The rationale for the inspection time index

doi:10.1016/0191-8869(86)90030-9

Personality and Individual Differences

Volume 7, Issue 5, 1986, Pages 609-623

https://doi.org/10.1016/0191-8869(86)90030-9 Get rights and content

Abstract

The inspection time (IT) index proposed and tested by Vickers, Nettelbeck and Willson [Perception1, 263–295 (1972)] imposed a number of experimental constraints in order to measure the time required by the S to make a single observation of the sensory input, the constraints in question being determined by certain general assumptions regarding the decision process mediating the S's responses. These constraints are re-examined in the light of recent experimental evidence which necessitates some modifications to the underlying conceptualization, particularly with reference to the assumptions concerning the sensory classification of observations and the factors influencing performance change. Implications for the measurement and interpretation of the IT index are then considered.

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Visual perceptual processing is unaffected by cognitive fatigue
2024, Consciousness and Cognition
Cognitive fatigue (CF) can lead to an increase in the latency of simple reaction time, although the processes involved in this delay are unknown. One potential explanation is that a longer time may be required for sensory processing of relevant stimuli. To investigate this possibility, the current study used a visual inspection time task to measure perceptual processing speed before and after a CF (math and memory) or non-fatiguing (documentary film) intervention. Subjective fatigue and simple reaction time significantly increased following the CF, but not the non-fatiguing intervention, confirming that CF was induced. Conversely, there was no effect of CF on inspection time task performance. It was therefore concluded that the speed of perceptual processing is not significantly impacted by CF, and thus is unlikely to underlie CF-related reaction time increases. Instead, increases in simple reaction time latency in CF may be due to delays in response preparation or initiation.
Maturation- and aging-related differences in electrophysiological correlates of error detection and error awareness
2020, Neuropsychologia
Citation Excerpt :
The test results for each age group, which are consistent with lifespan age gradients of fluid and crystalized intelligence measures in a larger and representative sample (Li et al., 2004), are summarized in Table 1. In addition, computerized versions of the inspection time task (Kranzler and Jensen, 1989; Vickers and Smith, 1986) and the identical pictures task (Lindenberger and Baltes, 1997) were also assessed in order to measure early (implicit) stimulus processing and overall speed of processing, respectively. During the inspection time task, subjects were asked to identify the longer of two lines that were presented only briefly on the screen (with 75 Hz refresh rate) and then covered by a mask.
The error-related negativity (ERN/Ne) as well as the early and late error positivity (Pe) are electrophysiological correlates known to reflect error detection and error awareness. Despite much evidence on age differences in mastering response conflicts, the development and the functional distinctiveness of these components across the lifespan is still unclear. Here we investigated maturation- and aging-related differences in the ERN/Ne, the early and late Pe during a response conflict task in a lifespan sample that included 45 children, 42 adolescents, 39 younger and 34 older adults. Lifespan age differences were characterized by marked declines of all three components in older age, whereas clear maturation effects from childhood to adolescence were only observed for error detection reflected in the ERN/Ne component. Furthermore, using regression analyses, we examined functional relationships of the error monitoring components to behavioral indicators of task performance. Across all age groups, both the ERN/Ne and the early Pe were related to response accuracy, but only the early Pe was further associated with performance in a covariate task indicative of perceptual processing and attention capacities. Our results suggest that the ERN/Ne, the early and late Pe reflect distinct but complementary processes of error monitoring across the lifespan.
Sports Vision: Vision Care for the Enhancement of Sports Performance
2020, Sports Vision: Vision Care for the Enhancement of Sports Performance
Early electro-cortical correlates of inspection time task performance
2011, Intelligence
Citation Excerpt :
However as to whether this reflects speed of post sensory or sensory processes or a combination of the two remains unclear. On the one side, individual differences in IT performance were originally hypothesized to be due to individual differences in the time required to make a single observation, this being all that is required to make a correct discrimination in the IT task (Vickers & Smith, 1986). More recent accounts of the inspection time task performance stress that IT is a measure of the quality of stimulus representation and memory capacity (Vickers, Pietsch, & Hemingway, 1995), and are thought to occur at a post sensory level.
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 visual-perceptual processing
2008, Vision Research
Citation Excerpt :
In their stead, another measure, inspection time (IT), has proven to account for a significant portion (approximately 25%) of the variance in human intelligence (Deary & Stough, 1996). Originally, the notion of IT was derived from a model of simple, perceptual decision-making (Vickers, Nettelbeck, & Wilson, 1972), and was designed to be fundamental enough as to be “relatively immune from influence by higher cognitive activities or by motivational and social factors” (Vickers & Smith, 1986). In its most prevalent form, the IT task begins with participants being warned of an impending stimulus by a simple cue figure (see Fig. 1a).
Inspection time (IT) is the most popular simple psychometric measure that is used to account for a large part of the variance in human mental ability, with the estimated corrected correlation between IT and IQ being −0.50. In this study, we investigate the relationship between IT and the performance and oculomotor variables measured during three simple visual tasks. Participants’ ITs were first measured using a slight variation of the standard IT task, which was followed by the three simple visual tasks that were designed to test participants’ visual–attentional control and visual working memory under varying degrees of difficulty; they included a visual search task, a comparative visual search task, and a visual memorization task. Significant correlations were found between IT and performance variables for each of the visual tasks. The implications of the correlation between IT and performance-related variables are discussed. Oculomotor variables on the other hand only correlated significantly with IT during the retrieval phase of the visual memorization task, which is likely a product of differences in participants’ ability to memorize objects during the loading phase of the experiment. This leads us to the conclusion that the oculomotor variables we measured do not correlate with IT in general, but may in the case where a systematic benefit would be realized.
A diffusion model explanation of the worst performance rule for reaction time and IQ
2008, Intelligence
The worst performance rule for cognitive tasks [Coyle, T.R. (2003). IQ, the worst performance rule, and Spearman's law: A reanalysis and extension. Intelligence, 31, 567–587] in which reaction time is measured is the result that IQ scores correlate better with longer (i.e., 0.7 and 0.9 quantile) reaction times than shorter (i.e., 0.1 and 0.3 quantile) reaction times. We show that this pattern of correlations can be predicted by the diffusion model [Ratcliff, R. (1978). A theory of memory retrieval. Psychological Review, 85, 59–108], in two ways: either assuming that the rate of accumulation of information toward a decision is higher for higher IQ subjects or assuming that the criterial amounts of information they require before a decision are lower. Importantly, the model explains both reaction times and accuracy, so the two possibilities can be distinguished.

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^☆: Paper presented at the 2nd Meeting of the International Society for the Study of Individual Differences, San Feliú, Spain, June 1985.

View full text

The rationale for the inspection time index☆

Abstract

J. math. Psychol.

Cog. Psychol.

J. math. Psychol.

Acta psychol.

Acta psychol.

Phenomenal simultaneity and the perceptual moment hypothesis

Br. J. Psychol.

Some alternative stochastic models of choice

Br. J. statistic. Psychol.

The interaction effects of perceptual difficulty and stimulus exposure time on age differences in speed and accuracy of response

Gerontologia

Intelligence and “inspection time”

Criterion control in signal detection in response to decreasing signal probability

The Processing of Information and Structure

Signal Detection Theory and Psychophysics

Sequential effects in absolute judgements of loudness without feedback

Method, finding, and theory in studies of visual masking

Psychol. Bull.

A recruitment theory of simple behavior

Psychometrika

Intelligence, reaction time and inspection time

Am. J. ment. Defic.

Information Theory of Choice-reaction Times

Adaptation of decision criteria in vigilance tasks

A sequential theory of psychological discrimination

Psychometrika

Effect of prior context on two-choice absolute judgements without feedback

Multiple regression analyses of sequential effects in loudness judgments

The effects of shock-induced anxiety on noise in the visual system

Perception

Individual differences in noise and associated perceptual indices of performance

Perception

Inspection time: an index for intelligence?

Q. Jl exp. Psychol.

Inspection time and mild mental retardation