Inspection time and its relation to intelligence: Issues of measurement and meaning

How Do People Perform an Inspection Time Task? An Examination of Visual Illusions, Task Experience, and Blinking

In the inspection time (IT) paradigm, participants view two lines of unequal length (called the Pi-figure) for a short exposure time, and then judge which of the two lines was longer. Early research has interpreted IT as a simple index of mental speed, which does not involve motor activity. However, more recent studies have associated IT with higher-level cognitive mechanisms, including focused attention, task experience, and the strategic use of visual illusions. The extent to which these factors affect IT is still a source of debate. We used an eye-tracker to capture participants' (N = 147) visual attention while performing IT trials. Results showed that blinking was time-dependent, with participants blinking less when the Pi-figure was visible as compared to before and after. Blinking during the presentation of the Pi-figure correlated negatively with response accuracy. Also, participants who reported seeing a brightness illusion had a higher response accuracy than those who did not. The first experiment was repeated with new participants (N = 159), enhanced task instructions, and the inclusion of practice trials. Results showed substantially improved response accuracy compared to the first experiment, and no significant difference in response accuracy between those who did and did not report illusions. IT response accuracy correlated modestly (r = 0.18) with performance on a short Raven's advanced progressive matrices task. In conclusion, performance at the IT task is affected by task familiarity and involves motor activity in the form of blinking. Visual illusions may be an epiphenomenon of understanding the IT task.

Do scores on a tachistoscope test correlate with baseball batting averages?

BACKGROUND

Millions of dollars are spent each year by individuals seeking to improve their athletic performance. One area of visual training is the use of the tachistoscope, which measures inspection time or visual recognition time. Although the potential of the tachistoscope as a training tool has received some research attention, its use as a means of measurement or predictor of athletic ability in sports has not been explored. The purpose of this pilot study is to assess the potential of the tachistoscope as a measurement instrument by determining if a baseball player's ability to identify a tachistoscopically presented picture of a pitch is correlated with hitting performance as measured by batting average.

METHODS

Using sport-specific slides, 20 subjects-all non-pitching members of the Pacific University Baseball Team-were administered a tachistoscopic test. The test consisted of identifying the type of pitch illustrated in 30 randomly ordered slides depicting a pitcher throwing four different baseball pitches. Each slide was presented for 0.2 sec. The results of the test were compared with the athlete's previous season's batting average.

RESULTS

A positive correlation was found between an athlete's ability to correctly identify a picture of a pitch presented tachistoscopically and batting average (r=0.648; P<0.01). These results suggest that a superior ability to recognize pitches presented via tachistoscope may correlate with a higher skill level in batting.

CONCLUSIONS

Tachistoscopic test scores correlated positively with batting averages. The tachistoscope may be an acceptable tool to help in assessing batting performance. Additional testing with players from different sports, different levels of ability, and different tachistoscopic times should be performed to determine if the tachistoscope is a valid measure of athletic ability. Implications may also be drawn in other areas such as military and police work.

Reductionism and intelligence: the case of inspection time

Successes in science tend to be successful attempts at reduction and causal interaction. The reduction of the interaction of bodies to the laws of motion and the reduction of chemical phenomena to elements and their interactions are good examples. In these cases reductionism leads to observed phenomena being explained by a relatively small number of basic concepts and the laws which govern the interaction of the concepts. The spectrum of inquiry that stretches from common sense to scientific psychology is infused with a tendency toward reductionism. Hippocrates and Galen originated and developed, respectively, the notion that temperamental differences might be reducible to the amounts of four bodily fluids, or humours (black bile, yellow bile, blood and phlegm), that a person produced. Astrologers reduced stable personality differences to the positions of the stars and planets at the time of birth. And differential psychologists have reduced the personality trait adjectives contained in the lexicon to about five major dimensions.

Cerebral asymmetries in inspection time?

Recent studies have suggested that there are low-level processing asymmetries across the cerebral hemispheres, with a right visual field-left hemisphere advantage in tasks involving temporal resolution. In the present report, one such task, inspection time, was measured separately for each cerebral hemisphere in 10 right-handed male subjects over 5 days. A number of methodological improvements were made on previous studies in which a general right visual field-left hemisphere advantage had been found relative to the left visual field-right hemisphere in inspection time performance. The present results suggest that there is no general left hemisphere advantage in inspection time, although there might be asymmetries in practice effects across the hemispheres. The findings also suggest the existence of individual differences in the extent and direction of hemispheric specialisation for this task (ranging from left hemisphere dominance to marked right hemisphere dominance for some subjects) even in right-handed subjects.

A Review of Three Approaches to Cognitive Assessment, and a Proposed Integrated Approach Based on a Unifying Theoretical Framework

In this article, the author reviews three traditions of cognitive assessment: the structural approach (based on factor analytic research), the information-processing approach, and the dynamic approach (based on learning theory). The theoretical background of each assessment approach is sketched and the advantages and disadvantages of each discussed. The author then proposes an integrated two-factor cognitive theory which accommodates all three traditions. Using this theory as a basis, he proposes a design for a test battery which would be appropriate for use in a multicultural context and would identify individuals likely to benefit from developmental opportunities.

Nonstationarity and the measurement of psychophysical response in a visual inspection-time task

Inspection time (IT) is an index of speed of early visual processing that correlates significantly with measures of higher cognitive ability. An obstacle to the understanding of this important association is the lack of an agreed mechanistic model of the processes involved in IT performance. It is argued here that, whereas in current attempts to model IT processing, stationarity in IT performance is assumed, it is necessary to address this key issue empirically. Two practised subjects undertook 38,400 trials on a standard two-choice visual IT discrimination task. Testing was spread evenly over 60 days. Isotonic regression analysis revealed that both subjects showed nonstationarity in performance over very long periods. The results were not merely due to long-term practice effects; one subject improved in some durations but worsened at others. Therefore, current attempts at modelling in which stationarity in IT performance is assumed must be altered to incorporate the temporal dynamics of IT performance, which might have individual differences.