VSearch: Macintosh software for experiments in visual search

In this paper, we describe software that turns a Macintosh computer into an off-the-shelf tool for experiments on visual search. Our design goals included portability (between members of the Macintosh computer family and between various research settings), user-friendliness (equivalent to Macintosh programming standards), flexibility (to allow replication and extension of important experiments on visual search), and adaptability (very short design-to-data and data-to-analysis turnaround times). We describe how the software meets these goals in three major phases of an experiment: stimulus construction, experimental control, and statistical analysis. We then list several landmark studies of visual search that can be easily designed and extended with the software. Finally, we outline plans for expanding the experimental variations that will be supported in future versions of the software.     

A computerized system for monitoring and controlling intracranial electrical self-stimulation behavior

An automated system for measuring intracranial self-stimulation behavior is described. The system consists of two Commodore 6502 microcomputers interfaced with a constant-current generator and a standard operant chamber. The system hardware allows sine- and square-wave stimulation. Stimulus intensity can be varied in 256 steps between 0 and 100, 0 and 500, or 0 and 1,000 /µA. The system programs, which are written in machine language, allow the control of various schedules of reinforcement, the counting of operant responses and reinforcements, the measurement of interresponse intervals, and the storage of the data on disk. The software is designed for the determination of the threshold of reinforcement, on the basis of the titration of postreinforcement pauses caused by changeover in schedule control between concurrent continuous reinforcement and fixed ratio schedules.     

Young infants’ perception of liquid coarticulatory influences on following stop consonants

Phonetic segments are coarticulated in speech. Accordingly, the articulatory and acoustic properties of the speech signal during the time frame traditionally identified with a given phoneme are highly context-sensitive. For example, due to carryover coarticulation, the front tongue-tip position for HI results in more fronted tongue-body contact for a /g/ preceded by /l/ than for a /g/ preceded by /r/. Perception by mature listeners shows a complementary sensitivity—when a synthetic /da/-/ga/ continuum is preceded by either /al/ or /ar/, adults hear more /g/s following HI rather than Irl. That is, some of the fronting information in the temporal domain of the stop is perceptually attributed to /l/ (Mann, 1980). We replicated this finding and extended it to a signaldetection test of discrimination with adults, using triads of disyllables. Three equidistant items from a /da/-/ga/ continuum were used preceded by /al/ and /ar/. In the identification test, adults had identified item ga5 as “ga”, and dal as “da”, following both /al/ and /ar/, whereas they identified the crucial item d/ga3 predominantly as “ga” after /al/ but as “da” after /ar/. In the discrimination test, they discriminated d/ga3 from dal preceded by /al/ but not /ar/; compatibly, they discriminated d/ga3 readily from ga5 preceded by /ar/ but poorly preceded by /al/. We obtained similar results with 4-month-old infants. Following habituation to either ald/ga3 or ard/ga3, infants heard either the corresponding ga5 or dal disyllable. As predicted, the infants discrimi-nated d/ga3 from dal following /al/ but not /ar/; conversely, they discriminated d/ga3 from ga5 following /ar/ but not /al/. The results suggest that prelinguistic infants disentangle consonant-consonant coarticulatory influences in speech in an adult-like fashion.     

Depression in patients with spinal cord injuries: A synthesis of cognitive and somatic processes

Depression in some patients with spinal cord injuries may be clinically significant and, when present, should be treated to decrease morbidity including decreased physical functioning. Depression associated with spinal cord injury (SCI) may be misevaluated, due to (1) nonspecific multifactorial production of depression symptoms and (2) SCI-specific decrease in somatic sensory central nervous system input. The Somatic Suppression Hypothesis suggests that SCI patients have difficulty experiencing any intense emotion because of suppression of physiological arousal. In addition, cognitive processes that may reduce depression in SCI patients include: (1) attribution of somatic symptoms of depression to medical (biological) causes, (2) realistic, positive expectations for physical improvement, and (3) the perception that the disability of the SCI is only minimally related to the patient’s self-care after complete evaluation. Health personnel should accept lack of depression in SCI, and should encourage positive realistic expectations of recovery.     

Who Uses the Cost-Benefit Rules of Choice? Implications for the Normative Status of Microeconomic Theory

We find three factors to be associated with use of cost-benefit rules in everyday decisions. These are effectiveness in achieving desirable life outcomes, intelligence, and training in economics. We argue that these empirical findings support the claim that cost-benefit reasoning is normative.     

人类颜色视觉的计算理论

该文有机地结合了计算视觉理论和生态学视觉理论,指出颜色信息处理的根本任务是检测环境中的光不变量。在此基础上,作者提出了颜色视觉的计算理论以及计算理论本身的生物学标准。初级视觉计算是典型的不适定问题,动物的视觉系统则利用视环境中存在的条件将该不适定问题转化为定解问题。本文引入颜色视觉计算的免要条件,客观性约束,以及颜色认知的神经表象,证明了上述约束下颜色算法的存在性。本文给出了构造颜色知觉的基本假设。同时,该文还讨论了与上述问题密切相关的几个基本问题:神经表象的完备性,主观色觉的客观性,明度知觉和颜色知觉的统一,人类主观色觉的实现方式。     

Consultation Contracts

Consultants enter into legal contracts each time they agree to a consultation arrangement outside of their regular work setting. They need to understand the legal context of contracts within which they perform their services and recognize the benefits a written agreement provides. Counselors often provide consultation services as a regular part of their job responsibilities. In such situations, a separate legal contract is not formed when a consultation relationship is created. A written understanding of the consultation arrangement, however, can be beneficial to the consultant and consultee even though a legal contract does not exist.     

HIV Disease: Current Concepts

The human immunodeficiency virus (HIV) causes a chronic, progressive, immune deficiency disease, the most severe phase of which is Acquired Immune Deficiency Syndrome (AIDS). HIV is a newly characterized human retrovirus transmitted only by direct exposure to blood or blood derivatives, certain acts of sexual intercourse, or transfer from infected mother to fetus or infant. In this article the author reviews the most important current epidemiologic, clinical, and virologic information about HIV and HIV disease and provides a factual framework for understanding the issues created by the epidemic.