Inspection time and IQ: Evidence for a mental speed—ability association

Two studies have tested a theory that individual differences in mental speed constitute an important component of differences in general intelligence by examining patterns of correlation between ‘inspection time’ (IT) and various ability measures assumed to reflect different kinds of speed. The first study was set within the framework of Cattell's theory about the structure of abilities. Results from 30 adult Ss whose IQs (Raven Advanced Progressive Matrices, RAPM) were in the average to above-average range suggested that IT is associated with a broad general ability variable and not with the primary abilities ‘perceptual speed’ or ‘speed of closure’. However, IT was significantly correlated with only a subgroup of those primary abilities that were significantly intercorrelated, and the outcome did not further elucidate the nature of speed as discussed within Cattell's formulation. The second study tested a relationship between IT and a measure of general ‘intellectual speed’, previously described as the major determinant of intellectual differences in a situation where two other critical variables, ‘accuracy’ and ‘continuance’ can exert no influence. It was measured for more than 40 adult Ss, whose IQs (Wechsler Adult Intelligence Scale—Revised) ranged from 81 to 138, and compared with times to produce the correct solution to individual items from the RPM. IT, IQ and solution times were all significantly intercorrelated but, nonetheless, IT and solution times appeared to be substantially reflecting different processes. It is concluded that IT can account for more than the 10% of variance in IQ commonly found to be shared with simple information-processing tasks. The present result of approx. 17% shared variance is probably an underestimate, given the restricted IQ samples used and certain procedural shortcomings. The nature of speed reflected by IT has not been determined and current measurement procedures may be confounded by internal noise.     

Intelligence and inspection time: Do high-IQ subjects use cognitive strategies?

It has been suggested that ‘inspection time’ (IT) can be aided by specific strategies, and that high-IQ Ss would therefore be advantaged on this task. However consideration of previously published findings from university students suggest that such strategies cannot currently be taught with any degree of success, and that strategy use may disrupt rather than explain the IT-IQ relationship. Correlations between IT and IQ for high-IQ Ss not using strategies are consistent with previously observed data, perhaps from -0.3 to -0.6. Despite considerable variation in the IT technique used, similar results are being obtained by different researchers. It is not possible to prove that no strategies at all have been used by Ss, but re-interpretation of current evidence suggests that this source of bias is overstressed. By applying Baron's formal criteria for identifying strategies, it becomes possible to test whether strategies have been used or not. Failing a clear statement of what counts as evidence of strategy use, particular strategies must be examined for their impact on IT when Ss have been fully trained in their use.     

Responding time: A response equivalent to inspection time

A response equivalent to ‘inspection time’ (IT) was developed using a reaction time task in which Ss were required to respond as quickly and accurately as possible to whichever one of two lights appeared on each of a number of trials. The appearance of the lights was followed on all trials by a backward mask. IT was estimated for each S as the shortest duration between the onsets of the light and the backward mask at which the S could respond accurately on virtually every trial. An estimate of ‘responding time’ was then made by setting the duration between the stimulus onset and the mask to each S's individual IT and gradually reducing the time between trials so that Ss had less and less time in which to respond correctly. Responding time was taken to be the shortest such interval at which the S could respond accurately on virtually every trial. This measure was found to be reliable although quantitatively different estimates were obtained using two different methods of presenting the stimulus trials. Responding time was longer for a group of lower-intelligence Ss than for a group of higher-intelligence Ss and the measure was also found to correlate with measured intelligence in the former group. However, it did not itself correlate significantly with IT suggesting that responding time and IT may be measuring different underlying processes.     

Early electro-cortical correlates of inspection time task performance

The concept of general intelligence (g) summarizes the well established finding that scores on separate cognitive tasks are positively correlated, indicating a trait common to many aspects of information processing. Inspection time is a well-established correlate of IQ, where those of a higher IQ can correctly identify a briefly presented stimulus with a greater level of accuracy than those of a lower IQ. This study used two age-matched samples, selected on the basis of their scores on Raven's Advanced Progressive Matrices from the undergraduate population of Bangor University. In order to address the confound of inspection time and IQ of previous ITT-ERP research, each participant of the presented study performed an IT task with the same five levels of stimulus duration while undergoing 64-channel EEG recording. The high IQ group made significantly fewer errors at each level of stimulus duration and exhibited a significantly larger N1 response. N1 latency and other ERP components did not distinguish the two IQ groups. Given the specificity of ERP group differences to the N1, the results of the present study suggest that the link between IT performance and g is attributable to individual differences in directing attention to a spatial region.     

Inspection time and IQ in young children

Three studies investigating the relationship between IQ, mental age (MA), chronological age (CA) and inspection time (IT) are reported. Forty-seven children participated: three age groups, 6, 8 and 10 yr, attending a London primary school and with IQs ranging from 75 to 141. The IT task was incorporated into a microcomputer-controlled video game and two measures of IT were obtained from two psychophysical procedures: method of limits and method of constant stimuli. All three studies found that a significant relationship was maintained for Ss over the full age range. Although, in general, IT decreased with increasing CA, bright 6-yr-olds had similar ITs to dull 10-yr-olds. Given that the latter have higher MA than the former and they have had more years experience of school, it is concluded that the IT/IQ relationship is primarily based on fundamental aspects of information processing, such as processing speed, rather than on task sophistication. The two psychophysical procedures produced different estimates of IT. However, it is concluded that using two methods can reduce the noisy effects of variability in responding of children. Reliabilities in the order of r = 0.45 are reported for the task.     

Inspection time: Does it measure intelligence?

The relationship between inspection time (IT) and intelligence id discussed in the context of the more general relationship between measures of mental speed and mental ability. Six issues are raised concerning IT, mental speed and intelligence: the size of the sample that have been studied; the inclusion of mentally-retarded Ss in these samples; the generality of IT; reaction time (RT) correlations with intelligence; IT and timed vs untimed IQ tests; and theoritical implications of the IT/IQ relationship. In the latter section, it is concluded that IT does not fit neatly into models accounting for RT/IQ correlates and that additional research will be required to obtain a better understanding of the nature of its relationship with intelligence.     

The ubiquity of g

We obtained the g-loading (unrotated first principal-component loading) of each of the cognitive ability measures used in the Hawaii Family Study of Cognition (HFSC) for each of the three major ethnic groups (Americans of European ancestry (AEA), Americans of Japanese ancestry (AJA) and homeland Koreans) who took part in the HFSC. The degree to which given tests (corrected for reliability) loaded on g was highly correlated with the association of cognitive test scores with the educational and occupational attainments of members of both the parent and offspring generations, with the degree of resemblance of spouses and biological relatives, and with the degree to which parental education and occupation predicted offspring cognitive test performance. For AEA and AJA families g was not found to be related to degree of mean within-sibship skew for each cognitive test, but was positively correlated with the degree of ‘hybrid vigor’ manifested by offspring of cross-ethnic matings. The above results suggest that g, as opposed to the non-g components of intelligence, is more influenced by additive genetic factors, although this is confounded by assortative mating for g, but provide only weak support for the hypothesis that g is more influenced by directional genetic dominance. While the correlations were similar in directionality for all groups, they varied considerably in magnitude, possibly because the groups differed substantially in environmental histories.     

An investigation into response blockaging

An investigation was carried out into the nature of recovery of responses where Ss claimed the response was recallable but were not immediately able to produce them. 20 Ss produced 206 such response blockages in 30 min sessions. Of these, 135 were recovered during the experimental session with a medium time of 17 sec, 15 were recovered following a second retrieval attempt 2–9 hours later. The experiment indicates that a ‘feeling of knowing’ is strongly related to later recall, as well as recognition (Hart, 1965).     

Inspection time and response strategies in a choice response task

The effects of varying stimulus duration on two response measures, percentage correct (p_c) and mean reaction time (RT) were investigated in a lights-keys RT task similar to an inspection time (IT) task. One of either N = 2, 4 or 8 lights came on as the stimulus, followed after a range of stimulus exposure durations (D) by all 8, as a backward mask. It was found that p_c was an ogival function of D for all three levels of choice, and that the standard deviations of the best-fitting normal ogives were equal. It is argued that the standard deviation can be taken as a measure of the neural noise, or error-inducing variability introduced by processing the stimulus, and so this result indicated that noise in the choice reaction task is independent of N. The effect of D on RT was as predicted by an optional accumulator model for 7 Ss with RT decreasing as D increased, while another 2 Ss appeared to have adopted a temporal deadline criterion giving RTs independent of D and equal error and correct RTs. The same two response styles were found in a re-analysis of RT data from an IT study. The p_c vs D curves were comparable for both response styles. The accumulator model commonly assumed to underly IT tasks thus does not describe the behaviour of all Ss. Such individual differences in strategic approach to the IT task should be investigated further, since assuming that all Ss use one approach may hide or confound relationships between IT and other measures of individual difference, such as intelligence. Recommendations for better IT measurement techniques are given.     

The relationship of personality to punctuality for a variety of types of appointment

The punctuality with which undergraduate students kept four distinct types of appointment was observed without their knowledge. Ss were asked to record, confidentially, the importance with which they regarded each appointment, using a 7-point scale. A frequency distribution of the proportion of appointments kept punctually approximated to a normal distribution (rather than the bimodal distribution predicted by ‘common sense’). Both punctuality and importance-rating were strongly affected by appointment type. Ss' scores on the P scale of the EPQ were inversely related to the importance they attributed to appointments, but showed little relationship to punctuality. Their scores on the E scale, on the other hand, were inversely related to punctuality for most types of appointment, but were not related to the importance attributed to appointments. Ss' N scores were positively related to punctuality for those appointments that were generally regarded as ‘extremely important’. A small interaction effect between gender of the Ss and type of appointment may have been due to the gender of the majority of the experimenters' collaborators. A principal-components analysis revealed a primary factor on which punctuality, importance-rating, E score and P score all load highly, i.e. a ‘concern for appointments’ factor.     

A preliminary investigation of cognitive and relaxation treatment of panic disorder: effects on intense anxiety vs 'background' anxiety

In this study, three adult males complaining of Panic Disorders were treated with cognitive therapy followed by relaxation training combined with cognitive therapy in a multiple-baseline across Ss design. All Ss demonstrated a decrease in the number and duration of episodes of heightened or intense anxiety, which was maintained at 3-month follow-up. Daily time-sampled ratings of ‘background’ anxiety, not necessarily associated with periods of intense anxiety, showed a substantial decrease for S2, which was maintained at 3-month follow-up. However, S 1 and S 3 evidenced an increase in background anxiety during the combined treatment phase in contrast to the effects of treatment on periods of ‘intense’ anxiety. These results suggest that psychological treatments for patients classified as suffering from Panic Disorder are effective and lend some support to the differentiation of panic from ‘general’ anxiety. Recent observations of relaxation-induced anxiety were also replicated in this clinical setting. These data also illustrate the advantages and difficulties of self-monitoring anxiety over a period of time.     

Effects of repeated exposure to sexually violent or nonviolent stimuli on sexual arousal to rape and nonrape depictions

The major purpose of this investigation was to examine the effects of repeated exposure to sexually violent stimuli (SVS) in relatively ‘naturalistic settings’ on sexual arousal to rape and nonrape stimuli. Repeated exposure effects using nonviolent erotica were also examined. Sixty-nine male Ss participated in the study. A preexposure session was conducted in which Ss were exposed to written and pictorial depictions of rape and mutually-consenting intercourse. Based on Ss' penile tumescence to these depictions, they were classified as either Force-oriented, Nonforce-oriented or Unclassifiable. Subsequently, Ss were randomly assigned to sexually violent (SVS), sexually nonviolent (SNVS) or control conditions within each force-orientation group. Those assigned to the SVS condition were then exposed to 10 SVS including feature-length films and written and pictorial depictions over a period of 4 weeks. Ss in the SNVS condition were exposed to 10 similar media presentations depicting sexually nonviolent activities only. Ss in the control condition were not exposed to any stimuli during this 4-week period. Soon after completion of the exposure phase, Ss returned for a postexposure laboratory session in which they were presented with four depictions that were similar in theme to those in the preexposure session. Penile tumescence scores and self-reports of sexual arousal were obtained. Results revealed that, for Force-oriented Ss, those exposed to either SVS or SNVS were less aroused to the rape depictions in the postexposure session than those in the control condition. A similar pattern occurred with the nonrape depictions for these Ss, though it was considerably less pronounced. No evidence of a similar ‘satiation’ pattern was obtained for either Nonforce-oriented or Unclassifiable Ss, with these Ss showing no significant differences among the three exposure conditions. The findings are discussed in the context of cognitions, personality differences, conditioning processes, stimulus parameters and response habituation theories. Social and clinical implications are also discussed.     

Concept identification with natural material.

Phonetic letters in Japanese (Hiragana, 23 in number) written by 6 adults (Ws) were presented one by one and the S was asked to guess by which W it was written. Immediately after the S made the guess, the code of correct W was given on each trial. The Ss were Japanese housewives, students etc., 53 in number. Rate of correct identification increased during 23 × 6 trials, but only from 0.3 to 0.4 on the average. The learning transferred to the remaining 23 letters of the same kind but not to letters of the other kind (Katakana). On each trial, the S verbally described cues upon which the guess was made. When the data were separately analysed according to Ws, it was found that letters of the W who was most difficult to identify were most ‘diffused’ in characterization by the Ss. The relevance of the present experiment to study of concept identification in general was also discussed.     

Interrogative suggestibility,delayed memory and self-concept

This study investigates the relationship between interrogative suggestibility as measured by the Gudjonsson Suggestibility Scale (GSS) and variables related to memory recall and self-esteem. There were 30 Ss, tested twice 1 week apart. After completing the GSS they were required to fill in a number of Semantic Differential scales relating to the concepts: Myself as I am generally, Myself during the experiment and The experimenter. Ss were generally more suggestible during the second interview when their memory about the context of the interrogation context had deteriorated. The exception was that negative feedback appeared to have most effect on suggestibility and self-esteem the first time it was applied. Self-esteem related to ‘competence’ and ‘potency’ correlated significantly with suggestibility, especially during the first interrogative session. Perceptions of the experimenter were generally not found to be significantly related to suggestibility.     

Return of fear: The role of inhibition

In a previous study investigating the relationship between subjective, physiological and behavioural changes during treatment of specific phobias, a marked between-session increase was found in subjective fear after high, but not after low intensity phobic stimulation although the groups showed similar fear ratings and heart rates immediately after treatment (Grey et al, 1979). It was hypothesized that the high intensity stimulation led to ‘treatment fatigue’; a state of deactivation, the recovery from which led to a return of fear.In this study high intensity in vivo stimulation was used for the treatment of phobic subjects under conditions of distributed and massed practice. No differences emerged between treatment conditions. A small group of Ss with a conspicuously high heart rate (mean level 120 bpm) when rating zero fear, showed a significant increase in fear after one week's interval, although they had shown similar improvement to the Ss during treatment. Subjects in both treatment conditions showed lower heart rate at all post-treatment assessments than pre-treatment. The high initial heart rate Ss continued to have higher heart rate than other Ss throughout the experiment, although they showed a decrease after treatment. It was only these Ss with desynchronously high heart rate, i.e. high heart rate with zero fear ratings, who suffered a return of fear, whereas high heart rate during high fear did not predict either response to treatment or return of fear. A further finding was a lack of correlation between the behavioural and physiological indices of fear, namely, between distance and heart rate at high levels of fear.     

Reinforced practice and reduction of different kinds of fears in adults and children

The purpose of this study was to determine whether or not fears with different origins, course and chronicity could be reduced by a common treatment program. A number of therapeutic procedures that had been experimentally demonstrated to be individually important in prior behavior modification studies with neurotic disorders were combined into a single therapeutic program called ‘reinforced practice.’ The combined elements were: graduated and repeated practice in approaching actual phobic stimuli: reinforcement for gains in performance; feedback of measurable progress; and instructions designed to arouse expectations of gradual success. In each of four experiments involving four different fears, namely fear of heights, snakes and electric shock in adults, and fear of darkness in young children, Ss who expeienced the ‘reinforced practice’ procedure improved their performance by a significant and substantial margin as compared to untreated control Ss. These results suggest that regardless of different etiologies, regardless of whether or not the fears are ‘rational’ or ‘irrational,’ and regardless of whether or not the fears are transitory or long lasting, the same treatment procedure can be equally effective in reducing escape-avoidance behavior.     

A follow-up developmental study of hypothesis behavior among mentally retarded and nonretarded children

To clarify the roles of IQ and mental age (MA) in hypothesis behavior, MA-matched subjects at three levels of IQ (70, 100, and 130) and three levels of MA ($\text{5}\text{1}\text{2}\text{, 7}\text{1}\text{2}\text{,}\text{and}\text{9}\text{1}\text{2}\text{years}$) received blank-trial discrimination learning problems using procedures designed to discourage position-oriented responding. With position responding discouraged, earlier findings were contradicted in that no hypothesis measure showed a main effect of IQ. This suggest that previously reported IQ group differences in hypothesis behavior may not reflect cognitive deficits inherently linked to low IQ, but instead may reflect the influence of specific methodological factors. The finding and interpretation are consistent with Zigler's (American Journal of Mental Deficiency, 1969, 73, 536–556) “developmental” theory of retardation and inconsistent with the general “difference” position. In additional findings, the predictions that subjects at all three MA levels would use hypotheses, and that retarded children from special-education classes would use hypotheses more often than retarded children “mainstreamed” in classes for the nonretarded were confirmed.     

The Relationship Between Diverse Components of Intelligence and Creativity

Intelligence and creativity are accounted for in terms of two different mental operations referred to as ‘convergent thinking’ and ‘divergent thinking’, respectively. Nevertheless, psychometric evidence on the relationship between intelligence and creativity has been controversial. To clarify their relationship, we characterized the relationship between diverse components of intelligence and creativity through the administration of psychometric tests on a large sample (WAIS, RPM, and TTCT‐figural: n = 215; TTCT‐verbal: n = 137). The general intelligence factor (g) score showed significant correlations with both TTCT‐figural and TTCT‐verbal scores. However, sub‐dimensional analysis demonstrated that their association was attributable to the specific components of both TTCTs (TTCT‐figural: Abstractness of Titles, Elaboration, and Resistance to Premature Closure; TTCT‐verbal: Flexibility) rather than to their common components (Fluency and Originality). Among the intelligence sub‐dimensions, crystallized intelligence (gC) played a pivotal role in the association between g and the specific components of both TTCTs. When the total sample was divided into two IQ groups, these phenomena were more evident in the average IQ group than in the high IQ group. These results suggest that the mental operation of creativity may be different from that of intelligence, but gC may be used as a resource for the mental operation of creativity.     

The influence of response compatibility on a semantic classification task

An experiment was carried out in which Ss had to decide whether or not a target word was a member of a prespecified semantic category. Poorly representative, or low conjoint frequency (LCF) exemplars were accepted less rapidly than representative, or high conjoint frequency (HCF) exemplars. This effect was considerably enhanced by requiring an incompatible response in which the Ss were asked to say ‘No’ when the target was a member of the category. The results show that the category membership judgement is a natural affirmative, and that the semantic distance effect of conjoint frequency has a magnitude dependent upon the processing demands of the task in which it is measured. The results are discussed in relation to theories of the mechanisms of category membership judgements. It is suggested that the influence of compatibility may be in load sharing between activation of a response rule and the judgement task per se.