Input-specific long-term potentiation in the rat lateral amygdala of horizontal slices

Long-term potentiation (LTP) at input synapses to the lateral nucleus of the amygdala (LA) is a candidate mechanism for memory storage during fear learning. Cellular mechanisms of LTP have been nearly exclusively investigated in coronal brain slices. In our experiments, we used a horizontal brain slice preparation of rats that preserved most of the connections to cortical areas and the hippocampus. The stimulation electrodes were located either within the external capsule (EC) or the LA. The aim of the present study was to investigate the mechanisms of LTP induced either by weak theta burst stimulation (TBS) or strong high frequency stimulation (HFS) using the two different stimulation sites. Whereas both TBS and HFS of afferences running through the LA induced stable LTP, TBS failed to induce LTP of EC-inputs to the LA. The present findings also show that LTP in the LA exhibits vulnerability at different time windows after induction. The time window was dependent on the kind of stimulated afferences. Later LTP becomes resistant to disruption by low frequency stimulation. We could show that both used inputs depended on NMDA receptors for LTP-induction. LTP induced by stimulation of fibers within the LA was not altered by nifedipine (10 microM). In contrast, EC-induced LTP was dependent on L-type voltage-gated calcium channels (VGCC). Finally, we found a higher magnitude of LTP in females using TBS, whereas HFS did not cause gender-specific differences. Our study supports the conclusion that the form of LA-LTP depend on which afferences are activated and what pattern of stimulation is used to induce LTP.     

The impact of letter detection on eye movement patterns during reading: Reconsidering lexical analysis in connected text as a function of task

A comparison was made between reading tasks performed with and without the additional requirement of detecting target letters. At issue was whether eye movement measures are affected by the additional requirement of detection. Global comparisons showed robust effects of task type with longer fixations and fewer word skippings when letter detection was required. Detailed analyses of target words, however, further showed that reading with and without letter detection yielded virtually identical effects of word class and text predictability for word-skipping rate and similar effects for different word viewing duration measures. The overall oculomotor pattern suggested that detection does not substantially shift normal reading movements in response to lexical cues and thereby indicated that detection tasks are informative about word and specifically word class processing in normal reading.     

Memory for word location during reading: Eye movements to previously read words are spatially selective but not precise

In two experiments, readers' use of spatial memory was examined by asking them to determine whether an individually shown probe word had appeared in a previously read sentence (Experiment 1) or had occupied a right or left sentence location (Experiment 2). Under these conditions, eye movements during the classification task were generally directed toward the right, irrespective of the location of the relevant target in the previously read sentence. In two additional experiments, readers' knowledge of prior sentence content was examined either without (Experiment 3) or with (Experiment 4) an explicit instruction to move the eyes to a target word in that sentence. Although regressions into the prior sentence were generally directed toward the target, they rarely reached it. In the absence of accurate spatial memories, readers reached previously read target words in two distinct steps--one that moved the eyes in the general vicinity of the target, and one that homed in on it.     

Loss of vision during the retinal stabilization of letters

Upper- and lower-case letters of the alphabet were stabilized until loss of vision occurred. Loss of straight-line visibility was the most frequently reported perceptual event. Occasionally, features of letters separated spatially before their loss of visibility. In both instances, loss of visibility often resulted in the perception of a less complex letter. Confidence ratings for each loss of letter visibility indicated that participants were quite certain about perceived fragmentations. In a control experiment, participants were asked to guess how letters would fragment during stabilization. Again, loss of line visibility was the most frequently reported event. However, spatial separation of features was rarely predicted and complex letters were not predicted to fragment into simpler letter forms. Furthermore, the confidence in predicted fragmentation was quite low. These results are consistent with the view that losses of visibility during retinal stabilization constitute a distinct perceptual experience. Fragmentations appear to be determined by the availability of less complex letter forms and by the loss of subletter information, consisting of letter features and information specifying spatial configurations.     

Educational and career aspirations of secondary school students in Grenada following the American intervention

This paper reports a study of educational and occupational aspirations of secondary school students in Grenada following the 1983 American intervention. Questionnaire data were obtained from 729 students attending 7 of the island's 18 secondary schools. A status attainment model containing parental and family characteristics was tested. It was discovered that Grenadian students have exceptionally and unrealistically high aspirations. Although the opportunity structure in Grenada is very limited compared to that in the United States, the island's students have higher levels of aspirations. The status attainment model was not very useful in explaining either educational or occupational aspirations, as the levels of explained variance were less than 5%. The implications of high aspirations and low opportunities for the future of Grenada are discussed.     

Higher frequency of left-breast cancer: a possible explanation

A study of 1027 women with unilateral breast cancer showed that ipsilateral breast cancer was more common before age 45 and contralateral thereafter. The data suggest a possible explanation of the higher incidence of left-breast cancer in American women. A higher percentage of left-handed women developed breast cancer before age 45, but the over-all incidence of unilateral breast cancer was not greater in left-handed women than in right-handed or ambihanded subjects.     

The effect of factivity on lexical retrieval and postlexical processes during eye fixations in reading

Subjects were required to read short passages of text while their eye movements were monitored. Each experimental passage contained a critical factive or nonfactive verb that was followed by a false complement. In half of the trials, subjects' reading was unimpaired; in the remainder of the trial, a central visual pattern mask, which moved in synchrony with the eyes, was applied. The results showed that (1) factive and nonfactive verbs did not receive different amounts of fixation time during the reading text. However, (2) false complements that followed nonfactive verbs. On the basis of this, it is concluded that individual word characteristics, such as factivity, are encoded automatically while sentence interpretation requires effort to be completed.     

Psychoanalysis at the Millennium: A Personal Odyssey

A review of my development from psychology intern and research assistant to the psychoanalytic tester and theoretician David Rapaport at the Menninger Clinic in the 1940s, through my career psychological testing and my psychoanalytic training in the Western New England Institute and my working successively at the Austen Riggs Center, Yale Department of Psychiatry, Yale Student Mental Health Center, Cornell Department of Psychiatry, and eventually private practice in New York City. During this period, I rose to the academic rank of Professor and the analytic position of Training Analyst. I have written extensively: first on testing, then more or less in turn on psychoanalytic ego psychology, action language for psychoanalysis, feminist issues, narrative in psychoanalysis, and the contemporary Kleinians of London. This memoir traces the intellectual continuity that characterizes these writings and my continuing development as a psychoanalyst—my first ambition and great love.     

Social anxiety and difficulty disengaging threat: evidence from eye-tracking

Theoretical models of social phobia propose that biased attention contributes to the maintenance of symptoms; however these theoretical models make opposing predictions. Specifically, whereas Rapee and Heimberg (1997) suggested the biases are characterised by hypervigilance to threat cues and difficulty disengaging attention from threat, Clark and Wells (1995) suggested that threat cues are largely avoided. Previous research has been limited by the almost exclusive reliance on behavioural response times to experimental tasks to provide an index of attentional biases. The current study evaluated the relationship between the time-course of attention and symptoms of social anxiety and depression. Forty-two young adults completed a dot-probe task with emotional faces while eye-movement data were collected. The results revealed that increased social anxiety was associated with attention to emotional (rather than neutral) faces over time as well as difficulty disengaging attention from angry expressions; some evidence was found for a relationship between heightened depressive symptoms and increased attention to fear faces.