Metacontrast and brightness discrimination

An attempt was made to obtain U-shaped masking functions in two metacontrast experiments. Trained Ss judged whether a square test stimulus (TS) was bright or dim. The TS was presented alone or in conjunction with an adjacent pair of square masking stimuli (MS) whose energy equaled the bright TS. The stimulus onset asynchronies (SOA) rangedfrom 0 to 125 msec. The task minimized the role of apparent movement cues as a reliable basis for judgrnent. Similar studies have employed TS plus MS vs MS alone as the alternatives, allowing apparent movement to be a cue. Brightness accuracy was a U-shaped function of SOA. This finding is consistent with neural-net models (Weisstein, 1968). However, analysis of Ss’ response bias suggested an alternative explanation involving the MS as a comparison stimulus at short SOA. It was concluded that U-shaped masking functions are also consistent with theories based upon independent component processes, e.g., Schurman and Eriksen (1970) and Uttal (1970).     

Sensitivity and decisional factors in the psychological refractory period

Three trained Ss responded to a pair of events presented at fixed interstimulus intervals (ISIs) of 33, 67, and 100 msec. Each event was the independent presence of a visual stimulus (S-P) or its absence (S-A), to which Ss were to respond or not, with a set for speed over accuracy. The probabilities of Sop occurrence [P(S)] to each of the events were varied. Pretrial verbal reports or behavioral hypotheses (BHs) werealso obtained. P(S), ISI, BH, and order (first vs second event) were all generally determinants of both RT to Sop and inhibition probability to S-A. However, when the RT data were corrected for inhibition probability, order was the only systematic effect that remained. The results were discussed in terms of approaches to the psychological refractory period derived from signal detection theory involving differential sensitivity as opposed to criterion.     

Hemispheric function and linguistic skill in the deaf

The nature of hemispheric processing in the prelingually deaf was examined in a picture-letter matching task. It was hypothesized that linguistic competence in the deaf would be associated with normal or near-normal laterality (i.e., a left hemisphere advantage for analytic linguistic tasks). Subjects were shown a simple picture of a common object (e.g., lamp), followed by brief unilateral presentation of a manually signed or orthographic letter, and they had to indicate as quickly as possible whether the letter was present in the spelling of the object's label. While hearing subjects showed a marked left hemisphere advantage, no such superiority was found for either a linguistically skilled or unskilled group of deaf students. In the skilled group, however, there was a suggestion of a right hemisphere advantage for manually signed letters. It was concluded that while hemispheric asymmetry of function does not develop normally in the deaf, the absence of this normal pattern does not preclude the development of the analytic skills needed to deal with the structure of language.     

ABSTRACTS OF LITERATURE

This is a report on the methodology for an outcome study of marital therapy, comparing an interpretative approach with a direct, behavioral approach based on operant conditioning principles. A control group will receive common sense, nondirective, and noninterpretive therapy. All three types of treatment will be given by the same therapist. Assessment will be done by an independent assessor, blind to treatment, and by questionnaires filled out separately by each partner, covering work, leisure, social, and sexual spheres, as well as symptoms. Sessions will be given every other week, usually up to ten sessions, but cases could be stopped earlier. An example of each of the three approaches is given, and preliminary impressions of treatment are reported.     

Not only base rates are neglected in the Engineer-Lawyer problem: An investigation of reasoners’ underutilization of complementarity

The standard Engineer-Lawyer problem (Kahneman & Tversky, 1973) points to the failure of reasoners to integrate mentioned base-rate information in arriving at likelihood estimates. Research in this area nevertheless has presupposed that participants respect complementarity (i.e., participants ensure that competing estimates add up to 100%). A survey of the literature leads us to doubt this pre-supposition. We propose that the participants' non-normative performance on the standard Engineer-Lawyer problem reflects a reluctance to view the task probabilistically and that normative responses become more prominent as probabilistic aspects of the task do. In the present experiments, we manipulated two kinds of probabilistic cues and determined the extent to which (1) base rates were integrated and (2) the complementarity constraint was respected. In Experiment 1, six versions of an Engineer-Lawyer-type problem (that varied three levels of cue to complementarity and two base rates) were presented. The results showed that base-rate integration increased as cues to complementary did. Experiment 2 confirmed that Gigerenzer, Hell, and Blank's (1988) random-draw paradigm facilitates base-rate integration; a second measure revealed that it also prompts respect for complementarity. In Experiment 3, we replicated two of our main findings in one procedure while controlling for the potential influence of extraneous task features. We discuss approaches that describe how probabilistic cues might prompt normative responding.     

A behavioural-pharmacological treatment of dually addicted patients

maintenance appears to be an effective means of treating narcotic addiction both because it blocks the effects of heroin and because patients are willing to accept methadone treatment. However, alcoholism has been found commonly to complicate methadone maintenance and to result in treatment failure. The regular ingestion of disulfiram, a drug which blocks ethanol metabolism, could provide a solution to this problem, but alcoholics tend not to persist in taking this drug, because unlike methadone it possesses no reinforcing properties. This paper describes a novel technique whereby the reinforcing action of methadone has been employed to maintain disulfiram-taking, and thus to arrest alcohol abuse and consequent treatment failure.     

Philosophy of Language and Meta-Ethics

Meta-ethical discussions commonly distinguish 'subjectivism' from 'emotivism', or 'expressivism'. But Frank Jackson and Philip Pettit have argued that plausible assumptions in the philosophy of language entail that expressivism collapses into subjectivism. Though there have been responses to their argument, I think the responses have not adequately diagnosed the real weakness in it. I suggest my own diagnosis, and defend expressivism as a viable theory distinct from subjectivism.