Past experience influences object representation in working memory

The nature of object representation in working memory is vital to establishing the capacity of working memory, which in turn shapes the limits of visual cognition and awareness. Although current theories discuss whether representations in working memory are feature-based or object-based, no theory has considered the role of past experience. However, work with humans and non-human primates suggests that once participants learn which features are important for category membership, these diagnostic features become more salient than non-diagnostic features in long-term memory and object recognition. Critically, the brain areas involved in this diagnosticity effect are also recruited during working memory tasks. We report two experiments testing whether a diagnosticity effect exists in working memory; and whether it is present when visual information is encoded into working memory, or if it is the result of maintenance within working memory. Results showed a diagnosticity effect which was present at encoding. Maintenance did not influence the nature of object representation in working memory. These findings show that the meaning we glean from our past experience has a profound influence on the nature of object representation in working memory.     

Hippocampal inactivation enhances taste learning

Learning tasks are typically thought to be either hippocampal-dependent (impaired by hippocampal lesions) or hippocampal-independent (indifferent to hippocampal lesions). Here, we show that conditioned taste aversion (CTA) learning fits into neither of these categories. Rats were trained to avoid two taste stimuli, one novel and one familiar. Muscimol infused through surgically implanted intracranial cannulae temporarily inactivated the dorsal hippocampus during familiarization, subsequent CTA training, or both. As shown previously, hippocampal inactivation during familiarization enhanced the effect of that familiarization on learning (i.e., hippocampal inactivation enhanced latent inhibition of CTA); more novel and surprising, however, was the finding that hippocampal inactivation during training sessions strongly enhanced CTA learning itself. These phenomena were not caused by specific aspects of our infusion technique--muscimol infusions into the hippocampus during familiarization sessions did not cause CTAs, muscimol infusions into gustatory cortex caused the expected attenuation of CTA, and hippocampal inactivation caused the expected attenuation of spatial learning. Thus, we suggest that hippocampal memory processes interfere with the specific learning mechanisms underlying CTA, and more generally that multiple memory systems do not operate independently.     

A device for concurrent bilateral measurement of outer eyelid closures in the rabbit

This paper describes a transducer that allows for the concurrent recording of outer eyelid closure on both the left and the right eyes of a rabbit. The device makes use of voltage induced across a current-carrying conductor when the conductor is exposed to a magnetic field perpendicular to its axis (the Hall effect). The transducer is relatively compact, inexpensive, and allows the animal to be loosely restrained.     

A telemetric device for measuring smoking topography

The Telemetric Topography Device (TTD) introduces new technology to the measurement of cigarette smoking topography that has advantages over existing instruments. It consists of a 90.8-g miniature vacuum transducer coupled to an FM transmitter contained within a 11/4-in.-diameter × 41/4-in. free-standing plastic cylinder. As a subject smokes through a modified commercial cigarette holder, the TTD transmits a tone proportional to the vacuum pressure change in the cylinder. Received tones are converted to voltage data and then digitized by an A/D board in a personal computer. This information can either be displayed and stored on line or recorded on audio tape and digitized during playback. The TTD has no visible electronic parts, thereby minimizing subjects’ awareness of monitoring.     

Green Crocodiles

The essence of spiritual counselling lies in the formal or informal teaching of meditation, where we turn away from the delusions of any achievement either psychological or material. These delusions, deeply embedded in psychotherapy and counselling, are essentially destructive. Real counselling lies in giving up ambitions and ideologies, not in acquiring more. Meditation can help us to live more fully in the present time.     

The restorative effects of smoking upon self-control resources: a negative reinforcement pathway

Based on a model in which self-control (SC) is considered to be a limited resource, research suggests that diminished SC resources may increase the likelihood of tobacco smoking. Yet, the inverse--how smoking may influence SC resources--has not been tested. The authors of this study utilized a randomized, 2 × 2 crossed-factorial (SC Depletion Manipulation × Smoking Manipulation), between-subjects design to test the hypothesis that smoking restores depleted SC resources. To manipulate SC depletion, experimenters instructed half of 132 nicotine dependent smokers to suppress their emotional reaction to a brief video depicting environmental damage (i.e., depletion), whereas the other half were instructed to "act natural" (i.e., no depletion) during viewing. Half of the participants in each condition then smoked a cigarette, whereas the other half sat patiently without smoking (i.e., smoke vs. no smoke). All participants then completed behavioral measures of SC. As hypothesized, an interaction occurred between the depletion and smoking manipulations for duration of time spent on a frustrating mirror-tracing task. That is, depletion reduced persistence on the task, unless depletion was followed by smoking. This effect was mediated by positive affect (PA). Thus, smoking appeared to restore depleted SC resources via modulation of PA, but independent of negative affect or smoking urges. These findings suggest that restoration of SC resources may represent another means by which smoking is negatively reinforced. The application of the self-control strength model to the study of nicotine dependence may inform the development of novel treatment modalities.     

Transgender individuals' workplace experiences: the applicability of sexual minority measures and models

The present study explored whether 3 existing measures of workplace constructs germane to the experiences of sexual minority people could be modified to improve their applicability with transgender individuals. To this end, the Workplace Heterosexist Experiences Questionnaire (WHEQ; C. R. Waldo, 1999); the Lesbian, Gay, Bisexual, and Transgendered Climate Inventory (LGBTCI; B. J. Liddle, D. A. Luzzo, A. L. Hauenstein, & K. Schuck, 2004); and the Workplace Sexual Identity Management Measure (WSIMM; M. Z. Anderson, J. M. Croteau, Y. B. Chung, & T. M. DiStefano, 2001) were modified to explicitly address the experiences of transgender individuals. Data from a sample of 263 transgender individuals were used to evaluate the psychometric properties of the modified measures. Analyses of the structures of the modified measures (Transgender Forms [TF]) suggested an alternative 2-factor structure for the WHEQ-TF, but provided support for the previously observed unidimensional structure for the LGBTCI-TF, and a slightly modified 3-factor structure for the WSIMM-TF. Cronbach's alpha reliability coefficients for scale or subscale items across the 3 measures were acceptable. Criterion-related validity was evident in theoretically consistent patterns of correlations between scores on the 3 modified measures and scores on indicators of job satisfaction and outness. These data provide preliminary support for transgender-specific versions of measures of 3 key constructs in the sexual minority vocational behavior research.     

A tutorial on approximate Bayesian computation

This tutorial explains the foundation of approximate Bayesian computation (ABC), an approach to Bayesian inference that does not require the specification of a likelihood function, and hence that can be used to estimate posterior distributions of parameters for simulation-based models. We discuss briefly the philosophy of Bayesian inference and then present several algorithms for ABC. We then apply these algorithms in a number of examples. For most of these examples, the posterior distributions are known, and so we can compare the estimated posteriors derived from ABC to the true posteriors and verify that the algorithms recover the true posteriors accurately. We also consider a popular simulation-based model of recognition memory (REM) for which the true posteriors are unknown. We conclude with a number of recommendations for applying ABC methods to solve real-world problems.     

Motivation,personal beliefs,and limited resources all contribute to self-control

What effects do motivation and beliefs have on self-control? We tested this question using a limited resource paradigm, which generally has found that people show poor self-control after prior exertions of self-control. Recent findings have suggested that motivation and even belief in unlimited willpower can render persons immune to ego depletion. We replicated those findings, but also showed they are limited to cases of mild depletion. When depletion is extensive, the effects of motivation and subjective belief vanished and in one case reversed. After performing only one self-control task, the typical pattern of self-regulation impairment was ameliorated among people who were encouraged to regard willpower as unlimited (Experiment 1) or motivated by task importance (Experiment 2). Those manipulations failed to improve performance among severely depleted persons who had done multiple self-control tasks. These findings integrate ideas of limited resources, motivation, and beliefs in understanding the nature of self-control over time.     

Laws and constrained kinds: a lesson from motor neuroscience

In this paper, I want to explore the question of whether or not there are laws in psychology. Jaegwon Kim has argued (Supervenience and mind. MIT press, Cambridge; 1993; Mind in a physical world. MIT press, Cambridge 1998) that there are no laws in psychology that contain reference to multiply realized kinds, because statements about such kinds fail to be projectible. After reviewing Kim??s argument for this claim, I show how his conclusion hinges on a hidden assumption: that a kind can only feature in a projectible statement if it is defined by an internal physical property. This assumption, however, is false: constrained kinds can feature in projectible statements, and yet they are not defined by any set of internal physical properties. I suggest that many mental terms actually refer to constrained kinds, and give an example from motor neuroscience of a constrained kind that is multiply realizable and ??projectible??: the intention to move voluntarily in a specific direction.