Communication theory and the constellation hypothesis of calculation

It is assumed that in translation tasks the brain behaves as an information-processing system for which the time-requirement (t) of a translation is strictly proportional to the information which must be handled in performing it. Writing Q[calc] for the information-requirement of a given calculation, the problem is to define a procedure Q which may be applied to calculations involving various arithmetical operations on numbers of varying magnitudes, such that Q[calc] ≈ k.t. The constant k would then give the information-handling rate.

Experiments with six subjects on seven types of simple addition-sum lead to a definition of Q which satisfies this condition for 25 out of 42 observations. Of the other 17 observations, 14 are accounted for by a modified definition of Q and at least one more on the assumption that “redundant information” may be handled in some cases. The main hypothesis, with these two subsidiary assumptions, accounts well for all observations in a further experiment with four subjects on six types of addition, subtraction and multiplication.

The definition of Q is next generalized by analogy to deal with more complex multiplications. A prediction concerning multiplications of the type [x. log x] is borne out by 11 out of 12 subjects and the subsidiary assumptions are not required. Information-rates found by this rapid method range from 2.07-5.78 binary units of Q[calc] per second (BU/sec.) and there is reason to believe that 1 BU is equivalent to 1 bit.     

EEG and fMRI agree: Mental arithmetic is the easiest form of imagery to detect

fMRI and EEG during mental imagery provide alternative methods of detecting awareness in patients with disorders of consciousness (DOC) without reliance on behaviour. Because using fMRI in patients with DOC is difficult, studies increasingly employ EEG. However, there has been no verification that these modalities provide converging information at the individual subject level. The present study examined simultaneous EEG and fMRI in healthy volunteers during six mental imagery tasks to determine whether one mental imagery task generates more robust activation across subjects; whether activation can be predicted from familiarity with the imagined activity; and whether EEG and fMRI converge upon the same conclusions about individual imagery performance. Mental arithmetic generated the most robust activation in the majority of subjects for both EEG and fMRI, and level of activation could not be predicted from familiarity, with either modality. We conclude that overall, EEG and fMRI agree regarding individual mental imagery performance.     

Dimensional complexity and power spectral measures of the EEG during functional versus predicative problem solving

Electroencephalograms were recorded in 22 men while solving tasks of visual-pattern completion and during mental relaxation. They were primed (by foregoing trials) to solve these tasks either in a predicative or functional mode of thinking. Predicative thinking required that in order to complete the pattern the subject had to get involved with the logic of the static structure of the pattern and therefore had to recognize the recurrence of certain features of the elements (e.g., shape, color, and size). Functional thinking required involvement in a dynamic reading of the logic of the pattern and therefore to search for operations and actions to be performed on the pattern elements (e.g., pushing, mirroring, and rotating). The EEG complexity during predicative thinking decreased in comparison to functional thinking and mental relaxation, with this reduction being most pronounced over the right parietal cortex. A reduction in dimensional complexity during functional thinking as compared to mental relaxation, which was concentrated over the left central cortex, although significant, was less clear. The reduced EEG complexity during predicative thought, dominant over the right hemisphere, could reflect increased competitive inhibition among respective cortical neuron assemblies in association with the visual analysis of static element features, converging upon those predicates relevant for the solution.     

The effect of stimulus amplitude on the threshold of fusion of paired flashes

Four experiments are described in which the threshold of fusion of paired flashes was measured. The intensity of the single flashes making up the pairs was varied independently. The results showed that when the first flash of the pair was the more intense, the threshold of fusion increased linearly as the difference in the log intensity of the two flashes. A proposal put forward to explain the results suggested the “noise” created by the first flash of the pair has to dissipate to a critical extent to allow the “signal” arising from the second flash to be detected.     

Self-schema for assertiveness: Extending the validity of the self-schema construct

This research attempted to extend the validity of the self-schema concept by examining a previously untested self-attribute and by examining self-schema effects on the interpretation of more realistic stimulus situations than used in past studies. The attribute was a self-schema for assertiveness and the validity of this self-knowledge structure was evaluated in two studies. In Stuty 1 assertion schematics and aschematics were compared for retrieval of schema-relevant information on a laboratory task of incidental recall. In Study 2 schematics and aschematics were compared on five different tasks that required elaboration of information about rights assertion conflict situations. Study 1 results revealed that schematics as compared to aschematics recalled more assertion related adjectives but did not differ in recall of domain-irrelevant words. Results from Study 2 showed that schematics as compared to aschematics recalled more past instances of assertive behaviors when asked to elaborate why an assertion adjective was endorsed as “Like me”. Also, schematics were significantly more certain they would behave assertively both in situations where assertion was appropriate and in those where compromise was more appropriate. On two perceptual factors known to correlate with assertive behavior, schematics were more likely to judge moderately legitimate requests (i.e., ambiguous requests) as more unreasonable and when asked to generate expected consequences for assertive responses focused more on self rather than other person consequences. The consistency of the results with respect to various hypothesized functions of the self-schema construct are discussed.     

Frontal brain electrical activity (EEG) distinguishes valence and intensity of musical emotions

Using recent regional brain activation/emotion models as a theoretical framework, we examined whether the pattern of regional EEG activity distinguished emotions induced by musical excerpts which were known to vary in affective valence (i.e., positive vs. negative) and intensity (i.e., intense vs. calm) in a group of undergraduates. We found that the pattern of asymmetrical frontal EEG activity distinguished valence of the musical excerpts. Subjects exhibited greater relative left frontal EEG activity to joy and happy musical excerpts and greater relative right frontal EEG activity to fear and sad musical excerpts. We also found that, although the pattern of frontal EEG asymmetry did not distinguish the intensity of the emotions, the pattern of overall frontal EEG activity did, with the amount of frontal activity decreasing from fear to joy to happy to sad excerpts. These data appear to be the first to distinguish valence and intensity of musical emotions on frontal electrocortical measures.     

A study of alpha hemispheric asymmetries for verbal and nonverbal stimuli in males and females

The alpha hemispheric asymmetries of males and females were examined with electroencephalographic (EEG) techniques during exposure to connected speech and nonlinguistic stimuli. The subject selection controlled for familial handedness and each subject was administered the Block Design and Vocabulary Subtests of the WAIS as a general measure of “visual-spatial” and “verbal” ability. The results showed that there was less alpha in the right hemisphere for nonverbal tasks and less alpha in the left hemisphere for verbal tasks. The females showed significantly more “lateralization” during the tasks as compared to the males. The results are discussed in terms of processing differences and the possible effects of subject variables, stimulus mode, stimulus presentation, and task requirements on neurolinguistic research results.     

Are people with high and low mental rotation abilities differently susceptible to the alignment effect?

We investigated whether the alignment effect (Levine et al, 1982 Journal of Experimental Psychology: General 111 157-175) is influenced by mental rotation abilities. In two experiments, groups of undergraduate students with high and low performance in mental rotation tasks were required to study either schematic (experiment 1) or more complex (experiment 2) maps, and to perform a number of pointing tasks adopting a perspective which could be aligned, misaligned (45 degrees, 135 degrees), or counteraligned (180 degrees) with the perspective assumed during learning. Cognitive styles in spatial representation have also been considered. Results of experiment 1 show that people with low performance in mental rotation tasks prefer to adopt a representation of space focused more on landmarks. Their performance in the pointing tasks depends on the alignment conditions, with more errors in the counteraligned condition followed by the two misaligned and aligned ones. In contrast to this, high-ability mental rotators prefer survey and route spatial representations and are affected only by the aligned and non-aligned conditions. In the second experiment, practice was studied as a function of mental rotation and alignment. The group high in mental rotation ability was found to be free from the alignment effect in the pointing tasks performed after the final of four learning phases.     

When simplifying life is not so bad: the link between rigidity, stressful life events, and mental health in an undergraduate population

Decades of research have generally shown that being more rigid is associated with poorer mental health. We investigated whether all aspects of what has been termed “rigidity” are harmful. In particular, we hypothesized that the desire for simple structure (DSS) will not be associated with poor mental health, and in some cases might be associated with better mental health. In contrast, the intolerance of uncertainty (IU) was hypothesized to be associated with a wide range of indices of poor mental health. We also hypothesized that people high in IU would be less resilient in the face of stressful life events. Results across two cross-sectional surveys (N=240; N=331) supported our hypotheses. DSS was associated with less hopelessness, whereas IU was associated with more depression, anxiety, stress, suicidal ideation, and hopelessness. In addition, moderational analysis supported the hypothesis that IU magnifies the adversive effect of stressful life events on depression, anxiety and hopelessness. IU was more strongly related to the negative indices of well-being than to the positive index of life satisfaction. The implications of these findings for cognitive behavioural therapy practice are discussed.     

Slow alpha in the EEG power spectrum as an indicator for conceptual arousal]

Based on previous findings (B?sel et al., 1990) it was assumed that in concept learning tasks generating on hypotheses on a concept which has to be developed is accompanied by increases of the Alpha 1 power (7.5-10 Hz) in the spontaneous EEG activity. In this study 16 subjects performed five problem solving tasks with similar processing requirements. EEG data were analyzed by means of post hoc comparisons of subjects differing in performance quality. Additionally, four control tasks were employed in which, based on previous studies, variations in the Theta frequency range were expected. An effect in the Alpha 1 frequency band was observed in tasks requiring reconstructive recall or testing the usefulness of an mathematical algorithm. The creation of a rank order or mental map is accompanied by power increases in the lower portions of the Alpha 1 frequency band (7.5-8.5 Hz). Moreover a high amount of controlled variance (eta2 up to 34%) was obtained for this effect. Increases in EEG Theta power, which presumably indicate subjects' component analysis, were found before the subjects recognized parts of geometric figures or before relevant features in the "buddhist monk problem" were discriminated. The dynamics of EEG power over time is in examples of frequency/time plots in a figure, illustrated.     

Definiteness and voice in the interpretation of active and passive sentences

In Experiment I, subjects were given active and passive sentences where the definiteness of nominals is varied and about which uncertainty was expressed, e.g. “I thought that the policeman had been injured by a gangster, but I was mistaken, in fact.”. Their task was to decide what was the target of the mistake by completing freely the sentence in such a way that the account would be corrected. When the nominals are differentially determined (a-the, the-a), the pattern of responses indicates that, for both active and passive, subjects were more likely to conclude that it was the non-definitely marked nominal that had been involved in the mistake rather than the definitely marked one. When both nominals are similarly determined (a-a, the-the), subjects were more likely to indicate the event itself as having been involved in the mistake. This supports the hypothesis that subjects are able to utilize definiteness to determine the relation between presupposed and assertional information. In Experiment II, subjects were given paired active and passive sentences with differentially determined nominals and were required to choose between the two syntactic forms of each pair the one they would prefer to use. The pattern of responses clearly shows that subjects were more likely to choose the voice allowing the hypothesized preferential order “Definitely marked grammatical subject-non-definitely marked grammatical object”. Passive transformational rule is thus interpreted as a particular case of a more general rule specifying the ways in which what is made known (comment) is nested on to what is already assumed to be the case (topic).     

Old wine in a new bottle: Impact of membership change on group creativity

The purpose of this study was to investigate the impact of membership change on group creativity. Based on the literature suggesting stimulating effects of membership change in groups, we hypothesized that membership change would enhance the creativity of groups. Membership change involved randomly rotating a subset of group members among groups during a series of creative tasks. Using an idea generation paradigm, we compared the creativity of open groups (i.e., groups that experienced a change in their membership across tasks) with that of closed groups (i.e., groups whose membership was invariant across tasks) in two experiments. In both experiments, we found that open groups generated more ideas and more different kinds of ideas than did closed groups. Moreover, Experiment 2 revealed that it was the productivity of “newcomers” (measured in terms of their creative idea generation in a previous task) that exerted a positive impact on groups. We also found that the entry of more productive newcomers increased the creativity of “oldtimers” (i.e., people who remained in one group across tasks). Implications for the role of membership change in groups are discussed.     

The relationship between mental toughness and affect intensity

Mentally tough athletes are conceptualized as being able to function effectively in stressful situations and recent research has found small to moderate correlations between mental toughness and coping. Despite this no research has thus far examined the possibility that mentally tough athletes experience less intense emotions. This paper tested the relationship between mental toughness and affect intensity to determine whether mentally tough athletes generally experienced more or less intense emotions. A sample of 112 sport performers (55 men and 57 women) aged between 18 and 51 years (M = 29.3, s = 10.3) acted as participants, and ranged from recreational to national level in a variety of sports. Mental toughness and affect intensity were found to be unrelated. This is an important finding because it suggests participants with high or low levels of mental toughness do not characteristically experience more or less intense emotions. Thus there is no evidence to suggest the ability of mentally tough athletes to remain relatively unaffected by pressure or adversity is due to lower levels of affect intensity. More research is required to understand how mentally tough athletes (in comparison to less tough athletes) maintain control and high levels of performance in stressful circumstances.     

A high density ERP comparison of mental rotation and mental size transformation

To compare mental rotation and mental size transformation, 128-channel EEG was recorded while subjects performed both tasks using random two-dimensional shapes as stimuli. Behavioural results showed significant linear effects of both size transformation and mental rotation on reaction times. Rotation ERPs showed experimental effects at two latencies: a bilateral component distributed over posterior parietal electrodes at a latency of approximately 232-300ms and a second component at approximately 424-492ms distributed over right anterior parietal electrodes. The latency and spatial distribution of this second effect is consistent with previous research indicating a functional connection between this component and mental rotation. ERPs for the size-transformation task showed an effect at 180-228ms distributed bilaterally over occipital-temporal electrodes. These results are consistent with previous hemodynamic imaging studies that show involvement of parietal cortex in mental rotation and also the involvement of BA 19 in size-transformation tasks. However, the superior temporal resolution of the present data indicates that BA 19 activation may occur at a latency that is more likely related to apparent motion than to the size-transformation operation per se.     

The representational bias of acquired memory processes

The notion that some memory processes are acquired has been around for at least two thousand years. However, acquired memory processes have been made the object of scientific investigation in only the past two decades. Traditionally, psychologists have assumed that acquired memory processes are equally effective across the entire range of memory tasks. This article reviews research that has investigated whether these processes are equally effective across tasks or are more effective for just certain tasks. The review indicates that most, if not all, acquired memory processes are biased to deal effectively just certain kinds of mental representation. The article proposes that these processes are representationally biased because (1) they activate basic memory processes (e.g. imagery, rehearsal) which themselves are biased to process certain representational attributes and because (2) their use of basic processes follows a sequence required by particular memory tasks. Increased understanding of the representational bias of acquired processes may be seen to enable better control of memory performance and to foster more powerful investigations of memory phenomena.     

Verbal ability and mental processing speed

The notion that verbal ability is related to mental processing speed was examined using tasks that systematically varied in semantic content. Subjects’ reaction times were measured in five tasks involving arrow matching, physical identity word matching, or taxonomic identity word matching. The findings indicated that matching tasks using different decision rules and different stimuli were all related to verbal ability. In fact, reaction time for subjects required to judge whether two arrows pointed in the same direction was the best predictor of verbal ability. One explanation of the results is that speed of information processing (a general factor) may be the important component of verbal ability which is measured by seemingly different matching tasks.     

13-18岁青少年表象能力的发展和脑电α波的关系

本研究以188名1318岁青少年为研究对象,采用脑电波超慢涨落分析技术(简称ET),对其12导联脑电波(EEG)进行了记录和分析,并对其表象能力进行了考察。重点探讨了表象能力的发展与脑α波特点之间的关系。结果表明:(1)13～18岁青少年随年龄增长,对表象任务正确反应需要的时间逐渐下降,其反应时变化的转折时期为16岁;(2)男女生之间差异不显著;(3)在句图匹配和心理旋转作业中好组10Hzα波的比率均高于差组,其它频率差异不显著,说明表象能力好组与占主频的α波相联系。     

Mental-task instructions and optokinetic nystagmus to the left and right

The frequency of elicited optokinetic nystagmus (OKN) in both directions was studied in subjects instructed to perform mental tasks thought to be asociated primarily with either the right or left hemisphere or a combination of both. A negative relationship between OKN frequency and right-hemisphere activity was more strongly confirmed than the alternative hypotheses that OKN frequency would be negatively related to the total amount of inner processing or to the amount of visualization required by a task. A significantly higher frequency of OKN was elicited (in nonmyopic subjects) when the stripes were moving in the direction contralateral to the hemisphere presumably involved in the instructed mental task. Subjects showing higher rates of right lateral eye shift (in an interview situation) made greater adjustments in OKN frequency according to the nature of the mental task.     

“Handedness” and skill

The variability of handedness with different tasks is discussed. Experiments are described which show under what conditions handedness becomes evident. Tasks involving three different levels of complexity were used. The simplest task measured the accuracy with which a particular pressure could be reproduced in isometric contraction of the flexors of the index finger on each side in 21 female subjects. In the second situation, the maximum speed of making an attempted tapping movement under the same conditions, was measured in ten of the same subjects using the same muscle group alternating with its antagonists. The same ten subjects were also tested on an aiming task which provided the third level of complexity. The results suggest that differences in performance between the two sides only occur where “timing” or the serial organization of muscle activity is required and that such differences may be due to training.

Whether handedness is inherited or acquired is briefly discussed, and a second series of experiments using the same tasks as before were carried out on one female and nine male subjects. In this instance, the first two tests were used on the big toe of each side as well as the index finger. The results confirm that differences in performance between the two sides on these tasks can be adequately explained in terms of usage or training.

The hypothesis that “timing” is therefore important in the learning of any movement where serial muscle contractions arc involved was tested and confirmed in a third experimental series. The consistency of timing of the application of force in turning a crank handle at maximum speed was measured in five male subjects before and after training. The implications of the results are discussed in relation to other researches on skills.