Language performance on visual processing tasks in right hemisphere lesion cases

Seven language tests were constructed or adapted to assess the performance of three groups of 10 right-handed adult subjects: a right hemisphere lesion (RHL) group, a left hemisphere lesion (LHL) group, and a neurologically normal (NN) control group. Both the LHL and RHL groups produced poorer scores than the NN group on six of the seven tests. On two of the six significant tests, the RHL performed more poorly than the NN group. Analyses of words uttered during an oral story telling test indicated that the RHL group told significantly fewer complete stories using significantly more nouns, adjectives, and conjunctions than the NN group. On a 7-point scale, three judges rated the overall communication abilities of the RHL group as having “mild problems,” a significantly different rating than the ratings of the LHL and NN groups. The findings suggest that underlying visual spatial and perceptual deficits may be accompanied by clearly recognizable language differences in certain subjects.     

Binocular interaction of orientation and spatial frequency channels: Evoked potentials and observer sensitivity

The interaction between size and orientation feature processing in the human visual system was investigated. Both observer sensitivity (d’ss) and the visual evoked potential (VEP) to test gratings flashed to one eye were investigated as a function of the nature of a continuously presented suppressing grating viewed either by that same eye or the opposite eye. The test and suppressing gratings were varied both in bar width (9′ss vs. 36′ss) and orientation (vertical vs. horizontal). The continuous grating intra- and interocularly suppressed the monocular VEPs to the flashed grating, the specificity of the suppression depending on the latency at which VEP amplitude was measured. VEP amplitude measured at early latencies (100–125 msec) was suppressed primarily when the flashed and continuous gratings were the same orientation, regardless of size. Starting at about 200 msec, and thereafter, VEP amplitudes were suppressed when the continuous bars were either the same orientationor size as the flashed bars. Late latencies, starting at 220 msec, and thereafter, were suppressed primarily when the bars in the two gratings were the same orientation and size. The reduction in observer sensitivity (d′ss) paralleled the changes found in the late VEP measures. These effects were evident under both the intraocular and interocular suppressing conditions. This pattern of VEP suppression, measured across eight points in the VEP waveform, was interpreted as indicating the existence of a sequence of channels that are specific first to a particular grating orientation, then to either a particular grating spatial frequency or orientation, and finally to the conjunction of a particular orientation and spatial frequency. Both sequential and parallel feature processing appears to take place in the human visual cortex, with grating orientation being encoded earlier than grating size.     

Information Processing and New Ideas — Lateral and Vertical Thinking*

‘Vertical thinking is concerned with digging the same hole deeper. Lateral thinking is concerned with digging the hole somewhere else.’ This is how the author differentiates between the two types of thinking. Education, according to the author, only teaches vertical thinking because lateral thinking has always seemed impossible to teach. He then outlines why (with the increased interest in creativity and the computer) there is growing interest in the thinking processes. Describing how the brain operates and how creative behaviour may be increased Dr. de Bono goes on to discuss the nature of vertical thinking. It is sequential, based on the idea that one must not be wrong, works on the most promising approach, only moves in a planned direction, only considers the relevant, and tends to build up large established patterns. To describe the lateral thinking process the author poses a number of problems discussing their solution and the difficulties which people normally encounter in solving these problems. Finally, he sets out the four main categories of the techniques of lateral thinking; and the reader's attention is drawn to several books which Dr. de Bono has written on the subject.     

Binocular brightness combinations: Additive and nonadditive aspects

A conjoint measurement procedure is used for the measurement of binocular brightness as a function of left and right luminance inputs. For nonzero stimulation, the data confirm earlier findings: the system can be described as additive with a scale exponent of 1. If zero stimulation is included, however, no additive solution can be found (due to Fechner’s paradox). This fact, combined with various critical remarks in the literature with respect to the existence of a real luminance-averaging system, has led us to propose a model which takes account of Fechner’s paradox, and incorporates “realistic” exponents without requiring a multistage processing mechanism where different levels are characterized by different sensory scales. The proposed model makes the weighting coefficients for the two eyes dependent in a continuous way on the strength of stimulation in the two eyes, especially on the amount of contrast of the monocular stimuli. For zero background stimulation, contrast can be expressed in terms of luminance of the stimulus. In this way, the model is reduced to a simple testable form. While it much simpler than Engel’s (1969) model, the experimental results indicate that it might also work for the more general case.     

A COMPARISON OF NORTH-AMERICAN AND BRAZILIAN COLLEGE STUDENTs' PERSONALITY PROFILES ON THE 16 PF QUESTIONNAIRE

Le questionnaire de personnalité 16 PF (Forme A) a été traduit en portugais et soumis à un échantillon représentatif des étudiants de Sao Paulo (Brésil), comprenant 770 H et 555 F. Pour chaque facteur, les résultats ont été comparés à ceux d'un échantillon standardisé d'étudiants américains: les étudiants brésiliens sont, en général, moins sociables (A —) et moins enthousiastes (F —), plus soupçonneux (L +) et plus imaginatifs (M +); ils sont également moins conservateurs (Qi +) et plus indépendants (Q2 +). l'analyse de second ordre fait apparaître les Brésiliens comme plus anxieux et plus introvertis, montrant également plus de spontanéité et de créativité que les sujets américains. On constate enfin l'existence de différences entre hommes et femmes, tant à l'intérieur de chaque groupe qu'entre les deux échantillons.