The framing of decisions and the psychology of choice.

The psychological principles that govern the perception of decision problems and the evaluation of probabilities and outcomes produce predictable shifts of preference when the same problem is framed in different ways. Reversals of preference are demonstrated in choices regarding monetary outcomes, both hypothetical and real, and in questions pertaining to the loss of human lives. The effects of frames on preferences are compared to the effects of perspectives on perceptual appearance. The dependence of preferences on the formulation of decision problems is a significant concern for the theory of rational choice.

Judgment under Uncertainty: Heuristics and Biases.

This article described three heuristics that are employed in making judgements under uncertainty: (i) representativeness, which is usually employed when people are asked to judge the probability that an object or event A belongs to class or process B; (ii) availability of instances or scenarios, which is often employed when people are asked to assess the frequency of a class or the plausibility of a particular development; and (iii) adjustment from an anchor, which is usually employed in numerical prediction when a relevant value is available. These heuristics are highly economical and usually effective, but they lead to systematic and predictable errors. A better understanding of these heuristics and of the biases to which they lead could improve judgements and decisions in situations of uncertainty.

Pupil diameter and load on memory.

During a short-term memory task, pupil diameter is a measure of the amount of material which is under active processing at any time. The pupil dilates as the material is presented and constricts during report. The rate of change of these functions is related to task difficulty.

Perceptual Deficit during a Mental Task.

Subjects monitored for a visual signal while engaged in a demanding mental task. The probability of detecting the signal depends on the time of its presentation during the 8 seconds of the task. A similar time course is observed for failures to detect and for changes of pupil size. Momentary variations in the load that the task imposes on the subject are reflected in both indices. Detection failures are not explained by the pupillary changes.

Functional imaging of neural responses to expectancy and experience of monetary gains and losses.

Neural responses accompanying anticipation and experience of monetary gains and losses were monitored by functional magnetic resonance imaging. Trials comprised an initial "prospect" (expectancy) phase, when a set of three monetary amounts was displayed, and a subsequent "outcome" phase, when one of these amounts was awarded. Hemodynamic responses in the sublenticular extended amygdala (SLEA) and orbital gyrus tracked the expected values of the prospects, and responses to the highest value set of outcomes increased monotonically with monetary value in the nucleus accumbens, SLEA, and hypothalamus. Responses to prospects and outcomes were generally, but not always, seen in the same regions. The overlap of the observed activations with those seen previously in response to tactile stimuli, gustatory stimuli, and euphoria-inducing drugs is consistent with a contribution of common circuitry to the processing of diverse rewards.

On the reality of cognitive illusions.

The study of heuristics and biases in judgement has been criticized in several publications by G. Gigerenzer, who argues that "biases are not biases" and "heuristics are meant to explain what does not exist" (1991, p. 102). The article responds to Gigerenzer's critique and shows that it misrepresents the authors' theoretical position and ignores critical evidence. Contrary to Gigerenzer's central empirical claim, judgments of frequency--not only subjective probabilities--are susceptible to large and systematic biases. A postscript responds to Gigerenzer's (1996) reply.

Joint comment on "when does duration matter in judgment and decision making?" (Ariely & Loewenstein, 2000).

Recent research has demonstrated that people care about the temporal relationships within a sequence of experiences. There is considerable evidence that people pay particular attention to the way experiences improve or deteriorate over time and to their maximum (peak) and final values. D. Kahneman and coauthors suggested in earlier articles that people ignore or severely underweight duration (which they referred to as duration neglect). In the preceding article, D. Ariely and G. Loewenstein (2000) challenged the generalizability of these findings and their normative implications. In the current commentary, D. Ariely, D. Kahneman, and G. Loewenstein jointly examine the issue to provide a better understanding of what they feel they have learned from this literature and to discuss the remaining open questions.

Determinants of the remembered utility of aversive sounds.

Retrospective evaluations of aversive episodes were studied in the context of a general model of "judgment by prototype" that has been applied in other situations. Unpleasant sounds of variable loudness and duration were the stimuli. In Experiment 1, continuous reports of annoyance closely tracked variations of noise intensity. Hypotheses about the determinants of retrospective evaluation were examined in Experiment 2. Experiment 3 confirmed a prediction of judgment by prototype: The effects of sound duration and intensity are additive in multitrial experiments. Experiment 4 confirmed a robust preference for aversive episodes that are "improved" by adding a period of reduced aversiveness.

Tests of the automaticity of reading: dilution of Stroop effects by color-irrelevant stimuli.

A color word shown next to a color bar can facilitate color naming if it is congruent with the correct response; otherwise it will interfere with color naming. The congruence and conflict effects are both diminished (diluted) by the presentation of a color-neutral word elsewhere in the field. A row of X's also produces some dilution. The dilution effect represents attentional interference rather than sensory interaction or response conflict. Because Stroop effects are susceptible to interference, the involuntary reading of color words does not satisfy one of the standard criteria of automaticity.

The cost of visual filtering.

Speeded choice responses (reading or naming) to a relevant stimulus under conditions of spatial uncertainty are delayed by the simultaneous occurrence of other events. This "filtering cost" occurs despite high discriminability of target and distractors, which allows parallel detection of the target in search through the same displays. Reading is also delayed when the removal of irrelevant objects from the field coincides with the onset of the target. Filtering costs are caused by the processing of events rather than by the mere presence of irrelevant items. They are eliminated by advance information about the location of the target or by advance presentation of maintained distractors.

Duration neglect in retrospective evaluations of affective episodes.

Two experiments documented a phenomenon of duration neglect in people's global evaluations of past affective experiences. In Study 1, 32 Ss viewed aversive film clips and pleasant film clips that varied in duration and intensity. Ss provided real-time ratings of affect during each clip and global evaluations of each clip when it was over. In Study 2, 96 Ss viewed these same clips and later ranked them by their contribution to an overall experience of pleasantness (or unpleasantness). Experimental Ss ranked the films from memory; control Ss were informed of the ranking task in advance and encouraged to make evaluations on-line. Effects of film duration on retrospective evaluations were small, entirely explained by changes in real-time affect and further reduced when made from memory. Retrospective evaluations appear to be determined by a weighted average of "snapshots" of the actual affective experience, as if duration did not matter.

The effect of stress on the suppression of erroneous competing responses.

Abstract Evidence exists that the intention to perform certain cognitive tasks activates, unintentionally, competing responses and computations that intrude on the performance of the intended tasks. For the intended task to be performed effectively, such intrusions must be controlled. Two experiments were carried out to test the hypothesis that stress heightens the difficulty of exercising effective control over erroneous competing responses, a possible explanation of decrements in the performance of cognitive tasks under stress. Participants performed four tasks, which contained features that could potentially prime or activate erroneous responses. The results demonstrated that the interference of these features with performance was more pronounced among stressed than among less-stressed participants. The need for a more comprehensive theory of the effects of stress on information processing is discussed.

Capacity sharing and refractoriness in successive reactions.

Subjects performed two rapidly successive tasks. They first pressed a key to stop a digital counter at one of three stopping times. The key-press was followed after a variable interval by the presentation of one of three lights, which required a choice response. 20 students and 20 flight cadets participated in the main experiment. Both responses showed impairment in the dual-task condition. The delay of the choice response was affected by the stopping time and by the interval between the key-press and the second stimulus. Complete refractoriness for a period of 200 msec. was observed only for the shortest stopping-time. In the other conditions, the delay of the second response decreased gradot support single-channel theory and are better explained by a capacity-sharing model on the assumption that preparation for a choice-response requires effort.

Understanding patients' decisions. Cognitive and emotional perspectives.

OBJECTIVE: To describe ways in which intuitive thought processes and feelings may lead patients to make suboptimal medical decisions. DESIGN: Review of past studies from the psychology literature. RESULTS: Intuitive decision making is often appropriate and results in reasonable choices; in some situations, however, intuitions lead patients to make choices that are not in their best interests. People sometimes treat safety and danger categorically, undervalue the importance of a partial risk reduction, are influenced by the way in which a problem is framed, and inappropriately evaluate an action by its subsequent outcome. These strategies help explain examples where risk perceptions conflict with standard scientific analyses. In the domain of emotions, people tend to consider losses as more significant than the corresponding gains, are imperfect at predicting future preferences, distort their memories of past personal experiences, have difficulty resolving inconsistencies between emotions and rationality, and worry with an intensity disproportionate to the actual danger. In general, such intangible aspects of clinical care have received little attention in the medical literature. CONCLUSION: We suggest that an awareness of how people reason is an important clinical skill that can be promoted by knowledge of selected past studies in psychology.

The reviewing of object files: object-specific integration of information.

A series of experiments explored a form of object-specific priming. In all experiments a preview field containing two or more letters is followed by a target letter that is to be named. The displays are designed to produce a perceptual interpretation of the target as a new state of an object that previously contained one of the primes. The link is produced in different experiments by a shared location, by a shared relative position in a moving pattern, or by successive appearance in the same moving frame. An object-specific advantage is consistently observed: naming is facilitated by a preview of the target, if (and in some cases only if) the two appearances are linked to the same object. The amount and the object specificity of the preview benefit are not affected by extending the preview duration to 1 s, or by extending the temporal gap between fields to 590 ms. The results are interpreted in terms of a reviewing process, which is triggered by the appearance of the target and retrieves just one of the previewed items. In the absence of an object link, the reviewing item is selected at random. We develop the concept of an object file as a temporary episodic representation, within which successive states of an object are linked and integrated.