Defense mechanisms in alexithymia

The Polish version of the Toronto Alexithymia Scale-20 and Defense Mechanisms Questionnaire were completed by 387 university students. Scores on alexithymia correlate significantly with scores on the whole group of 12 immature defenses (Pearson r = .39, p < .001) and with scores on such individual immature defense mechanisms as Autistic Fantasy (r = .39), Somatization (r = .37), Projection (r = .32), and Displacement (r = .32). These results support other findings indicating that alexithymia is significantly associated with immature ego defenses.     

Interactions between color and word processing in a flanker task

To examine interactions between color and word attributes, participants responded, either manually or vocally, to a central target (color patch or word) flanked by a Stroop stimulus. Color and word attributes of the flanker affected both vocal and manual responding to color patches. Color and word flankers also affected manual responding to word targets, but only word flanker affected vocal responding to word targets. These results are not consistent with models (e.g., translational models) of Stroop tasks, which posit that interactions between colors and words occur only when vocal responding is required.     

Speed, size, and edge-rate information for the detection of collision events

In the present study an alternative analysis to tau was considered that was based on perceived speed and size and that assumed constant deceleration for the detection of collision events. Observers were presented with displays simulating a 3-D environment with obstacles in the path of observer motion. During the trial, observer motion decelerated at a constant rate and was followed by a blackout prior to the end of the display. Observers had to detect which trials resulted in a collision. The results indicate that collision detection varied as a function of the size of the obstacles, observer speed, and edge rate--findings not predicted by an analysis of tau. The results suggest that observers use an analysis based on speed and size information. A model that assumes constant deceleration is proposed for braking control.     

Frequency of perseveration in normal subjects

Although perseveration is a recognized sign of disturbed brain function, it also occurs in normal individuals. Determination of the frequency of perseveration in normal subjects would enable clinicians to use perseveration as a marker of possible pathology. The purpose of this study was to document the extent of perseveration in normal young and older subjects. Thirty young normal individuals between the ages of 20 and 35 years and 30 older normal individuals between the ages of 60 and 75 years were given four tasks on which perseveration has been reported in brain-damaged individuals. Four percent of all responses were perseverative. No age or gender effects on frequency were observed. Of the four neuropsychological tasks, the Modified Wisconsin Card Sorting Test elicited the greatest number of perseverations.     

How "regular" is sentence comprehension in Broca's aphasia? It depends on how you select the patients

Grodzinsky, Pi?ango, Zurif, and Drai (1999) argue that a statistical analysis of pooled sentence comprehension data from published studies of Broca's aphasic patients supports the dominance of a differential pattern of performance on active and passive voice structures. They argue that these results counter a previous study in which individual patient data from published studies were analyzed. However, Grodzinsky et al. have not carried out a true test of their hypothesis, but have biased the outcome by selecting samples for analysis that support their claims.     

Oscillatory brain dynamics, wavelet analysis, and cognition

On the basis of a systems theoretical approach it was hypothesized that event-related potentials (ERPs) are superpositions of stimulus-evoked and time-locked EEG rhythms reflecting resonance properties of the brain (Ba?ar, 1980). This approach led to frequency analysis of ERPs as a way of analyzing evoked rhythms. The present article outlines the basic features of ERP frequency analysis in comparison to ERP wavelet analysis, a recently introduced method of time-frequency analysis. Both methods were used in an investigation of the functional correlates of evoked rhythms where auditory and visual ERPs were recorded from the cat brain. Intracranial electrodes were located in the primary auditory cortex and in the primary visual cortex thus permitting "cross-modality" experiments. Responses to adequate stimulation (e.g., visual ERP recorded from the visual cortex) were characterized by high amplitude alpha (8-16 Hz) responses which were not observed for inadequate stimulation. This result is interpreted as a hint at a special role of alpha responses in primary sensory processing. The results of frequency analysis and of wavelet analysis were quite similar, with possible advantages of wavelet methods for single-trial analysis. The results of frequency analysis as performed earlier were thus confirmed by wavelet analysis. This supports the view that ERP frequency components correspond to evoked rhythms with a distinct biological significance.     

Hemispheric asymmetry in lexical decisions: the effects of grammatical class and imageability

It has been suggested that neural systems for lexical processing of nouns and verbs are anatomically distinct. The aim of the present study was to investigate if brain asymmetry for the processing of these two grammatical classes is also different. Neurologically intact adults performed a lateralized lexical decision task with grammatically unambiguous words of high, medium, and low degrees of imagery. For error scores a right visual field (RVF) advantage and an overall effect of imageability were obtained. For latency scores grammatical class and imageability modified visual field differences: in the noun class a RVF advantage was obtained only for low imagery nouns, while for the verbs the RVF advantage was present for both medium and low imagery verbs. These results suggest that the participation of right hemisphere neural systems in the processing of verbs is more limited than in the processing of nouns.     

A Neuropsychological Approach to Intelligence

This paper proposes that current psychometric intelligence tests are limited in evaluating cognitive activity. From a neuropsychological perspective, they fail to measure some fundamental cognitive abilities such as executive functions, memory, and visuospatial abilities. The analysis of the Wechsler Intelligence Scale presented shows that the original rationale for selecting the specific subtests included in the WAIS was unclear. The concept of a g factor in cognition is also analyzed, with the conclusion that the g factor continues to be controversial. The value of intelligence tests in predicting school performance is also criticized. It is proposed that the psychometric concept of general intelligence should be deleted from cognitive and neurological sciences. Finally, it is proposed that, in the future, neuropsychological instruments sensitive to more specific cognitive abilities replace current psychometric intelligence tests.