The effects of experimentally induced stress on false recognition.

The fallibility of memory has become an issue of considerable practical and theoretical importance. Here we studied the impact of experimentally induced stress on the ability of human participants to accurately recognise words presented on a list. We found that stress selectively disrupted participants' ability to distinguish words that were presented for study from critical lure words that were semantically related, but not presented for study. This finding indicates that stress, possibly through its impact on the hippocampus and prefrontal cortex, can potentiate false memories.     

The dynamics of experimentally induced criterion shifts

Investigations of decision making have typically assumed stationarity, even though commonly observed "context effects" are dynamic by definition. Mirror effects are an important class of context effects that can be explained by changes in participants' decision criteria. When easy and difficult conditions are blocked alternately and a mirror effect is observed, participants must repeatedly change their decision criteria. The authors investigated the time course of these criterion changes and observed the buildup of mirror effects on a trial-by-trial basis. The data are consistent with slow, systematic changes in decision criteria that lag behind stimulus changes. The length of this lag is considerable: analysis of a simple dynamic signal-detection model suggests participants take an average of around 14 trials to adjust to new decision environments. This trial-level measurement of experimentally induced changes has implications for traditional blockwise analyses of data and for models of decision making.     

Modeling experimentally induced strategy shifts

In dynamic decision-making environments, observers must continuously adjust their decision-making strategies. Previous research has focused on internal fluctuations in decision mechanisms, without regard to how these changes are induced by environmental changes. We developed a simple paradigm in which we manipulated task difficulty, thereby inducing changes in decision processes. We applied this paradigm to recognition memory, manipulating task difficulty by changing the similarity of lures to targets. More difficult decision environments caused participants to make more careful decisions, but these changes did not appear immediately. We propose a simple theoretical account for these data, using a dynamic version of signal detection theory fitted to individual subjects. Our model represents a significant departure from existing models because it incorporates subject-controlled parameters that may adjust over time in response to environmental changes.     

The mnemonic effects of recall on immediate retention

In three experiments, we investigated the mnemonic effects of an initial recall on later recall in an immediate memory setting. Recall is generally assumed to interfere with the recall of subsequent items (output interference), but previous experiments have failed to control for the confounding effects of time. In the experiments reported here, the passage of time was held constant on all trials; what varied was whether an additional item was recalled (or simply presented) during the retention interval. The results revealed clear evidence of recall's mnemonic effects, but output interference seemed strongest when the initial recall was of an item that followed the target item in the memory list. When participants initially recalled an item immediately preceding the target, target recall improved. This pattern of results places constraints on current models of immediate retention.     

The effects of gender upon doctor-patient interaction

Abstract

Despite extensive research examining doctor-patient communication, relatively link attention has been directed to the impact of gender differences (Weisman and Teitelbaum, 1985). The present study examines the effect of doctor and patient gender on interaction. The consultations of 102 patients (47 male and 55 female) and 15 doctors (8 male and 7 female) were taped and then analysed using a modification of a method developed by Butler and Cox (1992). Measures were also taken of doctor and patient word count, the proportion of doctor dialogue relative to the patient and frequency of interaction exchange. Female patients initiated significantly more agendas than male patients (p >0.001). Those men who raised emotional agendas were more likely to reintroduce these agendas than female patients (p>0.01). particularly in the presence of female doctors (p0.001). Consultations with female patients revealed higher overall (p>0.01) and patient (P>0.01) word count than those with male patients. A positive effect of “gender congruence” upon word count was observed with female doctors only (p0.001).     

The effects of viscosity upon perceived sweetness

U.S. Army Natick Laboratories, Natick, Massachusetts 01760 Six concentrations of sucrose and six concentrations of sodium saccharin were presented as stimuli to 30 Ss. The concentrations were equally spaced logarithmically, covering a 32: I range for each solute. The 12 aqueous solutions were presented at four levels of viscosity, ranging approximately from I to 10,000 centipoises, with sodium carboxymethylcellulose (cellulose gum) as the thickening agent. Magnitude estimates indicate that perceived sweetness decreases with viscosity. In log-log coordinates the Viscosity-sweetness relation is roughly linear with a negative slope, suggesting that sweetness of both sodium saccharin and sucrose varies as a power function of viscosity, with an exponent between ?.20 and ?.25.     

The effects of mood upon imaginal thought

The effects of mood upon imaginal thought were explored with a highly trained undergraduate female hypnotic subject. She was hypnotically programmed to experience free-floating anxiety or pleasure in varying degrees just before the exposure of combinations of three Blacky Pictures, and to produce dreamlike imagery in response to the Blacky stimuli while under sway of the mood. Data from 98 dream trials, separated by amnesia, indicated that the affective states clearly influenced imaginal processes. Blind ratings by a psychoanalyst showed the anxiety moods to be more closely associated with primary-process features characteristic of nocturnal dreams, whereas pleasure had a relatively higher incidence of daydreamlike ratings. Empirical analysis of themes yielded significant relationships of anxiety to physical injury to the self and verbal aggression toward others; pleasure was associated with circular movements and overt sex themes.