Individual differences in susceptibility to inattentional blindness

Inattentional blindness refers to the finding that people do not always see what appears in their gaze. Though inattentional blindness affects large percentages of people, it is unclear if there are individual differences in susceptibility. The present study addressed whether individual differences in attentional control, as reflected by variability in working memory capacity, modulate susceptibility to inattentional blindness. Participants watched a classic inattentional blindness video (Simons & Chabris, 1999) and were instructed to count passes among basketball players, wherein 58% noticed the unexpected: a person wearing a gorilla suit. When participants were accurate with their pass counts, individuals with higher working memory capacity were more likely to report seeing the gorilla (67%) than those with lesser working memory capacity (36%). These results suggest that variability in attentional control is a potential mechanism underlying the apparent modulation of inattentional blindness across individuals.     

Individual differences in susceptibility to experimentally induced phantom sensations

We investigated individual differences in susceptibility to two vibration-induced phantom illusions, i.e. illusory arm extension and nose prolongation (“Pinocchio illusion”). Vibration was applied to the biceps brachii tendon of 32 healthy participants. Susceptibility to the illusions was quantified by vividness ratings and by ratings of the amount of illusory position changes of the arm and illusory shape changes of the nose. Participants also completed the Perceptual Aberration (PA) and the Need for Cognition (NFC) inventories. PA reflects the frequency of spontaneously experienced body schema alterations and NFC a person's tendency to cognitively structure experiences. PA was positively correlated with participants’ susceptibility to illusory arm extension and, exclusively for men, also to nose elongation. A high NFC was weakly associated with a high susceptibility for the Pinocchio illusion. By inference, these findings indicate a physiological basis of PA and a cognitive mediation of experimentally induced phantom sensations.     

Sustained attentional and disattentional abilities and arousability: Factor analysis and relationships to hypnotic susceptibility

The neurophysiologically separate dimensions of deeply focused, sustained attention and arousability are shown to be differentially related to hypnotic susceptibility. University undergraduates, 98 men and 112 women, were administered the Harvard Group Scale of Hypnotic Susceptibility; the Group Stanford Hypnotic Susceptibility Scale, Form C (SHSS:C); and questionnaires that assessed attentional abilities (Differential Attentional Processes Inventory (DAPI), Tellegen Absorption Scale (TAS)), Extraversion (Eysenck Personality Questionnaire), strength of the nervous system (Strelau Temperament Scale (STS)), augmenting-reducing (Vando Reducer-Augmenter Scale (RAS)), and emotionality (Affect Intensity Measure (AIM)). Women were significantly higher on TAS, DAPI dual attention physical-cognitive scale, and AIM; men were significantly higher on TAS and STI Strength of Excitation Scale. Separate factor analyses for men and women separately yielded fairly similar four-factor solutions. The first major factor, defined by DAPI Moderately Focused Attention and Dual Attention scales, represented moderately sustained attention in a complex environment with limited interference from competing stimuli. The extremely involved and focused attention factor, defined by the TAS and DAPI Extremely Focused Attention Scale, had hypnotic susceptibility loaded more strongly for men than women. The arousability factor was defined by EPQ Extraversion, STI Mobility of Nervous System (MNS) scale, and RAS. The neo-Pavlovian nervous system processes factor was defined by the STI Strength of Excitation and Strength of Inhibition scales; the STI MNS scale also loaded on this factor for men. Only for women were introverts more hypnotizable than extraverts. Results support H. J. Crawford and J. H. Gruzelier's (1992) in E. Fromm and M. Nash (Eds.) Contemporary Perspectives in Hypnosis Research (pp. 227–266) New York: Guildford Press) neurophysiological model of hypnosis that proposes that highly hypnotizable persons have a more efficient fronto-limbic sustained attentional and disattentional system.     

Individual differences in hypothetic-deductive reasoning: importance of cognitive skills and flexibility

Recent investigations show that people's differential performance when solving reasoning tasks is due to differences not only at computational level, but also at the rational or intentional level. This study is within the framework of this context and it specifically analyses individual differences in hypothetic-deductive reasoning, taking into account the characteristics associated with the task itself (content and instructions) as well as the individuals' differential characteristics. Two hundred and seventy-six students from the University of Santiago de Compostela participated in this study. Several psychometric tests were administered and participants were requested to solve various reasoning tasks. The results obtained confirm that, in effect, the differences between competent and non-competent reasoners are observed at both the above-mentioned levels: cognitive skills and abilities (algorithmic level) and cognitive flexibility (intentional level).     

Individual differences in cognition: Some relationships between personality and memory

Individual differences in cognition were studied in the form of the hypothesis that arousal, as indexed by personality measures of extraversion and neuroticism, affects the way in which verbal material is organized in memory. Subjects pretested on measures of these personality variables participated in either a paired-associates learning or a free-recall experiment. On the paired-associates task, subjects who were thought to be high on arousal made fewer errors when response terms were semantically similar than low arousal subjects. On the other hand, subjects thought low on arousal made fewer errors when response words were phonetically similar than high arousal subjects. On the free-recall task, low arousal subjects were found to cluster words together on the basis of semantic category at a higher rate than high arousal subjects. These results were taken to support the view that high arousal (as indexed by personality measures) leads to a focus on the physical aspects of verbal material, whereas low arousal leads to a memory organized around semantic aspects. The implications of these findings for other views of memory are discussed.     

Individual differences in susceptibility to false memory in the Deese-Roediger-McDermott paradigm

The authors addressed whether individual differences in the working memory capacity (WMC) of young adults influence susceptibility to false memories for nonpresented critical words in the Deese-Roediger-McDermott associative list paradigm. The results of 2 experiments indicated that individuals with greater WMC recalled fewer critical words than individuals with reduced WMC when participants were forewarned about the tendency of associative lists (e.g., bed, rest, . . .) to elicit illusory memories for critical words (e.g., sleep). In contrast, both high and low WMC participants used repeated study-test trials to reduce recall of critical words. These findings suggest that individual differences in WMC influence cognitive control and the ability to actively maintain task goals in the face of interfering information or habit.     

Individual differences in susceptibility to infection and illness following respiratory virus challenge

Abstract

The aim of the present research was to investigate whether susceptibility to experimentally-induced respiratory virus infections and illness is related to measures of personality, physiological state, performance efficiency, and subjective ratings of alertness and motivation obtained prior to virus challenge. Two studies, using different viruses, showed that volunteers who subsequently developed colds had higher temperatures prior to virus challenge than those who remained free from illness. Similarly, those who later had colds were worse than other volunteers on certain performance tests given in the pre-challenge period. The results also showed that task-related motivation was related to subsequent infection. Personality scores were poor predictors of infection and illness, the only exception being introversion, which, in one study, was related to the likelihood of developing a sub-clinical infection.     

Individual differences in resultant achievement motivation and latency to and persistence at an achievement task

Alternative hypotheses generated from the Atkinson (1957) and Atkinson and Feather (1966) risk-taking model of achievement motivation and the Atkinson and Birch (1970) dynamics of action theory comparing groups high and low in resultant achievement motivation (RAM) on latency to and persistence at an achievement task were tested. Subjects who had made two or more atypical shifts (choice of an easier task following success and choice of a more difficult task following failure) during 21 trials of a target-shooting game the first week were classified as low RAM (n=154), and subjects who had made 0 or 1 atypical shift were classified as high RAM (n=155). In week 2 subjects divided their time among two nonachievement tasks and the very easy, easy, intermediate, difficult, or most difficult levels of the achievement task. No main effects or interactions were found when latency to the achievement task was analyzed in a RAM by Difficulty level × Gender individual difference design. High-RAM subjects persisted significantly longer than low-RAM subjects across all conditions. Results are explained using the dynamic concepts of instigation, inhibition, and consummation. Analyses of sequential choices (week 1) among five difficulty levels did not support the Atkinson (1957) explanation of atypical shifts as avoidance of intermediate challenges for low-RAM subjects. Subjects who avoided the target-shooting game the second week more often persisted at the very easy task following success but not at the most difficult task following failure, results that are partially supportive of Feather's (1961) analysis of persistence.I wish to thank Dr. David Reuman, who suggested the research topic; the 24 undergraduate research assistants who ran subjects for this experiment; Rochelle Breitenbach, Laurie Colisanti, Kevin Kurkowski, Lee Ann McHenry, and Brenda Yee, who assisted with the data preparation and analyses; Ann Beck and Randi Gilbert, who provided editorial assistance; and Dr. Tilly Houtmans, who commented on an earlier version of this paper. A paper based on the dynamics of action research was presented at the Nags Head Conference on Motivation and Emotion on June 17, 1990. A paper based on the level of aspiration/achievement motivation results was presented at the Third International Meeting of the Society for the Advancement of Field Theory on September 16, 1988. A copy of the BASIC program for the Apple IIe computer is available to anyone who sends a 5 1/4-inch diskette.     

Individual differences in utilizing control to cope with job demands: effects on susceptibility to infectious disease

This study examined the interactive effects of job demands, control, and individual characteristics on upper respiratory illnesses and immune function. Having high job control appeared to lessen the linkage between job demands and poor health among individuals with high self-efficacy and those who perceived that they were not often responsible for negative job outcomes. Conversely, having high job control exacerbated the association between job demands and poor health among inefficacious individuals. Implications for promoting more healthful work environments and facilitating employee coping are discussed.     

Individual differences and interrelationships among a select set of cognitive skills

An experiment was conducted to investigate individual differences and interrelationships in performance on three short-term memory processing and visual processing tasks. Parameters of models for these tasks were correlated. High correlations (.97 and .83) were obtained for some intertask parameters. indicating that elemental component processes for different tasks can be identified that are similar or highly related. Psychometric measures (SATM and SATV) were also correlated with the information processing model parameters. High multiple correlations of SATV and SATM were obtained using model parameters as predictors. when the data were analyzed separately for female and male subjects. The results are suggestive of sex differences in the interrelationships of the cognitive processes under investigation.     

Individual differences in the capacity limitations of visuospatial short-term memory: Research on sighted and totally congenitally blind people

The study of visuospatial imagery processes in totally congenitally blind people makes it possible to understand the specific contribution of visual experience for imagery processes. We argue that blind people may have visuospatial imagery processes, but they suffer from some capacity limitations. Similar, although smaller, limitations and individual differences may be found in sighted people. Visuospatial imagery capacity was explored by asking people to follow an imaginary pathway through either two- or three-dimensional matrices of different complexity. The blind appear to use specific visuospatial processes in this task (Experiments 2 and 3), but they have difficulty with three-dimensional matrices; sighted people have no such difficulty with three-dimensional matrices (Experiment 1). On the other hand, when a three-dimensional pattern exceeded sighted capacity, the blind and sighted showed similar patterns of errors. Subsequent analyses suggested that both visuospatial processes and verbal mediation were used.     

Individual differences in working memory and reasoning-remembering relationships in solving class-inclusion problems

In the present experiment, we evaluated the effects of individual differences in reading span and variation in memory demands on class-inclusion performance. One hundred twenty college students whose reading spans ranged from low to medium to high (as indexed by a computerized version of the Daneman and Carpenter [1980] reading-span task) solved 48 class-inclusion problems. Half of the subjects had the solution information available when the problems were presented; the other half performed a detection task between solution information and problem presentation. The results from both standard statistical analyses and from a mathematical model indicated that differences in reading span and memory load had predictable, similar effects. Specifically, the sophistication of reasoning strategies declined when memory demands increased or when reading spans decreased. Surprisingly, these effects were primarily additive. The results were interpreted in terms of global resource models and findings from the developmental literature.     

Individual differences in circadian activity rhythms and their effects on roommate relationships

Individual differences in circadian activity rhythms were assessed and correlated with a number of measures of task orientation and time concern. Those who tend to be morning active completed the questionnaires more quickly than did others, expressed negative attitudes about wasting time, and scored higher on measures of achievement tendency and task leadership. Differences between college roommates in the tendency to be morning active were found to be related to negative evaluations of the roommate relationship. The results of this study suggest that the causes and effects of synchronized personal and social circadian rhythms warrant continued exploration.     

Enhancing hypnotic susceptibility: interpersonal and rapport factors

This research supported the hypothesis that hypnosis can be thought of as a set of potentially modifiable social-cognitive skills and attitudes. A low-interpersonal-training treatment devised by Gorassini and Spanos (1986) was compared with a treatment designed to modify not only cognitive factors but also to augment rapport with the trainer and diminish resistance to responding (high-interpersonal training). Fifty percent of the initially unhypnotizable subjects in the high-interpersonal condition tested as being highly susceptible to hypnosis (high susceptibles) at posttest on the Harvard Group Scale of Hypnotic Susceptibility (Shor & Orne, 1962); 25% of the unhypnotizable subjects in the low-interpersonal condition responded comparably. Eighty-three percent of the medium-susceptibility (medium susceptibles) subjects tested as being highly susceptible at posttest in both conditions. Practice-alone control subjects' performance was stable across testings. The study was the first to demonstrate that treatment gains generalize to a battery of novel, demanding suggestions (generalization index) that have been found to differentiate highly susceptible subjects from unhypnotizable simulating subjects. The importance of rapport was evidenced by the finding that rapport ratings paralleled group differences in hypnotic responding and that rapport correlated substantially with susceptibility scores at posttest and with the generalization index. Whereas initial hypnotizability scores correlated significantly with retest susceptibility scores, initial hypnotizability failed to correlate significantly with the generalization index.     

Individual differences in working memory: introduction to the special section.

This special section includes a set of 5 articles that examine the nature of inter- and intraindividual differences in working memory, using working memory span tasks as the main research tools. These span tasks are different from traditional short-term memory spans (e.g., digit or word span) in that they require participants to maintain some target memory items (e.g., words) while simultaneously performing some other tasks (e.g., reading sentences). In this introduction, a brief discussion of these working memory span tasks and their characteristics is provided first. This is followed by an overview of 2 major theoretical issues that are addressed by the subsequent articles--(a) the factors influencing the inter- and intraindividual differences in working memory performance and (b) the domain generality versus domain specificity of working memory--and also of some important issues that must be kept in mind when readers try to evaluate the claims regarding these 2 theoretical issues.     

Individual differences in sensitivity to violence

A survey of university students explored correlates of sensitivity to violence, defined as a person's average rating of the severity of violence of several behaviors. The 79 women were somewhat more sensitive than the 39 men. Sensitivity was associated with the tendency to describe oneself as violence sensitive or violence tolerant, with the person's manner of defining the concept of violence, and with the tendency to include verbal abuse and inaction as possible forms of violence. Sensitivity was not clearly associated with some other variables, such as attitudes toward bullying and acceptability of hunting. The potential utility of measuring sensitivity to violence, and further work suggested by these findings, are discussed.