The relation of field dependence to signal detection while imaging

Twelve field-dependent (FD) and 12 field-independent (FI) males were administered 260 trials of a signal detection task in four phases. Signal type (auditory, visual, or no signal) was crossed with four sets of imaging treatments (pure visual representations, pure sounds without visual counterparts, and two sets representing sounds with visual counterparts). Detection of a signal in isolation was 90% accurate, as was the detection of no signal while imaging. Cross-modality imaging interfered with detection of the stimulus but to a significantly lesser extent than did same-modality imaging. In all detection/imaging treatments, FIs were significantly more sensitive to the signal than were FDs; however, FDs and FIs did not differ in accuracy of detecting isolated signals. The results are discussed in terms of the commonalities shared by perception and imaging as they appear in the Perky effect and cognitive style.     

A COMPARISON OF COGNITIVE CONFLICT BETWEEN PERSONS IN WESTERN EUROPE AND THE UNITED STATES1

Etude comparative du conflit cognitif interpersonnel en Europe occidentale et aux Etats-Unis. — La recherche a été menée conjointement dans divers pays européens (Grande-Bretagne, France, Italie, RFA) et aux Etats-Unis, selon la même procédure. On induit des différences cognitives détetminées entre les 2 membres d'un groupe, en les entraînant différemment (ce dont ils ne sont pas conscients) dans une tâche d'apprentissage portant sur des problèmes politiques; il s'ensuit un conflit quand on réunit les deux sujets et qu'on leur demande d'aboutir à des solutions communes. Les résultats montrent que — a) les différences cognitives ne sont pas réduites en Europe alors qu'elles le sont, lentement, aux Etats-Unis; — b) les sujets européens aboutissent moins souvent que les sujets américains à des solutions de compromis; — c) les européens réagissent différemment à l'idée de « Contrôle de l'Etat ». Ce type de recherche peut être utilisé pour étudier le conflit cognitif sur une base interculturelle; les résultats font apparaître des problèmes importants qui n'ont pas encore été étudiés.     

Illusion in a three-dimensional Hering figure in relation to viewing distance

Two groups of 34 Ss each judged the amount of illusion in a three-dimensional Hering figure at three viewing distances (9, 18, and 36 ft). The horizontal bars could be located in the foremost frontal plane of the three-dimensional display or could be recessed within it. Group C-F began at the close distance and Group F-C at the furthest distance. Amount of illusion increased with viewing distance and was greater with the bars recessed within the display. At the furthest distance, but not at the other distances, amount of illusion was greater for Group F-C. The results confirm predictions from Gregory’s theory of primary constancy scaling but are also interpretable in terms of local effects at the intersections of parallel bars and background lines.     

Can probability theory explain why closure is both intuitive and prone to counterexamples?

Epistemic closure under known implication is the principle that knowledge of \(\varphi\) and knowledge of \(\varphi \rightarrow \psi\), together, imply knowledge of \(\psi\). This principle is intuitive, yet several putative counterexamples have been formulated against it. This paper addresses the question, why is epistemic closure both intuitive and prone to counterexamples? In particular, the paper examines whether probability theory can offer an answer to this question based on four strategies. The first probability-based strategy rests on the accumulation of risks. The problem with this strategy is that risk accumulation cannot accommodate certain counterexamples to epistemic closure. The second strategy is based on the idea of evidential support, that is, a piece of evidence supports a proposition whenever it increases the probability of the proposition. This strategy makes progress and can accommodate certain putative counterexamples to closure. However, this strategy also gives rise to a number of counterintuitive results. Finally, there are two broadly probabilistic strategies, one based on the idea of resilient probability and the other on the idea of assumptions that are taken for granted. These strategies are promising but are prone to some of the shortcomings of the second strategy. All in all, I conclude that each strategy fails. Probability theory, then, is unlikely to offer the account we need.     

Influence of time-of-day on joint Navon effect

The shared attention theory suggests that people devote greater cognitive resources to those features co-attended simultaneously with others, determining better performance in several types of tasks. When co-actors performed a go/no-go Navon task attending different features of target letters, the performance was impaired, reflecting a joint Navon effect (the representation of a co-actor’s attentional focus made it more difficult to select and apply one’s own focus of attention), probably due to asynchronous co-attention with a decrease in cognitive resources involved. Researches in chronobiology and chronopsychology demonstrated that not only selective attention (involved in a Navon task), but also cognitive resources have a daily fluctuations, mainly paralleling the circadian rhythm of body temperature (i.e. increasing values from the morning to evening with a subsequent decline in the night). The study was conducted to assess whether the presence of joint attention, as measured by the joint Navon effect, was influenced by the time-of-day. Sixteen pairs of participants sitting next to each other were required to respond to the identity letters in a go/no-go Navon task twice: in the morning (09:00–10:00) and early afternoon (13:00–14:00). The results showed a joint Navon effect in the morning session only, suggesting that joint attention was affected by the time-of-day effect on cognitive resources.