The Disjunction Effect: Does It Exist for Two-Step Gambles?

One of the basic axioms of the rational theory of decision under uncertainty is Savage's (1954) Sure Thing Principle. It states that if Prospect x is preferred to Prospect y knowing that Event A occurred, and if x is preferred to y knowing that A did not occur, then x should also be preferred to y when it is not known whether A occurred. Tversky and Shafir (1992) claim to have demonstrated a violation of this principle in two-step gambles, which is termed a disjunction effect. The present article evaluates the replicability of the disjunction effect for two-step gambles. The findings show that people do not violate the sure thing principle in repeated gambles. The validity of alleged violations in other paradigms is discussed.     

Case and Reanalysis

In this paper we discuss an asymmetry in the Case system of German and its implications for human sentence processing: the asymmetry between nominative/accusative and dative case. Starting from the assumption that dative case has a distinct grammatical representation--dative DPs are embedded into an extra structural layer KP--the results of two experiments will be presented, which show that dative assignment during reanalysis is accompanied by additional processing operations that are not needed when accusative or nominative are assigned. In particular, we show that dative assignment during reanalysis triggers reaccess to the mental lexicon, giving rise to greater processing difficulty. We conclude with a discussion of empirical and theoretical consequences of our findings.     

Right amygdalar and temporofrontal activation during autobiographic, but not during fictitious memory retrieval

What distinguishes the recall of real-life experiences from that of self-created, fictitious emotionally laden information? Both kinds of information belong to the episodic memory system. Autobiographic memories constitute that part of the episodic memory system that is composed of significant life episodes, primarily of the distant past. Functional imaging was used to study the neural networks engaged in retrieving autobiographic and fictitious information of closely similar content. The principally activated brain regions overlapped considerably and constituted temporal and inferior prefrontal regions plus the cerebellum. Selective activations of the right amygdala and the right ventral prefrontal cortex (at the level of the uncinate fascicle interconnnecting prefrontal and temporopolar areas) were found when subtracting fictitious from autobiographic retrieval. Furthermore, distinct foci in the left temporal lobe were engaged. These data demonstrate that autobiographic memory retrieval uses (at least in non-brain damaged individuals) a network of right hemispheric ventral prefrontal and temporopolar regions and left hemispheric lateral temporal regions. It is concluded that it is the experiential character, its special emotional infiltration and its arousal which distinguishes memory of real-life from that of fictitious episodes. Consequently, our results point to the engagement of a bi-hemispheric network in which the right temporo-prefrontal hemisphere is likely to be responsible for the affective/arousal side of information retrieval and the left-hemispheric temporal gyrus for its engram-like representation. Portions of the neural activation found during retrieval might, however, reflect re-encoding processes as well.     

Adaptation to field displacement during head movement unrelated to the constancy of visual direction

Adaptation to vertical field displacements dependent on head turning about a vertical axis was demonstrated under two conditions, rapid training with 100 head movements and 1-h-long training with continuous head turning. The effect of rapid training was measured with the slant estimation method. Adaptation after the longer training was ascertained by comparing the uncertainty ranges for apparent target immobility before and after the adaptation period. Adaptation to field displacements in directions parallel to the plane of the head rotation obtained under corresponding conditions was also measured and found to be somewhat greater than adaptation to vertical field displacements. The result of work by Wallach and Frey that adaptation to field displacement in the direction with the head rotation is greater than to displacement against it was corroborated. While the previous result had, been obtained with rapid adaptation and with the slant estimation method, we confirmed it with 1-h training and by measuring the uncertainty ranges before and after the adaptation period.     

The echoes of Wundt's work in the United States, 1887–1977: A quantitative citation analysis

Summary The frequency of references to Wundt's book-length publications in experimental papers appearing in the American Journal of Psychology was determined. The most widely cited work, by far, is the Grundzüge der physiologischen Psychologie. The distinct decline of Wundt's impact on American psychology is clearly reflected in the frequencies of the citations.     

Pavloviana inPsychology of the 20th Century: A special review

In the encyclopedicPsychology of the 20th Century three volumes are relevant to the work of I. P. Pavlov, his predecessors, contemporaries, and followers. Volume 1 (1976) provides an extensive account of the history of non-introspective, “objective” psychology. In Volume 4 (1977), examined in this review and consisting of sections on “Theories of Learning” and “Behavior Modification,” separate chapters are devoted to Pavlov’s life and work, and its continuation in the Soviet Union. Classical conditioning is considered in the context of S-R learning theories, interaction with operant conditioning, and development of behavior therapy. Additional materials are likely to be presented in Volume 6 (to be published) dealing with animal psychology, ethology, and physiological psychology.     

Watching diagnoses develop: Eye movements reveal symptom processing during diagnostic reasoning

Finding a probable explanation for observed symptoms is a highly complex task that draws on information retrieval from memory. Recent research suggests that observed symptoms are interpreted in a way that maximizes coherence for a single likely explanation. This becomes particularly clear if symptom sequences support more than one explanation. However, there are no existing process data available that allow coherence maximization to be traced in ambiguous diagnostic situations, where critical information has to be retrieved from memory. In this experiment, we applied memory indexing, an eye-tracking method that affords rich time-course information concerning memory-based cognitive processing during higher order thinking, to reveal symptom processing and the preferred interpretation of symptom sequences. Participants first learned information about causes and symptoms presented in spatial frames. Gaze allocation to emptied spatial frames during symptom processing and during the diagnostic response reflected the subjective status of hypotheses held in memory and the preferred interpretation of ambiguous symptoms. Memory indexing traced how the diagnostic decision developed and revealed instances of hypothesis change and biases in symptom processing. Memory indexing thus provided direct online evidence for coherence maximization in processing ambiguous information.     

Which kind of attention is captured by cues with the relative target colour?

Most theories of visual search maintain that attention is selectively tuned to the attributes of the search target (e.g., orange). Conversely, according to the relational account, attention is biased to the relative feature of the target (e.g., redder). However, previous studies that supported the relational account mainly measured mean response times. Hence, the results might not reflect early, perceptual mechanisms (e.g., signal enhancement) but later, decision-based mechanisms (channel selection). The current study tested the relational account against feature-specific theories in a spatial cueing task, in which the targets were backward-masked, and target identification accuracy was measured. The first experiment corroborated earlier results, demonstrating that relational effects are due to signal enhancement. In the second experiment, we chose highly discriminable colours along the blue–red continuum, and obtained results that were more consistent with broad feature-specific rather than relational tuning. The implications of these findings for current theories of attention are discussed.