the delay due to reconfiguration and avoiding the AB deficit.     

Focal distraction: spatial shifts of attentional focus are not required for contingent capture

Contingent capture occurs when distractors that share the target's defining attribute capture attention and slow down target identification. This slowdown has been attributed to an involuntary attentional shift to the location of a pertinent distractor. The present study examined an additional source of delay: the time spent in processing pertinent distractors. In 7 experiments, distractors were presented at fixation, and targets were presented either at fixation or peripherally. Contingent capture invariably occurred when a salient distractor was presented within about 600 ms before the target, even when spatial shifts in attentional focus were ruled out. A 2-stage model is proposed in which stimuli must pass an input filter tuned to the target's defining attribute before gaining access to a high-level stage that is unavailable while a distractor is being processed.     

Latent class analysis of college women's motivations for engaging in same-sex performativity

Same-sex performativity (SSP), or public performances of sexuality (e.g., kissing) between women who identify as heterosexual, is a relatively common relational experience among college-aged women. Identifying patterns of women's motivations for engaging in SSP can elucidate the heterogeneity among women's social and sexual behaviors during a critical developmental period (i.e., college). We used latent class analysis to identify classes of heterosexual undergraduate women who engaged in SSP (N = 282). We identified three classes of motivational patterns: Other-Motivated (i.e., notably motivated by male attention, wanting to shock others, wanting to bond, and social pressure), Ambiguously Motivated (i.e., most motivated by alcohol and fun, but minimally motivated overall), and Sexually Motivated (i.e., notably motivated by sexual desire and sexual experimentation). We then examined how class membership was associated with variables related to participants' evaluation of their SSP experience, self and identity, sexuality, and heterosexism. Classes significantly differed in SSP evaluations, as well as in certain facets of self and identity and sexuality (i.e., sorority membership and same-sex desire). These data provide evidence of substantial complexity in the characterizations of women who engage in SSP. We discuss the implications of the relationship between motivational patterns and women's evaluations of the SSP experience.     

A multisystems analysis of adolescent suicide attempters

The present study tested an ecologically based model, which predicted that hopelessness (individual level) mediates the effects of family dysfunction (interpersonal level) and socioeconomic status (sociocultural level) on both suicidal intent and suicidal ideation, within a sample of attempters. Subjects included adolescent males and females presenting at a general hospital emergency room following suicide attempts. Baron and Kenny's (1986) criteria for testing mediation models through multiple-regression analyses were employed. Little evidence of mediation was found. Hopelessness proved to be the best predictor of suicidal intent and ideation within a sample of attempters.     

Artificial legal standards in mental/emotional injury litigation

The courts historically have viewed mental and emotional injuries with suspicion. In attempting to ensure the genuineness of those claims that are brought to trial, most courts require that plaintiffs meet standards that go beyond those that are imposed for claims of physical injury, even though the value and validity of these additional standards have not been empirically assessed. Although the development of legal standards in the absence of empirical data is troubling, of particular concern is the fact that some of the imposed standards are artificial in that they refer to factors not directly related to the injury claimed. This study explores the impact of these standards on the litigation of claims for emotional injuries. The paper discusses the effects that artificial standards had upon claims pursued at the trial court level. According to these data, artificial standards are not warranted.