Gordon Mangan

Music and spatial IQ

Abstract Rauscher, Shaw and Ky (1993) have reported a significant and relatively large improvement in spatial IQ scores (up to eight points) after listening to Mozarts Sonata for two pianos in D major (K488) compared to either silence or relaxation music. This result if replicated may have considerable implications for improving spatial intelligence in educational and organizational settings. In order to replicate this relationship, 30 subjects participated in an experiment in which the effect of music (Mozart, popular dance music or silence) was measured on Raven Advanced Progressive Matrices scores. No significant effect of music on IQ performance was found.

Effects of post-learning smoking on memory consolidation

The effects of immediate post-learning smoking of low and medium nicotine delivery cigarettes were compared to those of smoking a denicotinised cigarette and a no-smoking control condition in a paired-associate learning task. Thirty-nine male smokers were tested for retention of the memorised material at 1 week post-learning. All subjects received all conditions in a repeated measures design. The low nicotine condition was associated with significantly fewer errors on first trial of recall and fewer total errors to criterion. There were no differences in performance reported between the no-smoking and zero nicotine conditions. The medium nicotine condition produced results part way between the no-smoking and low nicotine conditions. Results are discussed in terms of the effects of nicotine on long-term consolidation mechanisms.

Smoking, processing speed and attention in a choice reaction time task

Nineteen subjects performed a choice reaction time task in which two levels of choice (two and four stimuli), and two levels of spatial attention (narrow and wide) were manipulated under each of two smoking conditions: sham smoking (denicotinised cigarette) or regular smoking (0.8 mg nicotine cigarette). All three factors significantly affected reaction time, with the smallest reaction times being recorded to the two-choice narrow grouped stimuli recorded under the high nicotine condition. Nicotine appears to speed decision time for both complex and hard-to-attend tasks, which is compatible with a role for nicotinic receptors in systems jointly mediating attention, memory and processing speed.

Intelligence and Complexity of the Averaged Evoked Potential: An Attentional Theory.

Although the Hendricksons hae proposed that the string length measure of human auditory evoked potential complexity is positively related to psychometric intelligence, this relationship is variable and may even in some circumstances be revered. Previous studies relating string length to IQ are reviewed and it is proposed that inconsistencies between these reports reflect procedural differences in task—attention requirements or the absence thereof. In order to test this hypothesis, 21 subjects participated in two string length conditions: one in which attention was not required and one in which subjects were required ti count oddball stimuli. String length was shown to be the product of an interaction between intelligence and attention such that high-IQ subjects recorded lawer brain evoked potential string lengths in the attend condition, whereas low-IQ subjects showed maximal string lengths under attended conditions. This result is compatible with both the D.E. Hendrickson and Hendrickson (1980) and Bates and Eysenck (1993) findings of positive and negative IQ-string correlations, respectively, and supports the hypothesis that string length indexes efficiency and capacity under attended and unattended conditions, respectively. The string length correlation with IQ is thus suggested to result from opposite attention-induced changes in string length in high- and low-IQ subjects. This was supported by a correlational analysis of the difference in strtin length between high and low attention conditions revealing a wide spread high correlation maximal at frontal sites, where the difference measure accounted for over half the variance in intelligence test scores (uncorrected R2 = 0.53). It is suggested that the string difference measure is a more reliable estimate of intelligence than raw string length in either attended or unattended conditions. The neuural-efficiency model of intelligence is discussed in light of thses experimental findings.

Effects of nicotine on perceptual speed

Two experiments investigating the effects of nicotine on performance in the inspection time (IT) procedure are reported. Experiment 1 compared ITs in smoking (0.8 mg nicotine cigarette), sham-smoking, and no-smoking conditions. IT was significantly shorter in the smoking condition as compared to both the no-smoking or sham-smoking conditions, suggesting that nicotine enhances early information processing. This result is of particular interest because of the correlation between IT and IQ reported in previous experiments. The nicotine related decrease in IT raises the possibility that nicotine enhances at least a subset of the physiological processes underlying intellectual performance. Experiment 2 examined the persistence of this nicotine related enhancement in IT, and investigated the effects of nicotine across 480 IT trials. Results suggested that ITs derived from the last third of the 480 trials were significantly shorter in the 0.8 mg cigarette condition than in no-smoking condition. The results from these two experiments, taken together with recent work examining the effects of nicotine on the string length measure of AEP waveform complexity and Hick decision time (DT), and studies investigating cognitive functioning and cholinergic system dysfunction in dementia, suggest a role of the cholinergic system in intellectual performance.

Personality and conditioning with appetitive and aversive stimuli

Two studies examining relationships of extraversion (E), neuroticism (N) and psychoticism (P) to conditioning performance are reported. In the first, 31 male volunteers developed electrodermal CRs to appetitive or aversive stimuli of either weak or strong rated intensity. Factor analysis yielded general factors of classical CR acquisition and extinction across reinforcement type. Stability and E loaded the acquisition factor, these Ss, from post-hoc analysis, revealing superior conditioning in the strong appetitive condition. In the second study, 20 of these 31 Ss participated in two series of discrimination motor reaction time trials, in which attainment of criterion RT was reinforced by appetitive slides, and slower-than-criterion responding by aversive slides. Introversion was correlated with greater response acquisition under both conditions, although post-hoc analysis suggested that improvement under positive reinforcement did not differ from simple practice. Results are congruent with a model combining reinforcer preference with response potential to describe personality-conditioning relationships.

Inspection time and intelligence: further attempts to eliminate the apparent movement strategy

While the inspection time (IT) paradigm has proved itself as one of our best candidates for a reductive measure of general ability, some unsolved problems impede interpretation of the correlation between IQ scores and IT. Foremost among these are concerns that stimulus artifacts may reduce the validity of IT as a measure of processing speed. Attempts to use meta-contrast masks to eliminate apparent movement strategy have proven unsuccessful [Am J Psychol 106 (1993) 191.]. This paper reports on the effectiveness of three backward masks to reduce apparent motion strategies in the IT paradigm as well as assessing putative personality effects on masking and IT. The ability of subjects to use apparent motion was investigated using the traditional IT mask, and two new masks: flash and lines. Apparent motion was most frequently reported by subjects under the traditional masking condition. IQ scores based on a test of figural manipulation (Alice Heim 5 figural) were significantly negatively correlated with reported perception and use of apparent motion cues in the standard IT mask condition, but not in the new mask conditions. Significant negative correlations between IT and IQ were obtained in all masking conditions, suggesting that the use of apparent motion cues does not determine the significant and negative correlation between IT and IQ. Results suggested that future research should employ masks of the type tested here.

Smoking and raven IQ

Nicotine has recently been shown to enhance measures of information processing speed including the decision time (DT) component of simple and choice reaction time and the string length measure of evoked potential waveform complexity. Both (DT and string length) have been previously demonstrated to correlate with performance on standard intelligence tests (IQ). We therefore hypothesised that nicotine is acting to improve intellectual performance on the elementary information processing correlates of IQ. In the current experiment we tested this hypothesis using the Raven Advanced Progressive Matrices (APM) test. APM scores were significantly higher in the smoking session compared to the non-smoking session, suggesting that nicotine acts to enhance physiological processes underlying performance on intellectual tasks.

Smoking, string length and intelligence

Abstract Over the last decade a number of studies have reported significant relationships between physiological and semi-physiological measures of performance—the string length measure of AEP waveform complexity, inspection time (IT) and reaction time (RT) and psychometric intelligence. At present, the neurophysiological mechanism(s) mediating this relationship are unknown. However, some recent smoking studies have reported that RT and IT performance is significantly enhanced in smoking (nicotine) conditions compared to sham smoking (no nicotine) or no-smoking conditions, which suggests performance on such tasks may be mediated by cholinergic systems. In order to further investigate this relationship, the string length which arguably provides the highest correlation with IQ was measured under smoking and non-smoking conditions. As predicted, string lengths were significantly increased in the smoking condition, suggesting that nicotine may enhance the neurophysiological processes underlying general cognitive ability.

Perception and recall of aversive material as a function of personality type

Abstract Relationships between personality dimensions of extraversion (E), neuroticism (N), psychoticism (P) and barrier (B) and patterns of psychophysiological responding during exposure to and subsequent recall of aversive and non-aversive material were investigated. Sixteen male volunteers were asked to recall the critical features of 10 film segments containing either neutral or aversive material. Heart rate (HR), skin conductance (SC) and electromyographic (EMG) responses were recorded throughout the session. Analysis showed that during exposure to aversive material, high BE Ss recorded high levels of autonomic responding and low levels of muscle tension, while during recall, they showed reduced autonomic activity and significantly higher levels of muscle tension. Low BE Ss showed significantly higher levels of muscle tension during film presentation and significantly lower levels during recall, with little change in autonomic reactivity between treatments. Recall data indicate that high BE Ss had significantly better recall under all conditions. N and P differences were unrelated to patterns of psychophysiological responding or efficiency of recall.