Electroencephalograph Correlates of Threshold Regulation

Functional consequences of perceiving facial expressions of emotion without awareness

A substantial body of research has established that even when we are not consciously aware of the faces of others we are nevertheless sensitive to, and impacted by their facial expression. In this paper, we consider this body of research from a new perspective by examining the functions of unconscious perception revealed by these studies. A consideration of the literature from this perspective highlights that existing research methods are limited when it comes to revealing possible functions of unconscious perception. The critical shortcoming is that in all of the methods, the perceived facial expression remains outside of awareness. This is a problem because there are good reasons to believe that one important function of unconsciously perceived negative faces is to attract attention so that they are consciously perceived; such conscious perception, however, is never allowed with existing methodologies. We discuss recent studies of emotional face perception under conditions of visual search that address this issue directly. Further, we suggest that methodologies that do not examine cognitive processes as they occur in more natural settings may result in fundamental misunderstandings of human cognition.

Mathematical cognitive style and arithmetic sign comprehension: a study of EEG alpha and theta activity

The localization of arithmetic sign comprehension was investigated using EEG spectral parameters as indicators of cortical engagement. Right-handed male subjects were selected on the basis of scores on the Mathematics Cognitive Style Survey and assigned to 2 groups, a 'left hemisphere oriented (LHO)' (N = 9) and 'right hemisphere oriented (RHO)' (N = 9) group. Subjects were presented with 4 conditions, a motoric baseline condition, two arithmetic fact retrieval tasks employing either a sign operator or verbal operator and a sign comprehension task which required subjects to fill in a missing sign (e.g. 6 ? 4 = 24). Both across subject correlational analysis of EEG alpha 1 asymmetry and performance as well as within subject analysis of condition means indicated a somewhat unique contribution of the right hemisphere to sign comprehension. LHO subjects exhibited greater relative left mid-temporal lobe activation than RHO subjects but less relative left frontal activation (theta band) than RHO subjects during the verbal operator task. It was tentatively concluded that this frontal lobe asymmetry difference was due to a mismatch in strategy preference and coding requirements among RHO subjects.

Auditory subliminal stimulation: a re-examination

Unconscious or subliminal perception has historically been a thorny issue in psychology. It has been the subject of debate and experimentation since the turn of the century. While psychologists now agree that the phenomenon of visual subliminal stimulation is real, disagreement continues over the effects of such stimulation as well as to its existence in other sensory modalities, notably the auditory. The present paper provides an overview of unresolved issues in auditory subliminal stimulation which explains much of the difficulty that has been encountered in experimental work in this area. A context is proposed for considering the effects of auditory subliminal stimulation and an overview of current investigations in this field is provided.

Tachistoscopic and questionnaire methods for the measurement of psychological defences

Only few attempts have been made to compare different methods aiming at quantifying defensive strategies. In this study the tachistoscopic Defence Mechanism Test (Kragh, 1960b and 1985) is compared to paper-and-pencil tests of defence. There were virtually no correlations between the DMT and the other measures of defence. This may indicate that the concept of defence is a highly complex one. It is suggested that the Defence Mechanism Test may be measuring primary defence while defence questionnaires may be assessing more secondary forms of defence. The two questionnaires used for assessing defence correlated significantly, while a scale for social desirability showed no correlation with DMT or the two defence questionnaires.

Effect of artificial pupil size on recognition threshold

Recognition thresholds for neutral and taboo words increased with a decrease in artificial pupil size for 3 Ss. Under a fully dilated condition without artificial pupils, there was a slight increase in recognition threshold. No differences were observed between neutral and taboo conditions. These results support the suggestion that pupil size may be a plausible mechanism in perceptual defense.